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Kimemia BB, Musila L, Langat S, Odoyo E, Cinkovich S, Abuom D, Yalwala S, Khamadi S, Johnson J, Garges E, Ojwang E, Eyase F. Detection of pathogenic bacteria in ticks from Isiolo and Kwale counties of Kenya using metagenomics. PLoS One 2024; 19:e0296597. [PMID: 38687700 PMCID: PMC11060535 DOI: 10.1371/journal.pone.0296597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 04/09/2024] [Indexed: 05/02/2024] Open
Abstract
Ticks are arachnid ectoparasites that rank second only to mosquitoes in the transmission of human diseases including bacteria responsible for anaplasmosis, ehrlichiosis, spotted fevers, and Lyme disease among other febrile illnesses. Due to the paucity of data on bacteria transmitted by ticks in Kenya, this study undertook a bacterial metagenomic-based characterization of ticks collected from Isiolo, a semi-arid pastoralist County in Eastern Kenya, and Kwale, a coastal County with a monsoon climate in the southern Kenyan border with Tanzania. A total of 2,918 ticks belonging to 3 genera and 10 species were pooled and screened in this study. Tick identification was confirmed through the sequencing of the Cytochrome C Oxidase Subunit 1 (COI) gene. Bacterial 16S rRNA gene PCR amplicons obtained from the above samples were sequenced using the MinION (Oxford Nanopore Technologies) platform. The resulting reads were demultiplexed in Porechop, followed by trimming and filtering in Trimmomatic before clustering using Qiime2-VSearch. A SILVA database pretrained naïve Bayes classifier was used to classify the Operational Taxonomic Units (OTUs) taxonomically. The bacteria of clinical interest detected in pooled tick assays were as follows: Rickettsia spp. 59.43% of pools, Coxiella burnetii 37.88%, Proteus mirabilis 5.08%, Cutibacterium acnes 6.08%, and Corynebacterium ulcerans 2.43%. These bacteria are responsible for spotted fevers, query fever (Q-fever), urinary tract infections, skin and soft tissue infections, eye infections, and diphtheria-like infections in humans, respectively. P. mirabilis, C. acnes, and C. ulcerans were detected only in Isiolo. Additionally, COI sequences allowed for the identification of Rickettsia and Coxiella species to strain levels in some of the pools. Diversity analysis revealed that the tick genera had high levels of Alpha diversity but the differences between the microbiomes of the three tick genera studied were not significant. The detection of C. acnes, commonly associated with human skin flora suggests that the ticks may have contact with humans potentially exposing them to bacterial infections. The findings in this study highlight the need for further investigation into the viability of these bacteria and the competency of ticks to transmit them. Clinicians in these high-risk areas also need to be appraised for them to include Rickettsial diseases and Q-fever as part of their differential diagnosis.
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Affiliation(s)
- Bryson Brian Kimemia
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
- Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Lillian Musila
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI), Centre for Microbiology Research, Nairobi, Kenya
| | - Solomon Langat
- Kenya Medical Research Institute (KEMRI), Centre for Virus Research, Nairobi, Kenya
| | - Erick Odoyo
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
| | - Stephanie Cinkovich
- United States Armed Forces Health Surveillance Division, Global Emerging Infections Surveillance Branch, Silver Spring, Maryland, United States of America
| | - David Abuom
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
| | - Santos Yalwala
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
| | - Samoel Khamadi
- Kenya Medical Research Institute (KEMRI), Centre for Virus Research, Nairobi, Kenya
| | - Jaree Johnson
- United States Armed Forces Pest Management Board, Silver Spring, Maryland, United States of America
| | - Eric Garges
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
| | - Elly Ojwang
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
| | - Fredrick Eyase
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa (USAMRD-A), Nairobi, Kenya
- Kenya Medical Research Institute (KEMRI), Centre for Virus Research, Nairobi, Kenya
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Moore CO, André MR, Šlapeta J, Breitschwerdt EB. Vector biology of the cat flea Ctenocephalides felis. Trends Parasitol 2024; 40:324-337. [PMID: 38458883 PMCID: PMC11168582 DOI: 10.1016/j.pt.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 02/12/2024] [Accepted: 02/12/2024] [Indexed: 03/10/2024]
Abstract
Ctenocephalides felis, the cat flea, is among the most prevalent and widely dispersed vectors worldwide. Unfortunately, research on C. felis and associated pathogens (Bartonella and Rickettsia spp.) lags behind that of other vectors and vector-borne pathogens. Therefore, we aimed to review fundamental aspects of C. felis as a vector (behavior, epidemiology, phylogenetics, immunology, and microbiome composition) with an emphasis on key techniques and research avenues employed in other vector species. Future laboratory C. felis experimental infections with Bartonella, Rickettsia, and Wolbachia species/strains should examine the vector-pathogen interface utilizing contemporary visualization, transcriptomic, and gene-editing techniques. Further environmental sampling will inform the range and prevalence of C. felis and associated pathogens, improving the accuracy of vector and pathogen modeling to improve infection/infestation risk assessment and diagnostic recommendations.
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Affiliation(s)
- Charlotte O Moore
- Intracellular Pathogens Research Laboratory, Department of Clinical Science, North Carolina State University, NC, USA
| | - Marcos Rogério André
- Vector-Borne Bioagents Laboratory (VBBL), Department of Pathology, Reproduction, and One Health, Faculty of Agrarian and Veterinary Sciences, São Paulo State University (FCAV/UNESP), Jaboticabal, SP 14884-900, Brazil
| | - Jan Šlapeta
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, New South Wales, Australia
| | - Edward B Breitschwerdt
- Intracellular Pathogens Research Laboratory, Department of Clinical Science, North Carolina State University, NC, USA.
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Minahan NT, Wu WJ, Tsai KH. Rickettsia felis is an emerging human pathogen associated with cat fleas: A review of findings in Taiwan. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2023; 56:10-19. [PMID: 36585292 DOI: 10.1016/j.jmii.2022.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 12/03/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
Rickettsia felis is an emerging rickettsial agent principally associated with cat fleas (Ctenocephalides felis), formerly discovered in 1990. Since then, clinical cases of R. felis infection have been identified globally by specific DNA sequences in patients with undifferentiated febrile illness, including in Taiwan, but such evidence is limited. R. felis rickettsiosis is self-limiting and easily treated with doxycycline, but its diagnosis remains a challenge. Environmental risk factors for R. felis rickettsiosis have yet to be clearly demonstrated, and its transmission biology is incompletely understood. Cat fleas are naturally infected with R. felis at varying rates, and vector competence in the transmission of R. felis has been demonstrated in animal models, including dogs, which may serve as reservoir hosts. In northern Taiwan, despite ∼20% of cat fleas infesting companion animals consistently found to be infected with R. felis, only a few cases of potential R. felis infection have been identified through a retrospective serological investigation, though without molecular confirmation. Ecological studies have identified divergent R. felis-like organisms in different arthropod hosts, but these strains appear to serve as nonpathogenic endosymbionts. Although its association with disease is limited, we believe cat flea-borne R. felis warrants increased recognition in an aging population due to immunosenescence and the proximity of companion animals to the elderly. Adopting a One Health approach involving collaboration and communication between clinicians, veterinarians, public health practitioners, and environmental scientists will improve our knowledge about this neglected pathogen and promote the prevention and control of vector-borne diseases.
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Affiliation(s)
- Nicholas T Minahan
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Wen-Jer Wu
- Department of Entomology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Kun-Hsien Tsai
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Entomology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan; Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan.
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Moore C, Breitschwerdt EB, Kim L, Li Y, Ferris K, Maggi R, Lashnits E. The association of host and vector characteristics with Ctenocephalides felis pathogen and endosymbiont infection. Front Microbiol 2023; 14:1137059. [PMID: 36950155 PMCID: PMC10025546 DOI: 10.3389/fmicb.2023.1137059] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/14/2023] [Indexed: 03/08/2023] Open
Abstract
Surveillance of the fleas and flea-borne pathogens infecting cats is important for both human and animal health. Multiple zoonotic Bartonella and Rickettsia species are known to infect the most common flea infesting cats and dogs worldwide: Ctenocephalides felis, the cat flea. The ability of other flea species to transmit pathogens is relatively unexplored. We aimed to determine cat host and flea factors independently associated with flea Bartonella and Rickettsia infection. We also assessed flea and cat infection by flea-host pair and location. To accomplish these aims, we performed qPCR for the detection of Bartonella, hemotropic Mycoplasma, Rickettsia, and Wolbachia DNA using paired cat and flea samples obtained from free-roaming cats presenting for spay or neuter across four locations in the United States. A logistic regression model was employed to identify the effect of cat (sex, body weight, geographic location, and Bartonella, hemotropic Mycoplasma, and Rickettsia spp., infection) and flea (clade and Rickettsia and Wolbachia infection) factors on C. felis Bartonella clarridgeiae infection. From 189 free roaming cats, we collected 84 fleas: Ctenocephalides felis (78/84), Cediopsylla simplex (4/84), Orchopeas howardi (1/84), and Nosopsyllus fasciatus (1/84). Ctenocephalides felis were phylogenetically assigned to Clades 1, 4, and 6 by cox1 gene amplification. Rickettsia asembonensis (52/84) and B. clarridgeiae (16/84) were the most common pathogenic bacteria detected in fleas. Our model identified host cat sex and weight as independently associated with B. clarridgeiae infection in fleas. Rickettsia asembonensis (52/84), Rickettsia felis (7/84) and Bartonella henselae (7/84) were detected in specific clades: R. felis was detected only in Clades 1 and 6 while B. henselae and R. asembonensis were detected only in Clade 4. Wolbachia spp., also displayed clade specificity with strains other than Wolbachia wCfeT only infecting fleas from Clade 6. There was poor flea and host agreement for Bartonella spp., infection; however, there was agreement in the Bartonella species detected in cats and fleas by geographic location. These findings reinforce the importance of considering reservoir host attributes and vector phylogenetic diversity in epidemiological studies of flea-borne pathogens. Widespread sampling is necessary to identify the factors driving flea-borne pathogen presence and transmission.
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Affiliation(s)
- Charlotte Moore
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Edward B. Breitschwerdt
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Lisa Kim
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, United States
| | - Yiyao Li
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, United States
| | - Kelli Ferris
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Ricardo Maggi
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Erin Lashnits
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, United States
- *Correspondence: Erin Lashnits,
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Rickettsia felis and species of fleas parasitizing on household dogs in the Central Highlands of Vietnam. Comp Immunol Microbiol Infect Dis 2023; 92:101926. [PMID: 36473364 DOI: 10.1016/j.cimid.2022.101926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 11/12/2022] [Accepted: 11/25/2022] [Indexed: 11/27/2022]
Abstract
Rickettsia felis is an obligate intracellular gra m-negative bacterium that belongs to the family of Rickettsiaceae. Ctenocephalides felis, cat flea, is the primary vector of the bacteria. The flea is the most common ectoparasite in dogs and associated with flea-borne spotted fever in humans. Information on R. felis and flea species parasitizing on dogs in Vietnam is limited. This study aimed to identify the species of fleas collected from dogs in the Central Highlands of Vietnam and detected the existence of R. felis in these fleas utilizing molecular tools. Morphological identification of 1618 fleas and molecular confirmation revealed the predominance of C. felis orientis parasitizing on dogs in the Central Highlands of Vietnam. Sixty-eight out of 100 fleas collected from household dogs were positive for spotted fever group rickettsiae; whilst R. felis was detected in 97.06 % (66/68) of C. felis orientis and C. felis felis. The results of this study indicate the potentially high risk of R. felis infection to humans and animals.
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Current Data on Rickettsia felis Occurrence in Vectors, Human and Animal Hosts in Europe: A Scoping Review. Microorganisms 2022; 10:microorganisms10122491. [PMID: 36557744 PMCID: PMC9781214 DOI: 10.3390/microorganisms10122491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Rickettsia felis is an emerging pathogen with increasing reports of human cases and detection in arthropod and animal host species worldwide. In this scoping review we record the newest data reported for R. felis in Europe: the vector and host species found to be infected, and the geographical distribution and prevalence of R. felis infection in vectors and hosts. A total of 15 European countries reported the occurrence of R. felis in hosts and vectors during 2017−2022. The vectors found to be infected by R. felis were flea, tick and mite species; Ctenocephalides felis and Ixodes ricinus were the dominant ones. The hosts found to be infected and/or exposed to R. felis were humans, cats and small mammals. Physicians should be aware of the epidemiology and include illness caused by R. felis in the differential diagnosis of febrile disease. Veterinarians should keep training pet owners on the need for effective year-round arthropod control on their pets, especially for fleas.
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Manvell C, Berman H, Callahan B, Breitschwerdt E, Swain W, Ferris K, Maggi R, Lashnits E. Identification of microbial taxa present in Ctenocephalides felis (cat flea) reveals widespread co-infection and associations with vector phylogeny. Parasit Vectors 2022; 15:398. [PMID: 36316689 PMCID: PMC9623975 DOI: 10.1186/s13071-022-05487-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 09/14/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Ctenocephalides felis, the cat flea, is the most common ectoparasite of cats and dogs worldwide. As a cause of flea allergy dermatitis and a vector for two genera of zoonotic pathogens (Bartonella and Rickettsia spp.), the effect of the C. felis microbiome on pathogen transmission and vector survival is of substantial medical importance to both human and veterinary medicine. The aim of this study was to assay the pathogenic and commensal eubacterial microbial communities of individual C. felis from multiple geographic locations and analyze these findings by location, qPCR pathogen prevalence, and flea genetic diversity. METHODS 16S Next Generation Sequencing (NGS) was utilized to sequence the microbiome of fleas collected from free-roaming cats, and the cox1 gene was used for flea phylogenetic analysis. NGS data were analyzed for 168 individual fleas from seven locations within the US and UK. Given inconsistency in the genera historically reported to constitute the C. felis microbiome, we utilized the decontam prevalence method followed by literature review to separate contaminants from true microbiome members. RESULTS NGS identified a single dominant and cosmopolitan amplicon sequence variant (ASV) from Rickettsia and Wolbachia while identifying one dominant Bartonella clarridgeiae and one dominant Bartonella henselae/Bartonella koehlerae ASV. Multiple less common ASVs from these genera were detected within restricted geographical ranges. Co-detection of two or more genera (Bartonella, Rickettsia, and/or Wolbachia) or multiple ASVs from a single genus in a single flea was common. Achromobacter, Peptoniphilus, and Rhodococcus were identified as additional candidate members of the C. felis microbiome on the basis of decontam analysis and literature review. Ctenocephalides felis phylogenetic diversity as assessed by the cox1 gene fell within currently characterized clades while identifying seven novel haplotypes. NGS sensitivity and specificity for Bartonella and Rickettsia spp. DNA detection were compared to targeted qPCR. CONCLUSIONS Our findings confirm the widespread coinfection of fleas with multiple bacterial genera and strains, proposing three additional microbiome members. The presence of minor Bartonella, Rickettsia, and Wolbachia ASVs was found to vary by location and flea haplotype. These findings have important implications for flea-borne pathogen transmission and control.
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Affiliation(s)
- Charlotte Manvell
- Intracellular Pathogens Research Laboratory, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
| | - Hanna Berman
- Department of Population Health and Pathobiology, College of Veterinary Medicine and Bioinformatics Research Center, North Carolina State University, Raleigh, NC USA
| | - Benjamin Callahan
- Department of Population Health and Pathobiology, College of Veterinary Medicine and Bioinformatics Research Center, North Carolina State University, Raleigh, NC USA
| | - Edward Breitschwerdt
- Intracellular Pathogens Research Laboratory, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
| | - William Swain
- Intracellular Pathogens Research Laboratory, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
- School of Veterinary Medicine, One Health Institute, University of California, Davis, CA USA
| | - Kelli Ferris
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
| | - Ricardo Maggi
- Intracellular Pathogens Research Laboratory, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
| | - Erin Lashnits
- Intracellular Pathogens Research Laboratory, College of Veterinary Medicine, North Carolina State University, Raleigh, NC USA
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI USA
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Molecular characterization of Rickettsia spp., Bartonella spp., and Anaplasma phagocytophilum in hard ticks collected from wild animals in Benin, West Africa. Trop Anim Health Prod 2022; 54:306. [DOI: 10.1007/s11250-022-03286-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 08/31/2022] [Indexed: 10/14/2022]
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Chiuya T, Villinger J, Falzon LC, Alumasa L, Amanya F, Bastos ADS, Fèvre EM, Masiga DK. Molecular screening reveals non-uniform malaria transmission in western Kenya and absence of Rickettsia africae and selected arboviruses in hospital patients. Malar J 2022; 21:268. [PMID: 36115978 PMCID: PMC9482282 DOI: 10.1186/s12936-022-04287-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
In sub-Saharan Africa, malaria is the common diagnosis for febrile illness and related clinical features, resulting in the under-diagnosis of other aetiologies, such as arboviruses and Rickettsia. While these may not be significant causes of mortality in malaria-endemic areas, they affect the daily life and performance of affected individuals. It is, therefore, important to have a clear picture of these other aetiologies to institute correct diagnoses at hospitals and improve patient outcomes.
Methods
Blood samples were collected from patients with fever and other clinical features associated with febrile illness at selected hospitals in the malaria-endemic counties of Busia, Bungoma, and Kakamega, and screened for Crimean-Congo haemorrhagic fever, Sindbis, dengue and chikungunya viruses, Rickettsia africae, and Plasmodium spp. using high-throughput real-time PCR techniques. A logistic regression was performed on the results to explore the effect of demographic and socio-economic independent variables on malaria infection.
Results
A total of 336 blood samples collected from hospital patients between January 2018 and February 2019 were screened, of which 17.6% (59/336) were positive for Plasmodium falciparum and 1.5% (5/336) for Plasmodium malariae. Two patients had dual P. falciparum/P. malariae infections. The most common clinical features reported by the patients who tested positive for malaria were fever and headache. None of the patients were positive for the arboviruses of interest or R. africae. Patients living in Busia (OR 5.2; 95% CI 2.46–11.79; p < 0.001) and Bungoma counties (OR 2.7; 95% CI 1.27–6.16; p = 0.013) had higher odds of being infected with malaria, compared to those living in Kakamega County.
Conclusions
The reported malaria prevalence is in line with previous studies. The absence of arboviral and R. africae cases in this study may have been due to the limited number of samples screened, low-level circulation of arboviruses during inter-epidemic periods, and/or the use of PCR alone as a detection method. Other sero-surveys confirming their circulation in the area indicate that further investigations are warranted.
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de Macedo LO, Bezerra-Santos MA, Filho CRCU, da Silva Sales KG, de Sousa-Paula LC, da Silva LG, Dantas-Torres F, do Nascimento Ramos RA, Otranto D. Vector-borne pathogens of zoonotic concern in dogs from a Quilombola community in northeastern Brazil. Parasitol Res 2022; 121:3305-3311. [PMID: 36102968 PMCID: PMC9556415 DOI: 10.1007/s00436-022-07661-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/06/2022] [Indexed: 12/01/2022]
Abstract
Canine vector-borne pathogens (CVBPs) comprise a group of disease agents mainly transmitted by ticks, fleas, mosquitoes and sand flies. In this study, we assessed the presence of CVBPs in an Afro-descendent community (Quilombola) of northeastern, Brazil. Dog blood samples (n = 201) were collected and analyzed by rapid test for the detection of antibodies against Leishmania spp., Anaplasma spp., Ehrlichia spp. and Borrelia burgdorferi sensu lato (s.l.), and antigens of Dirofilaria immitis. In addition, polymerase chain reactions were performed for Anaplasmataceae, Babesia spp., Hepatozoon spp., Rickettsia spp. and B. burgdorferi s.l. Overall, 66.7% of the dogs scored positive to at least one pathogen at serological and/or molecular methods. Antibodies against Ehrlichia spp. were the most frequently detected (57.2%; n = 115/201), followed by Anaplasma spp. (8.5%; n = 17/201), Leishmania spp. (8.5%; n = 17/201) and B. burgdorferi s.l. (0.5%; n = 1/201). For D. immitis, 11 out of 201 (5.5%) animals scored positive. At the molecular analysis, 10.4% (n = 21/201) of the samples scored positive for Babesia spp./Hepatozoon spp., followed by Anaplasmataceae (5.0%; n = 10/201) and Rickettsia spp. (3.0%; n = 6/201). All samples were negative for B. burgdorferi s.l. Our data demonstrated the presence of CVBPs in the studied population, with a high seropositivity for Ehrlichia spp. In addition, considering the detection of zoonotic pathogens in dogs and their relationship with people from Quilombola communities, effective control strategies are advocated for minimizing the risk of infection in this socially vulnerable human population and their pets.
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Affiliation(s)
- Lucia Oliveira de Macedo
- Graduate Program in Animal Biosciences, Federal Rural University of Pernambuco, Recife, Brazil
- Laboratory of Parasitology, Federal University of the Agreste of Pernambuco, Garanhuns, Brazil
| | | | - Carlos Roberto Cruz Ubirajara Filho
- Graduate Program in Animal Biosciences, Federal Rural University of Pernambuco, Recife, Brazil
- Laboratory of Parasitology, Federal University of the Agreste of Pernambuco, Garanhuns, Brazil
| | - Kamila Gaudêncio da Silva Sales
- Laboratory of Immunoparasitology, Department of Immunology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation (Fiocruz), Recife, Brazil
| | - Lucas C de Sousa-Paula
- Laboratory of Immunoparasitology, Department of Immunology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation (Fiocruz), Recife, Brazil
| | - Lidiane Gomes da Silva
- Laboratory of Immunoparasitology, Department of Immunology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation (Fiocruz), Recife, Brazil
| | - Filipe Dantas-Torres
- Laboratory of Immunoparasitology, Department of Immunology, Aggeu Magalhães Institute, Oswaldo Cruz Foundation (Fiocruz), Recife, Brazil
| | | | - Domenico Otranto
- Department of Veterinary Medicine, University of Bari, Valenzano, Italy.
- Department of Pathobiology, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran.
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Abstract
Ticks are hematophagous ectoparasites capable of transmitting multiple human pathogens. Environmental changes have supported the expansion of ticks into new geographical areas that have become the epicenters of tick-borne diseases (TBDs). The spotted fever group (SFG) of Rickettsia frequently infects ticks and causes tick-transmitted rickettsioses in areas of endemicity where ixodid ticks support host transmission during blood feeding. Ticks also serve as a reservoir for SFG Rickettsia. Among the members of SFG Rickettsia, R. rickettsii causes Rocky Mountain spotted fever (RMSF), the most lethal TBD in the United States. Cases of RMSF have been reported for over a century in association with several species of ticks in the United States. However, the isolation of R. rickettsii from ticks has decreased, and recent serological and epidemiological studies suggest that novel species of SFG Rickettsia are responsible for the increased number of cases of RMSF-like rickettsioses in the United States. Recent analyses of rickettsial genomes and advances in genetic and molecular studies of Rickettsia provided insights into the biology of Rickettsia with the identification of conserved and unique putative virulence genes involved in the rickettsial life cycle. Thus, understanding Rickettsia-host-tick interactions mediating successful disease transmission and pathogenesis for SFG rickettsiae remains an active area of research. This review summarizes recent advances in understanding how SFG Rickettsia species coopt and manipulate ticks and mammalian hosts to cause rickettsioses, with a particular emphasis on newly described or emerging SFG Rickettsia species.
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Mediannikov O, Bechah Y, Amanzougaghene N, Lepidi H, Bassene H, Sambou M, Lienhard C, Benkacimi L, Dieme C, Sokhna C, Fenollar F, Raoult D. Booklice Liposcelis bostrychophila naturally infected by Rickettsia felis cause fever and experimental pneumonia in mammals. J Infect Dis 2022; 226:1075-1083. [PMID: 35776143 DOI: 10.1093/infdis/jiac282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 06/30/2022] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Rickettsia felis is emergent in tropical areas. Despite its high morbidity, its natural history has not yet been fully determined. We investigated the role of the common household booklouse, Liposcelis bostrychophila, recently found to harbour R. felis. METHODS Blood samples from 372 febrile patients from Senegalese villages, as well as nasal and skin samples from 264 asymptomatic individuals, were tested for cat flea-associated and booklice-associated strains of R. felis. Dust samples from beds were collected to isolate booklice and R. felis. Mice were infected with aerosol of R. felis strain from naturally infected booklice. RESULTS Forty febrile patients (11%) were infected by R. felis, including 26 (7%) by the booklice-associated strain. Nine nasal samples (3.4%) and 28 skin samples (10.6%) contained R. felis, including seven and 24, respectively, with the booklice-associated strain. The presence of live L. bostrychophila was observed in 32 dust samples (16.8%); R. felis was identified in 62 dust samples (32.5%). Several mice samples were positive for R. felis; interstitial lymphohistiocytic infiltrates were identified in lungs. CONCLUSIONS L. bostrychophila may be a reservoir of R. felis. The booklice-associated strain is pathogenic in mammals causing pneumonia. Human infection may be acquired via inhalation of infected booklice particles.
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Affiliation(s)
- Oleg Mediannikov
- Aix Marseille Univ, IRD, AP-HM, MEPHII, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
| | - Yassina Bechah
- Aix Marseille Univ, IRD, AP-HM, MEPHII, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
| | - Nadia Amanzougaghene
- Aix Marseille Univ, IRD, AP-HM, MEPHII, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
| | - Hubert Lepidi
- Aix Marseille Univ, IRD, AP-HM, MEPHII, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
| | | | - Masse Sambou
- VITROME, Campus International UCAD-IRD, Dakar, Senegal
| | | | - Linda Benkacimi
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
| | | | - Cheikh Sokhna
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
| | - Florence Fenollar
- IHU-Méditerranée Infection, Marseille, France.,Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
| | - Didier Raoult
- Aix Marseille Univ, IRD, AP-HM, MEPHII, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
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13
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Adeyeye SAO, Ashaolu TJ, Bolaji OT, Abegunde TA, Omoyajowo AO. Africa and the Nexus of poverty, malnutrition and diseases. Crit Rev Food Sci Nutr 2021; 63:641-656. [PMID: 34259104 DOI: 10.1080/10408398.2021.1952160] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This review examines the nexus of poverty, malnutrition and diseases in Africa, the challenges, implications and their mitigation. The paper takes a critical look at available literatures on the primary causes, modes, implications and solutions to the problems of poverty, malnutrition and diseases in Africa continent. Poverty and malnutrition are outcomes of uncontrolled rapid population growth, inefficient agricultural and industrial practices, high debt profile of many African countries due to poor governance and corruption, diseases such as AIDS epidemic, malaria, Ebola virus and COVID-19 pandemic, poor and inadequate health infrastructure and armed conflicts. African poverty scenario entails non-availability of basic human needs which makes many Africans to be very poor. Despite abundance of natural resources, the gross domestic product per capita of many African countries is among the lowest of list of nations of the world. According United Nation in 2009, 22 of 24 nations among the "Low Human Development" nations of the world on the UN's Human Development Index were found in sub-Saharan Africa. Out of the 50 countries on the United Nation list of least developed countries, 34 of them were in Africa. According to FAO data over 200 million people in sub-Saharan Africa were undernourished in 2014-2016. The prevalence of undernourishment in sub-Saharan Africa rose from 181 million in 2010 to 222 million in 2016. In 2016, Africa had the highest prevalence of undernourishment in the world and estimated to be 20% of the population. While this was alarming in Eastern Africa where one-third of the population is suspected to be undernourished. In a similar data, World Bank also found that sub-Saharan Africa Poverty and Equity Data was 47% with over 500 million people in abject poverty in 2012. Poverty is the major cause of hunger and malnutrition in Africa while hunger and malnutrition escalated the problem of diseases in African continent. Poverty has continued to torment Africa as a result of poor and harmful economic policies, conflict and war, environmental factors like drought and climate change and population growth, poor leadership and greed. With the advent of COVID-19, the problem of poverty, malnutrition and diseases has been escalated and in many African countries people find it difficult to make ends meet.
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Affiliation(s)
- Samuel Ayofemi O Adeyeye
- Department of Food Technology, Hindustan Institute of Technology & Science, Hindustan University, Chennai, Tamil Nadu, India
| | - Tolulope J Ashaolu
- Institute of Research and Development, Duy Tan University, Da Nang, Viet Nam.,Faculty of Environmental and Chemical Engineering, Duy Tan University, Da Nang, Viet Nam
| | - Olusola T Bolaji
- Department of Food Technology, Lagos State Polytechnic, Ikorodu, Nigeria
| | | | - Adetola O Omoyajowo
- Department of Food Science & Technology, Federal University of Agriculture, Abeokuta, Nigeria
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14
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Assessment of the burden of malaria and bacteraemia by retrospective molecular diagnosis in febrile illnesses and first-line anti-infectives in Côte d'Ivoire. Travel Med Infect Dis 2021; 43:102105. [PMID: 34146685 DOI: 10.1016/j.tmaid.2021.102105] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 04/21/2021] [Accepted: 06/04/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND The aetiologies of fever are poorly understood in sub-Saharan Africa. We aimed to assess the burden of malaria and bacteria in Côte d'Ivoire. METHODS Blood samples from 438 febrile and 346 afebrile people were screened using molecular tools. RESULTS Plasmodium falciparum was the most common microorganism associated with fever (46.8% in febrile, 23.4% in afebrile people; p < 0.001). Bacteraemia was detected in 21.7% of febrile people and 12.7% of afebrile people (p = 0.001). Streptococcus pneumoniae was the main cause of bacteraemia (7.1% of febrile and 0.6% of afebrile individuals; p < 0.001). Non-typhoidal Salmonella spp. was detected in 4.5% of febrile people and 1.2% of afebrile individuals (p < 0.001). Salmonella enterica Typhi and S. enterica Paratyphi were only detected in febrile subjects (1.4% and 2.1%), as well as Tropheryma whipplei (0.9%), Streptococcus pyogenes (0.7%), and Plasmodium ovale (4.6%). The prevalence in febrile and afebrile people was similar for Staphylococcus aureus (3.6-4.9%), Rickettsia felis (5.5-6.4%), Mansonella perstans (3.0-3.2%), and Plasmodium malariae (1.6-2.3%). Comorbidities were higher in febrile than in afebrile subjects (10.3% versus 5.5%; p = 0.01); 82% involving P. falciparum. All patients co-infected with P. falciparum and S. pneumoniae were febrile whereas 30% of those infected by P. falciparum alone were not (p = 0.02). Among febrile participants, 30.4% with malaria and 54.7% with bacteraemia had received neither antimalarial nor antibiotic therapy. CONCLUSION Identification of etiologies of acute febrile diseases in sub-Saharan Africa proposes keys to successful treatment and prevention of infectious diseases. Vaccination campaigns may decrease the morbidity of mono- and co-infections by preventable microorganisms.
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15
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Araújo FSD, Barcelos RM, Mendes TADO, Mafra C. Molecular Evidence of Rickettsia felis in Phereoeca sp. ACTA ACUST UNITED AC 2021; 30:e015620. [PMID: 33909832 DOI: 10.1590/s1984-29612021017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 02/09/2021] [Indexed: 11/22/2022]
Abstract
Rickettsia felis is an obligate intracellular bacterium capable of infecting ticks, fleas, lice, and other arthropods. This bacterium is classified as a member of the Transitional Group (TRG) Rickettsia. It is known the evidence of R. felis mutualistic and obligatory relationship with some eukaryote organisms. However, there aren't scientific accounts of R. felis and moths of the order Lepidoptera association. The current work reports the first identification of the bacteria R. felis in Phereoeca sp. For that, a polymerase chain reaction (PCR) assay using gltA, ompA, and ompB genes was used. The nucleotide sequences showed 100% of identity with other Rickettsia felis sequences. The genus-level identification of the moth larvae was performed by morphological taxonomic keys and PCR analysis of the cytochrome oxidase I (COI) gene. The nucleotide sequenced showed 94.94% similarity with the species Phereoeca praecox. However, with the low number of sequences deposited in the databases, the species was classified as Phereoeca sp. The results suggest that R. felis may develop in an organism without blood-feeding behavior (Lepidoptera), as it has been demonstrated for booklice (Psocoptera). Further investigation is necessary in order to confirm pathogenic or mutualistic association with moths.
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Affiliation(s)
- Fernanda Sales de Araújo
- Departamento de Bioquímica e Biologia Molecular, Universidade de Viçosa - UFV, Viçosa. MG, Brasil
| | - Rafael Mazioli Barcelos
- Departamento de Bioquímica e Biologia Molecular, Universidade de Viçosa - UFV, Viçosa. MG, Brasil
| | | | - Cláudio Mafra
- Departamento de Bioquímica e Biologia Molecular, Universidade de Viçosa - UFV, Viçosa. MG, Brasil
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16
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Raoult D. Rickettsioses: "A Treasure Is Hidden in This Garden". Clin Infect Dis 2021; 72:1179-1180. [PMID: 31999822 DOI: 10.1093/cid/ciaa096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 01/28/2020] [Indexed: 11/14/2022] Open
Affiliation(s)
- Didier Raoult
- Microbes, Evolution, Phylogeny and Infection, IRD, Aix Marseille University, AP-HM, Marseille, France.,IHU-Méditerranée Infection, Marseille, France
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17
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Caravedo Martinez MA, Ramírez-Hernández A, Blanton LS. Manifestations and Management of Flea-Borne Rickettsioses. Res Rep Trop Med 2021; 12:1-14. [PMID: 33574726 PMCID: PMC7873028 DOI: 10.2147/rrtm.s274724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 01/26/2021] [Indexed: 12/16/2022] Open
Abstract
Murine typhus and flea-borne spotted fever are undifferentiated febrile illnesses caused by Rickettsia typhi and Rickettsia felis, respectively. These organisms are small obligately intracellular bacteria and are transmitted to humans by fleas. Murine typhus is endemic to coastal areas of the tropics and subtropics (especially port cities), where rats are the primary mammalian host and rat fleas (Xenopsylla cheopis) are the vector. In the United States, a cycle of transmission involving opossums and cat fleas (Ctenocephalides felis) are the presumed reservoir and vector, respectively. The incidence and distribution of murine typhus appear to be increasing in endemic areas of the US. Rickettsia felis has also been reported throughout the world and is found within the ubiquitous cat flea. Flea-borne rickettsioses manifest as an undifferentiated febrile illness. Headache, malaise, and myalgia are frequent symptoms that accompany fever. The incidence of rash is variable, so its absence should not dissuade the clinician to consider a rickettsial illness as part of the differential diagnosis. When present, the rash is usually macular or papular. Although not a feature of murine typhus, eschar has been found in 12% of those with flea-borne spotted fever. Confirmatory laboratory diagnosis is usually obtained by serology; the indirect immunofluorescence assay is the serologic test of choice. Antibodies are seldom present during the first few days of illness. Thus, the diagnosis requires acute- and convalescent-phase specimens to document seroconversion or a four-fold increase in antibody titer. Since laboratory diagnosis is usually retrospective, when a flea-borne rickettsiosis is considered, empiric treatment should be initiated. The treatment of choice for both children and adults is doxycycline, which results in a swift and effective response. The following review is aimed to summarize the key clinical, epidemiological, ecological, diagnostic, and treatment aspects of flea-borne rickettsioses.
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Affiliation(s)
- Maria A Caravedo Martinez
- Department of Internal Medicine – Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Lucas S Blanton
- Department of Internal Medicine – Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
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18
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Otiang E, Chen D, Jiang J, Maina AN, Farris CM, Luce-Fedrow A, Richards AL. Pathogen Carriage by Peri-Domestic Fleas in Western Kenya. Vector Borne Zoonotic Dis 2021; 21:256-263. [PMID: 33481673 DOI: 10.1089/vbz.2020.2709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Fleas are carriers for many largely understudied zoonotic, endemic, emerging, and re-emerging infectious disease agents, but little is known about their prevalence and role as a vector in Africa. The aim of this study was to determine the diversity of fleas and the prevalence of infectious agents in them collected from human dwellings in western Kenya. A total of 306 fleas were collected using light traps from 33 human dwellings; 170 (55.56%) were identified as Ctenocephalides spp., 121 (39.54%) as Echidnophaga gallinacea, 13 (4.25%) as Pulex irritans, and 2 (0.65%) as Xenopsylla cheopis. Of the 306 individual fleas tested, 168 (54.9%) tested positive for rickettsial DNA by a genus-specific quantitative real-time PCR (qPCR) assay based on the 17-kDa antigen gene. Species-specific qPCR assays and sequencing revealed presence of Rickettsia asembonensis in 166 (54.2%) and Rickettsia felis in 2 (0.7%) fleas. Borrelia burgdorferi, normally known to be carried by ticks, was detected in four (1.3%) flea DNA preparations. We found no evidence of Yersinia pestis, Bartonella spp., or Orientia spp. Not only were Ctenocephalides spp. the most predominant flea species in the human dwellings, but also almost all of them were harboring R. asembonensis.
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Affiliation(s)
- Elkanah Otiang
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Daniel Chen
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Ju Jiang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Alice N Maina
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Christina M Farris
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Alison Luce-Fedrow
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA.,Department of Biology, Shippensburg University, Shippensburg, Pennsylvania, USA
| | - Allen L Richards
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA.,Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
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19
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Hoseini Z, Alipour H, Azizi K, Soltani A. Molecular-based Survey of Rickettsia spp. and Coxiella burnetii in Mosquitoes (Diptera: Culicidae) from Fars Province, Southern Iran, during 2017-18. Open Microbiol J 2020. [DOI: 10.2174/1874434602014010281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Objectives:
Since there have not been any studies on the roles of the Iranian mosquitoes in the transmission of Rickettsia spp. and Coxiella burneti, the present study investigates the roles of mosquitoes in the transmission of the pathogens using the PCR techniques for the first time in Iran.
Methods:
The present study was conducted in Fars province during the activity seasons of mosquitoes in 2017-18. The primer design was done to investigate the probability of mosquito’s contamination with Rickettsia spp. and Coxiella burnetii. The conventional PCR was used after the extraction of DNA from mosquitoes to study the contamination.
Results:
A total of 1103 adult mosquitoes were collected and identified. Among them, 3 genera and 11 species were identified, including Anopheles (25.74%), Culex (51.84%) and Culiseta (22.39%) genera. All tested mosquitoes were negative in terms of contamination to Rickettsia spp. and Coxiella burnetii.
Conclusion:
Based on the results, mosquitoes are not considered as vectors of Rickettsia spp. and Coxiella burnetii in this part of the country currently. Further studies on a larger scale are needed to examine the exact role of mosquitoes (as a possible vector with high abundance and mobility) in the transmission of these pathogens in tropical areas of Iran.
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Humans infested with Ixodes ricinus are exposed to a diverse array of tick-borne pathogens in Serbia. Ticks Tick Borne Dis 2020; 12:101609. [PMID: 33260091 DOI: 10.1016/j.ttbdis.2020.101609] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/24/2020] [Accepted: 11/05/2020] [Indexed: 12/19/2022]
Abstract
Tick-borne pathogens (TBPs) pose a major threat to human health in Europe and the whole northern hemisphere. Despite a high prevalence of TBPs in Ixodes ricinus ticks, knowledge on the incidence of tick-borne diseases in humans infested by this tick species is limited. This study was conducted in the year 2019 on patients who presented themselves to the Pasteur Institute Novi Sad with tick infestations. Ticks (n = 31) feeding on human (n = 30) and blood samples from the same individuals were collected by physicians and a microfluidic real-time high-throughput PCR system was used to test the genomic DNA of the samples for the presence of 27 bacterial and eight parasitic microorganisms in Serbia. Except for one Rhipicephalus sanguineus s.l. adult male tick, all ticks infesting humans were morphologically identified as I. ricinus. A high proportion of ticks (74 %, 23/31) were infected with at least one of the tested TB microorganisms, being Rickettsia helvetica (54 %, 17/31) the most common pathogen, but Borrelia afzelii (9 %, 3/31), Anaplasma phagocytophilum (6 %, 2/31), Borrelia miyamotoi (6 %, 2/31), and Francisella like-endosymbiont (6 %, 2/31), Borrelia valaisiana (3 %, 1/31), Borrelia lusitaniae (3 %, 1/31), Rickettsia felis (3 %, 1/31) and Rickettsia aeschlimannii (3 %, 1/31) were also identified. Despite the high infection rate of TBPs in ticks, only two human blood samples (6 %, 2/30) tested positive for the presence of TBPs, one patient (code H12, 67 years old female) was diagnosed with Borrelia spp. and the other patient was diagnosed (code H17, 71 years old female) with R. felis infection. The tick infesting patient H12 tested positive for B. afzelii, and R. helvetica and the tick infesting patient H17 tested positive for R. felis. Upon clinical examination, both patients were diagnosed with erythema migrans. No additional discomfort was reported by the patient and no additional pathology was observed by the physician. We concluded that humans bitten by I. ricinus in Serbia are exposed to a diverse array of TBPs with clinical impact in the Serbian cohort studied.
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Tsai KH, Yen TY, Wu WJ, Carvalho R, Raoult D, Fournier PE. Investigation of Ctenocephalides felis on domestic dogs and Rickettsia felis infection in the Democratic Republic of Sao Tome and Principe. Zoonoses Public Health 2020; 67:892-902. [PMID: 33145971 DOI: 10.1111/zph.12776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 11/29/2022]
Abstract
Rickettsia felis is an obligate intracellular Gram-negative bacterium which causes flea-borne spotted fever in humans. In the past decades, R. felis has been detected worldwide in Ctenocephalides felis fleas and various other arthropods. However, due to its shared symptoms with other common vector-borne diseases, human infection is prone to be underestimated or misdiagnosed, especially in the malaria-endemic areas including sub-Saharan Africa, where confirmatory laboratory diagnoses are not usually available. In this study, a 'One Health' approach was adopted to explore potential vector-borne and zoonotic pathogens in the Democratic Republic of Sao Tome and Principe (DRSTP), an island nation in the Gulf of Guinea. By collaborating with local veterinarians, 1,187 fleas were collected from 95 domestic dogs across the country and later identified as Ct. felis using taxonomic keys. A cytochrome oxidase gene-based phylogenetic analysis revealed that all collected fleas belonged to a single haplotype and were identical to isolates from Ivory Coast and Brazil that clustered into a clade of tropical distribution. Additional samples of 14 chigoe fleas (Tunga penetrans) were collected from the surrounding environment of the dogs' resting spots. Rickettsia felis infection in fleas was examined by molecular methods targeting the citrate synthase (gltA)- and outer membrane protein A (ompA)-coding genes as well as the R. felis-specific pRF plasmid. The bacterial DNA was detected in 21.01% (146/695) of cat fleas but none of the chigoe fleas. Microimmunofluorescence assay was then performed to assess pathogen exposure of the residents. Of 240 dried blood spots from participants with dog contacts, 8 (3.33%) exhibited R. felis antibodies. Our findings demonstrated the presence of R. felis in DRSTP. Further extensive epidemiological studies regarding its prevalence and its role in causing febrile illness while the nation is entering pre-elimination stage of malaria will be carried out.
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Affiliation(s)
- Kun-Hsien Tsai
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan.,Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan.,Department of Entomology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Tsai-Ying Yen
- Institute of Environmental and Occupational Health Sciences, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Wen-Jer Wu
- Department of Entomology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan
| | - Ronalg Carvalho
- Taiwanese Medical Mission, Sao Tome, Democratic Republic of Sao Tome and Principe
| | - Didier Raoult
- Aix-Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU Méditerranée Infection, Marseille, France.,French Reference Center for Rickettsioses, Q fever and Bartonelloses, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE) UM63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France
| | - Pierre-Edouard Fournier
- Aix-Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU Méditerranée Infection, Marseille, France.,French Reference Center for Rickettsioses, Q fever and Bartonelloses, Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes (URMITE) UM63, CNRS 7278, IRD 198, Inserm 1095, Marseille, France
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Onono J, Mutua P, Kitala P, Gathura P. Knowledge of pastoralists on livestock diseases and exposure assessment to brucellosis within rural and peri-urban areas in Kajiado, Kenya. F1000Res 2019; 8:1916. [PMID: 33204408 PMCID: PMC7642991 DOI: 10.12688/f1000research.20573.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/07/2019] [Indexed: 12/01/2022] Open
Abstract
Background: Livestock diseases impact the livelihoods of pastoralists. Brucellosis, a neglected zoonotic disease is highly prevalent in this system with an estimated 16% of livestock population in sub-Saharan Africa infected with the disease. The objective of this study was to assess knowledge of livestock diseases and the risk of exposure to brucellosis among pastoralists living in Kajiado County of Kenya. Methods: The study sites included pastoralist communities living in rural and peri-urban areas within the County. Both primary and secondary data were collected using participatory methods including pairwise ranking, proportional piling and probing and a review of the published literature. Exposure risk assessment was conducted according to the CODEX Alimentarius framework: Hazard identification, hazard characterization, exposure assessment and risk estimation. Results: According to pastoralists, livestock diseases that frequently occurred in their flocks and herds were contagious caprine pleuropneumonia, lumpy skin disease and foot and mouth disease; but zoonoses, including anthrax and brucellosis, were also mentioned during focus group discussions. Potential pathways of exposure to brucellosis and other zoonoses included consumption of unpasteurized milk, handling infected aborted materials without protective measures and consumption of raw meat and raw blood. Consumption of unpasteurized milk and handling infected aborted materials without protectives were linked with high risk of exposure to household members living in rural areas, with the risk level within the peri-urban areas ranked very low to low for most of these risk practices. Conclusions: The results call for enhanced public education targeting vulnerable groups to mitigate risks of disease spread and other impacts of brucellosis within the affected pastoralist production systems.
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Affiliation(s)
- Joshua Onono
- Department of Public Health Pharmacology and Toxicology, University of Nairobi, Nairobi, 00625, Kenya
| | - Penina Mutua
- Department of Public Health Pharmacology and Toxicology, University of Nairobi, Nairobi, 00625, Kenya
- Ministry of Agriculture Livestock Fisheries and Irrigation, Meat Training Institute, Athi River, Private bag, Kangemi, Nairobi, 00625, Kenya
| | - Philip Kitala
- Department of Public Health Pharmacology and Toxicology, University of Nairobi, Nairobi, 00625, Kenya
| | - Peter Gathura
- Department of Public Health Pharmacology and Toxicology, University of Nairobi, Nairobi, 00625, Kenya
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Abanda B, Paguem A, Abdoulmoumini M, Kingsley MT, Renz A, Eisenbarth A. Molecular identification and prevalence of tick-borne pathogens in zebu and taurine cattle in North Cameroon. Parasit Vectors 2019; 12:448. [PMID: 31511038 PMCID: PMC6737592 DOI: 10.1186/s13071-019-3699-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 09/03/2019] [Indexed: 02/03/2023] Open
Abstract
Background Public interest for tick-borne pathogens in cattle livestock is rising due to their veterinary and zoonotic importance. Consequently, correct identification of these potential pathogens is crucial to estimate the level of exposition, the risk and the detrimental impact on livestock and the human population. Results Conventional PCR with generic primers was used to identify groups of tick-borne pathogens in cattle breeds from northern Cameroon. The overall prevalence in 1260 blood samples was 89.1%, with 993 (78.8%) positive for Theileria/Babesia spp., 959 (76.1%) for Anaplasma/Ehrlichia spp., 225 (17.9%) for Borrelia spp., and 180 (14.3%) for Rickettsia spp. Sanger sequencing of a subset of positively-tested samples revealed the presence of Theileria mutans (92.2%, 130/141), T. velifera (16.3%, 23/141), Anaplasma centrale (10.9%, 15/137), A. marginale (30.7%, 42/137), A. platys (51.1%, 70/137), Anaplasma sp. ‘Hadesa’ (10.9%, 15/137), Ehrlichia ruminantium (0.7%, 1/137), E. canis (0.7%, 1/137), Borrelia theileri (91.3%, 42/46), Rickettsia africae (59.4%, 19/32) and R. felis (12.5%, 4/32). A high level of both intra- and inter-generic co-infections (76.0%) was observed. To the best of our knowledge, B. theileri, T. mutans, T. velifera, A. platys, Anaplasma sp. ‘Hadesa’, R. felis and E. canis are reported for the first time in cattle from Cameroon, and for R. felis it is the first discovery in the cattle host. Babesia spp. were not detected by sequencing. The highest number of still identifiable species co-infections was up to four pathogens per genus group. Multifactorial analyses revealed a significant association of infection with Borrelia theileri and anemia. Whereas animals of older age had a higher risk of infection, the Gudali cattle had a lower risk compared to the other local breeds. Conclusion Co-infections of tick-borne pathogens with an overall high prevalence were found in all five study sites, and were more likely to occur than single infections. Fulani, Namchi and Kapsiki were the most infected breed in general; however, with regions as significant risk factor. A better-adapted approach for tick-borne pathogen identification in co-infected samples is a requirement for epidemiological investigations and tailored control measures.
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Affiliation(s)
- Babette Abanda
- Institute of Evolution and Ecology, Department of Comparative Zoology, University of Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany. .,Programme Onchocercoses field station of the University of Tübingen, P.O. Box 65, Ngaoundéré, Cameroon. .,Department of Biological Sciences, University of Ngaoundéré, P.O. Box 454, Ngaoundéré, Cameroon.
| | - Archile Paguem
- Institute of Evolution and Ecology, Department of Comparative Zoology, University of Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.,Programme Onchocercoses field station of the University of Tübingen, P.O. Box 65, Ngaoundéré, Cameroon
| | - Mamoudou Abdoulmoumini
- School of Veterinary Medicine and Sciences, Department of Parasitology and Parasitological Diseases, University of Ngaoundéré, Ngaoundéré, Cameroon
| | - Manchang Tanyi Kingsley
- Institute of Agricultural Research for Development (IRAD), Wakwa Regional Centre, P.O. Box 65, Ngaoundéré, Cameroon
| | - Alfons Renz
- Institute of Evolution and Ecology, Department of Comparative Zoology, University of Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany
| | - Albert Eisenbarth
- Institute of Evolution and Ecology, Department of Comparative Zoology, University of Tübingen, Auf der Morgenstelle 28, 72076, Tübingen, Germany.,Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
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24
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Munyua PM, Njenga MK, Osoro EM, Onyango CO, Bitek AO, Mwatondo A, Muturi MK, Musee N, Bigogo G, Otiang E, Ade F, Lowther SA, Breiman RF, Neatherlin J, Montgomery J, Widdowson MA. Successes and challenges of the One Health approach in Kenya over the last decade. BMC Public Health 2019; 19:465. [PMID: 32326940 PMCID: PMC6696663 DOI: 10.1186/s12889-019-6772-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
More than 75% of emerging infectious diseases are zoonotic in origin and a transdisciplinary, multi-sectoral One Health approach is a key strategy for their effective prevention and control. In 2004, US Centers for Disease Control and Prevention office in Kenya (CDC Kenya) established the Global Disease Detection Division of which one core component was to support, with other partners, the One Health approach to public health science. After catalytic events such as the global expansion of highly pathogenic H5N1 and the 2006 East African multi-country outbreaks of Rift Valley Fever, CDC Kenya supported key Kenya government institutions including the Ministry of Health and the Ministry of Agriculture, Livestock, and Fisheries to establish a framework for multi-sectoral collaboration at national and county level and a coordination office referred to as the Zoonotic Disease Unit (ZDU). The ZDU has provided Kenya with an institutional framework to highlight the public health importance of endemic and epidemic zoonoses including RVF, rabies, brucellosis, Middle East Respiratory Syndrome Coronavirus, anthrax and other emerging issues such as anti-microbial resistance through capacity building programs, surveillance, workforce development, research, coordinated investigation and outbreak response. This has led to improved outbreak response, and generated data (including discovery of new pathogens) that has informed disease control programs to reduce burden of and enhance preparedness for endemic and epidemic zoonotic diseases, thereby enhancing global health security. Since 2014, the Global Health Security Agenda implemented through CDC Kenya and other partners in the country has provided additional impetus to maintain this effort and Kenya’s achievement now serves as a model for other countries in the region. Significant gaps remain in implementation of the One Health approach at subnational administrative levels; there are sustainability concerns, competing priorities and funding deficiencies.
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Affiliation(s)
- Peninah M Munyua
- Division of Global Health Protection, US Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.
| | - M Kariuki Njenga
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, Washington, USA
| | - Eric M Osoro
- Zoonotic Disease Unit, Kenya Ministry of health, Nairobi, Kenya
| | - Clayton O Onyango
- Division of Global Health Protection, US Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya
| | - Austine O Bitek
- Zoonotic Disease Unit, Ministry of Agriculture Livestock and Fisheries, Nairobi, Kenya
| | - Athman Mwatondo
- Zoonotic Disease Unit, Kenya Ministry of health, Nairobi, Kenya
| | - Mathew K Muturi
- Zoonotic Disease Unit, Ministry of Agriculture Livestock and Fisheries, Nairobi, Kenya
| | - Norah Musee
- Division of Global Health Protection, US Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya
| | - Godfrey Bigogo
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Elkanah Otiang
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Fredrick Ade
- Center for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Sara A Lowther
- Division of Global Health Protection, US Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.,Division of Global Health Protection, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Robert F Breiman
- Emory Global Health Institute, Emory University, Atlanta, GA, USA
| | - John Neatherlin
- Division of Global Health Protection, US Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.,Division of Global Health Protection, US Centers for Disease Control and Prevention, Atlanta, GA, USA.,Division of Global Health Protection, US Centers for Disease Control and Prevention, Dakar, Senegal
| | - Joel Montgomery
- Division of Global Health Protection, US Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Marc-Alain Widdowson
- Division of Global Health Protection, US Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya.,Division of Global Health Protection, US Centers for Disease Control and Prevention, Atlanta, GA, USA
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25
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Moonga LC, Hayashida K, Nakao R, Lisulo M, Kaneko C, Nakamura I, Eshita Y, Mweene AS, Namangala B, Sugimoto C, Yamagishi J. Molecular detection of Rickettsia felis in dogs, rodents and cat fleas in Zambia. Parasit Vectors 2019; 12:168. [PMID: 30975188 PMCID: PMC6460736 DOI: 10.1186/s13071-019-3435-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 04/05/2019] [Indexed: 11/24/2022] Open
Abstract
Background Flea-borne spotted fever is a zoonosis caused by Rickettsia felis, a Gram-negative obligate intracellular bacterium. The disease has a worldwide distribution including western and eastern sub-Saharan Africa where it is associated with febrile illness in humans. However, epidemiology and the public health risks it poses remain neglected especially in developing countries including Zambia. While Ctenocephalides felis (cat fleas) has been suggested to be the main vector, other arthropods including mosquitoes have been implicated in transmission and maintenance of the pathogen; however, their role in the epidemiological cycle remains to be elucidated. Thus, the aim of this study was to detect and characterize R. felis from animal hosts and blood-sucking arthropod vectors in Zambia. Methods Dog blood and rodent tissue samples as well as cat fleas and mosquitoes were collected from various areas in Zambia. DNA was extracted and screened by polymerase chain reaction (PCR) targeting genus Rickettsia and amplicons subjected to sequence analysis. Positive samples were further subjected to R. felis-specific real-time quantitative polymerase chain reactions. Results Rickettsia felis was detected in 4.7% (7/150) of dog blood samples and in 11.3% (12/106) of rodent tissue samples tested by PCR; this species was also detected in 3.7% (2/53) of cat fleas infesting dogs, co-infected with Rickettsia asembonensis. Furthermore, 37.7% (20/53) of cat flea samples tested positive for R. asembonensis, a member of spotted fever group rickettsiae of unknown pathogenicity. All the mosquitoes tested (n = 190 pools) were negative for Rickettsia spp. Conclusions These observations suggest that R. felis is circulating among domestic dogs and cat fleas as well as rodents in Zambia, posing a potential public health risk to humans. This is because R. felis, a known human pathogen is present in hosts and vectors sharing habitat with humans. Electronic supplementary material The online version of this article (10.1186/s13071-019-3435-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lavel Chinyama Moonga
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Kyoko Hayashida
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Ryo Nakao
- Laboratory of Parasitology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-Ku, Sapporo, Hokkaido, 060-0818, Japan
| | - Malimba Lisulo
- The University of Edinburgh, College of Medicine and Veterinary Medicine, Deanery of Biomedical Sciences, 1 George Square, Edinburgh, EH8 9JZ, UK
| | - Chiho Kaneko
- Project for Zoonoses Education and Research, Faculty of Agriculture, University of Miyazaki, 1-1, Gakuen-kibanadai-nishi, Miyazaki, 889-2192, Japan
| | - Ichiro Nakamura
- Unit of International Cooperation, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Yuki Eshita
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan
| | - Aaron S Mweene
- Department of Disease Control, School of Veterinary Medicine, University of Zambia, P. O. Box 32379, Lusaka, Zambia.,African Centre of Excellence for Infectious Diseases of Human and Animals, University of Zambia, PO Box 32379, Lusaka, Zambia
| | - Boniface Namangala
- Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, PO Box 32379, Lusaka, Zambia.,African Centre of Excellence for Infectious Diseases of Human and Animals, University of Zambia, PO Box 32379, Lusaka, Zambia
| | - Chihiro Sugimoto
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan.,Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Junya Yamagishi
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Kita 20, Nishi 10, Kita-Ku, Sapporo, Hokkaido, 001-0020, Japan. .,Global Station for Zoonosis Control, GI-CoRE, Hokkaido University, Sapporo, Hokkaido, Japan.
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26
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Maina AN, Jiang J, Luce-Fedrow A, St John HK, Farris CM, Richards AL. Worldwide Presence and Features of Flea-Borne Rickettsia asembonensis. Front Vet Sci 2019; 5:334. [PMID: 30687724 PMCID: PMC6338025 DOI: 10.3389/fvets.2018.00334] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/14/2018] [Indexed: 11/15/2022] Open
Abstract
Rickettsia asembonensis, the most well-characterized rickettsia of the Rickettsia felis-like organisms (RFLO), is relatively unknown within the vector-borne diseases research community. The agent was initially identified in peri-domestic fleas from Asembo, Kenya in an area in which R. felis was associated with fever patients. Local fleas collected from domestic animals and within homes were predominately infected with R. asembonensis with < 10% infected with R. felis. Since the identification of R. asembonensis in Kenya, it has been reported in other locations within Africa, Asia, the Middle East, Europe, North America, and South America. With the description of R. asembonensis-like genotypes across the globe, a need exists to isolate these R. asembonensis genotypes in cell culture, conduct microscopic, and biological analysis, as well as whole genome sequencing to ascertain whether they are the same species. Additionally, interest has been building on the potential of R. asembonensis in infecting vertebrate hosts including humans, non-human primates, dogs, and other animals. The current knowledge of the presence, prevalence, and distribution of R. asembonensis worldwide, as well as its arthropod hosts and potential as a pathogen are discussed in this manuscript.
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Affiliation(s)
- Alice N Maina
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Ju Jiang
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Alison Luce-Fedrow
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.,Department of Biology, Shippensburg University, Shippensburg, PA, United States
| | - Heidi K St John
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Christina M Farris
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Allen L Richards
- Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.,Department of Preventative Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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27
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Le-Viet N, Le VN, Chung H, Phan DT, Phan QD, Cao TV, Abat C, Raoult D, Parola P. Prospective case-control analysis of the aetiologies of acute undifferentiated fever in Vietnam. Emerg Microbes Infect 2019; 8:339-352. [PMID: 30866787 PMCID: PMC6455186 DOI: 10.1080/22221751.2019.1580539] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/24/2019] [Accepted: 01/29/2019] [Indexed: 01/15/2023]
Abstract
Acute undifferentiated fever (AUF) is frequently observed in tropical settings, but diagnosing the cause of AUF is often a challenge for local physicians and the physicians treating returning travellers. We conducted a case-control study in central Vietnam in 2016. A total of 378 febrile adult patients (AUFs) with a fever for ≤21 days, no evidence of localized infection and negative screening tests for dengue and malaria, and 384 afebrile adult patients (Controls) were prospectively enrolled. Whole blood, plasma, eschar swab, throat swab and urine specimens were collected and analysed. Quantitative PCR and RT-PCR were used to test for 55 bacteria, viruses and their subtypes. Serological tests were also used to test for rickettsial agents. The most common aetiology was influenza virus (20.9% in AUFs vs. 0% in Controls), followed by rickettsial agents (mainly Orientia tsutsugamushi and Rickettsia typhi) (10.8% vs. 0.3%), dengue virus (7.7% vs. 0.5%), Leptospira (4.8% vs. 0.8%), adenovirus (4.8% vs. 1.0%), and enterovirus (2.1% vs. 0%) (p < .05). The real proportion of dengue in AUF cases was underestimated because patients with dengue-positive rapid diagnosis tests were excluded from the study. The emerging agent Rickettsia felis, which had not been previously observed in Vietnam, was detected in this study. In total, 216 patients (57.1%) were given causative diagnoses, comprising 143 (66.2%) monoinfections and 73 (33.8%) coinfections. The infections caused by these agents should be considered in clinical practice and further studies. Additionally, agents susceptible to doxycycline were detected in 15.6% of AUFs; thus, this drug should be included in the panel used to treat AUF patients.
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Affiliation(s)
- Nhiem Le-Viet
- Aix Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
- Department of Tropical Medicine, Quang Nam Central General Hospital, Quang Nam, Vietnam
| | - Viet-Nho Le
- School of Medicine and Pharmacy, Danang University, Danang, Vietnam
| | - Hai Chung
- Department of Tropical Medicine, Quang Nam Central General Hospital, Quang Nam, Vietnam
| | - Duc-Tuan Phan
- Department of Internal Medicine II, Quang Nam Northern Mountainous Region General Hospital, Quang Nam, Vietnam
| | - Quang-Duong Phan
- Department of Internal Medicine B, Quang Nam Regional General Hospital, Quang Nam, Vietnam
| | - Thanh-Van Cao
- Department of Tropical Medicine, Quang Nam Provincial General Hospital, Quang Nam, Vietnam
| | - Cédric Abat
- IHU-Méditerranée Infection, Marseille, France
| | - Didier Raoult
- IHU-Méditerranée Infection, Marseille, France
- Aix Marseille University, IRD, AP-HM, MEPHI, Marseille, France
| | - Philippe Parola
- Aix Marseille University, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
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28
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Fenollar F, Mediannikov O. Emerging infectious diseases in Africa in the 21st century. New Microbes New Infect 2018; 26:S10-S18. [PMID: 30402238 PMCID: PMC6205565 DOI: 10.1016/j.nmni.2018.09.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 08/29/2018] [Accepted: 09/06/2018] [Indexed: 11/25/2022] Open
Abstract
Many infectious diseases have emerged or reemerged in Africa in the 21st century. Some of them are associated with newly discovered microorganisms such as Rickettsia felis and Tropheryma whipplei; others are known, historical diseases such as plague and cholera. In addition are diseases related to previously known microorganisms which recently have been involved for the first time in massive outbreaks with worldwide impacts (such as Ebola virus, Zika virus and Chikungunya virus). Research on emerging infectious diseases needs to be identified as a priority.
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Affiliation(s)
| | - O Mediannikov
- IRD, AP-HM, MEPHI, Aix-Marseille Université, IRD, IHU-Méditerranée Infection, Marseille, France
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29
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Mediannikov O, Abat C, Sokhna C, Raoult D. Parallel Decline of Malaria and Rickettsia felis Infections in Senegal. Am J Trop Med Hyg 2018; 99:360-361. [PMID: 29869598 DOI: 10.4269/ajtmh.17-0194] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Rickettsia felis is a common emerging pathogen in sub-Saharan Africa. Comparing dynamics of morbidities due to malaria and R. felis infections in two Senegalese villages, we found a strong and significant correlation between them. Malaria morbidity is strongly decreasing because of the implementation of long-lasting insecticidal nets, so we hypothesize that the same measure may decrease the R. felis infections.
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Affiliation(s)
- Oleg Mediannikov
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France.,Campus International IRD-UCAD Hann Maristes, Dakar, Senegal
| | - Cédric Abat
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
| | - Cheikh Sokhna
- Aix-Marseille Univ, IRD, APHM, VITROME, IHU-Méditerranée Infection, Marseille, France.,Campus International IRD-UCAD Hann Maristes, Dakar, Senegal
| | - Didier Raoult
- Aix-Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France
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30
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Mullins KE, Maina AN, Krueger L, Jiang J, Cummings R, Drusys A, Williams G, Dhillon M, Richards AL. Rickettsial Infections among Cats and Cat Fleas in Riverside County, California. Am J Trop Med Hyg 2018; 99:291-296. [PMID: 29869607 DOI: 10.4269/ajtmh.17-0706] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Presently, few studies have investigated the role of domestic cats (Felis catus) in the recrudescence of flea-borne rickettsioses in California and the southern United States. In this study, we aimed to investigate the presence of Rickettsia typhi or Rickettisa felis in domestic cats (F. catus) and the fleas (primarily Ctenocephalides felis, the cat flea) associated with these cats in Riverside County, California. Thirty cats and 64 pools of fleas collected from these cats were investigated for rickettsial infections. Three cats and 17 flea pools (from 10 cats) tested positive for rickettsial infections. polymerase chain reaction and DNA sequencing indicated that one of the cats was positive for R. felis infections, whereas two were positive for Candidatus Rickettsia senegalensis infection. In addition, 12 of the flea pools were positive for R. felis, whereas five were positive for Ca. R. senegalensis. By contrast, no cats or their associated fleas tested positive for R. typhi. Finally, eight sera from these cats contained spotted fever group Rickettsia (SFGR) antibodies. The detection of R. felis and SFGR antibodies and the lack of R. typhi and TGR antibodies support R. felis as the main rickettsial species infecting cat fleas. The detection of Ca. R. senegalensis in both fleas and cats also provides additional evidence that cats and their associated fleas are infected with other R. felis-like organisms highlighting the potential risk for human infections with R. felis or R. felis-like organisms.
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Affiliation(s)
- Kristin E Mullins
- Naval Medical Research Center, Silver Spring, Maryland.,University of Maryland School of Medicine, Baltimore, Maryland
| | - Alice N Maina
- Naval Medical Research Center, Silver Spring, Maryland
| | - Laura Krueger
- Orange County Mosquito and Vector Control District, Garden Grove, California
| | - Ju Jiang
- Naval Medical Research Center, Silver Spring, Maryland
| | - Robert Cummings
- Orange County Mosquito and Vector Control District, Garden Grove, California
| | - Allan Drusys
- Riverside County Department of Animal Services, Riverside, California
| | - Greg Williams
- Northwest Mosquito and Vector Control District, Corona, California
| | - Major Dhillon
- Northwest Mosquito and Vector Control District, Corona, California
| | - Allen L Richards
- Uniformed Services University of the Health Sciences, Bethesda, Maryland.,Naval Medical Research Center, Silver Spring, Maryland
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31
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Serum cytokine responses in Rickettsia felis infected febrile children, Ghana. Med Microbiol Immunol 2018; 207:243-248. [PMID: 29736763 PMCID: PMC6096778 DOI: 10.1007/s00430-018-0544-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 04/24/2018] [Indexed: 11/13/2022]
Abstract
The intracellular pathogen Rickettsia felis causes flea-borne spotted fever and is increasingly recognized as an emerging cause of febrile illness in Africa, where co-infection with Plasmodium falciparum is common. Rickettsiae invade endothelial cells. Little is known, however, about the early immune responses to infection. In this study, we characterize for the first time the cytokine profile in the acute phase of illness caused by R. felis infection, as well as in plasmodial co-infection, using serum from 23 febrile children < 15 years of age and 20 age-matched healthy controls from Ghana. Levels of IL-8 (interleukin-8), IP-10 (interferon-γ-induced protein-10), MCP-1 (monocyte chemotactic protein-1), MIP-1α (macrophage inflammatory protein-1α) and VEGF (vascular endothelial growth factor) were significantly elevated in R. felis mono-infection; however, IL-8 and VEGF elevation was not observed in plasmodial co-infections. These results have important implications in understanding the early immune responses to R. felis and suggest a complex interplay in co-infections.
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32
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Oyas H, Holmstrom L, Kemunto NP, Muturi M, Mwatondo A, Osoro E, Bitek A, Bett B, Githinji JW, Thumbi SM, Widdowson MA, Munyua PM, Njenga MK. Enhanced surveillance for Rift Valley Fever in livestock during El Niño rains and threat of RVF outbreak, Kenya, 2015-2016. PLoS Negl Trop Dis 2018; 12:e0006353. [PMID: 29698487 PMCID: PMC5919633 DOI: 10.1371/journal.pntd.0006353] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 02/28/2018] [Indexed: 12/16/2022] Open
Abstract
Background In mid-2015, the United States’ Pandemic Prediction and Forecasting Science and Technical Working Group of the National Science and Technology Council, Food and Agriculture Organization Emergency Prevention Systems, and Kenya Meteorological Department issued an alert predicting a high possibility of El-Niño rainfall and Rift Valley Fever (RVF) epidemic in Eastern Africa. Methodology/Principal findings In response to the alert, the Kenya Directorate of Veterinary Services (KDVS) carried out an enhanced syndromic surveillance system between November 2015 and February 2016, targeting 22 RVF high-risk counties in the country as identified previously through risk mapping. The surveillance collected data on RVF-associated syndromes in cattle, sheep, goats, and camels from >1100 farmers through 66 surveillance officers. During the 14-week surveillance period, the KDVS received 10,958 reports from participating farmers and surveillance officers, of which 362 (3.3%) had at least one syndrome. The reported syndromes included 196 (54.1%) deaths in young livestock, 133 (36.7%) abortions, and 33 (9.1%) hemorrhagic diseases, with most occurring in November and December, the period of heaviest rainfall. Of the 69 herds that met the suspect RVF herd definition (abortion in flooded area), 24 (34.8%) were defined as probable (abortions, mortalities in the young ones, and/or hemorrhagic signs) but none were confirmed. Conclusion/Significance This surveillance activity served as an early warning system that could detect RVF disease in animals before spillover to humans. It was also an excellent pilot for designing and implementing syndromic surveillance in animals in the country, which is now being rolled out using a mobile phone-based data reporting technology as part of the global health security system. Occurrence of Rift Valley Fever (RVF) outbreak is associated with heavy El-Niño rainfall. In July 2015, an alert on the likelihood of El-Niño rainfall and RVF outbreak in Eastern Africa region was issued by the United States, Food and Agriculture Organization, and Kenya Meteorological Department. In response to the alert, the Kenya Directorate of Veterinary Services (KDVS) carried out an enhanced syndromic surveillance system between November 2015 and February 2016 in the 22 counties that had previously been identified as RVF high-risk counties. The surveillance system collected data on RVF-associated syndromes and risk factors in cattle, sheep, goats and camels from more than 1100 farmers. Of the 10,958 field reports submitted, 45 were consistent with suspect RVF disease and 24 of these identified as probable RVF, triggering an immediate response. Whereas investigations of the suspect cases and laboratory testing did not confirm RVF cases, the surveillance system served as an excellent early warning system that could detect disease in animal before spillover to humans.
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Affiliation(s)
- Harry Oyas
- Veterinary Epidemiology and Economics Unit, Kenya Ministry of Agriculture, livestock and Fisheries, Nairobi, Kenya
| | - Lindsey Holmstrom
- College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | - Naomi P. Kemunto
- Washington State University Global Health Program-Kenya, Washington State University, Nairobi, Kenya
| | - Matthew Muturi
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Athman Mwatondo
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Eric Osoro
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Austine Bitek
- Kenya Zoonotic Disease Unit, Ministry of Health and Ministry of Agriculture, Livestock and Fisheries, Nairobi, Kenya
| | - Bernard Bett
- Animal and Human Health Program, International Livestock Research Institute, Nairobi, Kenya
| | - Jane W. Githinji
- Veterinary Epidemiology and Economics Unit, Kenya Ministry of Agriculture, livestock and Fisheries, Nairobi, Kenya
| | - Samuel M. Thumbi
- Washington State University Global Health Program-Kenya, Washington State University, Nairobi, Kenya
| | - Marc-Alain Widdowson
- Division of Global Health Protection, United States’ Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Peninah M. Munyua
- Division of Global Health Protection, United States’ Centers for Disease Control and Prevention, Nairobi, Kenya
| | - M. Kariuki Njenga
- Washington State University Global Health Program-Kenya, Washington State University, Nairobi, Kenya
- * E-mail:
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The epidemiology of Rickettsia felis infecting fleas of companion animals in eastern Australia. Parasit Vectors 2018; 11:138. [PMID: 29554953 PMCID: PMC5859732 DOI: 10.1186/s13071-018-2737-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/22/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Flea-borne spotted fever (FBSF) caused by Rickettsia felis is an arthropod-borne zoonosis. This study aimed to determine the prevalence, primary species and genotype(s) of R. felis infecting fleas from dogs and cats. RESULTS All fleas were identified as Ctenocephalides felis felis. All rickettsial DNA detected in fleas was identified as being 100% homologous to R. felis URRWXCal2, with positivity within tropical, subtropical and temperate regions noted at 6.7%, 13.2% and 15.5%, respectively. Toy/small breed dogs were found to be at a lower odds of harboring R. felis-positive fleas compared with large breed dogs on univariate analysis, while DMH and pedigree breed cats were at a lower odds compared to DSH cats. Cooler minimum temperature ranges of between 15 to 20 °C and between 8 to 15 °C increased the odds of R. felis positivity in fleas, as did a constrained maximum temperature range of between 27 to 30 °C on multivariable analysis. CONCLUSIONS Environmental temperature may play a part in influencing R. felis prevalence and infectivity within its flea host. Regional climatic differences need to be considered when approaching public health risk mitigation strategies for FBSF.
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Oguntomole O, Nwaeze U, Eremeeva ME. Tick-, Flea-, and Louse-Borne Diseases of Public Health and Veterinary Significance in Nigeria. Trop Med Infect Dis 2018; 3:E3. [PMID: 30274402 PMCID: PMC6136614 DOI: 10.3390/tropicalmed3010003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 12/15/2017] [Accepted: 12/20/2017] [Indexed: 12/03/2022] Open
Abstract
Mosquito-borne diseases are common high-impact diseases in tropical and subtropical areas. However, other non-mosquito vector-borne pathogens (VBPs) may share their geographic distribution, seasonality, and clinical manifestations, thereby contributing their share to the morbidity and mortality caused by febrile illnesses in these regions. The purpose of this work was to collect and review existing information and identify knowledge gaps about tick, flea-, and louse-borne diseases of veterinary and public health significance in Nigeria. Full-length articles about VBPs were reviewed and relevant information about the vectors, their hosts, geographic distribution, seasonality, and association(s) with human or veterinary diseases was extracted. Specific laboratory tools used for detection and identification of VBPs in Nigeria were also identified. A total of 62 original publications were examined. Substantial information about the prevalence and impacts of ticks and fleas on pet and service dogs (18 articles), and livestock animals (23 articles) were available; however, information about their association with and potential for causing human illnesses was largely absent despite the zoonotic nature of many of these peri-domestic veterinary diseases. Recent publications that employed molecular methods of detection demonstrated the occurrence of several classic (Ehrlichia canis, Rickettsia africae, Bartonella sp.) and emerging human pathogens (R. aeschlimannii, Neoehrlichia mikurensis) in ticks and fleas. However, information about other pathogens often found in association with ticks (R. conorii) and fleas (R. typhi, R. felis) across the African continent was lacking. Records of louse-borne epidemic typhus in Nigeria date to 1947; however, its current status is not known. This review provides an essential baseline summary of the current knowledge in Nigeria of non-mosquito VBPs, and should stimulate improvements in the surveillance of the veterinary and human diseases they cause in Nigeria. Due to increasing recognition of these diseases in other African countries, veterinary and public health professionals in Nigeria should expand the list of possible diseases considered in patients presenting with fever of unknown etiology.
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Affiliation(s)
- Oluwaseun Oguntomole
- Jiann-Ping Hsu College of Public Health, Georgia Southern University, 501 Forest Drive, Statesboro, GA 30458-8015, USA.
| | - Ugochukwu Nwaeze
- Jiann-Ping Hsu College of Public Health, Georgia Southern University, 501 Forest Drive, Statesboro, GA 30458-8015, USA.
| | - Marina E Eremeeva
- Jiann-Ping Hsu College of Public Health, Georgia Southern University, 501 Forest Drive, Statesboro, GA 30458-8015, USA.
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Essbauer S, Hofmann M, Kleinemeier C, Wölfel S, Matthee S. Rickettsia diversity in southern Africa: A small mammal perspective. Ticks Tick Borne Dis 2017; 9:288-301. [PMID: 29174365 DOI: 10.1016/j.ttbdis.2017.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Revised: 11/01/2017] [Accepted: 11/09/2017] [Indexed: 10/18/2022]
Abstract
Worldwide, including Africa, rickettsioses are recognized as emerging or re-emerging infections. To date, little is known about the diversity of Rickettsia species that are naturally associated with small mammals in southern Africa. The aim of the study was to screen a diversity of small mammals for the presence of rickettsial DNA. Animals were trapped at 38 localities in South Africa and Namibia. In total, 1616 ear-tissue samples from 23 species representing 17 genera were tested using real-time (rt)PCR and multi-locus sequence typing (MLST). Of the 1616 samples 251 (15.5%) were positive in an initial rtPCR. In 16 of the 23 investigated animal species rickettsial DNA was detected with an average prevalence of 15.7%. We herein describe for the first time four Rickettsia (R.) species known to be pathogenic for humans in rodents from South Africa, R. conorii, R. massiliae, R. felis and R. helvetica. In addition, by MLST and subsequent phylogenetic analyses so far undescribed Rickettsia species, Candidatus Rickettsia africaustralis, Candidatus Rickettsia rhabdomydis, and Candidatus Rickettsia muridii were confirmed. Further four new genotypes, genotype Rickettsia hofmannii, genotype Rickettsia stutterheimensis, genotype Rickettsia hogsbackensis and genotype Rickettsia kaalplaasensis, respectively, are described. The data indicate a surprisingly high diversity of Rickettsia in small mammals in South Africa and might indicate their possible role as reservoirs for Rickettsia. Ecological questions concerning their natural hosts such as small mammals, but also the role of livestock or pet animals, require further investigation. Particularly, data on the relevance of these rickettsiae for diseases in humans are of further interest.
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Affiliation(s)
- Sandra Essbauer
- Bundeswehr Institute of Microbiology, Department Virology and Rickettsiology, Neuherbergstr. 11, 80937 Muenchen, Germany.
| | - Mirja Hofmann
- Bundeswehr Institute of Microbiology, Department Virology and Rickettsiology, Neuherbergstr. 11, 80937 Muenchen, Germany
| | - Christoph Kleinemeier
- Bundeswehr Institute of Microbiology, Department Virology and Rickettsiology, Neuherbergstr. 11, 80937 Muenchen, Germany
| | - Silke Wölfel
- Bundeswehr Institute of Microbiology, Department Virology and Rickettsiology, Neuherbergstr. 11, 80937 Muenchen, Germany
| | - Sonja Matthee
- Department of Conservation Ecology and Entomology, Stellenbosch University, Matieland, South Africa
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Ehounoud C, Fenollar F, Dahmani M, N’Guessan J, Raoult D, Mediannikov O. Bacterial arthropod-borne diseases in West Africa. Acta Trop 2017; 171:124-137. [PMID: 28365316 DOI: 10.1016/j.actatropica.2017.03.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Indexed: 01/18/2023]
Abstract
Arthropods such as ticks, lice, fleas and mites are excellent vectors for many pathogenic agents including bacteria, protozoa and viruses to animals. Moreover, many of these pathogens can also be accidentally transmitted to humans throughout the world. Bacterial vector-borne diseases seem to be numerous and very important in human pathology, however, they are often ignored and are not well known. Yet they are in a phase of geographic expansion and play an important role in the etiology of febrile episodes in regions of Africa. Since the introduction of molecular techniques, the presence of these pathogens has been confirmed in various samples from arthropods and animals, and more rarely from human samples in West Africa. In this review, the aim is to summarize the latest information about vector-borne bacteria, focusing on West Africa from 2000 until today in order to better understand the epidemiological risks associated with these arthropods. This will allow health and veterinary authorities to develop a strategy for surveillance of arthropods and bacterial disease in order to protect people and animals.
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Healy SP, Brown LD, Hagstrom MR, Foil LD, Macaluso KR. Effect of Rickettsia felis Strain Variation on Infection, Transmission, and Fitness in the Cat Flea (Siphonaptera: Pulicidae). JOURNAL OF MEDICAL ENTOMOLOGY 2017; 54:1037-1043. [PMID: 28399259 PMCID: PMC5850810 DOI: 10.1093/jme/tjx046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Indexed: 05/12/2023]
Abstract
Rickettsia felis is a human pathogen transmitted by the cat flea, Ctenocephalides felis (Bouché) (str. LSU), as well as an obligate symbiont of the parthenogenic booklouse Liposcelis bostrychophila (Badonnel) (str. LSU-Lb). The influence of genetic variability in these two strains of R. felis on host specialization and fitness and possible resulting differences on infection and transmission kinetics in C. felis is unknown. Utilizing an artificial host system, cat fleas were exposed to a R. felis str. LSU-Lb-infected bloodmeal and monitored for infection at 7-d intervals for 28 d. Quantitative real-time PCR was used to determine rickettsial load and infection density in newly exposed cat fleas, and transmission frequency between cat fleas. The effect of persistent R. felis infection on cat flea F1 progeny was also assessed. At 7 d postexposure 76.7% of the cat fleas successfully acquired R. felis str. LSU-Lb. In R. felis str. LSU-Lb-exposed cat fleas, the mean infection load (6.15 × 106), infection density (0.76), and infection prevalence (91/114) were significantly greater than R. felis str. LSU infection load (3.09 × 106), infection density (0.68), and infection prevalence (76/113). A persistent R. felis str. LSU-Lb infection was detected for 28 d in adult cat fleas but neither female:male ratio distortion nor vertical transmission was observed in F1 progeny. While infection kinetics differed, with higher intensity associated with R. felis str. LSU-Lb, no distinct phenotype was observed in the F1 progeny.
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Affiliation(s)
- Sean P. Healy
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803 (; ; ; )
- Department of Entomology, Louisiana State University, Baton Rouge, LA 70803 ()
| | - Lisa D. Brown
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803 (; ; ; )
- Current address: Department of Biological Science, Vanderbilt University, Nashville, TN 37235
| | - Melena R. Hagstrom
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803 (; ; ; )
- Current address: Iowa State University, College of Veterinary Medicine, Ames, IA 50011
| | - Lane D. Foil
- Department of Entomology, Louisiana State University, Baton Rouge, LA 70803 ()
| | - Kevin R. Macaluso
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Vector-Borne Disease Laboratories, Baton Rouge, LA 70803 (; ; ; )
- Corresponding author, e-mail:
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Koka H, Sang R, Kutima HL, Musila L. The Detection of Spotted Fever Group Rickettsia DNA in Tick Samples From Pastoral Communities in Kenya. JOURNAL OF MEDICAL ENTOMOLOGY 2017; 54:774-780. [PMID: 28073909 PMCID: PMC5850802 DOI: 10.1093/jme/tjw238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
In this study, ticks from pastoral communities in Kenya were tested for Rickettsia spp. infections in geographical regions where the presence of tick-borne arboviruses had previously been reported. Rickettsial and arbovirus infections have similar clinical features which makes differential diagnosis challenging when both diseases occur. The tick samples were tested for Rickettsia spp. by conventional PCR using three primer sets targeting the gltA, ompA, and ompB genes followed by amplicon sequencing. Of the tick pools screened, 25% (95/380) were positive for Rickettsia spp. DNA using the gltA primer set. Of the tick-positive pools, 60% were ticks collected from camels. Rickettsia aeschlimannii and R. africae were the main Rickettsia spp. detected in the tick pools sequenced. The findings of this study indicate that multiple Rickettsia species are circulating in ticks from pastoral communities in Kenya and could contribute to the etiology of febrile illness in these areas. Diagnosis and treatment of rickettsial infections should be a public health priority in these regions.
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Affiliation(s)
- Hellen Koka
- Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya ( ; )
- US Army Medical Research Directorate - Kenya, P. O. Box 606-00621, Nairobi, Kenya ( )
| | - Rosemary Sang
- Kenya Medical Research Institute, Centre for Virus Research, P. O. Box 54628-00200, Nairobi, Kenya ( )
- International Centre for Insect Physiology and Ecology, P. O. Box 30772-00100, Nairobi, Kenya
| | - Helen Lydia Kutima
- Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62000-00200, Nairobi, Kenya (; )
| | - Lillian Musila
- US Army Medical Research Directorate - Kenya, P. O. Box 606-00621, Nairobi, Kenya
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Molecular and serological evidence of flea-associated typhus group and spotted fever group rickettsial infections in Madagascar. Parasit Vectors 2017; 10:125. [PMID: 28259176 PMCID: PMC5336680 DOI: 10.1186/s13071-017-2061-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/24/2017] [Indexed: 12/25/2022] Open
Abstract
Background Rickettsiae are obligate intracellular bacteria responsible for many febrile syndromes around the world, including in sub-Saharan Africa. Vectors of these pathogens include ticks, lice, mites and fleas. In order to assess exposure to flea-associated Rickettsia species in Madagascar, human and small mammal samples from an urban and a rural area, and their associated fleas were tested. Results Anti-typhus group (TGR)- and anti-spotted fever group rickettsiae (SFGR)-specific IgG were detected in 24 (39%) and 21 (34%) of 62 human serum samples, respectively, using indirect ELISAs, with six individuals seropositive for both. Only two (2%) Rattus rattus out of 86 small mammals presented antibodies against TGR. Out of 117 fleas collected from small mammals, Rickettsia typhi, a TGR, was detected in 26 Xenopsylla cheopis (24%) collected from rodents of an urban area (n = 107), while two of these urban X. cheopis (2%) were positive for Rickettsia felis, a SFGR. R. felis DNA was also detected in eight (31%) out of 26 Pulex irritans fleas. Conclusions The general population in Madagascar are exposed to rickettsiae, and two flea-associated Rickettsia pathogens, R. typhi and R. felis, are present near or in homes. Although our results are from a single district, they demonstrate that rickettsiae should be considered as potential agents of undifferentiated fever in Madagascar.
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Ndeereh D, Thaiyah A, Muchemi G, Miyunga AA. Molecular surveillance of spotted fever group rickettsioses in wildlife and detection of <i>Rickettsia sibirica</i> in a Topi (<i>Damaliscus lunatus</i> ssp. <i>jimela</i>) in Kenya. Onderstepoort J Vet Res 2017; 84:e1-e7. [PMID: 28155284 PMCID: PMC6238814 DOI: 10.4102/ojvr.v84i1.1265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/17/2016] [Accepted: 08/17/2016] [Indexed: 11/30/2022] Open
Abstract
Spotted fever group rickettsioses are a group of tick-borne zoonotic diseases caused by intracellular bacteria of the genus Rickettsia. The diseases are widely reported amongst international travellers returning from most sub-Saharan Africa with fever, yet their importance in local populations largely remains unknown. Although this has started to change and recently there have been increasing reports of the diseases in livestock, ticks and humans in Kenya, they have not been investigated in wildlife. We examined the presence, prevalence and species of Rickettsia present in wildlife in two regions of Kenya with a unique human–wildlife–livestock interface. For this purpose, 79 wild animals in Laikipia County and 73 in Maasai Mara National Reserve were sampled. DNA extracted from blood was tested using the polymerase chain reaction (PCR) to amplify the intergenic spacer rpmE-tRNAfMet and the citrate synthase-encoding gene gltA. Rickettsial DNA was detected in 2 of the 79 (2.5%) animals in Laikipia and 4 of the 73 (5.5%) in Maasai Mara. The PCR-positive amplicons of the gltA gene were sequenced to determine the detected Rickettsia species. This revealed Rickettsia sibirica in a Topi (Damaliscus lunatus ssp. jimela). This is the first report of spotted fever group rickettsioses in wildlife and the first to report R. sibirica in Kenya. The finding demonstrates the potential role of wild animals in the circulation of the diseases.
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Affiliation(s)
- David Ndeereh
- Department of Veterinary Services, Kenya Wildlife Service.
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Teoh YT, Hii SF, Graves S, Rees R, Stenos J, Traub RJ. Evidence of exposure to Rickettsia felis in Australian patients. One Health 2016; 2:95-98. [PMID: 28616481 PMCID: PMC5441329 DOI: 10.1016/j.onehlt.2016.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Revised: 05/31/2016] [Accepted: 06/03/2016] [Indexed: 11/22/2022] Open
Abstract
Rickettsia felis is an emerging zoonosis, causing flea-borne spotted fever (FBSF). Serological diagnosis is typically confounded by cross-reactivity with typhus group rickettsiae and prior to the development of specific serological methods, cases of FBSF in Australia were misdiagnosed. Patient sera tested between August 2010 and December 2013 and known to be seropositive to R. typhi by immunofluorescence antibody testing (IFAT) were subsequently retested against R. felis using an R. felis-specific IFAT. Sera of 49 patients were of a sufficient quality to be included in re-analysis. A classification of FBSF and murine typhus (MT) was attributed to fourteen and seven patients respectively, based on a minimum four-fold higher antibody titre to R. felis than to R. typhi and vice versa. Twenty-eight patients were classified as indeterminate for either R. felis or R. typhi (antibody titres within two-fold of one another). Historically, it is likely that Australian patients clinically ill with FBSF were misdiagnosed. It is important that medical practitioners consider FBSF as part of their differential diagnoses, and obtain relevant history with regard to patient's exposure to domestic pets and their fleas. Australian microbiology diagnostic laboratories should include serological testing for R. felis as part of the diagnostic panel for febrile diseases. Veterinarians are encouraged to increase their awareness of this emerging zoonosis and advocate flea control in pets.
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Affiliation(s)
- Yen Thon Teoh
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Sze Fui Hii
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Stephen Graves
- The Australian Rickettsial Reference Laboratory, University Hospital, Geelong, VIC 3220, Australia
| | - Robert Rees
- Bayer Animal Health, Tingalpa, QLD 4173, Australia
| | - John Stenos
- The Australian Rickettsial Reference Laboratory, University Hospital, Geelong, VIC 3220, Australia
| | - Rebecca J. Traub
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC 3052, Australia
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Blanton LS, Walker DH. Flea-Borne Rickettsioses and Rickettsiae. Am J Trop Med Hyg 2016; 96:53-56. [PMID: 27799640 PMCID: PMC5239709 DOI: 10.4269/ajtmh.16-0537] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/20/2016] [Indexed: 12/22/2022] Open
Abstract
Rickettsia typhi and Rickettsia felis are flea-borne rickettsiae that are distributed throughout the world. This mini-review outlines the ecology and epidemiology of flea-borne rickettsioses; highlights important clinical, diagnostic, and therapeutic considerations; and discusses areas of uncertainty regarding Rickettsia felis and other rickettsiae harbored by fleas.
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Affiliation(s)
- Lucas S Blanton
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas
| | - David H Walker
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas
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Verhoeve VI, Jirakanwisal K, Utsuki T, Macaluso KR. Differential Rickettsial Transcription in Bloodfeeding and Non-Bloodfeeding Arthropod Hosts. PLoS One 2016; 11:e0163769. [PMID: 27662479 PMCID: PMC5035074 DOI: 10.1371/journal.pone.0163769] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 09/14/2016] [Indexed: 11/21/2022] Open
Abstract
Crucial factors influencing the epidemiology of Rickettsia felis rickettsiosis include pathogenesis and transmission. Detection of R. felis DNA in a number of arthropod species has been reported, with characterized isolates, R. felis strain LSU and strain LSU-Lb, generated from the cat flea, Ctenocephalides felis, and the non-hematophagous booklouse, Liposcelis bostrychophila, respectively. While it is realized that strain influence on host biology varies, the rickettsial response to these distinct host environments remained undefined. To identify a panel of potential rickettsial transmission determinants in the cat flea, the transcriptional profile for these two strains of R. felis were compared in their arthropod hosts using RNAseq. Rickettsial genes with increased transcription in the flea as compared to the booklouse were identified. Genes previously associated with bacterial virulence including LPS biosynthesis, Type IV secretion system, ABC transporters, and a toxin-antitoxin system were selected for further study. Transcription of putative virulence-associated genes was determined in a flea infection bioassay for both strains of R. felis. A host-dependent transcriptional profile during bloodfeeding, specifically, an increased expression of selected transcripts in newly infected cat fleas and flea feces was detected when compared to arthropod cell culture and incubation in vertebrate blood. Together, these studies have identified novel, host-dependent rickettsial factors that likely contribute to successful horizontal transmission by bloodfeeding arthropods.
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Affiliation(s)
- Victoria I. Verhoeve
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, 70803, United States of America
| | - Krit Jirakanwisal
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, 70803, United States of America
| | - Tadanobu Utsuki
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, 70803, United States of America
| | - Kevin R. Macaluso
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, 70803, United States of America
- * E-mail:
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Maina AN, Jiang J, Omulo SA, Cutler SJ, Ade F, Ogola E, Feikin DR, Njenga MK, Cleaveland S, Mpoke S, Ng'ang'a Z, Breiman RF, Knobel DL, Richards AL. High prevalence of Rickettsia africae variants in Amblyomma variegatum ticks from domestic mammals in rural western Kenya: implications for human health. Vector Borne Zoonotic Dis 2016; 14:693-702. [PMID: 25325312 DOI: 10.1089/vbz.2014.1578] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Tick-borne spotted fever group (SFG) rickettsioses are emerging human diseases caused by obligate intracellular Gram-negative bacteria of the genus Rickettsia. Despite being important causes of systemic febrile illnesses in travelers returning from sub-Saharan Africa, little is known about the reservoir hosts of these pathogens. We conducted surveys for rickettsiae in domestic animals and ticks in a rural setting in western Kenya. Of the 100 serum specimens tested from each species of domestic ruminant 43% of goats, 23% of sheep, and 1% of cattle had immunoglobulin G (IgG) antibodies to the SFG rickettsiae. None of these sera were positive for IgG against typhus group rickettsiae. We detected Rickettsia africae-genotype DNA in 92.6% of adult Amblyomma variegatum ticks collected from domestic ruminants, but found no evidence of the pathogen in blood specimens from cattle, goats, or sheep. Sequencing of a subset of 21 rickettsia-positive ticks revealed R. africae variants in 95.2% (20/21) of ticks tested. Our findings show a high prevalence of R. africae variants in A. variegatum ticks in western Kenya, which may represent a low disease risk for humans. This may provide a possible explanation for the lack of African tick-bite fever cases among febrile patients in Kenya.
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Affiliation(s)
- Alice N Maina
- 1 Jomo Kenyatta University of Agriculture and Technology , Nairobi, Kenya
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Mourembou G, Lekana-Douki JB, Mediannikov O, Nzondo SM, Kouna LC, Essone JCBB, Fenollar F, Raoult D. Possible Role of Rickettsia felis in Acute Febrile Illness among Children in Gabon. Emerg Infect Dis 2016; 21:1808-15. [PMID: 26402580 PMCID: PMC4593428 DOI: 10.3201/eid2110.141825] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infection is widespread but most prevalent among young, rural residents with fever. Rickettsia felis has been reported to be a cause of fever in sub-Saharan Africa, but this association has been poorly evaluated in Gabon. We assessed the prevalence of this bacterium among children <15 years of age in 4 areas of Gabon; the locations were in urban, semiurban, and rural areas. DNA samples from 410 febrile children and 60 afebrile children were analyzed by quantitative PCR. Overall, the prevalence of R. felis among febrile and afebrile children was 10.2% (42/410 children) and 3.3% (2/60 children), respectively. Prevalence differed among febrile children living in areas that are urban (Franceville, 1.3% [1/77]), semiurban (Koulamoutou, 2.1% [3/141]), and rural (Lastourville, 11.2% [15/134]; Fougamou, 39.7% [23/58]). Furthermore, in a rural area (Fougamou), R. felis was significantly more prevalent in febrile (39.7% [23/58]) than afebrile children (5.0% [1/20]). Additional studies are needed to better understand the pathogenic role of R. felis in this part of the world.
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Angelakis E, Mediannikov O, Parola P, Raoult D. Rickettsia felis: The Complex Journey of an Emergent Human Pathogen. Trends Parasitol 2016; 32:554-564. [PMID: 27155905 DOI: 10.1016/j.pt.2016.04.009] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/14/2016] [Accepted: 04/12/2016] [Indexed: 11/16/2022]
Abstract
Rickettsia felis is an obligate intracellular bacterium that is different from other officially recognized rickettsial species. It has multiple genes of different origins, an incubation temperature of less than 32°C, and a conjugative plasmid. This Rickettsia is commonly detected in febrile patients in sub-Saharan Africa. R. felis is frequently detected in cat fleas, but recently mosquitoes have been suspected to be able to transmit the bacterium. However, many aspects of the ecology and epidemiology of R. felis are not completely understood and remain to be uncovered. We aim here to give an update of the current knowledge about this fascinating organism.
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Affiliation(s)
- Emmanouil Angelakis
- URMITE, UM63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, 27 Bd Jean Moulin, 13385 Marseille, France.
| | - Oleg Mediannikov
- URMITE, UM63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, 27 Bd Jean Moulin, 13385 Marseille, France
| | - Philippe Parola
- URMITE, UM63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, 27 Bd Jean Moulin, 13385 Marseille, France
| | - Didier Raoult
- URMITE, UM63, CNRS 7278, IRD 198, Inserm 1095, Aix Marseille Université, 27 Bd Jean Moulin, 13385 Marseille, France
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Brown LD, Banajee KH, Foil LD, Macaluso KR. Transmission mechanisms of an emerging insect-borne rickettsial pathogen. Parasit Vectors 2016; 9:237. [PMID: 27117813 PMCID: PMC4847369 DOI: 10.1186/s13071-016-1511-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/14/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Vector-borne pathogens must overcome arthropod infection and escape barriers (e.g. midgut and salivary glands) during the extrinsic incubation period (EIP) before subsequent transmission to another host. This particular timespan is undetermined for the etiological agent of flea-borne spotted fever (Rickettsia felis). Artificial acquisition of R. felis by blood-feeding cat fleas revealed dissemination to the salivary glands after seven days; however, this length of time is inconsistent with co-feeding studies that produced infectious cat fleas within 24 h of infection. In the current study, we demonstrated that an alternative mechanism is responsible for the early-phase transmission that typifies flea-borne R. felis spread. METHODS Co-feeding transmission bioassays were constructed to assess temporal dynamics of R. felis amongst cat fleas, including exposure time to produce infectious fleas and association time to transmit infection to naïve fleas. Additional experiments examined the proportion of R. felis-exposed cat fleas with contaminated mouthparts, as well as the likelihood for cat fleas to release R. felis from their mouthparts following exposure to an infectious bloodmeal. The potential for mechanical transmission of R. felis by co-feeding cat fleas was further examined using fluorescent latex beads, as opposed to a live pathogen, which would not require a biological mechanism to achieve transmission. RESULTS Analyses revealed that R. felis-infected cat fleas were infectious to naïve fleas less than 24 h after exposure to the pathogen, but showed no rickettsial dissemination to the salivary glands during this early-phase transmission. Additionally, the current study revealed that R. felis-infected cat fleas must co-feed with naïve fleas for more than 12 h in order for early-phase transmission to occur. Further evidence supported that contaminated flea mouthparts may be the source of the bacteria transmitted early, and demonstrated that R. felis is released from the mouthparts during brief probing events. Moreover, the use of fluorescent latex beads supports the notion that early-phase transmission of R. felis is a mechanical mechanism. CONCLUSIONS Determination of the transmission mechanisms utilized by R. felis is essential to fully understand the vulnerability of susceptible vertebrate hosts, including humans, to this pathogen.
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Affiliation(s)
- Lisa D. Brown
- />Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, SVM-3213, Baton Rouge, LA 70803 USA
| | - Kaikhushroo H. Banajee
- />Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, SVM-3213, Baton Rouge, LA 70803 USA
| | - Lane D. Foil
- />Department of Entomology, Louisiana State University Agricultural Center, LSB-413, Baton Rouge, LA 70803 USA
| | - Kevin R. Macaluso
- />Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, SVM-3213, Baton Rouge, LA 70803 USA
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Mourembou G, Nzondo SM, Ndjoyi-Mbiguino A, Lekana-Douki JB, Kouna LC, Matsiegui PB, Manego RZ, Moukandja IP, Keïta AK, Tissot-Dupont H, Fenollar F, Raoult D. Co-circulation of Plasmodium and Bacterial DNAs in Blood of Febrile and Afebrile Children from Urban and Rural Areas in Gabon. Am J Trop Med Hyg 2016; 95:123-32. [PMID: 27114297 DOI: 10.4269/ajtmh.15-0751] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 03/13/2016] [Indexed: 12/11/2022] Open
Abstract
Malaria is considered to be the most common etiology of fever in sub-Saharan Africa while bacteremias exist but are under assessed. This study aimed to assess bacteremias and malaria in children from urban and rural areas in Gabon. DNA extracts from blood samples of 410 febrile and 60 afebrile children were analyzed using quantitative polymerase chain reaction. Plasmodium spp. was the microorganism most frequently detected in febrile (78.8%, 323/410) and afebrile (13.3%, 8/60) children, (P < 0.001). DNA from one or several bacteria were detected in 15 febrile patients (3.7%) but not in the controls (P = 0.1). This DNA was more frequently detected as co-infections among febrile children tested positive for Plasmodium (4.6%, 15/323) than in those tested negative for Plasmodium (0%, 0/87; P = 0.04). The bacteria detected were Streptococcus pneumoniae 2.4% (10/410), Staphylococcus aureus 1.7% (7/410), Salmonella spp. 0.7% (3/410), Streptococcus pyogenes 0.2% (1/410) and Tropheryma whipplei 0.2% (1/410) only in febrile children. Coxiella burnetii, Borrelia spp., Bartonella spp., Leptospira spp., and Mycobacterium tuberculosis were not observed. This paper reports the first detection of bacteremia related to T. whipplei in Gabon and shows that malaria decreases in urban areas but not in rural areas. Co-infections in febrile patients are common, highlighting the need to improve fever management strategies in Gabon.
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Affiliation(s)
- Gaël Mourembou
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE), Aix Marseille Université, Marseille, France. Ecole Doctorale Régionale d'Afrique Centrale, Franceville, Gabon
| | - Sydney Maghendji Nzondo
- Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon
| | - Angélique Ndjoyi-Mbiguino
- Département de Microbiologie, Laboratoire National de Référence IST/sida, Faculté de Médecine, Université des Sciences de la Santé, Libreville, Gabon
| | - Jean Bernard Lekana-Douki
- Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon. Département de Parasitologie Mycologie et de Médecine Tropicale, Université des Sciences de la Santé, Libreville, Gabon
| | - Lady Charlène Kouna
- Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon
| | | | | | - Irene Pegha Moukandja
- Unité de Parasitologie Médicale, Centre International de Recherches Médicales de Franceville (CIRMF), Franceville, Gabon
| | - Alpha Kabinet Keïta
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE), Aix Marseille Université, Marseille, France
| | - Hervé Tissot-Dupont
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE), Aix Marseille Université, Marseille, France
| | - Florence Fenollar
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE), Aix Marseille Université, Marseille, France
| | - Didier Raoult
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Émergentes (URMITE), Aix Marseille Université, Marseille, France.
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Abstract
Rickettsia felis is an emerging insect-borne rickettsial pathogen and the causative agent of flea-borne spotted fever. First described as a human pathogen from the USA in 1991, R. felis is now identified throughout the world and considered a common cause of fever in Africa. The cosmopolitan distribution of this pathogen is credited to the equally widespread occurrence of cat fleas (Ctenocephalides felis), the primary vector and reservoir of R. felis. Although R. felis is a relatively new member of the pathogenic Rickettsia, limited knowledge of basic R. felis biology continues to hinder research progression of this unique bacterium. This is a comprehensive review examining what is known and unknown relative to R. felis transmission biology, epidemiology of the disease, and genetics, with an insight into areas of needed investigation.
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Affiliation(s)
- Lisa D. Brown
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, SVM-3213, Baton Rouge, LA 70803 USA
| | - Kevin R. Macaluso
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, SVM-3213, Baton Rouge, LA 70803 USA
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50
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Brown LD, Christofferson RC, Banajee KH, Del Piero F, Foil LD, Macaluso KR. Cofeeding intra- and interspecific transmission of an emerging insect-borne rickettsial pathogen. Mol Ecol 2016; 24:5475-89. [PMID: 26414611 PMCID: PMC4831916 DOI: 10.1111/mec.13403] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/09/2015] [Accepted: 09/22/2015] [Indexed: 12/26/2022]
Abstract
Cat fleas (Ctenocephalides felis) are known as the primary vector and reservoir of Rickettsia felis, the causative agent of flea-borne spotted fever; however, field surveys regularly report molecular detection of this infectious agent from other blood-feeding arthropods. The presence of R. felis in additional arthropods may be the result of chance consumption of an infectious bloodmeal, but isolation of viable rickettsiae circulating in the blood of suspected vertebrate reservoirs has not been demonstrated. Successful transmission of pathogens between actively blood-feeding arthropods in the absence of a disseminated vertebrate infection has been verified, referred to as cofeeding transmission. Therefore, the principal route from systemically infected vertebrates to uninfected arthropods may not be applicable to the R. felis transmission cycle. Here, we show both intra- and interspecific transmission of R. felis between cofeeding arthropods on a vertebrate host. Analyses revealed that infected cat fleas transmitted R. felis to naïve cat fleas and rat fleas (Xenopsylla cheopis) via fleabite on a nonrickettsemic vertebrate host. Also, cat fleas infected by cofeeding were infectious to newly emerged uninfected cat fleas in an artificial system. Furthermore, we utilized a stochastic model to demonstrate that cofeeding is sufficient to explain the enzootic spread of R. felis amongst populations of the biological vector. Our results implicate cat fleas in the spread of R. felis amongst different vectors, and the demonstration of cofeeding transmission of R. felis through a vertebrate host represents a novel transmission paradigm for insect-borne Rickettsia and furthers our understanding of this emerging rickettsiosis.
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Affiliation(s)
- Lisa D Brown
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Rebecca C Christofferson
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Kaikhushroo H Banajee
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Fabio Del Piero
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
| | - Lane D Foil
- Department of Entomology, Louisiana State University Agricultural Center, LSB-413, Baton Rouge, LA, 70803, USA
| | - Kevin R Macaluso
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Skip Bertman Drive, Baton Rouge, LA, 70803, USA
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