1
|
Pustijanac E, Buršić M, Millotti G, Paliaga P, Iveša N, Cvek M. Tick-Borne Bacterial Diseases in Europe: Threats to public health. Eur J Clin Microbiol Infect Dis 2024; 43:1261-1295. [PMID: 38676855 DOI: 10.1007/s10096-024-04836-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 04/22/2024] [Indexed: 04/29/2024]
Abstract
BACKGROUND Tick-borne diseases, caused by bacterial pathogens, pose a growing threat to public health in Europe. This paper provides an overview of the historical context of the discovery of the most impactful pathogens transmitted by ticks, including Borrelia burgdorferi sensu lato, Rickettsia spp., Anaplasma spp., Francisella spp., Ehrlichia spp., and Neoehrlichia mikurensis. Understanding the historical context of their discovery provides insight into the evolution of our understanding of these pathogens. METHODS AND RESULTS Systematic investigation of the prevalence and transmission dynamics of these bacterial pathogens is provided, highlighting the intricate relationships among ticks, host organisms, and the environment. Epidemiology is explored, providing an in-depth analysis of clinical features associated with infections. Diagnostic methodologies undergo critical examination, with a spotlight on technological advancements that enhance detection capabilities. Additionally, the paper discusses available treatment options, addressing existing therapeutic strategies and considering future aspects. CONCLUSIONS By integrating various pieces of information on these bacterial species, the paper aims to provide a comprehensive resource for researchers and healthcare professionals addressing the impact of bacterial tick-borne diseases in Europe. This review underscores the importance of understanding the complex details influencing bacterial prevalence and transmission dynamics to better combat these emerging public health threats.
Collapse
Affiliation(s)
- Emina Pustijanac
- Faculty of Natural Sciences, Juraj Dobrila University of Pula, Zagrebačka 30, 52100, Pula, Croatia.
| | - Moira Buršić
- Faculty of Natural Sciences, Juraj Dobrila University of Pula, Zagrebačka 30, 52100, Pula, Croatia
| | - Gioconda Millotti
- Faculty of Natural Sciences, Juraj Dobrila University of Pula, Zagrebačka 30, 52100, Pula, Croatia
| | - Paolo Paliaga
- Faculty of Natural Sciences, Juraj Dobrila University of Pula, Zagrebačka 30, 52100, Pula, Croatia
| | - Neven Iveša
- Faculty of Natural Sciences, Juraj Dobrila University of Pula, Zagrebačka 30, 52100, Pula, Croatia
| | - Maja Cvek
- Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51000, Rijeka, Croatia
- Teaching Institute of Public Health of the Region of Istria, Nazorova 23, 52100, Pula, Croatia
| |
Collapse
|
2
|
Moorthy GS, Rubach MP, Maze MJ, Refuerzo RP, Shirima GM, Lukambagire AS, Bodenham RF, Cash-Goldwasser S, Thomas KM, Sakasaka P, Mkenda N, Bowhay TR, Perniciaro JL, Nicholson WL, Kersh GJ, Kazwala RR, Mmbaga BT, Buza JJ, Maro VP, Haydon DT, Crump JA, Halliday JE. Prevalence and risk factors for Q fever, spotted fever group rickettsioses, and typhus group rickettsioses in a pastoralist community of northern Tanzania, 2016-2017. Trop Med Int Health 2024; 29:365-376. [PMID: 38480005 PMCID: PMC11073910 DOI: 10.1111/tmi.13980] [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] [Indexed: 04/11/2024]
Abstract
BACKGROUND In northern Tanzania, Q fever, spotted fever group (SFG) rickettsioses, and typhus group (TG) rickettsioses are common causes of febrile illness. We sought to describe the prevalence and risk factors for these zoonoses in a pastoralist community. METHODS Febrile patients ≥2 years old presenting to Endulen Hospital in the Ngorongoro Conservation Area were enrolled from August 2016 through October 2017. Acute and convalescent blood samples were collected, and a questionnaire was administered. Sera were tested by immunofluorescent antibody (IFA) IgG assays using Coxiella burnetii (Phase II), Rickettsia africae, and Rickettsia typhi antigens. Serologic evidence of exposure was defined by an IFA titre ≥1:64; probable cases by an acute IFA titre ≥1:128; and confirmed cases by a ≥4-fold rise in titre between samples. Risk factors for exposure and acute case status were evaluated. RESULTS Of 228 participants, 99 (43.4%) were male and the median (interquartile range) age was 27 (16-41) years. Among these, 117 (51.3%) had C. burnetii exposure, 74 (32.5%) had probable Q fever, 176 (77.2%) had SFG Rickettsia exposure, 134 (58.8%) had probable SFG rickettsioses, 11 (4.8%) had TG Rickettsia exposure, and 4 (1.8%) had probable TG rickettsioses. Of 146 participants with paired sera, 1 (0.5%) had confirmed Q fever, 8 (5.5%) had confirmed SFG rickettsioses, and none had confirmed TG rickettsioses. Livestock slaughter was associated with acute Q fever (adjusted odds ratio [OR] 2.54, 95% confidence interval [CI] 1.38-4.76) and sheep slaughter with SFG rickettsioses case (OR 4.63, 95% CI 1.08-23.50). DISCUSSION Acute Q fever and SFG rickettsioses were detected in participants with febrile illness. Exposures to C. burnetii and to SFG Rickettsia were highly prevalent, and interactions with livestock were associated with increased odds of illness with both pathogens. Further characterisation of the burden and risks for these diseases is warranted.
Collapse
Affiliation(s)
- Ganga S. Moorthy
- Division of Pediatric Infectious Diseases, Duke University Medical Center, Durham, United States of America
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
| | - Matthew P. Rubach
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, United States of America
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
- Programme in Emerging Infectious Diseases, Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Michael J. Maze
- Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Regina P. Refuerzo
- School of Biodiversity, One Health and Veterinary Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Gabriel M. Shirima
- Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha, Tanzania
| | - AbdulHamid S. Lukambagire
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
- EcoHealth Alliance, New York, United States of America
| | | | - Shama Cash-Goldwasser
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
| | - Kate M. Thomas
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | | | - Nestory Mkenda
- Endulen Hospital, Endulen, Ngorongoro Conservation Area, Tanzania
| | - Thomas R. Bowhay
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Jamie L. Perniciaro
- Rickettsial Zoonoses Branch, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - William L. Nicholson
- Rickettsial Zoonoses Branch, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Gilbert J. Kersh
- Rickettsial Zoonoses Branch, US Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Rudovick R. Kazwala
- Department of Veterinary Medicine and Public Health, Sokoine University of Agriculture, Morogoro, Tanzania
| | - Blandina T. Mmbaga
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
- Kilimanjaro Clinical Research Institute, Moshi, Tanzania
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | - Joram J. Buza
- Nelson Mandela African Institution of Science and Technology, School of Life Sciences and Bioengineering, Arusha, Tanzania
| | - Venance P. Maro
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
- Kilimanjaro Christian Medical Centre, Moshi, Tanzania
| | - Daniel T. Haydon
- School of Biodiversity, One Health and Veterinary Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - John A. Crump
- Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
- Division of Infectious Diseases and International Health, Duke University Medical Center, Durham, United States of America
- Kilimanjaro Christian Medical University College, Tumaini University, Moshi, Tanzania
- Centre for International Health, University of Otago, Dunedin, New Zealand
| | - Jo E.B. Halliday
- School of Biodiversity, One Health and Veterinary Medicine, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| |
Collapse
|
3
|
Hsueh YL, Chen HF, Chang MC, Yen TY, Su CL, Chiu HC, Hu HC, Chung YT, Shu PY, Yang SL. Epidemiology of Murine Typhus in Taiwan from 2013 to 2020. Am J Trop Med Hyg 2024; 110:768-778. [PMID: 38471176 PMCID: PMC10993848 DOI: 10.4269/ajtmh.23-0155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 12/13/2023] [Indexed: 03/14/2024] Open
Abstract
Murine typhus is a flea-borne disease caused by Rickettsia typhi infection. The disease is a notifiable infectious disease in Taiwan. Specimens from suspected cases are required to be sent to the Taiwan Centers for Disease Control and Prevention for laboratory diagnosis. In this study, 204 cases of murine typhus were identified by bacterial isolation, real-time polymerase chain reaction, or indirect immunofluorescence assay between 2013 and 2020. The average incidence rate was 0.11/100,000 person-years (95% CI: 0.08-0.13). Murine typhus occurred throughout the year, but it was most prevalent in summer (May to August). The majority of patients were males (75%), residents of Kaohsiung city (31%), and worked in agriculture, forestry, fishing, and animal husbandry (27%). Fever was the most common symptom, present in 95.6% of patients, followed by headache (41%), myalgia (33%), and liver dysfunction (33%). Only 13% of patients had a rash. Up to 80% of cases were among hospitalized patients, and 43% of patients developed severe manifestations. Serological assays also indicated coinfection events. Seven patients showed a 4-fold increase in antibody titers against Orientia tsutsugamushi (N = 2), Coxiella burnetii (n = 2), and Leptospira (N = 3). In conclusion, murine typhus is an endemic and important zoonotic rickettsial disease in Taiwan that cannot be ignored. Further epidemiological surveillance and clinical characteristics should be continuously investigated to prevent and control murine typhus.
Collapse
Affiliation(s)
- Yeou-Lin Hsueh
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Hsiang-Fei Chen
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Mei-Chun Chang
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Tsai-Ying Yen
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Chien-Ling Su
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Hsien-Chun Chiu
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Huai-Chin Hu
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Ya-Ting Chung
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Pei-Yun Shu
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| | - Su-Lin Yang
- Center for Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taiwan, Republic of China
| |
Collapse
|
4
|
Riffaud CM, Rucks EA, Ouellette SP. Persistence of obligate intracellular pathogens: alternative strategies to overcome host-specific stresses. Front Cell Infect Microbiol 2023; 13:1185571. [PMID: 37284502 PMCID: PMC10239878 DOI: 10.3389/fcimb.2023.1185571] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/05/2023] [Indexed: 06/08/2023] Open
Abstract
In adapting to the intracellular niche, obligate intracellular bacteria usually undergo a reduction of genome size by eliminating genes not needed for intracellular survival. These losses can include, for example, genes involved in nutrient anabolic pathways or in stress response. Living inside a host cell offers a stable environment where intracellular bacteria can limit their exposure to extracellular effectors of the immune system and modulate or outright inhibit intracellular defense mechanisms. However, highlighting an area of vulnerability, these pathogens are dependent on the host cell for nutrients and are very sensitive to conditions that limit nutrient availability. Persistence is a common response shared by evolutionarily divergent bacteria to survive adverse conditions like nutrient deprivation. Development of persistence usually compromises successful antibiotic therapy of bacterial infections and is associated with chronic infections and long-term sequelae for the patients. During persistence, obligate intracellular pathogens are viable but not growing inside their host cell. They can survive for a long period of time such that, when the inducing stress is removed, reactivation of their growth cycles resumes. Given their reduced coding capacity, intracellular bacteria have adapted different response mechanisms. This review gives an overview of the strategies used by the obligate intracellular bacteria, where known, which, unlike model organisms such as E. coli, often lack toxin-antitoxin systems and the stringent response that have been linked to a persister phenotype and amino acid starvation states, respectively.
Collapse
|
5
|
Xiao Y, Beare PA, Best SM, Morens DM, Bloom ME, Taubenberger JK. Genetic sequencing of a 1944 Rocky Mountain spotted fever vaccine. Sci Rep 2023; 13:4687. [PMID: 36949107 PMCID: PMC10031714 DOI: 10.1038/s41598-023-31894-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 03/20/2023] [Indexed: 03/24/2023] Open
Abstract
Rocky Mountain spotted fever (RMSF) is a rapidly progressive and often fatal tick-borne disease caused by Rickettsia rickettsii. Its discovery and characterization by Howard Ricketts has been hailed as a remarkable historical example of detection and control of an emerging infectious disease, and subsequently led to the establishment of the Rocky Mountain Laboratories (RML). Here, we examined an unopened bottle of a vaccine, labeled as containing RMSF inactivated by phenol-formalin of infected ticks, developed prior to 1944 at RML by DNA analysis using Illumina high throughput sequencing technology. We found that it contains DNA from the Rocky Mountain wood tick (Dermacentor andersoni), the vector of RMSF, the complete genome of Rickettsia rickettsii, the pathogen of RMSF, as well as the complete genome of Coxiella burnetii, the pathogen of Q-fever. In addition to genomic reads of Rickettsia rickettsii and Coxiella burnetii, smaller percentages of the reads are from Rickettsia rhipicephali and Arsenophonus nasoniae, suggesting that the infected ticks used to prepare the vaccine carried more than one pathogen. Together, these findings suggest that this early vaccine was likely a bivalent vaccine for RMSF and Q-fever. This study is the among the first molecular level examinations of an historically important vaccine.
Collapse
Affiliation(s)
- Yongli Xiao
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 33 North Drive MSC 3203, Bethesda, MD, 20892-3203, USA.
| | - Paul A Beare
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Sonja M Best
- Innate Immunity and Pathogenesis Section, Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - David M Morens
- Office of the Director, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Marshall E Bloom
- Biology of Vector-Borne Viruses Section, Laboratory of Virology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Jeffery K Taubenberger
- Viral Pathogenesis and Evolution Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 33 North Drive MSC 3203, Bethesda, MD, 20892-3203, USA
| |
Collapse
|
6
|
Rickettsia Vaccine Candidate pVAX1-OmpB24 Stimulates TCD4+INF-γ+ and TCD8+INF-γ+ Lymphocytes in Autologous Co-Culture of Human Cells. Vaccines (Basel) 2023; 11:vaccines11010173. [PMID: 36680017 PMCID: PMC9865178 DOI: 10.3390/vaccines11010173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND In recent years, promising vaccination strategies against rickettsiosis have been described in experimental animal models and human cells. OmpB is considered an immunodominant antigen that is recognized by T and B cells. The aim of this study was to identify TCD4+INF-γ+ and TCD8+INF-γ+ lymphocytes in an autologous system with macrophages transfected with the vaccine candidate pVAX1-OmpB24. Lymphocytes and monocytes from 14 patients with Rickettsia were isolated from whole blood. Monocytes were differentiated into macrophages and transfected with the plasmid pVAX1-OmpB24 pVax1. Isolated lymphocytes were cultured with transfected macrophages. IFN-γ-producing TCD4+ and TCD8+ lymphocyte subpopulations were identified by flow cytometry, as was the percentage of macrophages expressing CD40+, CD80+, HLA-I and HLA-II. Also, we analyzed the exhausted condition of the T lymphocyte subpopulation by PD1 expression. Macrophages transfected with pVAX1-OmpB24 stimulated TCD4+INF-γ+ cells in healthy subjects and patients infected with R. typhi. Macrophages stimulated TCD8+INF-γ+ cells in healthy subjects and patients infected with R. rickettsii and R. felis. Cells from healthy donors stimulated with OmpB-24 showed a higher percentage of TCD4+PD1+. Cells from patients infected with R. rickettsii had a higher percentage of TCD8+PD-1+, and for those infected with R. typhi the larger number of cells corresponded to TCD4+PD1+. Human macrophages transfected with pVAX1-OmpB24 activated TCD4+IFN-γ+ and CD8+IFN-γ+ in patients infected with different Rickettsia species. However, PD1 expression played an important role in the inhibition of T lymphocytes with R. felis.
Collapse
|
7
|
Rao RSP, Ghate SD, Shastry RP, Kurthkoti K, Suravajhala P, Patil P, Shetty P. Prevalence and heterogeneity of antibiotic resistance genes in Orientia tsutsugamushi and other rickettsial genomes. Microb Pathog 2023; 174:105953. [PMID: 36529286 DOI: 10.1016/j.micpath.2022.105953] [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: 10/22/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/16/2022]
Abstract
Despite a million infections every year and an estimated one billion people at risk, scrub typhus is regarded as a neglected tropical disease. The causative bacterium Orientia tsutsugamushi, a member of rickettsiae, seems to be intrinsically resistant to several classes of antibiotics. The emergence of antibiotic-resistant scrub typhus is likely to become a global public health concern. Yet, it is unknown as to how common antibiotic resistance genes are in O. tsutsugamushi, and how variable these loci are among the genomes of rickettsiae. By using the comprehensive antibiotic resistance database, we explored 79 complete genomes from 24 species of rickettsiae for antibiotic resistance loci. There were 244 unique antibiotic resistance genes in rickettsiae. Both the total and unique antibiotic resistance genes in O. tsutsugamushi were significantly less compared to other members of rickettsiae. However, antibiotic resistance genes in O. tsutsugamushi genomes were more unique and highly variable. Many genes such as resistant variants of evgS, and vanS A/G were present in numerous copies. These results will have important implications in the context of antibiotic-resistant scrub typhus.
Collapse
Affiliation(s)
- R Shyama Prasad Rao
- Center for Bioinformatics, NITTE deemed to be University, Mangaluru, 575018, India.
| | - Sudeep D Ghate
- Center for Bioinformatics, NITTE deemed to be University, Mangaluru, 575018, India
| | - Rajesh P Shastry
- Division of Microbiology and Biotechnology, Yenepoya Research Center, Yenepoya deemed to be University, Mangaluru, 575018, India
| | - Krishna Kurthkoti
- Mycobacterium Research Laboratory, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, 695014, India
| | - Prashanth Suravajhala
- Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Clappana PO, 690525, Kerala, India
| | - Prakash Patil
- Central Research Laboratory, KS Hegde Medical Academy (KSHEMA), NITTE deemed to be University, Mangaluru, 575018, India
| | - Praveenkumar Shetty
- Central Research Laboratory, KS Hegde Medical Academy (KSHEMA), NITTE deemed to be University, Mangaluru, 575018, India; Department of Biochemistry, KS Hegde Medical Academy (KSHEMA), NITTE deemed to be University, Mangaluru, 575018, India
| |
Collapse
|
8
|
Spotted Fever Group Rickettsioses in Central America: The Research and Public Health Disparity among Socioeconomic Lines. INSECTS 2022; 13:insects13080674. [PMID: 35893029 PMCID: PMC9332791 DOI: 10.3390/insects13080674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/14/2022] [Accepted: 07/19/2022] [Indexed: 01/27/2023]
Abstract
Simple Summary Tick-borne diseases are an important public health issue globally. Spotted fever group rickettsioses (SFGR), a group of related tick-borne pathogens, can cause significant disease, but is widely underreported and likely misdiagnosed. In Central America, there is little known about SFGR, and there seems to be a socioeconomic-related difference between the most-developed and least-developed countries in the region. The least-developed countries (El Salvador, Guatemala, Honduras, and Nicaragua) disproportionately underreport research or studies regarding SFGR disease compared to the most-developed countries (Belize, Panama, and Costa Rica). We compared human development and poverty indicators among Central American countries for this review of SFGR Rickettsia-related articles. The least-developed countries are at a higher risk or are more vulnerable to SFGR disease than the most-developed countries in this region. Abstract Tick-borne diseases including rickettsial diseases are increasing in incidence worldwide. Many rickettsial pathogens can cause disease which is commonly underdiagnosed and underreported; Rickettsia pathogens in the spotted fever group (SFGR) are thus classified as neglected bacterial pathogens. The Central American region shoulders a large proportion of the global neglected disease burden; however, little is known regarding SFGR disease here. Although development varies, four of the seven countries in this region have both the highest poverty rates and SFGR disease burdens (El Salvador, Honduras, Guatemala, and Nicaragua), compared to Belize, Panama, and Costa Rica. Utilizing the Human Development Index (HDI), we compared published articles related to SFGR Rickettsia prevalence in the lowest-HDI-scoring countries to the highest-HDI-scoring countries. Our analysis identified a distinct dichotomy in publication, and by proxy, potentially awareness and knowledge of SFGR tick-borne disease in Central America, where the least-developed countries are at the highest risk for, yet the most vulnerable to, SFGR disease.
Collapse
|
9
|
Ngamprasertchai T, Hanboonkunupakarn B, Piyaphanee W. Rickettsiosis in Southeast Asia: Summary for International Travellers during the COVID-19 Pandemic. Trop Med Infect Dis 2022; 7:tropicalmed7020018. [PMID: 35202213 PMCID: PMC8879928 DOI: 10.3390/tropicalmed7020018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 01/23/2022] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
Rickettsiosis is an important cause of febrile illness among travellers visiting Southeast Asia (SEA). The true incidence of rickettsiosis is underestimated; however, murine typhus and scrub typhus are widely distributed across SEA. Among travellers visiting SEA, scrub typhus was mostly reported from Thailand, whereas murine typhus was frequently found in Indonesia. Although most cases are self-limited or present with mild symptoms, a few cases with severe clinical manifestations have been reported. Doxycycline remains the key treatment of rickettsiosis. Some travellers, such as backpackers, trekkers, or cave explorers, are at a higher risk for rickettsiosis than others. Therefore, in resource-limited conditions, empirical treatment should be considered in these travellers. The coronavirus disease 2019 (COVID-19) pandemic has contributed to difficulty in the diagnosis of rickettsiosis because of the clinical similarities between these diseases. In addition, physical distancing mandated by COVID-19 management guidelines limits accurate physical examination, resulting in misdiagnosis and delayed treatment of rickettsiosis. This review summarises the characteristics of murine typhus and scrub typhus, describes travel-associated rickettsiosis, and discusses the impact of the COVID-19 pandemic on rickettsiosis.
Collapse
|
10
|
Mediterranean Spotted Fever: Current Knowledge and Recent Advances. Trop Med Infect Dis 2021; 6:tropicalmed6040172. [PMID: 34698275 PMCID: PMC8544691 DOI: 10.3390/tropicalmed6040172] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/17/2021] [Accepted: 09/21/2021] [Indexed: 12/15/2022] Open
Abstract
Mediterranean spotted fever (MSF) is an emerging tick-borne rickettsiosis of the spotted fever group (SFG), endemic in the Mediterranean basin. By virtue of technological innovations in molecular genetics, it has been determined that the causative agent of MSF is Rickettsia conorii subspecies conorii. The arthropod vector of this bacterium is the brown dog tick Rhipicephalus sanguineus. The true nature of the reservoir of R. conorii conorii has not been completely deciphered yet, although many authors theorize that the canine population, other mammals, and the ticks themselves could potentially contribute as reservoirs. Typical symptoms of MSF include fever, maculopapular rash, and a characteristic eschar (“tache noire”). Atypical clinical features and severe multi-organ complications may also be present. All of these manifestations arise from the disseminated infection of the endothelium by R. conorii conorii. Several methods exist for the diagnosis of MSF. Serological tests are widely used and molecular techniques have become increasingly available. Doxycycline remains the treatment of choice, while preventive measures are focused on modification of human behavior and vector control strategies. The purpose of this review is to summarize the current knowledge on the epidemiology, pathogenesis, clinical features, diagnosis, and treatment of MSF.
Collapse
|
11
|
Vaccine Design and Vaccination Strategies against Rickettsiae. Vaccines (Basel) 2021; 9:vaccines9080896. [PMID: 34452021 PMCID: PMC8402588 DOI: 10.3390/vaccines9080896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/10/2021] [Accepted: 08/11/2021] [Indexed: 12/30/2022] Open
Abstract
Rickettsioses are febrile, potentially lethal infectious diseases that are a serious health threat, especially in poor income countries. The causative agents are small obligate intracellular bacteria, rickettsiae. Rickettsial infections are emerging worldwide with increasing incidence and geographic distribution. Nonetheless, these infections are clearly underdiagnosed because methods of diagnosis are still limited and often not available. Another problem is that the bacteria respond to only a few antibiotics, so delayed or wrong antibiotic treatment often leads to a more severe outcome of the disease. In addition to that, the development of antibiotic resistance is a serious threat because alternative antibiotics are missing. For these reasons, prophylactic vaccines against rickettsiae are urgently needed. In the past years, knowledge about protective immunity against rickettsiae and immunogenic determinants has been increasing and provides a basis for vaccine development against these bacterial pathogens. This review provides an overview of experimental vaccination approaches against rickettsial infections and perspectives on vaccination strategies.
Collapse
|