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Chaorattanakawee S, Tachavarong W, Hananantachai H, Bunsermyos W, Chanarat N, Promsathaporn S, Tippayachai B, Sakolvaree J, Pitaksajjakul P, Benjathummarak S, Srinoppawan K, Saunders D, Lindroth EJ, Takhampunya R. Seasonal pattern of questing ticks and prevalence of pathogenic Rickettsia and Anaplasmataceae in Khao Yai national park, Thailand. Travel Med Infect Dis 2024; 58:102696. [PMID: 38360157 DOI: 10.1016/j.tmaid.2024.102696] [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: 10/12/2023] [Revised: 01/08/2024] [Accepted: 02/12/2024] [Indexed: 02/17/2024]
Abstract
BACKGROUND Tick-borne diseases (TBD) are considered neglected diseases in Thailand with disease burden likely underestimated. To assess risk for emerging TBD in Thailand, the seasonality of questing tick and pathogen prevalence were studied in Khao Yai National Park, a top tourist destination. METHODS During 2019, questing ticks around tourist attractions were systematically collected bimonthly and analyzed for Rickettsia and Anaplasmataceae bacterial species by polymerase chain reaction and DNA sequencing. RESULTS Larvae and nymphs of questing ticks peaked in Khao Yai National Park during the late rainy-winter season, though no specific trends were observed in adult ticks. Winter (November to February) was the highest risk for human tick-bites due to higher numbers of both ticks and visitors. Of the total 5916 ticks analyzed (651 pools), Anaplasma phagocytophilum, Neoehrlichia mikurensis, Ehrlichia ewingii, and Ehrlichia chaffeensis were detected at low rates (≤0.05%). There was a higher prevalence of human rickettsioses (0.2-7%) in ticks surveyed with Rickettsia tamurae, Rickettsia raoultii, and Rickettsia montana the major species. Amblyomma ticks had the highest prevalence of Rickettsia (85%, 35/44 Amblyomma adults), in which only R. tamurae and R. raoultii were found in Amblyomma with mixed species infections common. We report the first detection of R. africae-like and N. mikurensis in Ixodes granulatus adults in Thailand, suggesting I. granulatus as a potential vector for these pathogens. CONCLUSION This study demonstrated the risk of emerging TBD in Thailand and underscores the need for tick-bite prevention among tourists in Thailand.
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Affiliation(s)
- Suwanna Chaorattanakawee
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand.
| | - Wirunya Tachavarong
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Hathairad Hananantachai
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Watanyu Bunsermyos
- Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Bangkok, Thailand
| | - Nitima Chanarat
- Department of Entomology, Armed Forces Research Institute of Medical Sciences-United States Army Medical Directorate, Bangkok, Thailand
| | - Sommai Promsathaporn
- Department of Entomology, Armed Forces Research Institute of Medical Sciences-United States Army Medical Directorate, Bangkok, Thailand
| | - Bousaraporn Tippayachai
- Department of Entomology, Armed Forces Research Institute of Medical Sciences-United States Army Medical Directorate, Bangkok, Thailand
| | - Jira Sakolvaree
- Department of Entomology, Armed Forces Research Institute of Medical Sciences-United States Army Medical Directorate, Bangkok, Thailand
| | - Pannamthip Pitaksajjakul
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Center of Excellence for Antibody Research, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Surachet Benjathummarak
- Center of Excellence for Antibody Research, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Kanchit Srinoppawan
- Department of National Parks, Wildlife and Plant Conservation, Bangkok, Thailand
| | - David Saunders
- Uniformed Services University School of Medicine, Bethesda, MD, USA
| | - Erica J Lindroth
- Department of Entomology, Armed Forces Research Institute of Medical Sciences-United States Army Medical Directorate, Bangkok, Thailand
| | - Ratree Takhampunya
- Department of Entomology, Armed Forces Research Institute of Medical Sciences-United States Army Medical Directorate, Bangkok, Thailand
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2
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Huynh LN, Diarra AZ, Pham QL, Le-Viet N, Berenger JM, Ho VH, Nguyen XQ, Parola P. Morphological, molecular and MALDI-TOF MS identification of ticks and tick-associated pathogens in Vietnam. PLoS Negl Trop Dis 2021; 15:e0009813. [PMID: 34582467 PMCID: PMC8500424 DOI: 10.1371/journal.pntd.0009813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/08/2021] [Accepted: 09/13/2021] [Indexed: 11/19/2022] Open
Abstract
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a promising and reliable tool for arthropod identification, including the identification of alcohol-preserved ticks based on extracted leg protein spectra. In this study, the legs of 361 ticks collected in Vietnam, including 251 Rhiphicephalus sanguineus s.l, 99 Rhipicephalus (Boophilus) microplus, two Amblyomma varanensis, seven Dermacentor auratus, one Dermacentor compactus and one Amblyomma sp. were submitted for MALDI-TOF MS analyses. Spectral analysis showed intra-species reproducibility and inter-species specificity and the spectra of 329 (91%) specimens were of excellent quality. The blind test of 310 spectra remaining after updating the database with 19 spectra revealed that all were correctly identified with log score values (LSV) ranging from 1.7 to 2.396 with a mean of 1.982 ± 0.142 and a median of 1.971. The DNA of several microorganisms including Anaplasma platys, Anaplasma phagocytophilum, Anaplasma marginale, Ehrlichia rustica, Babesia vogeli, Theileria sinensis, and Theileria orientalis were detected in 25 ticks. Co-infection by A. phagocytophilum and T. sinensis was found in one Rh. (B) microplus.
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Affiliation(s)
- Ly Na Huynh
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
- Institute of Malariology, Parasitology and Entomology, Quy Nhon (IMPE-QN), Vietnam
| | - Adama Zan Diarra
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
| | - Quang Luan Pham
- Institute of Malariology, Parasitology and Entomology, Quy Nhon (IMPE-QN), Vietnam
| | - Nhiem Le-Viet
- School of Medicine and Pharmacy, The University of Da Nang (UD), Da Nang, Vietnam
| | - Jean-Michel Berenger
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
| | - Van Hoang Ho
- Institute of Malariology, Parasitology and Entomology, Quy Nhon (IMPE-QN), Vietnam
| | - Xuan Quang Nguyen
- Institute of Malariology, Parasitology and Entomology, Quy Nhon (IMPE-QN), Vietnam
| | - Philippe Parola
- Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France
- IHU-Méditerranée Infection, Marseille, France
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3
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Zhai J, Wu Y, Chen J, Zou J, Shan F, Li W, Chen W, Zhou N. Identification of Amblyomma javanense and detection of tick-borne Ehrlichia spp. in confiscated Malayan Pangolins. Int J Parasitol Parasites Wildl 2021; 14:107-116. [PMID: 33598400 PMCID: PMC7868807 DOI: 10.1016/j.ijppaw.2021.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/12/2021] [Accepted: 01/21/2021] [Indexed: 11/29/2022]
Abstract
Due to habitat destruction and illegal hunting and trade, the number of pangolins has been sharply reduced. To protect pangolins from extinction, relevant departments are combined and active action have been taken. A total of 21 confiscated Malayan pangolins were rescued in 2019, but died continuously for unknown reasons. This study aimed to investigate the reasons for the death of these pangolin and rescue them. 19 of the 21 confiscated pangolins had ticks on their body integument. A total of 303 ticks were collected and identified as Amblyomma javanense (A. javanense) according to their morphology and the sequences of 16S rRNA and internal transcribed spacer 2 (ITS2). There were multi-organ damages in the dead pangolins, especially congestion and hemorrhage in lung, heart and kidney and inflammation of which were observed using HE staining. Pathogens' nucleic acid detection showed ticks were only positive for Ehrlichia spp, with 56.7% positive rate of collected ticks (127/224), which was further confirmed in tissues from dead pangolins. Our findings confirm that ehrlichiosis caused by Ehrlichia spp. from A. javanense might accelerate the confiscated pangolin's death. More attention should be payed to tick-elimination work and the diagnoses and treatment of tick-borne diseases in the follow-up rescue operation.
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Affiliation(s)
- Junqiong Zhai
- Guangzhou Zoo, Guangzhou, 510070, China
- Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China
| | - Yajiang Wu
- Guangzhou Zoo, Guangzhou, 510070, China
- Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China
| | - Jinping Chen
- Guangdong Institute of Applied Biological Resources, Guangzhou, 510260, China
| | - Jiejian Zou
- Guangdong Provincial Wildlife Rescue Center, Guangzhou, 510520, China
| | - Fen Shan
- Guangzhou Zoo, Guangzhou, 510070, China
- Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China
| | - Wanping Li
- Guangzhou Zoo, Guangzhou, 510070, China
- Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China
| | - Wu Chen
- Guangzhou Zoo, Guangzhou, 510070, China
- Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China
| | - Niu Zhou
- Guangzhou Zoo, Guangzhou, 510070, China
- Wildlife Microbiology Laboratory, Guangzhou Wildlife Research Center, Guangzhou, 510070, China
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Abstract
In 2018, an immunosuppressed woman in southern Taiwan had onset of fever, chills, myalgia, malaise, thrombocytopenia, lymphocytopenia, and elevated hepatic transaminases. Investigation revealed infection with Ehrlichia chaffeensis. This autochthonous case of human monocytotropic ehrlichiosis was confirmed by PCR, DNA sequencing, and seroconversion.
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5
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Low VL, Tan TK, Khoo JJ, Lim FS, AbuBakar S. An overview of rickettsiae in Southeast Asia: Vector-animal-human interface. Acta Trop 2020; 202:105282. [PMID: 31778642 DOI: 10.1016/j.actatropica.2019.105282] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/24/2019] [Accepted: 11/24/2019] [Indexed: 02/07/2023]
Abstract
Rickettsioses are emerging, and re-emerging diseases caused by obligate intracellular arthropod-borne bacteria that infect humans and animals worldwide. Various rickettsiae such as Orientia, Rickettsia, Anaplasma and Ehrlichia have been circulated in companion, domesticated and wild animals through bites of infected ticks, fleas, lice or mites. This review summarizes the infections of rickettsiae, including the newly discovered regional species Rickettsia thailandii, Candidatus Rickettsia sepangensis, Candidatus Rickettsia johorensis, Candidatus Rickettsia laoensis, Candidatus Rickettsia mahosotii, Candidatus Rickettsia khammouanensis, Candidatus Anaplasma pangolinii, and other novel genotypes in vectors, humans and animals in Southeast Asia. Issues on some unidentified rickettsiae that elicit immune responses and production of antibodies that are cross-reactive with the antigens used are discussed. Knowledge gaps which required attention are also identified in this review.
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Affiliation(s)
- Van Lun Low
- Higher Institution Centre of Excellence (HICoE), Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.
| | - Tiong Kai Tan
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Jing Jing Khoo
- Higher Institution Centre of Excellence (HICoE), Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Fang Shiang Lim
- Higher Institution Centre of Excellence (HICoE), Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Higher Institution Centre of Excellence (HICoE), Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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6
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Koh FX, Kho KL, Kisomi MG, Wong LP, Bulgiba A, Tan PE, Lim YAL, Nizam QNH, Panchadcharam C, Tay ST. Ehrlichia and Anaplasma Infections: Serological Evidence and Tick Surveillance in Peninsular Malaysia. JOURNAL OF MEDICAL ENTOMOLOGY 2018; 55:269-276. [PMID: 29202206 DOI: 10.1093/jme/tjx204] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Indexed: 06/07/2023]
Abstract
Little information is available on human anaplasmosis and ehrlichiosis in Southeast Asia despite increasing reports of the detection of Anaplasma spp. and Ehrlichia spp. in the ticks. We report herein the serological findings against the tick-borne pathogens in a group of animal farm workers (n = 87) and indigenous people (n = 102) in Peninsular Malaysia. IgG antibodies against Ehrlichia chaffeensis were detected from 29.9% and 34.3% of farm workers and indigenous people, respectively, using commercial indirect immunofluorescence assays. Comparatively, only 6.9% of the indigenous people but none of the animal farm workers were seropositive to Anaplasma phagocytophilum. A polymerase chain reaction (PCR) assay targeting the 16S rRNA gene of Anaplasmataceae was used to identify Anaplastamataceae in ticks collected from various locations adjacent to the areas where the serological survey was conducted. In this study, a total of 61.5% of ticks infesting farm animals, 37.5% of ticks infesting peri-domestic animals in rural villages, 27.3% of ticks collected from wildlife animals, and 29.1% of questing ticks collected from forest vegetation were positive for Anaplasmataceae DNA. Sequence analyses of 16S rRNA gene region (238 bp) provide the identification for Anaplasma marginale, Anaplasma bovis, Anaplasma platys, A. phagocytophilum, and Anaplasma spp. closely related to Candidatus Cryptoplasma californiense in ticks. E. chaffeensis DNA was not detected from any ticks, instead, Ehrlichia sp. strain EBm52, Ehrlichia mineirensis and Candidatus Ehrlichia shimanensis are the only Ehrlichia sp. identified from cattle ticks in this study. Further investigation is required to ascertain the occurrence of zoonotic transmission of Ehrlichia and Anaplasma infections in Peninsular Malaysia.
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Affiliation(s)
- Fui Xian Koh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kai Ling Kho
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Masoumeh Ghane Kisomi
- Julius Centre University of Malaya, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Li Ping Wong
- Julius Centre University of Malaya, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Awang Bulgiba
- Julius Centre University of Malaya, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Poai Ean Tan
- Department of Wildlife and National Parks Peninsular Malaysia, Kuala Lumpur, Malaysia
| | - Yvonne Ai Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Quaza Nizamuddin Hassan Nizam
- Department of Veterinary Services, Ministry of Agriculture and Agro-Based Industry Malaysia, Federal Government Administrative Center, Putrajaya, Malaysia
| | - Chandrawathani Panchadcharam
- Department of Veterinary Services, Ministry of Agriculture and Agro-Based Industry Malaysia, Federal Government Administrative Center, Putrajaya, Malaysia
| | - Sun Tee Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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7
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Robinson MT, Vongphayloth K, Hertz JC, Brey P, Newton PN. Tick-transmitted human infections in Asia. MICROBIOLOGY AUSTRALIA 2018. [DOI: 10.1071/ma18064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Vector-borne pathogens of human significance cause a predicted 17% of infectious diseases worldwide, of which, ~23% are tick transmitted1. Although second to mosquitoes in terms of impact, ticks are thought to carry a greater diversity of pathogens than other arthropod vectors2. Asia is a key region for tick-borne pathogens, with tick species typically restricted to latitudes below 60–55°N3 where the climate is warmer and wetter – from the steppe regions of Russia to the tropical rainforests of South East Asia.
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8
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Blacksell SD, Kantipong P, Watthanaworawit W, Turner C, Tanganuchitcharnchai A, Jintawon S, Laongnuanutit A, Nosten FH, Day NPJ, Paris DH, Richards AL. Underrecognized arthropod-borne and zoonotic pathogens in northern and northwestern Thailand: serological evidence and opportunities for awareness. Vector Borne Zoonotic Dis 2017; 15:285-90. [PMID: 25988437 PMCID: PMC4449621 DOI: 10.1089/vbz.2015.1776] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Although scrub typhus and murine typhus are well-described tropical rickettsial illnesses, especially in Southeast Asia, only limited evidence is available for rickettsia-like pathogens contributing to the burden of undifferentiated febrile illness. Using commercially available kits, this study measured immunoglobulin G (IgG) antibody seroprevalence for Coxiella burnetii, Ehrlichia chaffeensis, Bartonella henselae, Anaplasma phagocytophilum, and spotted fever group rickettsiae (SFGR) in 375 patients enrolled in undifferentiated febrile illness studies at Chiangrai (northern Thailand) and Mae Sot (Thai–Myanmar border). Ehrlichia and SFGR were the most common causes of IgG seropositivity. A distinct relationship between age and seropositivity was found in Chiangrai with acquisition of IgG titers against Ehrlichia, Bartonella, Anaplasma, and SFGR in young adulthood, suggesting cumulative exposure to these pathogens. At Mae Sot, high early IgG titers against Ehrlichia and SFGR were common, whereas Anaplasma and Bartonella IgG titers increased at 50–60 years. Q fever associated with low IgG positivity at both study sites, with significantly higher prevalence at 30 years of age in Chiangrai. These data suggest that other rickettsial illnesses could contribute to the burden of febrile illness in Thailand and possibly adjacent regions. Improved diagnostics and better understanding of antibody longevity and cross-reactivity will improve identification and management of these easily treatable infectious diseases.
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Affiliation(s)
- Stuart D Blacksell
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Wanitda Watthanaworawit
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,4Shoklo Malaria Research Unit (SMRU), Tak, Thailand
| | | | - Ampai Tanganuchitcharnchai
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sutathip Jintawon
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - François H Nosten
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,4Shoklo Malaria Research Unit (SMRU), Tak, Thailand
| | - Nicholas P J Day
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Daniel H Paris
- 1Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Allen L Richards
- 5Viral and Rickettsial Diseases Department, Naval Medical Research Center, Silver Spring, Maryland.,6Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, Maryland
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9
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Ghane Kisomi M, Wong LP, Tay ST, Bulgiba A, Zandi K, Kho KL, Koh FX, Ong BL, Jaafar T, Hassan Nizam QN. Factors Associated with Tick Bite Preventive Practices among Farmworkers in Malaysia. PLoS One 2016; 11:e0157987. [PMID: 27341678 PMCID: PMC4920353 DOI: 10.1371/journal.pone.0157987] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 06/08/2016] [Indexed: 12/30/2022] Open
Abstract
Background Farmworkers are at high-risk for tick bites, which potentially transmit various tick-borne diseases. Previous studies show that personal prevention against tick bites is key, and certain factors namely, knowledge, experience of tick bites, and health beliefs influence compliance with tick bites preventive behaviour. This study aimed to assess these factors and their associations with tick bite preventive practices among Malaysian farmworkers. Methods A total of eight cattle, goat and sheep farms in six states in Peninsular Malaysia participated in a cross-sectional survey between August and October 2013 Results A total of 151 (72.2%) out of 209 farmworkers answered the questionnaire. More than half of the farmworkers (n = 91) reported an experience of tick bites. Farms with monthly acaricide treatment had significantly (P<0.05) a low report of tick bites. Tick bite exposure rates did not differ significantly among field workers and administrative workers. The mean total knowledge score of ticks for the overall farmworkers was 13.6 (SD±3.2) from 20. The mean total tick bite preventive practices score for all farmworkers was 8.3 (SD±3.1) from 15. Fixed effect model showed the effects of four factors on tick bite prevention: (1) farms, (2) job categories (administrative workers vs. field workers), (3) perceived severity of tick bites, and (4) perceived barriers to tick bite prevention. Conclusions A high proportion of farmworkers, including administrative workers, reported an experience of tick bites. The effectiveness of monthly acaricide treatment was declared by low reports of tick bites on these farms. Tick bite preventive practices were insufficient, particularly in certain farms and for administrative workers. Our findings emphasise the need to have education programmes for all farmworkers and targeting farms with low prevention practices. Education and health programmes should increase the perception of the risk of tick bites and remove perceived barriers of tick bite prevention.
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Affiliation(s)
- Masoumeh Ghane Kisomi
- Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Li Ping Wong
- Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- Julius Centre University of Malaya (JCUM), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
| | - Sun Tee Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Awang Bulgiba
- Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- Julius Centre University of Malaya (JCUM), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Keivan Zandi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kai Ling Kho
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Fui Xian Koh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Bee Lee Ong
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, University Malaysia Kelantan, Kelantan, Malaysia
| | - Tariq Jaafar
- Department of Veterinary Services, Ministry of Agriculture and Agro-Based Industry Malaysia, Federal Government Administrative Centre, Putrajaya, Malaysia
| | - Quaza Nizamuddin Hassan Nizam
- Department of Veterinary Services, Ministry of Agriculture and Agro-Based Industry Malaysia, Federal Government Administrative Centre, Putrajaya, Malaysia
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10
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Luo L, Sun J, Yan J, Wang C, Zhang Z, Zhao L, Han H, Tong Z, Liu M, Wu Y, Wen H, Zhang R, Xue Z, Sun X, Li K, Ma D, Liu J, Huang Y, Ye L, Li W, Jiang J, Yu XJ. Detection of a Novel Ehrlichia Species in Haemaphysalis longicornis Tick from China. Vector Borne Zoonotic Dis 2016; 16:363-7. [PMID: 27135624 DOI: 10.1089/vbz.2015.1898] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We collected 2460 Haemaphysalis longicornis ticks from vegetation in Jiaonan County, Shandong Province, in June of 2013 and Daishan County, Zhejiang Province, China, in May of 2015. The tick DNA was subsequently amplified with nested polymerase chain reaction using Ehrlichia common 16S rRNA gene primers and Ehrlichia ewingii species-specific groEL and gltA primers. We found 0.4% (3/780) of the ticks from Zhejiang Province contained Ehrlichia DNA that was different from all known Ehrlichia species, but most closely related to E. ewingii. We concluded that a novel Ehrlichia species exists in H. longicornis ticks in China.
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Affiliation(s)
- Limei Luo
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Jimin Sun
- 2 Zhejiang Province Center for Disease Control and Prevention , Hangzhou, Zhejiang, China
| | - Jianbo Yan
- 3 Zhoushan City Center for Disease Control and Prevention , Zhoushan, Zhejiang, China
| | - Chengwei Wang
- 4 Daishan County Center for Disease Control and Prevention , Daishan, Zhejiang, China
| | - Zhentang Zhang
- 5 Huangdao District Center for Disease Control and Prevention , Qingdao, Shandong, China
| | - Li Zhao
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Huiju Han
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Zhendong Tong
- 3 Zhoushan City Center for Disease Control and Prevention , Zhoushan, Zhejiang, China
| | - Miaomiao Liu
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Yuyan Wu
- 2 Zhejiang Province Center for Disease Control and Prevention , Hangzhou, Zhejiang, China
| | - Hongling Wen
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Rong Zhang
- 2 Zhejiang Province Center for Disease Control and Prevention , Hangzhou, Zhejiang, China
| | - Zaifeng Xue
- 5 Huangdao District Center for Disease Control and Prevention , Qingdao, Shandong, China
| | - Xifeng Sun
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Kefeng Li
- 3 Zhoushan City Center for Disease Control and Prevention , Zhoushan, Zhejiang, China
| | - Dongqiang Ma
- 5 Huangdao District Center for Disease Control and Prevention , Qingdao, Shandong, China
| | - Jianwei Liu
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Yuting Huang
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Ling Ye
- 4 Daishan County Center for Disease Control and Prevention , Daishan, Zhejiang, China
| | - Wenqian Li
- 1 School of Public Health, Shandong University , Jinan, Shandong, China
| | - Jianmin Jiang
- 2 Zhejiang Province Center for Disease Control and Prevention , Hangzhou, Zhejiang, China
| | - Xue-Jie Yu
- 1 School of Public Health, Shandong University , Jinan, Shandong, China .,6 Department of Pathology, University of Texas Medical Branch , Galveston, Texas
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11
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Rar V, Golovljova I. Anaplasma, Ehrlichia, and “Candidatus Neoehrlichia” bacteria: Pathogenicity, biodiversity, and molecular genetic characteristics, a review. INFECTION GENETICS AND EVOLUTION 2011; 11:1842-61. [DOI: 10.1016/j.meegid.2011.09.019] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 09/23/2011] [Accepted: 09/23/2011] [Indexed: 12/18/2022]
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12
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Ndip LM, Labruna M, Ndip RN, Walker DH, McBride JW. Molecular and clinical evidence of Ehrlichia chaffeensis infection in Cameroonian patients with undifferentiated febrile illness. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2010; 103:719-25. [PMID: 20030996 DOI: 10.1179/000349809x12554106963753] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
In the U.S.A., human monocytotropic ehrlichiosis (HME) caused by Ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. In Cameroon, where E. canis, E. chaffeensis and E. ewingii have recently been detected in dogs and/or ticks (Rhipicephalus sanguineus), the potential exists for human infections. Patients from the coastal region of Cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time PCR that amplifies part of a genus-specific gene (dsb) that codes for a disulphide-bond formation protein. Ehrlichial blood was detected in the peripheral blood from 12 (10%) of the 118 patients investigated by PCR. When the 12 amplicons from the positive cases were sequenced, they were found to be identical to each other and to the corresponding dsb sequence of an Arkansas strain of E. chaffeensis. The 12 patients who were PCR-positive for E. chaffeensis suffered from fever (100%), headache (67%), myalgia (42%), arthralgia (58%), pulmonary involvement (17%) and/or a diffuse rash (17%).
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Affiliation(s)
- L M Ndip
- Department of Biochemistry and Microbiology, University of Buea, South West Region, Cameroon
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13
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Ndip LM, Ndip RN, Esemu SN, Walker DH, McBride JW. Predominance of Ehrlichia chaffeensis in Rhipicephalus sanguineus ticks from kennel-confined dogs in Limbe, Cameroon. EXPERIMENTAL & APPLIED ACAROLOGY 2010; 50:163-168. [PMID: 19693681 PMCID: PMC2797824 DOI: 10.1007/s10493-009-9293-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Accepted: 07/14/2009] [Indexed: 05/28/2023]
Abstract
Rhipicephalus sanguineus ticks (n = 63) collected from five dogs (two adults and three puppies) housed in a kennel were screened for Ehrlichial agents (Ehrlichia canis, E. chaffeensis, and E. ewingii) using a species-specific multicolor real-time TaqMan PCR amplification of the disulphide bond formation protein (dsb) gene. Ehrlichia chaffeensis DNA was detected in 33 (56%) ticks, E. canis DNA was detected in four (6%) ticks, and one tick was coinfected. The E. chaffeensis and E. canis nucleotide sequences of the amplified dsb gene (374 bp) obtained from the Cameroonian R. sanguineus ticks were identical to the North American genotypes.
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Affiliation(s)
- Lucy M Ndip
- Department of Biochemistry, University of Buea, P. O. Box 63, Buea, Cameroon.
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14
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Yabsley MJ. Natural history of Ehrlichia chaffeensis: vertebrate hosts and tick vectors from the United States and evidence for endemic transmission in other countries. Vet Parasitol 2009; 167:136-48. [PMID: 19819631 DOI: 10.1016/j.vetpar.2009.09.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ehrlichia chaffeensis, an intracellular gram-negative zoonotic bacterium, is the causative agent of human monocytotropic ehrlichiosis (HME). In humans, the disease can range from a mild, non-specific illness with few to no clinical signs to a moderately severe to fatal disease, especially those with compromised immune systems. E. chaffeensis is maintained in a complex cycle involving white-tailed deer (WTD; Odocoileus virginianus) as a primary reservoir and the lone star tick (LST; Amblyomma americanum) as a primary vector. Numerous other species are naturally exposed to E. chaffeensis and disease has been documented in some domestic animals and wildlife including domestic dogs and ring-tailed lemurs. The organism has been found throughout the natural range of the LST and as the tick continues to expand its range, the geographic range of risk for E. chaffeensis infections will likely continue to expand. Recent data have indicated that E. chaffeensis, or a closely related organism, has been found in many species of ticks and vertebrate hosts in numerous countries.
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Affiliation(s)
- Michael J Yabsley
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA.
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15
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Bell CA, Patel R. A real-time combined polymerase chain reaction assay for the rapid detection and differentiation of Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Ehrlichia ewingii. Diagn Microbiol Infect Dis 2005; 53:301-6. [PMID: 16263231 DOI: 10.1016/j.diagmicrobio.2005.06.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 06/30/2005] [Indexed: 10/25/2022]
Abstract
A rapid real-time polymerase chain reaction (PCR) assay capable of the simultaneous detection and differentiation of Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Ehrlichia ewingii was developed using the LightCyclertrade mark instrument (Roche Applied Sciences, Indianapolis, IN). The assay targets the operon groEL of the heat shock protein. Base pair mismatches in amplified DNA in regions of detection probe hybridization allowed organism differentiation by melting curve analysis. The analytical sensitivity was at least 10 copies per reaction. DNA extracts from 59 specimens previously confirmed positive for A. phagocytophilum (n = 37), E. chaffeensis (n = 19), or E. ewingii (n = 3) were used to evaluate the assay. All of the specimens positive for 1 of the 3 organisms by conventional PCR were likewise positive by the LightCycler method. Sensitivity and specificity were at least 100% compared with conventional PCR. This assay provides a rapid method for the detection and differentiation of the causative agents of human ehrlichiosis in the United States.
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Affiliation(s)
- Constance A Bell
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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16
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Ndip LM, Ndip RN, Esemu SN, Dickmu VL, Fokam EB, Walker DH, McBride JW. Ehrlichial infection in Cameroonian canines by Ehrlichia canis and Ehrlichia ewingii. Vet Microbiol 2005; 111:59-66. [PMID: 16181750 DOI: 10.1016/j.vetmic.2005.08.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2005] [Revised: 08/02/2005] [Accepted: 08/08/2005] [Indexed: 10/25/2022]
Abstract
Ehrlichia chaffeensis and Ehrlichia ewingii are agents of emerging human ehrlichioses in North America and are transmitted primarily by Amblyomma americanum ticks, while Ehrlichia canis is the globally distributed cause of canine monocytic ehrlichiosis (CME) and is transmitted by the brown dog tick, Rhipicephalus sanguineus. Although E. canis and Ehrlichia ruminantium are endemic in Africa, the presence of ehrlichial agents in dogs and ticks in Cameroon has not been investigated. The objective of this study was to determine the prevalence of ehrlichial infections in Cameronian dogs using a combination of serologic and molecular methods. Peripheral blood was collected, clinical signs and the presence or absence of ticks on dogs (n=104) presenting for various reasons at local veterinary clinics around the Mount Cameroon region were noted. IFA identified 33 dogs (32%) with antibodies reactive with E. canis, and reactivity of these sera with all major E. canis antigens (200, 140, 95, 75, 47, 36, 28, and 19-kDa) was confirmed by immunoblotting. Multicolor real-time PCR detected ehrlichial DNA (E. canis (15) and E. ewingii (2)) in 17 dogs (16.3%), all of which had attached ticks at time of presentation. The dsb amplicons (378 bp) from E. canis and E. ewingii were identical to gene sequences from North American isolates. This study identifies canine ehrlichiosis as a prevalent unrecognized cause of disease in Cameroonian canines.
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Affiliation(s)
- L M Ndip
- Department of Life Sciences, University of Buea, Cameroon
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17
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Telford SR, Goethert HK. Emerging tick-borne infections: rediscovered and better characterized, or truly ‘new’? Parasitology 2005; 129 Suppl:S301-27. [PMID: 15940821 DOI: 10.1017/s0031182003004669] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The emergence of Lyme borreliosis as a public health burden within the last two decades has stimulated renewed interest in tick-borne infections. This attention towards ticks, coupled with advances in detection technologies, has promoted the recognition of diverse emergent or potentially emerging infections, such as monocytic and granulocytic ehrlichiosis, local variants of spotted fever group rickettsioses, WA-1 babesiosis, or a Lyme disease mimic (Masters' Disease). The distribution of pathogens associated with well-described tick-borne zoonoses such as human babesiosis due toBabesia microtiorB.divergensseems wider than previously thought. Bartonellae, previously known to be maintained by fleas, lice or sandflies, have been detected within ticks. Purported ‘new’ agents, mainly identified by sequencing of PCR products and comparison with those sequences present in GenBank, are being increasingly reported from ticks. We briefly review the diversity of these infectious agents, identify aetiological enigmas that remain to be solved, and provide a reminder about ‘old friends’ that should not be forgotten in our pursuit of novelty. We suggest that newly recognised agents or tick/pathogen associations receive careful scrutiny before being declared as potential public health burdens.
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Affiliation(s)
- S R Telford
- Tufts University School of Veterinary Medicine, Division of Infectious Diseases, 200 Westboro Road, North Grafton, MA 01536, USA.
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18
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Kim CM, Kim MS, Park MS, Park JH, Chae JS. Identification of Ehrlichia chaffeensis, Anaplasma phagocytophilum, and A. bovis in Haemaphysalis longicornis and Ixodes persulcatus ticks from Korea. Vector Borne Zoonotic Dis 2003; 3:17-26. [PMID: 12804377 DOI: 10.1089/153036603765627424] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A total of 1,467 tick (1,463 of Haemaphysalis longicornis, three of Ixodes persulcatus and one of I. turdus) collected from nine provinces of Korea were examined by TaqMan real-time PCR for the presence of Ehrlichia and Anaplasma species. One set of primers and a probe were designed for detection of all of the Ehrlichia and Anaplasma species. Template DNAs (total 803) were prepared either from pools of larvae, nymphs, adult males and females, or from the salivary gland and midgut of adult ticks. Only DNAs positive in TaqMan PCR were examined for A. phagocytophilum with nested PCR and for E. chaffeensis with PCR. Four A. phagocytophilum 16S rRNA gene PCR products were sequenced for comparison with sequences previously reported. Amplification of a 16S rRNA gene fragment of Ehrlichia and Anaplasma species was observed in 364 tick DNAs (45.3% of the total). Of these 364 positive ticks, species-specific PCRs confirmed that 35 H. longicornis and one I. persulcatus were positive for A. phagocytophilum and one I. persulcatus was positive in E. chaffeensis. Except for one (AB-GGHL, GenBank accession number [GAN] AF470698), three of the four 16S rRNA gene fragment sequences of the A. phagocytophilum-positive samples were similar or identical to the sequences of variants of A. phagocytophilum deposited in GenBank. The 16S rRNA gene fragment sequence of AB-GGHL was similar to that of Anaplasma (Ehrlichia) bovis 16S rRNA (GAN U03775). The identities of the Anaplasmataceae genus and species DNA in the 327 ticks that could not be confirmed infected with either E. chaffeensis, A. phagocytophilum, or A. bovis are not known. This study is the first to demonstrate the presence of E. chaffeensis, A. phagocytophilum and A. bovis in Korean ticks.
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Affiliation(s)
- Chul-Min Kim
- Bio-safety Research Institute, College of Veterinary Medicine, Chonbuk National University, Jeonju, Jeonbuk, Korea
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19
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Parola P, Cornet JP, Sanogo YO, Miller RS, Thien HV, Gonzalez JP, Raoult D, Telford III SR, Wongsrichanalai C. Detection of Ehrlichia spp., Anaplasma spp., Rickettsia spp., and other eubacteria in ticks from the Thai-Myanmar border and Vietnam. J Clin Microbiol 2003; 41:1600-8. [PMID: 12682151 PMCID: PMC153861 DOI: 10.1128/jcm.41.4.1600-1608.2003] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2002] [Revised: 11/06/2002] [Accepted: 01/23/2003] [Indexed: 11/20/2022] Open
Abstract
A total of 650 ticks, including 13 species from five genera, were collected from animals, from people, or by flagging of the vegetation at sites on the Thai-Myanmar border and in Vietnam. They were tested by PCR to detect DNA of bacteria of the order RICKETTSIALES: Three Anaplasma spp. were detected in ticks collected in Thailand, including (i) Anaplasma sp. strain AnDa465, which was considered a genotype of Anaplasma platys (formerly Ehrlichia platys) and which was obtained from Dermacentor auratus ticks collected from dogs; (ii) Anaplasma sp. strain AnAj360, which was obtained from Amblyomma javanense ticks collected on a pangolin; and (iii) Anaplasma sp. strain AnHl446, which was closely related to Anaplasma bovis and which was detected in Haemaphysalis lagrangei ticks collected from a bear. Three Ehrlichia spp. were identified, including (i) Ehrlichia sp. strain EBm52, which was obtained from Boophilus microplus ticks collected from cattle from Thailand; (ii) Ehrlichia sp. strain EHh324, which was closely related to Ehrlichia chaffeensis and which was detected in Haemaphysalis hystricis ticks collected from wild pigs in Vietnam; and (iii) Ehrlichia sp. strain EHh317, which was closely related to Ehrlichia sp. strain EBm52 and which was also detected in H. hystricis ticks collected from wild pigs in Vietnam. Two Rickettsia spp. were detected in Thailand, including (i) Rickettsia sp. strain RDla420, which was detected in Dermacentor auratus ticks collected from a bear, and (ii) Rickettsia sp. strain RDla440, which was identified from two pools of Dermacentor larvae collected from a wild pig nest. Finally, two bacteria named Eubacterium sp. strain Hw124 and Eubacterium sp. strain Hw191 were identified in Haemaphysalis wellingtoni ticks collected from chicken in Thailand; these strains could belong to a new group of bacteria.
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Affiliation(s)
- Philippe Parola
- Department of Immunology and Medicine, Armed Forces Research Institute of Medical Sciences, Bangkok.
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20
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Abstract
Ehrlichia chaffeensis is an obligately intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. The moderate to severe disease caused by E. chaffeensis in humans, first identified in 1986 and reported for more than 1,000 patients through 2000, represents a prototypical "emerging infection." Knowledge of the biology and natural history of E. chaffeensis, and of the epidemiology, clinical features, and laboratory diagnosis of the zoonotic disease it causes (commonly referred to as human monocytic ehrlichiosis [HME]) has expanded considerably in the period since its discovery. In this review, we summarize briefly the current understanding of the microbiology, pathogenesis, and clinical manifestations associated with this pathogen but focus primarily on discussing various ecological factors responsible for the recent recognition of this important and potentially life-threatening tick-borne disease. Perhaps the most pivotal element in the emergence of HME has been the staggering increases in white-tailed deer populations in the eastern United States during the 20th century. This animal serves as a keystone host for all life stages of the principal tick vector (Amblyomma americanum) and is perhaps the most important vertebrate reservoir host for E. chaffeensis. The contributions of other components, including expansion of susceptible human populations, growth and broadening geographical distributions of other potential reservoir species and A. americanum, and improvements in confirmatory diagnostic methods, are also explored.
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Affiliation(s)
- Christopher D Paddock
- Viral and Rickettsial Zoonoses Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Kelly DJ, Richards AL, Temenak J, Strickman D, Dasch GA. The past and present threat of rickettsial diseases to military medicine and international public health. Clin Infect Dis 2002; 34:S145-69. [PMID: 12016590 DOI: 10.1086/339908] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Morbidity and mortality caused by rickettsioses have had a major influence on military activities and public health for >2000 years. The threat posed by the rickettsioses is reviewed, focusing on the impact and epidemiology of those that have adversely influenced wartime operations and the current challenges posed by these diseases. With their uneven worldwide distribution, the discovery of drug-refractory strains of Orientia tsutsugamushi, the increased threat of their use in acts of bioterrorism, frequent deployment of troops to regions of endemicity, and exposures due to increased humanitarian missions, these diseases continue to be a threat to military personnel in the field. Effective strategies to reduce the impact of these diseases include development of effective vaccines, enhanced surveillance, and development of new safe, effective, and odorless repellants. The continuation of a proven, highly productive military infectious disease research program is essential for providing solutions to these daunting tasks.
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Affiliation(s)
- Daryl J Kelly
- Department of Molecular Genetics, Ohio State University, Columbus, OH, USA.
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Childs JE, Paddock CD. The ascendancy of Amblyomma americanum as a vector of pathogens affecting humans in the United States. ANNUAL REVIEW OF ENTOMOLOGY 2002; 48:307-337. [PMID: 12414740 DOI: 10.1146/annurev.ento.48.091801.112728] [Citation(s) in RCA: 319] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Until the 1990s, Amblyomma americanum was regarded primarily as a nuisance species, but a tick of minor importance as a vector of zoonotic pathogens affecting humans. With the recent discoveries of Ehrlichia chaffeensis, Ehrlichia ewingii, and "Borrelia lonestari," the public health relevance of lone star ticks is no longer in question. During the next 25 years, the number of cases of human disease caused by A. americanum-associated pathogens will probably increase. Based on current trajectories and historic precedents, the increase will be primarily driven by biological and environmental factors that alter the geographic distribution and intensity of transmission of zoonotic pathogens. Sociologic and demographic changes that influence the likelihood of highly susceptible humans coming into contact with infected lone star ticks, in addition to advances in diagnostic capabilities and national surveillance efforts, will also contribute to the anticipated increase in the number of recognized cases of disease.
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Affiliation(s)
- James E Childs
- Viral and Rickettsial Zoonoses Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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23
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Suksawat J, Xuejie Y, Hancock SI, Hegarty BC, Nilkumhang P, Breitschwerdt EB. Serologic and Molecular Evidence of Coinfection with Multiple Vector-Borne Pathogens in Dogs from Thailand. J Vet Intern Med 2001. [DOI: 10.1111/j.1939-1676.2001.tb01574.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Cao WC, Gao YM, Zhang PH, Zhang XT, Dai QH, Dumler JS, Fang LQ, Yang H. Identification of Ehrlichia chaffeensis by nested PCR in ticks from Southern China. J Clin Microbiol 2000; 38:2778-80. [PMID: 10878087 PMCID: PMC87030 DOI: 10.1128/jcm.38.7.2778-2780.2000] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A total of 717 ticks collected from southern China were examined by nested PCR for the presence of Ehrlichia chaffeensis. Sixteen (55. 2%) of 29 adult Amblyomma testudinarium ticks and 28 (11.7%) of 240 adult and at least 4.2% of 215 nymphal (pooled specimens) Haemaphysalis yeni ticks tested positive. Four other species of ticks were negative. Selected positive amplicons were confirmed by DNA sequencing.
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Affiliation(s)
- W C Cao
- Institute of Microbiology and Epidemiology, Beijing 100071, China.
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