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Zhang Y, Hai Y, Duan B, Long H, Xie X, Teng Z, Yin F, Wang M, Xiong Y, Shao Z, Guo W, Qin A. A seminested recombinase polymerase amplification assay to detect rickettsial pathogens in clinical samples. Diagn Microbiol Infect Dis 2023; 107:116067. [PMID: 37751629 DOI: 10.1016/j.diagmicrobio.2023.116067] [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: 06/12/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 09/28/2023]
Abstract
Treatment at the early stage of onset is vital for the prognosis of rickettsioses. But the absence of specific clinical symptoms complicates the diagnosis of this condition. Herein we established a seminested recombinase polymerase amplification assay (snRPA-nfo) that enables quick detection and differentiation of rickettsial pathogens in clinical samples with high sensitivity and specificity. The conserved 17-kDa protein gene of Rickettsia sibirica and the 47-kDa protein gene of Orientia tsutsugamushi were targeted for the duplex RPA-nfo assay. The snRPA-nfo assay exhibited an increased LOD in spiked blood samples, up to 1000-fold in comparison to standard RPA-nfo, and a better detection rate (83.3%, 5/6) than TaqMan PCR (16.6%, 1/6, Ct ≤ 35) in clinically confirmed patient blood samples. Thus, snRPA-nfo assay represents a promising alternative to TaqMan PCR in the early diagnosis of rickettsioses for point-of-care testing as well as in resource-limited settings.
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Affiliation(s)
- Ying Zhang
- Center for Disease Control and Prevention of Xilingol League, Xilinhaote, Inner Mongolia, China; State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yan Hai
- Center for Disease Control and Prevention of Inner Mongolia, Hohhot, Inner Mongolia, China
| | - Biao Duan
- Institute of Endemic Diseases Control and Prevention of Yunnan, Dali, Yunnan, China
| | - Hu Long
- Center for Disease Control and Prevention of Guilin City, Guilin, Guangxi, China
| | - Xiaofei Xie
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China; Hainan Medical College, Haikou, Hainan, China
| | - Zhongqiu Teng
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Feifei Yin
- Hainan Medical College, Haikou, Hainan, China
| | - Mingliu Wang
- Center for Disease Control and Prevention of Guangxi, Nanning, Guangxi, China
| | - Yanwen Xiong
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zhujun Shao
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Weidong Guo
- Center for Disease Control and Prevention of Xilingol League, Xilinhaote, Inner Mongolia, China; Institute of Endemic Diseases Control and Prevention of Yunnan, Dali, Yunnan, China.
| | - Aiping Qin
- State Key Laboratory of Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
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Ali A, Obaid MK, Almutairi MM, Alouffi A, Numan M, Ullah S, Rehman G, Islam ZU, Khan SB, Tanaka T. Molecular detection of Coxiella spp. in ticks (Ixodidae and Argasidae) infesting domestic and wild animals: with notes on the epidemiology of tick-borne Coxiella burnetii in Asia. Front Microbiol 2023; 14:1229950. [PMID: 37577446 PMCID: PMC10415105 DOI: 10.3389/fmicb.2023.1229950] [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: 05/30/2023] [Accepted: 07/03/2023] [Indexed: 08/15/2023] Open
Abstract
Tick-borne Coxiella spp. are emerging in novel regions infecting different hosts, but information regarding their occurrence is limited. The purpose of this study was the molecular screening of Coxiella spp. in various ticks infesting goats, sheep, camels, cattle, wild mice, and domestic fowls (Gallus gallus domesticus) in various districts of Khyber Pakhtunkhwa, Pakistan. Morphologically identified tick species were confirmed by obtaining their cox1 sequences and were molecularly screened for Coxiella spp. by sequencing GroEL fragments. Almost 345 out of 678 (50.9%) hosts were infested by nine tick species. Regarding the age groups, the hosts having an age >3 years were highly infested (192/345, 55.6%), while gender-wise infestation was higher in female hosts (237/345, 68.7%). In collected ticks, the nymphs were outnumbered (613/1,119, 54.8%), followed by adult females (293/1,119, 26.2%) and males (213/1,119, 19.7%). A total of 227 ticks were processed for molecular identification and detection of Coxiella spp. The obtained cox1 sequences of nine tick species such as Hyalomma dromedarii, Hyalomma anatolicum, Haemaphysalis cornupunctata, Haemaphysalis bispinosa, Haemaphysalis danieli, Haemaphysalis montgomeryi, Rhipicephalus haemaphysaloides, Rhipicephalus microplus, and Argas persicus showed maximum identities between 99.6% and 100% with the same species and in the phylogenetic tree, clustered to the corresponding species. All the tick species except Ha. danieli and R. microplus were found positive for Coxiella spp. (40/227, 17.6%), including Coxiella burnetii (15/40, 6.7%), Coxiella endosymbionts (14/40, 6.3%), and different Coxiella spp. (11/40, 4.9%). By the BLAST results, the GroEL fragments of Coxiella spp. showed maximum identity to C. burnetii, Coxiella endosymbionts, and Coxiella sp., and phylogenetically clustered to the corresponding species. This is the first comprehensive report regarding the genetic characterization of Coxiella spp. in Pakistan's ticks infesting domestic and wild hosts. Proper surveillance and management measures should be undertaken to avoid health risks.
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Affiliation(s)
- Abid Ali
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Muhammad Kashif Obaid
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Mashal M. Almutairi
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Abdulaziz Alouffi
- King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Muhammad Numan
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Shafi Ullah
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Gauhar Rehman
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Zia Ul Islam
- Department of Biotechnology, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Sher Bahadar Khan
- College of Animal Husbandry and Veterinary Sciences, Abdul Wali Khan University Mardan, Mardan, Khyber Pakhtunkhwa, Pakistan
| | - Tetsuya Tanaka
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
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Fomda BA, Khan A, Mir YB, Baqal S, Fomda AB, Rashid Kaul RU. Seroprevalence of Rickettsial disease: A population-based survey from kashmir valley, North India. Indian J Public Health 2023; 67:347-351. [PMID: 37929373 DOI: 10.4103/ijph.ijph_1597_22] [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] [Indexed: 11/07/2023] Open
Abstract
Background Limited studies have been done regarding the prevalence of Rickettsial diseases in India and as far as UT of Jammu and Kashmir is concerned, only a few hospital-based studies are available. Objectives The present study was therefore planned to find the seroprevalence of Rickettsial diseases in Kashmir Valley. Materials and Methods A multistage sampling procedure was used for the collection of samples from 10 districts of Kashmir Valley and a total of 1740 samples were collected. In addition, 802 healthy blood donors were included to establish baseline titers for Weil-Felix (WF) Test. Results Of 1734 subjects, 73 were positive by the WF test. The overall seroprevalence of Rickettsial diseases was 4.1% with the highest prevalence of scrub typhus (2.30%) followed by the spotted fever group (1.5%) and typhus group (0.40%). Maximum seropositive subjects were from district Kulgam (6.97%) followed by Pulwama (5.92%), Shopian (5.79%), Anantnag (5.47%), Ganderbal (5.00%), Kupwara (4.72%), Baramulla (4.62%), Srinagar (2.63%), Bandipora (2.41%), and Budgam (0.54%), respectively. Seropositivity was higher in females and subjects who had contact with ticks and mites like those involved in the collection of firewood and grass or had contact with uncut grass or shrub. The seropositivity was also significantly higher in those working in paddy fields and those living near the forest (P < 0.05). Conclusion The results of the present study confirm the existence of Rickettsial diseases in this region. This data would promote awareness of rickettsioses among local physicians and will also serve as a baseline to detect changing prevalence in the future.
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Affiliation(s)
- Bashir Ahmad Fomda
- Professor and Head, Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - Asiya Khan
- Senior Research Fellow, Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - Yaawar Bashir Mir
- PhD Scholar, Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - Sehrish Baqal
- Lab Technician, Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
| | - Anis Bashir Fomda
- Junior Resident, Department of Psychiatry, All India Institute of Medical Sciences, New Delhi, India
| | - Rauf Ur Rashid Kaul
- Professor, Department of Community Medicine, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India
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Krishnamoorthi S, Goel S, Kaur J, Bisht K, Biswal M. A Review of Rickettsial Diseases Other Than Scrub Typhus in India. Trop Med Infect Dis 2023; 8:tropicalmed8050280. [PMID: 37235328 DOI: 10.3390/tropicalmed8050280] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 05/01/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Rickettsial diseases (RD) are widely reported all over the world. Scrub typhus (ST) is a major tropical infection which is well documented all over India. Therefore, the index of suspicion of scrub typhus is high among physicians with regard to patients presenting with acute febrile illness (AFI) and acute undifferentiated febrile illness (AUFI) in India. Rickettsial diseases other than ST (non-ST RDs), which include spotted fever group (SFG) rickettsioses and typhus group (TG) rickettsioses are not uncommon in India, but the index of suspicion is not as high as ST unless there is a history of the presence of fever with rashes and/or recent arthropod bites. This review aims to look into the Indian scenario on the epidemiology of non-ST RDs, especially the SFG and TG rickettsioses based on various investigations, spectrum of clinical presentation, challenges and gaps in knowledge to suspect and diagnose these infections.
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Affiliation(s)
| | - Shriya Goel
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Jasleen Kaur
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Kamlesh Bisht
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Manisha Biswal
- Department of Medical Microbiology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
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Walker DH, Mendell NL. A scrub typhus vaccine presents a challenging unmet need. NPJ Vaccines 2023; 8:11. [PMID: 36759505 PMCID: PMC9910236 DOI: 10.1038/s41541-023-00605-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/17/2023] [Indexed: 02/11/2023] Open
Abstract
Scrub typhus caused by the obligately intracellular bacterium, Orientia tsutsugamushi, is a major cause of life-threatening acute undifferentiated febrile illness in eastern Asia and the islands of the Western Pacific and Indian oceans. Since the estimation of an incidence of 1 million cases annually two decades ago, the number of cases has increased substantially in endemic regions, reappeared where the disease was forgotten, and spread northward. Trombiculid mites are both reservoir and vector. Despite 80 years of efforts to develop a vaccine, there is none. Protective immunity is mediated by antibodies and CD8 and CD4 T cells. Previous efforts have failed because of gaps in understanding immunity to O. tsutsugamushi, particularly the requirements for vaccine-induced immunity, lack of knowledge regarding immune memory in scrub typhus, and lack of attention to addressing the issue of cross-protection between strains. There are numerous strains of O. tsutsugamushi, and modestly durable immunity is strain-specific. Antibodies to the strain that caused infection are protective against challenges with the homologous strain but, despite reactivity with other immunodominant antigens, the immune serum does not protect against heterologous strains. Among the antigens detected by western immunoblot in immune sera (22-, 47-, 56-, 58-, and 110 kDa proteins), only the 56 kDa protein stimulates strong protection. This protein contains four hypervariable regions which are likely, on the basis of limited data, to be the targets of neutralizing antibodies. However, a method that definitively detects neutralizing antibody has yet to be developed. Only one study has used genomic data to pursue the discovery of protective antigens. Three conserved autotransporters were identified, and only immunization with ScaA provided protection against the homologous strain, but only 40% of animals were protected against challenge with a heterologous strain. A multiplex vaccine containing conformational antigens of the hypervariable regions of the 56 kDa protein of the strains of the greatest clinical and epidemiological importance, as well as conserved regions of the 56 kDa protein, ScaA, and other protective antigens identified by future genomic and bioinformatics methods should be developed and tested.
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Affiliation(s)
- David H. Walker
- grid.176731.50000 0001 1547 9964Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
| | - Nicole L. Mendell
- grid.176731.50000 0001 1547 9964Department of Pathology, The University of Texas Medical Branch at Galveston, 301 University Blvd., Galveston, TX 77555 USA
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Wilairatana P, Kuraeiad S, Rattaprasert P, Kotepui M. Prevalence of malaria and scrub typhus co-infection in febrile patients: a systematic review and meta-analysis. Parasit Vectors 2021; 14:471. [PMID: 34521454 PMCID: PMC8442375 DOI: 10.1186/s13071-021-04969-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 08/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Little information is available about malaria and scrub typhus co-infection. This study aimed to investigate the pooled prevalence of malaria and scrub typhus co-infection in febrile patients. Further, it aimed to estimate the prevalence of scrub typhus infection among patients with malaria and the odds of co-infection. This will aid the diagnosis and management of co-infected patients in endemic areas. METHODS We searched for relevant studies in three databases: PubMed, Scopus, and Web of Science. We assessed the quality of the included studies using the Joanna Briggs Institute checklist for analytical cross-sectional studies. We estimated (1) the pooled prevalence of malaria and scrub typhus co-infection, (2) the pooled prevalence of scrub typhus infection in malaria-positive patients, and (3) the pooled odds of co-infection using the DerSimonian-Laird method for random-effects models. The study results and summary estimates were visualized on a forest plot as point estimates (effect size, prevalence) and 95% confidence intervals (CI). We assessed the heterogeneity of the studies by Cochrane Q or I2 statistics. We performed subgroup analyses of countries and scrub typhus diagnostic tests to explore the sources of heterogeneity of the included studies. We assessed publication bias if more than 10 studies were used to estimate the outcome. All data analyses were conducted using Stata version 14 (StataCorp, College Station, TX, USA). RESULTS Of the 542 studies retrieved from three databases, we included 14 meeting the inclusion criteria in the systematic review and meta-analysis. The pooled prevalence of malaria and scrub typhus co-infection (56 cases) among febrile patients (7920 cases) was 1% (95% CI: 0-1%, I2: 78.28%), while the pooled prevalence of scrub typhus infection (321 cases) in patients with malaria (1418 cases) was 21% (95% CI: 12-30%, I2: 98.15%). Subgroup analysis showed that the pooled prevalence of scrub typhus infection among patients with malaria in India was 8% (95% CI: 4-13%, I2: 85.87%, nine studies with 59/794 cases), while the pooled prevalence of scrub typhus infection among patients with malaria in Thailand was 35% (95% CI: 7-64%, I2: 98.9%, four studies with 262/624 cases). The co-infections did not occur by chance (P = 0.013, odds: 0.43, 95% CI: 0.22-0.84%, I2: 60.9%). In the sensitivity analysis, the pooled prevalence of malaria and scrub typhus co-infection among febrile patients was 0% (95% CI: 0-1%, I2: 59.91%). CONCLUSIONS The present study showed the pooled prevalence and a significant association between malaria and scrub typhus. The results show the status of co-infection. Further research into co-infection in endemic areas is needed, in particular, to determine whether co-infection can accelerate disease progression or protect against severe disease.
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Affiliation(s)
- Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Saruda Kuraeiad
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, 80160, Thailand
| | - Pongruj Rattaprasert
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Manas Kotepui
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, 80160, Thailand.
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Sahu R, Rawool DB, Dhaka P, Yadav JP, Mishra SP, Kumar M, Vergis J, Malik SS, Barbuddhe SB. Current perspectives on the occurrence of Q fever: highlighting the need for systematic surveillance for a neglected zoonotic disease in Indian subcontinent. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:138-158. [PMID: 33314653 DOI: 10.1111/1758-2229.12918] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Coxiellosis or Q fever is an important global occupational zoonotic disease caused by one of the most contagious bacterial pathogens - Coxiella burnetii, which ranks one among the 13 global priority zoonoses. The detection of C. burnetii infection is exhibiting an increasing trend in high-risk personnel around the globe. It has increasingly been detected from foods of animal origin (including bulk milk, eggs, and meat) as well as tick vectors in many parts of the world. Coxiellosis is reported to be an important public health threat causing spontaneous abortions in humans and potential reproductive failure, which would result in production losses among livestock. Further, comprehensive coverage of the reports and trends of Q fever in developing countries, where this infection is supposed to be widely prevalent appears scarce. Also, the pathogen remains grossly neglected and underreported. Moreover, policymakers and funding agencies do not view it as a priority problem, especially in the Indian subcontinent, including Sri Lanka, Bhutan, Pakistan, Nepal, Bangladesh and Maldives. Here, we review the occurrence and epidemiology of the disease in a global context with special emphasis on its status in the Indian subcontinent.
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Affiliation(s)
- Radhakrishna Sahu
- Division of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243 122, India
| | - Deepak Bhiwa Rawool
- ICAR- National Research Centre on Meat, Hyderabad, Telangana, 500 092, India
| | - Pankaj Dhaka
- School of Public Health and Zoonoses, College of Veterinary Science, GADVASU, Ludhiana, Punjab, 141004, India
| | - Jay Prakash Yadav
- Division of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243 122, India
| | - Sidharth Prasad Mishra
- Department of Animal Genetics and Breeding, West Bengal University of Animal and Fishery Sciences, Kolkata, West Bengal, 700037, India
| | - Manesh Kumar
- Division of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243 122, India
| | - Jess Vergis
- Division of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243 122, India
| | - Satyaveer Singh Malik
- Division of Veterinary Public Health, ICAR- Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, 243 122, India
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Dhimal M, Dumre SP, Sharma GN, Khanal P, Ranabhat K, Shah LP, Lal BK, Jha R, Upadhyaya BP, Acharya B, Shrestha SK, Davidson SA, Charoensinphon P, Karki KB. An outbreak investigation of scrub typhus in Nepal: confirmation of local transmission. BMC Infect Dis 2021; 21:193. [PMID: 33602136 PMCID: PMC7893900 DOI: 10.1186/s12879-021-05866-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 02/02/2021] [Indexed: 12/13/2022] Open
Abstract
Background Scrub typhus is a largely ignored tropical disease and a leading cause of undifferentiated febrile illness in the areas of tsutsugamushi triangle caused by Orientia tsutsugamushi. It is frequently diagnosed in South Asian countries, although clear epidemiological information is not available from Nepal. After the 2015 earthquake in Nepal, a sudden upsurge in scrub typhus cases was reported. The objective of this study was to investigate epidemiology of scrub typhus and its causative agents in humans, animals, and chigger mites to understand the ongoing transmission ecology. Methods Scrub typhus cases with confirmed diagnosis throughout the country were included in the analysis. Studies were concentrated in the Chitwan district, the site of a major outbreak in 2016. Additional nation-wide data from 2015 to 2017 available from the government database included to analyse the disease distribution by geographical mapping. Results From 2015 to 2017, 1239 scrub typhus cases were confirmed with the largest outbreak occurring in 2016 with 831 (67.1%) cases. The case fatality rate was 5.7% in 2015 which declined to 1.1% in 2017. A nationwide outbreak of scrub typhus was declared as the cases were detected in 52 out of the 75 districts of Nepal. Seasonal trend was observed with a peak during August and September. In addition to the human cases, the presence of O. tsutsugamushi was also confirmed in animals (rodents) and chigger mites (Leptotrombidium imphalum) from the outbreak areas of southern Nepal. Conclusion The detection of O. tsutsugamushi in humans, animals, and chigger mites from outbreak locations and wide-spread reports of scrub typhus throughout the country consecutively for 3 years confirms the ongoing transmission of O. tsutsugamushi with a firmly established ecology in Nepal. The country’s health system needs to be strengthened for systematic surveillance, early outbreak detection, and immediate actions including treatment and preventive measures. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-021-05866-6.
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Affiliation(s)
- Meghnath Dhimal
- Nepal Health Research Council (NHRC), Ramshah Path, Kathmandu, Nepal.
| | - Shyam Prakash Dumre
- Central Department of Microbiology, Tribhuvan University, Kathmandu, Nepal.,Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Guna Nidhi Sharma
- Epidemiology and Disease Control Division, Department of Health Services, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal.,Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | - Pratik Khanal
- Nepal Health Research Council (NHRC), Ramshah Path, Kathmandu, Nepal.,Institute of Medicine, Tribhuvan University, Kathmandu, Nepal
| | - Kamal Ranabhat
- Institute of Medicine, Tribhuvan University, Kathmandu, Nepal.,Department of Health Services, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | - Lalan Prasad Shah
- Department of Health Services, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | - Bibek Kumar Lal
- Epidemiology and Disease Control Division, Department of Health Services, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | - Runa Jha
- National Public Health Laboratory, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | - Bishnu Prasad Upadhyaya
- National Public Health Laboratory, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | - Bhim Acharya
- Epidemiology and Disease Control Division, Department of Health Services, Ministry of Health and Population, Government of Nepal, Kathmandu, Nepal
| | | | - Silas A Davidson
- Armed Forces Research Institute of Medical Sciences (AFRIMS), Bangkok, Thailand
| | | | - Khem B Karki
- Nepal Health Research Council (NHRC), Ramshah Path, Kathmandu, Nepal.,Institute of Medicine, Tribhuvan University, Kathmandu, Nepal
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Paris DH, Kelly DJ, Fuerst PA, Day NPJ, Richards AL. A Brief History of the Major Rickettsioses in the Asia-Australia-Pacific Region: A Capstone Review for the Special Issue of TMID. Trop Med Infect Dis 2020; 5:tropicalmed5040165. [PMID: 33121158 PMCID: PMC7709643 DOI: 10.3390/tropicalmed5040165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 12/19/2022] Open
Abstract
The rickettsioses of the "Far East" or Asia-Australia-Pacific region include but are not limited to endemic typhus, scrub typhus, and more recently, tick typhus or spotted fever. These diseases embody the diversity of rickettsial disease worldwide and allow us to interconnect the various contributions to this special issue of Tropical Medicine and Infectious Disease. The impact of rickettsial diseases-particularly of scrub typhus-was substantial during the wars and "police actions" of the last 80 years. However, the post-World War II arrival of effective antibiotics reduced their impact, when recognized and adequately treated (chloramphenicol and tetracyclines). Presently, however, scrub typhus appears to be emerging and spreading into regions not previously reported. Better diagnostics, or higher population mobility, change in antimicrobial policies, even global warming, have been proposed as possible culprits of this phenomenon. Further, sporadic reports of possible antibiotic resistance have received the attention of clinicians and epidemiologists, raising interest in developing and testing novel diagnostics to facilitate medical diagnosis. We present a brief history of rickettsial diseases, their relative importance within the region, focusing on the so-called "tsutsugamushi triangle", the past and present impact of these diseases within the region, and indicate how historically, these often-confused diseases were ingeniously distinguished from each another. Moreover, we will discuss the importance of DNA-sequencing efforts for Orientia tsutsugamushi, obtained from patient blood, vector chiggers, and rodent reservoirs, particularly for the dominant 56-kD type-specific antigen gene (tsa56), and whole-genome sequences, which are increasing our knowledge of the diversity of this unique agent. We explore and discuss the potential of sequencing and other effective tools to geographically trace rickettsial disease agents, and develop control strategies to better mitigate the rickettsioses.
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Affiliation(s)
- Daniel H. Paris
- Department of Medicine, Swiss Tropical and Public Health Institute, 4051 Basel, Switzerland
- Department of Clinical Research, University of Basel, 4051 Basel, Switzerland
- Correspondence: ; Tel.: +41-61-284-8111
| | - Daryl J. Kelly
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA; (D.J.K.); (P.A.F.)
| | - Paul A. Fuerst
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210, USA; (D.J.K.); (P.A.F.)
| | - Nicholas P. J. Day
- Mahidol-Oxford Tropical Medicine Research Programme, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithee Road, Bangkok 10400, Thailand;
- Center for Tropical Medicine, Nuffield Department of Clinical Medicine, Churchill Hospital, Old Road, Headington, Oxford OX3 7LJ, UK
| | - Allen L. Richards
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA;
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10
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Optimization and Evaluation of a Multiplex Quantitative PCR Assay for Detection of Nucleic Acids in Human Blood Samples from Patients with Spotted Fever Rickettsiosis, Typhus Rickettsiosis, Scrub Typhus, Monocytic Ehrlichiosis, and Granulocytic Anaplasmosis. J Clin Microbiol 2020; 58:JCM.01802-19. [PMID: 32493778 DOI: 10.1128/jcm.01802-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 05/25/2020] [Indexed: 01/09/2023] Open
Abstract
Spotted fever group rickettsioses (SFGR), typhus group rickettsioses (TGR), scrub typhus (caused by Orientia tsutsugamushi), ehrlichiosis, and anaplasmosis often present as undifferentiated fever but are not treated by agents (penicillins and cephalosporins) typically used for acute febrile illness. Inability to diagnose these infections when the patient is acutely ill leads to excess morbidity and mortality. Failure to confirm these infections retrospectively if a convalescent blood sample is not obtained also impairs epidemiologic and clinical research. We designed a multiplex real-time quantitative PCR (qPCR) assay to detect SFGR, TGR, O. tsutsugamushi, and infections caused by Anaplasma phagocytophilum and Ehrlichia chaffeensis with the ompA, 17-kDa surface antigen gene, tsa56, msp2 (p44), and vlpt gene targets, respectively. Analytical sensitivity was ≥2 copies/μl (linear range, 2 to 2 × 105) and specificity was 100%. Clinical sensitivities for SFGR, TGR, and O. tsutsugamushi were 25%, 20%, and 27%, respectively, and specificities were 98%, 99%, and 100%, respectively. Clinical sensitivities for A. phagocytophilum and E. chaffeensis were 93% and 84%, respectively, and specificities were 99% and 98%, respectively. This multiplex qPCR assay could support early clinical diagnosis and treatment, confirm acute infections in the absence of a convalescent-phase serum sample, and provide the high-throughput testing required to support large clinical and epidemiologic studies. Because replication of SFGR and TGR in endothelial cells results in very low bacteremia, optimal sensitivity of qPCR for these rickettsioses will require use of larger volumes of input DNA, which could be achieved by improved extraction of DNA from blood and/or extraction of DNA from a larger initial volume of blood.
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11
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Khan SA, Bora T, Saikia J, Shah A, Richards AL, Chattopadhyay S, Kakati S, Rahi M, Kaur H. Seroprevalence of typhus group rickettsial infections in the north-east region of India. Indian J Med Res 2020; 150:203-205. [PMID: 31670277 PMCID: PMC6829774 DOI: 10.4103/ijmr.ijmr_332_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Siraj Ahmed Khan
- Medical Entomology, Arbovirology & Rickettsial Diseases Division, ICMR- Regional Medical Research Centre, Dibrugarh 786 002, Assam, India
| | - Trishna Bora
- Medical Entomology, Arbovirology & Rickettsial Diseases Division, ICMR- Regional Medical Research Centre, Dibrugarh 786 002, Assam, India
| | - Jahnabi Saikia
- Medical Entomology, Arbovirology & Rickettsial Diseases Division, ICMR- Regional Medical Research Centre, Dibrugarh 786 002, Assam, India
| | - Anisha Shah
- Medical Entomology, Arbovirology & Rickettsial Diseases Division, ICMR- Regional Medical Research Centre, Dibrugarh 786 002, Assam, India
| | - Allen L Richards
- Naval Medical Research Centre, Rickettsial Disease Research Unit, Maryland 20910-7500, USA
| | | | - Sanjeeb Kakati
- Department of Medicine, Assam Medical College & Hospital, Dibrugarh 786 002, Assam, India
| | - Manju Rahi
- Division of Epidemiology & Communicable Diseases, Indian Council of Medical Research, New Delhi 110 029, India
| | - Harpreet Kaur
- Division of Epidemiology & Communicable Diseases, Indian Council of Medical Research, New Delhi 110 029, India
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12
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Sekeyová Z, Danchenko M, Filipčík P, Fournier PE. Rickettsial infections of the central nervous system. PLoS Negl Trop Dis 2019; 13:e0007469. [PMID: 31465452 PMCID: PMC6715168 DOI: 10.1371/journal.pntd.0007469] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
As a result of migrations and globalization, people may face a possible increase in the incidence of central nervous system rickettsial infections (CNS R). These diseases, caused by Rickettsia species and transmitted to humans by arthropod bites, are putatively lethal. However, the diagnosis of CNS R is challenging and often delayed due to their nonspecific clinical presentation and the strict intracellular nature of rickettsiae. Furthermore, transfer of rickettsiae to the brain parenchyma is not yet understood. The aim of this review is to analyze and summarize the features and correlated findings of CNS R in order to focus attention on these intriguing but frequently neglected illnesses. We also incorporated data on CNS infections caused by Rickettsia-related microorganisms.
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Affiliation(s)
- Zuzana Sekeyová
- Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, Bratislava, Slovakia
| | - Monika Danchenko
- Institute of Virology, Slovak Academy of Sciences, Dubravska cesta, Bratislava, Slovakia
| | - Peter Filipčík
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta, Bratislava, Slovakia
| | - Pierre Edouard Fournier
- Aix-Marseille Univ, IRD, AP-HM, SSA, VITROME, IHU Mediterranée-Infection, Marseille, France
- Centre National de Référence des Rickettsia, Coxiella et Bartonella, IHU Mediterranée-Infection, Marseille, France
- * E-mail:
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