1
|
Peng PY, Duan HY, Xu L, Zhang LT, Sun JQ, Zu Y, Ma LJ, Sun Y, Yan TL, Guo XG. Epidemiologic changes of a longitudinal surveillance study spanning 51 years of scrub typhus in mainland China. Sci Rep 2024; 14:3138. [PMID: 38326459 PMCID: PMC10850489 DOI: 10.1038/s41598-024-53800-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 02/05/2024] [Indexed: 02/09/2024] Open
Abstract
Scrub typhus may be one of the world's most prevalent, neglected and serious, but easily treatable, febrile diseases. It has become a significant potential threat to public health in China. In this study we used national disease surveillance data to analyze the incidence and spatial-temporal distribution of scrub typhus in mainland China during 1952-1989 and 2006-2018. Descriptive epidemiological methods and spatial-temporal epidemiological methods were used to investigate the epidemiological trends and identify high-risk regions of scrub typhus infection. Over the 51-year period, a total of 182,991 cases and 186 deaths were notified. The average annual incidence was 0.13 cases/100,000 population during 1952-1989. The incidence increased sharply from 0.09/100,000 population in 2006 to 1.93/100,000 population in 2018 and then exponentially increased after 2006. The incidence was significantly higher in females than males (χ2 = 426.32, P < 0.001). Farmers had a higher incidence of scrub typhus than non-farmers (χ2 = 684.58, P < 0.001). The majority of cases each year were reported between July and November with peak incidence occurring during October each year. The trend surface analysis showed that the incidence of scrub typhus increased gradually from north to south, and from east and west to the central area. The spatial autocorrelation analysis showed that a spatial positive correlation existed in the prevalence of scrub typhus on a national scale, which had the characteristic of aggregated distribution (I = 0.533, P < 0.05). LISA analysis showed hotspots (High-High) were primarily located in the southern and southwestern provinces of China with the geographical area expanding annually. These findings provide scientific evidence for the surveillance and control of scrub typhus which may contribute to targeted strategies and measures for the government.
Collapse
Affiliation(s)
- Pei-Ying Peng
- Institute of Microbiology of Qujing Medical College, Qujing, 655011, Yunnan Province, China.
| | - Hui-Ying Duan
- Institute of Microbiology of Qujing Medical College, Qujing, 655011, Yunnan Province, China
| | - Lei Xu
- Institute of Microbiology of Qujing Medical College, Qujing, 655011, Yunnan Province, China
| | - Lin-Tao Zhang
- Institute of Microbiology of Qujing Medical College, Qujing, 655011, Yunnan Province, China
| | - Ji-Qin Sun
- Department of Clinical Laboratory, Qujing Second People's Hospital, Qujing, 655011, Yunnan Province, China
| | - Ya Zu
- Department of Clinical Laboratory, Qujing Second People's Hospital, Qujing, 655011, Yunnan Province, China
| | - Li-Juan Ma
- Department of Clinical Laboratory, Qujing Second People's Hospital, Qujing, 655011, Yunnan Province, China
| | - Yan Sun
- Institute of Microbiology of Qujing Medical College, Qujing, 655011, Yunnan Province, China
| | - Ting-Liang Yan
- Institute of Microbiology of Qujing Medical College, Qujing, 655011, Yunnan Province, China
| | - Xian-Guo Guo
- Institute of Pathogens and Vectors, Yunnan Provincial Key Laboratory for Zoonosis Control and Prevention, Dali University, Dali, 671000, Yunnan, China
| |
Collapse
|
2
|
Kumaraswamy J, Govindasamy P, Nagarajan LS, Gunasekaran K, Abhilash KPP, Prakash JAJ. Genotyping of Orientia tsutsugamushi circulating in and around Vellore (South India) using TSA 56 gene. Indian J Med Microbiol 2024; 47:100483. [PMID: 37890413 DOI: 10.1016/j.ijmmb.2023.100483] [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: 05/11/2023] [Revised: 08/05/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023]
Abstract
PURPOSE The immunodominant TSA 56 gene of Orientia tsutsugamushi, (scrub typhus agent) has four variable regions (VD-I to VD-IV) making it useful for genotyping. This study was undertaken to determine Orientia tsutsugamushi genotypes circulating in and around Vellore using complete and partial TSA 56 gene. METHODS Of the 162 patients positive by 47 kDa qPCR, on 21 samples PCR to amplify the complete TSA 56 gene (≈1605 bp: Long protocol) and the partial gene sequence using the Horinouchi (≈650bp) and the Furuya (≈480 bp) protocol was performed. Sanger and Nanopore sequencing was performed to obtain sequence data for assigning genotype. For 13 amplicons partial and complete gene data was obtained. RESULTS Phylogenetic analysis of the complete gene (Long protocol) which includes VD-I to VD-IV region and partial gene (Horinouchi) which amplifies the VD-I to VD-III regions showed identical genotypes. Twelve belonged to TA763 genotype and one belongs to Karp genotype. The Furuya sequence (in silico) correctly identified the Karp genotype and 10 of the TA763 genotypes. Two TA763 genotypes (identified by complete and 650 bp partial gene analysis) were misidentified by Furuya sequence analysis as Karp genotype. CONCLUSIONS Analysis of the 13 complete 56 kDa gene sequences suggests that TA763 is the commonest genotype in Vellore. Sanger sequencing of the 650 bp fragment gives similar results. However, these results need to be validated by larger prospective multi-centric studies.
Collapse
Affiliation(s)
- Janaki Kumaraswamy
- Department of Clinical Microbiology, Christian Medical College, Vellore, 632004, Tamil Nadu, India.
| | - Punitha Govindasamy
- Department of Clinical Microbiology, Christian Medical College, Vellore, 632004, Tamil Nadu, India.
| | - Lakshmi Surya Nagarajan
- Department of Clinical Microbiology, Christian Medical College, Vellore, 632004, Tamil Nadu, India.
| | - Karthik Gunasekaran
- Department of Medicine, Christian Medical College, Vellore, Tamil Nadu, India.
| | - K P P Abhilash
- Emergency Medicine, Christian Medical College, Vellore, 632004, Tamil Nadu, India.
| | - John Antony Jude Prakash
- Department of Clinical Microbiology, Christian Medical College, Vellore, 632004, Tamil Nadu, India.
| |
Collapse
|
3
|
Bhardwaj P, Behera SP, Nanaware N, Zaman K, Deval H, Kant R, Kulkarni S, Kumar R, Dwivedi GR, Singh R. Phylogenetic and immunological investigations of complete TSA56 ORF of Orientia tsutsugamushi present in acute encephalitis syndrome cases from eastern Uttar Pradesh, India. Arch Microbiol 2023; 205:178. [PMID: 37029825 PMCID: PMC10082565 DOI: 10.1007/s00203-023-03492-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 04/09/2023]
Abstract
Scrub typhus (ST) caused by Orientia tsutsugamushi (OT), has long been known to cause acute encephalitis syndrome (AES) and acute febrile illness (AFI). The immunodominant 56 kDa protein of OT, which is encoded by the 56 kDa gene (1600 bp encoding 516-541 amino acids) is a commonly studied antigen for genotype and serotype assignment. Previous studies from India have utilized partial type specific antigen (TSA) 56 kDa sequences for OT strain characterisation. On the other hand, understanding the antigenic diversity of current OT strains, is critical for developing specific diagnostic tests and vaccines against ST. As a result, the current study analyses antigenic variants using the entire TSA56 ORF of OT from AES cases. Phylogenetic investigation using complete TSA56 ORF sequences revealed Karp and Gilliam were the circulating predominant strains of OT. Furthermore, Immuno-informatical analysis demonstrated that the majority of high-binding affinity CD4 TCEs against the most prevalent Indian human leukocyte antigen alleles were present in the S-VDIII/IV and S-VDIV spacer regions of TSA56 ORF. TSA56 conserved spacer is crucial for OT immunological response investigations. Further, the pathophysiological effects of spacer domains in ST require further investigation. Furthermore, the characterization of the TSA56 spacer region of the OT from different parts of India is critical for developing region-specific ST diagnostic assays and vaccines.
Collapse
Affiliation(s)
- Pooja Bhardwaj
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Sthita Pragnya Behera
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Nikita Nanaware
- ICMR-National AIDS Research Institute, Bhosari, Pune, 411026, India
| | - Kamran Zaman
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
- ICMR-National Institute of Traditional Medicine, Belagavi, Karnatka, India
| | - Hirawati Deval
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajni Kant
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Smita Kulkarni
- ICMR-National AIDS Research Institute, Bhosari, Pune, 411026, India
| | - Rajesh Kumar
- RGSC, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India
| | - Gaurav Raj Dwivedi
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India
| | - Rajeev Singh
- ICMR-Regional Medical Research Centre, BRD Medical College Campus, Gorakhpur, 273013, India.
| |
Collapse
|
4
|
Swain SK, Sahu BP, Panda S, Sarangi R. Molecular characterization and evolutionary analysis of Orientia tsutsugamushi in eastern Indian population. Arch Microbiol 2022; 204:221. [PMID: 35338394 PMCID: PMC8956147 DOI: 10.1007/s00203-022-02823-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/24/2022] [Accepted: 02/27/2022] [Indexed: 01/13/2023]
Abstract
Scrub typhus is a bacterial zoonotic acute febrile illness (AFI) caused by the obligate intracellular bacterium Orientia tsutsugamushi, which is an antigenically diverse strain frequently observed in the tropical region of Southeast Asian countries. The recent investigation was conducted to delineate the genotype identification of Orientia tsutsugamushi predominating in the eastern zone of India such as Odisha to decipher its strain type, and evaluate its diversity as well as evolutionary pattern based on the nucleotide analysis of the immune dominant 56 KDa gene. During this study, we have investigated 100 clinical samples (2014-2018), out of which 28 were positive for scrub typhus followed by its molecular characterization and phylogenetic analysis utilizing 56 KDa partial genes. Population genetic parameters showed the presence of 287 polymorphic sites within the analyzed 56 KDa gene. The gene diversity (Hd) and sequence diversity (π) was estimated 0.638 and 0.280, respectively. Selection pressure analysis (θ = dN/dS) having the value 0.222 suggests that the gene lied under purifying selection. The present study suggested a high rate of genetic diversity within the isolates. This research study sheds light on the hereditary and evolutionary relationships of Orientia strains found in the eastern Indian population. Understanding regional genetic variation is critical for vaccine development and sero-diagnostics methods. A significant level of genetic variability was observed during this study. This information has a way to understand more about antigen diversity that leads to develop an effective vaccine candidate for this pathogen.
Collapse
Affiliation(s)
- Subrat Kumar Swain
- Department of Pediatrics, IMS and SUM Hospital, Siksha "O" Anusandhan Deemed to be University, Bhubaneswar, Odisha, 751003, India
| | - Basanta Pravas Sahu
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, 453552, India
| | - Subhasmita Panda
- Department of Pediatrics, IMS and SUM Hospital, Siksha "O" Anusandhan Deemed to be University, Bhubaneswar, Odisha, 751003, India
| | - Rachita Sarangi
- Department of Pediatrics, IMS and SUM Hospital, Siksha "O" Anusandhan Deemed to be University, Bhubaneswar, Odisha, 751003, India.
| |
Collapse
|
5
|
Prakash JAJ, Kamarasu K, Samuel PP, Govindarajan R, Govindasamy P, Johnson LA, Ramalingam P, Nirmalson J, Seran KC. Detection of Orientia tsutsugamushi in Novel Trombiculid Mite Species in Northern Tamil Nadu, India: Use of Targeting the Multicopy traD Gene. JOURNAL OF MEDICAL ENTOMOLOGY 2022; 59:693-699. [PMID: 34850037 DOI: 10.1093/jme/tjab180] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Detection of Orientia tsutsugamushi DNA in a trombiculid mite chigger species suggests that it might be a potential vector of scrub typhus in an endemic area. Over a period of 20 mo, 85 rats were trapped, 57 had chiggers that were identified by standard morphometric techniques. The chigger pools were assessed by performing PCR assays targeting fragments of the single-copy genes 56 kDa type-specific antigen gene (TSA56) by nested PCR and the 47 kDa (htrA) quantitative real-time PCR (qPCR). The novel traD SYBR green assay that detects a multicopy gene was also performed. In total, 27 chigger pools were positive by traD qPCR, of which only 7 were positive by 47 kDa qPCR and in 3 of these, 56 kDa gene was amplified by nested PCR. Orientia tsutsugamushi-specific DNA was detected in Ascoschoengastia spp., Schoengastiella ligula, Leptotrombidium rajasthanense, Leptotrombidium deliense, and Leptotrombidium jayawickremei chigger pools. Therefore, they could be potential vectors of scrub typhus in Southern India. The three 56 kDa sequences belonged to TA716 genotype and Kato genogroup. Further studies are needed to confirm these chigger species as scrub typhus vectors in Northern Tamil Nadu.
Collapse
Affiliation(s)
- John Antony Jude Prakash
- Department of Clinical Microbiology, Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - Kannan Kamarasu
- Institute of Vector Control and Zoonoses, 150 Titan Jewellery Road, SIPCOT Phase I, Hosur Tamil Nadu 635126, India
| | - P Philip Samuel
- ICMR-Vector Control Research Centre Field Station, 4, Sarojini St, Chinna Chokikulam, Madurai Tamil Nadu 625002, India
| | - Renu Govindarajan
- ICMR-Vector Control Research Centre Field Station, 4, Sarojini St, Chinna Chokikulam, Madurai Tamil Nadu 625002, India
| | - Punitha Govindasamy
- Department of Clinical Microbiology, Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - Liji Anna Johnson
- Department of Clinical Microbiology, Christian Medical College, Ida Scudder Road, Vellore, Tamil Nadu 632004, India
| | - P Ramalingam
- Institute of Vector Control and Zoonoses, 150 Titan Jewellery Road, SIPCOT Phase I, Hosur Tamil Nadu 635126, India
| | - J Nirmalson
- Institute of Vector Control and Zoonoses, 150 Titan Jewellery Road, SIPCOT Phase I, Hosur Tamil Nadu 635126, India
| | - K C Seran
- Department of Community Medicine, Madras Medical College, Near Park Town Station, Chennai, Tamil Nadu 600003, India
| |
Collapse
|
6
|
Lu J, Liu Y, Ma X, Li M, Yang Z. Impact of Meteorological Factors and Southern Oscillation Index on Scrub Typhus Incidence in Guangzhou, Southern China, 2006-2018. Front Med (Lausanne) 2021; 8:667549. [PMID: 34395468 PMCID: PMC8355740 DOI: 10.3389/fmed.2021.667549] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 05/31/2021] [Indexed: 11/16/2022] Open
Abstract
Background: Scrub typhus was epidemic in the western Pacific Ocean area and East Asia, scrub typhus epidemic in densely populated areas in southern China. To better understand the association between meteorological variables, Southern Oscillation Index (SOI), and scrub typhus incidence in Guangzhou was benefit to the control and prevention. Methodology/Principal Findings: We collected weekly data for scrub typhus cases and meteorological variables in Guangzhou, and Southern Oscillation Index from 2006 to 2018, and used the distributed lag non-linear models to evaluate the relationships between meteorological variables, SOI and scrub typhus. The median value of each variable was set as the reference. The high-risk occupations were farmer (51.10%), house worker (17.51%), and retiree (6.29%). The non-linear relationships were observed with different lag weeks. For example, when the mean temperature was 27.7°C with1-week lag, the relative risk (RR) was highest as 1.08 (95% CI: 1.01–1.17). The risk was the highest when the relative humidity was 92.0% with 9-week lag, with the RR of 1.10 (95% CI: 1.02–1.19). For aggregate rainfall, the highest RR was 1.06 (95% CI: 1.03–1.11), when it was 83.0 mm with 4-week lag. When the SOI was 19 with 11-week lag, the highest RR was 1.06 (95% CI: 1.01–1.12). Most of the extreme effects of SOI and meteorological factors on scrub typical cases were statistically significant. Conclusion/Significance: The high-risk occupations of scrub typhus in Guangzhou were farmer, house worker, and retiree. Meteorological factors and SOI played an important role in scrub typhus occurrence in Guangzhou. Non-linear relationships were observed in almost all the variables in our study. Approximately, mean temperature, and relative humidity positively correlated to the incidence of scrub typhus, on the contrary to atmospheric pressure and weekly temperature range (WTR). Aggregate rainfall and wind velocity showed an inverse-U curve, whereas the SOI appeared the bimodal distribution. These findings can be helpful to facilitate the development of the early warning system to prevent the scrub typhus.
Collapse
Affiliation(s)
- Jianyun Lu
- Department of Infectious Disease Control and Prevention, Guangzhou Center for Disease Control and Prevention, Guangzhou, China
| | - Yanhui Liu
- Department of Infectious Disease Control and Prevention, Guangzhou Center for Disease Control and Prevention, Guangzhou, China
| | - Xiaowei Ma
- Department of Public Health Emergency Preparedness and Response, Guangzhou Center for Disease Control and Prevention, Guangzhou, China
| | - Meixia Li
- Department of Infectious Disease Control and Prevention, Guangzhou Center for Disease Control and Prevention, Guangzhou, China
| | - Zhicong Yang
- Guangzhou Center for Disease Control and Prevention, Guangzhou, China
| |
Collapse
|
7
|
Scrub Typhus and Molecular Characterization of Orientia tsutsugamushi from Central Nepal. Pathogens 2021; 10:pathogens10040422. [PMID: 33916224 PMCID: PMC8066985 DOI: 10.3390/pathogens10040422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/30/2021] [Accepted: 03/30/2021] [Indexed: 11/17/2022] Open
Abstract
Scrub typhus is a vector-borne, acute febrile illness caused by Orientia tsutsugamushi. Scrub typhus continues to be an important but neglected tropical disease in Nepal. Information on this pathogen in Nepal is limited to serological surveys with little information available on molecular methods to detect O. tsutsugamushi. Limited information exists on the genetic diversity of this pathogen. A total of 282 blood samples were obtained from patients with suspected scrub typhus from central Nepal and 84 (30%) were positive for O. tsutsugamushi by 16S rRNA qPCR. Positive samples were further subjected to 56 kDa and 47 kDa molecular typing and molecularly compared to other O. tsutsugamushi strains. Phylogenetic analysis revealed that Nepalese O. tsutsugamushi strains largely cluster together and cluster away from other O. tsutsugamushi strains from Asia and elsewhere. One exception was the sample of Nepal_1, with its partial 56 kDa sequence clustering more closely with non-Nepalese O. tsutsugamushi 56 kDa sequences, potentially indicating that homologous recombination may influence the genetic diversity of strains in this region. Knowledge on the circulating strains in Nepal is important to the development of diagnostic tests and vaccines to support public health measures to control scrub typhus in this country.
Collapse
|