Scrub typhus seroprevalence from an eastern state of India: findings from the state-wide serosurvey

Unveiling the burden of scrub typhus in acute febrile illness cases across India: A systematic review & meta-analysis

Background & objectives Scrub typhus is an emerging mite-borne zoonotic infection that has been overlooked, despite being one of the most widespread severe vector-borne diseases. With an estimated one billion people at risk worldwide and one million annual cases, it poses a significant public health concern. While various studies have investigated the prevalence of scrub typhus in different regions of India, a comprehensive regional systematic review and meta-analysis on the seropositivity of scrub typhus among acute febrile cases has been lacking. To address this gap, we conducted a systematic review and meta-analysis to compile information on the current seroprevalence of scrub typhus in acute febrile illness cases in India. Methods A literature search of multiple databases on prevalence of scrub typhus in acute febrile illness in India, 60 eligible studies out of 573 studies. The prevalence of individual studies was double arcsine transformed, and the pooled prevalence was calculated using inverse variance method. Results In total, these studies encompassed 34,492 febrile cases. The overall seroprevalence of scrub typhus among acute febrile illness cases in India was found to be 26.41 per cent [95% confidence interval (CI): 22.03-31.03]. Additionally, the pooled case fatality rate (based on data from six studies) among scrub typhus-positive cases yielded a case fatality rate of 7.69 per cent (95% CI: 4.37-11.72). Interpretation & conclusions This meta-analysis shows that scrub typhus is a significant health threat in India. Preventive measures to control scrub typhus need to be given priority.

Human rickettsial infections in India - A review

Rickettsial infections are emerging and/or re-emerging disease that poses a serious global threat to humans and animals. Transmission to humans and animals is through the bite of the ectoparasites including ticks, fleas and chigger mites. Most of the rickettsial diseases are endemic in India, but underdiagnosed. This review is aimed at analyzing the prevalence of rickettsiosis in India and the advancement of rickettsial diagnosis. We have conducted a systematic review on the prevalence of rickettsial disease in India ranging from 1.3% to 46.6% for spotted fever, 2.4% to 77.8% for scrub typhus and 1% to 46.4% for Q fever, based on the literature published with the evidence of isolation, serological, and molecular diagnostics. Search engines Medline/PubMed, Science Direct, ProQuest, and EBSCO were used to retrieve the articles from electronic databases by using appropriate keywords to track the emergence of these rickettsial diseases in India for the period of 1865 to till date. We retrieved 153 published rickettsial articles on hospital-based studies from India that were purely made on the basis of prevalence and the laboratory parameters viz., Weil-Felix test (WF) and Rapid Immunochromatographic tests (RICT) with reference to the gold standard IFA and ELISA. More epidemiological studies are required for epidemic typhus to know the exact prevalence status of this louse-borne rickettsiosis in India. Currently, there is no confirmed specific inflammatory marker for rickettsial diseases. Moreover, serological cross-reactivity is an important aspect, and it should be investigated in endemic areas, there is also a need to include molecular diagnostic techniques for further confirmation in healthcare settings.

Odisha tribal family health survey: methods, tools, and protocols for a comprehensive health assessment survey

Tribal or indigenous communities have unique health behaviors, challenges, and inequities that nationally representative surveys cannot document. Odisha has one of India's largest and most diverse tribal populations, constituting more than a fifth of the state. State and tribe-specific health data generation is recommended in India's national roadmap of tribal health. The Odisha tribal family health survey (OTFHS) aims to describe and compare the health status of tribal communities in the state of Odisha and to estimate the prevalence of key maternal-child health indicators and chronic diseases. This paper summarizes the methodology, protocols, and tools used in this survey. This is a population-based cross-sectional survey with a multistage random sampling design in 13 (tribal sub-plan areas) districts of Odisha, India. We will include participants of all age groups and gender who belong to tribal communities. The sample size was calculated for each tribe and aggregated to 40,921, which will be collected from 10,230 households spread over 341 clusters. The survey data will be collected electronically in modules consisting of Village, Household, and Individual level questionnaires. The age-group-specific questionnaires were adapted from other national family health surveys with added constructs related to specific health issues of tribal communities, including-critical indicators related to infectious and non-communicable diseases, multimorbidity, nutrition, healthcare-seeking behavior, self-rated health, psycho-social status, maternal and child health and geriatric health. A battery of laboratory investigations will be conducted at the household level and the central laboratory. The tests include liver function tests, kidney function tests, lipid profile, iron profile, and seroprevalence of scrub typhus and hepatitis infections. The datasets from household questionnaires, field measurements and tests and laboratory reports will be connected using a common unique ID in the database management system (DBMS) built for this survey. Robust quality control measures have been built into each step of the survey. The study examines the data focused on different aspects of family health, including reproductive health, adolescent and child health, gender issues in the family, ageing, mental health, and other social problems in a family. Multistage random sampling has been used in the study to enable comparison between tribes. The anthropometric measurements and biochemical tests would help to identify the indicators of chronic diseases among various age groups of the population.