Detection of Wuchereria bancrofti DNA in wild caught vector and non-vector mosquitoes: implications for elimination of lymphatic filariasis.

BACKGROUND: Transmission Assessment Survey (TAS) is the WHO recommended method used for decision-making to stop or continue the MDA in lymphatic filariasis (LF) elimination programme. The WHO has also recommended Molecular Xenomonitoring (MX) of LF infection in vectors as an adjunct tool in settings under post-MDA or validation period. Screening of non-vectors by MX in post-MDA / validation settings could be useful to prevent a resurgence of LF infection, as there might be low abundance of vectors, especially in some seasons. In this study, we investigated the presence of LF infection in non-vectors in an area endemic for LF and has undergone many rounds of annual MDA with two drugs (Diethylcarbamazine and Albendazole, DA) and two rounds of triple drug regimens (Ivermectin + DA). METHODS AND RESULTS: Mosquitoes were collected from selected villages of Yadgir district in Karnataka state, India, during 2019. A total of 680 female mosquitoes were collected, identified morphologically by species and separated as pools. The female mosquitoes belonging to 3 species viz., Anopheles subpictus, Culex gelidus and Culex quinquefaciatus were separated, pooled, and the DNA extracted using less expensive method and followed by LDR based real-time PCR assay for detecting Wuchereria bancrofti infection in vector as well as non-vector mosquitoes. One pool out of 6 pools of An. subpictus, 2 pools out of 6 pools of Cx. gelidus, and 4 pools out of 8 pools of Cx. quinquefaciatus were found to be positive for W. bancrofti infection by RT-PCR. The infection rate in vectors and non-vectors was found to be 1.8% (95% CI: 0.5-4.2%) and 0.9% (95% CI: 0.2-2.3%), respectively. CONCLUSIONS: Our study showed that non-vectors also harbour W. bancrofti, thus opening an opportunity of using these mosquitoes as surrogate vectors for assessing risk of transmission to humans in LF endemic and post MDA areas.

National Burden Estimates of healthy life lost in India, 2017: an analysis using direct mortality data and indirect disability data.

BACKGROUND: Many countries, including India, seek locally constructed disease burden estimates comprising mortality and loss of health to aid priority setting for the prevention and treatment of diseases. We created the National Burden Estimates (NBE) to provide transparent and understandable disease burdens at the national and subnational levels, and to identify gaps in knowledge. METHODS: To calculate the NBE for India, we combined 2017 UN death totals with national and subnational mortality rates for 2010-17 and causes of death from 211 166 verbal autopsy interviews in the Indian Million Death Study for 2010-14. We calculated years of life lost (YLLs) and years lived with disability (YLDs) for 2017 using published YLD-YLL ratios from WHO Global Health Estimates. We grouped causes of death into 45 groups, including ill-defined deaths, and summed YLLs and YLDs to calculate disability-adjusted life-years (DALYs) for these causes in eight age groups covering rural and urban areas and 21 major states of India. FINDINGS: In 2017, there were about 9·7 million deaths and 486 million DALYs in India. About three quarters of deaths and DALYs occurred in rural areas. More than a third of national DALYs arose from communicable, maternal, perinatal, and nutritional disorders. DALY rates in rural areas were at least twice those of urban areas for perinatal and nutritional conditions, chronic respiratory diseases, diarrhoea, and fever of unknown origin. DALY rates for ischaemic heart disease were greater in urban areas. Injuries caused 11·4% of DALYs nationally. The top 15 conditions that accounted for the most DALYs were mostly those causing mortality (ischaemic heart disease, perinatal conditions, chronic respiratory diseases, diarrhoea, respiratory infections, cancer, stroke, road traffic accidents, tuberculosis, and liver and alcohol-related conditions), with disability mostly due to a few conditions (nutritional deficiencies, neuropsychiatric conditions, vision and other sensory loss, musculoskeletal disorders, and genitourinary diseases). Every condition that was common in one part of India was uncommon elsewhere, suggesting state-specific priorities for disease control. INTERPRETATION: The NBE method quantifies disease burden using transparent, intuitive, and reproducible methods. It provides a simple, locally operable tool to aid policy makers in priority setting in India and other low-income and middle-income countries. The NBE underlines the need for many more countries to collect nationally representative cause of death data, paired with focused surveys of disability. FUNDING: Ministry of Health and Family Welfare, Government of India.

Tuberculosis among the homeless in Chennai city, South India.

Background: In India from a national perspective, the incidence/prevalence of active tuberculosis (TB) among the homeless are unknown. Methods: Homeless individuals, aged 15 years and above, were screened for TB by radiography and smear examination in Chennai city. Results: 301 individuals were enrolled and screened for TB; 8% (24/301) had chest symptoms; 5.6% (17/301) found X-ray abnormalities. The overall prevalence of TB was 1661/100 000; prevalence of culture-positive TB was 997/100 000 and smear-positive TB was 664/100 000 population. Conclusion: There is a need to address TB control among homeless populations. The current pilot study showed that the prevalence of TB was disproportionately high and there is a need for a larger study with an adequately powered sample size.

Psycho-Socio-Economic Issues Challenging Multidrug Resistant Tuberculosis Patients: A Systematic Review.

BACKGROUND: Limited treatment options, long duration of treatment and associated toxicity adversely impact the physical and mental well-being of multidrug-resistant tuberculosis (MDR-TB) patients. Despite research advances in the microbiological and clinical aspects of MDR-TB, research on the psychosocial context of MDR-TB is limited and less understood. METHODOLOGY: We searched the databases of PubMed, MEDLINE, Embase and Google Scholar to retrieve all published articles. The final manuscripts included in the review were those with a primary focus on psychosocial issues of MDR-TB patients. These were assessed and the information was thematically extracted on the study objective, methodology used, key findings, and their implications. Intervention studies were evaluated using components of the methodological and quality rating scale. Due to the limited number of studies and the multiple methodologies employed in the observational studies, we summarized these studies using a narrative approach, rather than conducting a formal meta-analysis. We used 'thematic synthesis' method for extracting qualitative evidences and systematically organised to broader descriptive themes. RESULTS: A total of 282 published articles were retrieved, of which 15 articles were chosen for full text review based on the inclusion criteria. Six were qualitative studies; one was a mixed methods study; and eight were quantitative studies. The included studies were divided into the following issues affecting MDR-TB patients: a) psychological issues b) social issues and economic issues c) psychosocial interventions. It was found that all studies have documented range of psychosocial and economic challenges experienced by MDR-TB patients. Depression, stigma, discrimination, side effects of the drugs causing psychological distress, and the financial constraints due to MDR-TB were some of the common issues reported in the studies. There were few intervention studies which addressed these psychosocial issues most of which were small pilot studies. There is dearth of large scale randomized psychosocial intervention studies that can be scaled up to strengthen management of MDR-TB patients which is crucial for the TB control programme. CONCLUSION: This review has captured the psychosocial and economic issues challenging MDR patients. However there is urgent need for feasible, innovative psychosocial and economic intervention studies that help to equip MDR-TB patients cope with their illness, improve treatment adherence, treatment outcomes and the overall quality of life of MDR-TB patients.

Pulmonary tuberculosis among tribals in India: A systematic review & meta-analysis.

BACKGROUND & OBJECTIVES: There has been limited investigation on the prevalence of tuberculosis (TB) in tribal communities in India, a vulnerable section of Indian society. The lack of a population-based estimate prompted us to conduct a meta-analysis of existing studies to provide a single, population-based estimate of the TB prevalence for tribals. METHODS: Literature search was conducted in PubMed using the keywords - "tuberculosis", "tribals", "India", "prevalence", and "survey". References cited in the articles retrieved were also reviewed, and those found relevant were selected. TB prevalence rates estimated by the studies were used for our calculation of a pooled-estimate. RESULTS: The pooled estimate, based on the random effects model, was 703 per 100,000 population with a 95 % CI of 386-1011. The associated heterogeneity measures in terms of Cochran's Q was significant ( p=0 0.08 <0.1) and I [2] was moderate at 48 per cent. INTERPRETATION & CONCLUSIONS: The meta-analysis demonstrated a large variability in pulmonary TB prevalence estimates among the different studies with poor representation of the various tribal groups. The moderate level of heterogeneity found across the studies suggests that the pooled-estimate needs to be treated with caution. Our findings also highlight the need to assess the pulmonary TB burden in India.

Prevalence and risk factors for adult pulmonary tuberculosis in a metropolitan city of South India.

BACKGROUND: The present study measured the community prevalence and risk factors of adult pulmonary tuberculosis (PTB) in Chennai city, and also studied geographical distribution and the presence of different M. tuberculosis strains in the survey area. METHODS: A community-based cross sectional survey was carried out from July 2010 to October 2012 in Chennai city. Prevalence of bacteriologically positive PTB was estimated by direct standardization method. Univariate and multivariate analyses were carried out to identify significant risk factors. Drug susceptibility testing and spoligotyping was performed on isolated M. tuberculosis strains. Mapping of PTB cases was done using geographic positioning systems. RESULTS: Of 59,957 eligible people, 55,617 were screened by X-ray and /or TB symptoms and the prevalence of smear, culture, and bacteriologically positive PTB was estimated to be 228 (95% CI 189-265), 259 (95% CI 217-299) and 349 (95% CI 330-428) per 100,000 population, respectively. Prevalence of smear, culture, and bacteriologically positive PTB was highest amongst men aged 55-64 years. Multivariate analysis showed that occurrence of both culture and bacteriologically positive PTB disease was significantly associated with: age >35 years, past history of TB treatment, BMI <18.5 Kgs/m2, solid cooking fuel, and being a male currently consuming alcohol. The most frequent spoligotype family was East African Indian. Spatial distribution showed that a high proportion of patients were clustered in the densely populated north eastern part of the city. CONCLUSION: Our findings demonstrate that TB is a major public health problem in this urban area of south India, and support the use of intensified case finding in high risk groups. Undernutrition, slum dwelling, indoor air pollution and alcohol intake are modifiable risk factors for TB disease.

Prevalence of tobacco use in urban, semi urban and rural areas in and around Chennai City, India.

BACKGROUND: Tobacco use leads to many health complications and is a risk factor for the occurrence of cardio vascular diseases, lung and oral cancers, chronic bronchitis etc. Almost 6 million people die from tobacco-related causes every year. This study was conducted to measure the prevalence of tobacco use in three different areas around Chennai city, south India. METHODS: A survey of 7510 individuals aged > = 15 years was undertaken covering Chennai city (urban), Ambattur (semi-urban) and Sriperumbudur (rural) taluk. Details on tobacco use were collected using a questionnaire adapted from both Global Youth Tobacco Survey and Global Adults Tobacco Survey. RESULTS: The overall prevalence of tobacco use was significantly higher in the rural (23.7%) compared to semi-urban (20.9%) and urban (19.4%) areas (P value <0.001) Tobacco smoking prevalence was 14.3%, 13.9% and 12.4% in rural, semi-urban and urban areas respectively. The corresponding values for smokeless tobacco use were 9.5%, 7.0% and 7.0% respectively. Logistic regression analysis showed that the odds of using tobacco (with smoke or smokeless forms) was significantly higher among males, older individuals, alcoholics, in rural areas and slum localities. Behavioural pattern analysis of current tobacco users led to three groups (1) those who were not reached by family or friends to advice on harmful effects (2) those who were well aware of harmful effects of tobacco and even want to quit and (3) those are exposed to second hand/passive smoking at home and outside. CONCLUSIONS: Tobacco use prevalence was significantly higher in rural areas, slum dwellers, males and older age groups in this region of south India. Women used mainly smokeless tobacco. Tobacco control programmes need to develop strategies to address the different subgroups among tobacco users. Public health facilities need to expand smoking cessation counseling services as well as provide pharmacotherapy where necessary.

Epidemiological assessment of eight rounds of mass drug administration for lymphatic filariasis in India: implications for monitoring and evaluation.

BACKGROUND: Monitoring and evaluation guidelines of the programme to eliminate lymphatic filariasis require impact assessments in at least one sentinel and one spot-check site in each implementation unit (IU). Transmission assessment surveys (TAS) that assess antigenaemia (Ag) in children in IUs that have completed at least five rounds of mass drug administration (MDA) each with >65% coverage and with microfilaria (Mf) levels <1% in the monitored sites form the basis for stopping the MDA. Despite its rigour, this multi-step process is likely to miss sites with transmission potential ('hotspots') and its statistical assumptions for sampling and threshold levels for decision-making have not been validated. We addressed these issues in a large-scale epidemiological study in two primary health centres in Thanjavur district, India, endemic for bancroftian filariasis that had undergone eight rounds of MDA. METHODOLOGY/PRINCIPAL FINDINGS: The prevalence and intensity of Mf (per 60 µl blood) were 0.2% and 0.004 respectively in the survey that covered >70% of 50,363 population. The corresponding values for Ag were 2.3% and 17.3 Ag-units respectively. Ag-prevalence ranged from 0.7 to 0.9%, in children (2-10 years) and 2.7 to 3.0% in adults. Although the Mf-levels in the survey and the sentinel/spot check sites were <1% and Ag-level was <2% in children, we identified 7 "residual" (Mf-prevalence ≥ 1%, irrespective of Ag-status in children) and 17 "transmission" (at least one Ag-positive child born during the MDA period) hotspots. Antigenaemic persons were clustered both at household and site levels. We identified an Ag-prevalence of ~1% in children (equivalent to 0.4% community Mf-prevalence) as a possible threshold value for stopping MDA. CONCLUSIONS/SIGNIFICANCE: Existence of 'hotspots' and spatial clustering of infections in the study area indicate the need for developing good surveillance strategies for detecting 'hotspots', adopting evidence-based sampling strategies and evaluation unit size for TAS.