Space time analysis of dengue fever diagnosed through a network of laboratories in India from 2014-2017.

BACKGROUND & OBJECTIVES: The Department of Health Research and the Indian Council of Medical Research, Government of India, have established Virus Research and Diagnostic Laboratory Network (VRDLN) to strengthen the laboratory capacity in the country for providing timely diagnosis of disease outbreaks. Fifty-one VRDLs were functional as on December 2017 and had reported about dengue fever across Indian states. The objectives of the study were to detect space time clusters and purely temporal clusters of dengue using Kulldorff's SaTScan statistics using patient level information; and to identify regions at greater risk of developing the disease using Kriging technique aggregating at district level. METHODS: A total of 211,432 patients from 51 VRDLs were investigated for IgM antibodies or NS1 antigen against dengue virus during the period from 1 January 2014 to 31 December 2017 and among them 60,096 (28.4%) were found to be positive. Kulldorff's space time analysis was used to identify significant clusters over space and time. Kriging technique was used to interpolate dengue data for areas not physically sampled using the relationship in the spatial arrangement of the data set. Maps obtained using both the methods were overlaid to identify the regions at greater risk of developing the disease. RESULTS: Kulldorff Space time Scan Statistics using the Bernoulli model with monthly precision revealed eight statistically significant clusters (P <0.001) for the time period, 1 January 2014 to 31 December 2017. Eight significant clusters identified were districts of Nagpur, Jhunjhunu, Gadag, Dakshin Kannada, Kancheepuram, Sivaganga, Ernakulam and Malda. The purely temporal clusters occurred during the last quarter of 2015 and 2016. The Kriging technique identified north eastern part of the country (Arunachal Pradesh, Nagaland and Manipur) and Gujarat. INTERPRETATION & CONCLUSION: Dengue fever has spread in all directions in the country. Hence, it is need of the hour to perform an in-depth investigation.

An Analysis of Levels and Trends in HIV Prevalence Among Pregnant Women Attending Antenatal Clinics in Karnataka, South India, 2003-2019.

BACKGROUND AND OBJECTIVE: Periodic tracking of the trends and the levels of HIV prevalence at regional and district levels helps to strengthen a state's HIV/AIDS response. HIV prevalence among pregnant women is crucial for the HIV prevalence estimation of the general population. Karnataka is one of the high HIV prevalence states in India. Probing regional and district levels and trends of HIV prevalence provides critical insights into district-level epidemic patterns. This paper analyzes the region- and district-wise levels and trends of HIV prevalence among pregnant women attending the antenatal clinics (ANC) from 2003 to 2019 in Karnataka, South India. METHODS: HIV prevalence data collected from pregnant women in Karnataka during HIV Sentinel Surveillance (HSS) between 2003 and 2019 was used for trend analysis. The consistent sites were grouped into four zones (Bangalore, Belgaum, Gulbarga and Mysore regions), totaling 60 sites, including 30 urban and 30 rural sites. Regional and district-level HIV prevalence was calculated; trend analysis using Chi-square trend test and spatial analysis using QGIS software was done. For the last three HSS rounds, HIV prevalence based on sociodemographic variables was calculated to understand the factors contributing to HIV positivity in each region. RESULTS: In total, 254,563 pregnant women were recruited. HIV prevalence in Karnataka was 0.22 (OR: 0.15 95% CI: 0.16 - 0.28) in 2019. The prevalence was 0.24, 0.32, 0.17 and 0.14 in Bangalore, Belgaum, Gulbarga, and Mysore regions, respectively. HIV prevalence had significantly (P< 0.05) declined in 26 districts. CONCLUSION AND GLOBAL HEALTH IMPLICATIONS: HIV prevalence among pregnant women was comparatively higher in Bangalore and Belgaum regions. Analysis of contextual factors associated with the transmission risk and evidence-based targeted interventions will strengthen HIV management in Karnataka. Regionalized, disaggregated, sub-national analyses will help identify emerging pockets of infections, concentrated epidemic zones and contextual factors driving the disease transmission.

Epidemiology of chikungunya based on laboratory surveillance data-India, 2016-2018.

BACKGROUND: We analysed the laboratory surveillance data generated by the network of virology laboratories from January 2016 to July 2018 to describe the epidemiology of chikungunya in India. METHODS: Suspected patients reporting to virology laboratories are investigated for the presence of immunoglobulin M (IgM) antibodies against chikungunya virus (CHIKV) as evidence of recent infection. We analysed the data to describe the distribution of seropositive individuals by time, place and demographic characteristics. RESULTS: Of the 49 380 sera tested from suspected patients, 20.5% were seropositive. CHIKV IgM positivity was seen throughout the year, with a peak between September and December. The laboratories diagnosed 28 outbreaks of chikungunya during the study period. CONCLUSIONS: Laboratory surveillance data indicate continued transmission of CHIKV in many regions of India.

Epidemiology of Hepatitis A and Hepatitis E Based on Laboratory Surveillance Data-India, 2014-2017.

Hepatitis A and hepatitis E viruses (HAV and HEV) are the most common etiologies of viral hepatitis in India. To better understand the epidemiology of these infections, laboratory surveillance data generated during 2014-2017, by a network of 51 virology laboratories, were analyzed. Among 24,000 patients tested for both HAV and HEV, 3,017 (12.6%) tested positive for HAV, 3,865 (16.1%) for HEV, and 320 (1.3%) for both HAV and HEV. Most (74.6%) HAV patients were aged ≤ 19 years, whereas 76.9% of HEV patients were aged ≥ 20 years. These laboratories diagnosed 12 HAV and 31 HEV clusters, highlighting the need for provision of safe drinking water and improvements in sanitation. Further expansion of the laboratory network and continued surveillance will provide data necessary for informed decision-making regarding introduction of hepatitis-A vaccine into the immunization program.