Severe disease during both primary and secondary dengue virus infections in pediatric populations.

Dengue is a global epidemic causing over 100 million cases annually. The clinical symptoms range from mild fever to severe hemorrhage and shock, including some fatalities. The current paradigm is that these severe dengue cases occur mostly during secondary infections due to antibody-dependent enhancement after infection with a different dengue virus serotype.

Analysis of dengue specific memory B cells, neutralizing antibodies and binding antibodies in healthy adults from India.

Background: The Indian population is facing highest dengue burden worldwide supporting an urgent need for vaccines. For vaccine introduction, evaluation and interpretation it is important to gain a critical understanding of immune memory induced by natural exposure. However, immune memory to dengue remains poorly characterized in this region.

Emergence of new genotypes and lineages of dengue viruses during the 2012-15 epidemics in southern India.

Objectives: To genotypically characterize dengue virus (DENV) isolates among dengue-infected children from 2012-13/2014-15 outbreaks in southern India.

Methods: Children hospitalized with suspected dengue were tested for dengue RT-PCR targeting Capsid-preMembrane (C-prM) and Envelope (Env) regions. Following virologic confirmation (n=612), a representative selection of DENV isolates (n=99) were sequenced for C-prM, aligned using ClustalW and subjected to phylogenetic analysis by maximum-likelihood method in MEGA6.

Correction: A High Malaria Prevalence Identified by PCR among Patients with Acute Undifferentiated Fever in India.

[This corrects the article DOI: 10.1371/journal.pone.

Enhancing the sensitivity of Dengue virus serotype detection by RT-PCR among infected children in India.

Dengue surveillance relies on reverse transcription-polymerase chain reaction (RT-PCR), for confirmation of dengue virus (DENV) serotypes. We compared efficacies of published and modified primer sets targeting envelope (Env) and capsid-premembrane (C-prM) genes for detection of circulating DENV serotypes in southern India. Acute samples from children with clinically-diagnosed dengue were used for RT-PCR testing.

Evaluation of a pan-serotype point-of-care rapid diagnostic assay for accurate detection of acute dengue infection.

The catastrophic rise in dengue infections in India and globally has created a need for an accurate, validated low-cost rapid diagnostic test (RDT) for dengue. We prospectively evaluated the diagnostic performance of NS1/IgM RDT (dengue day 1) using 211 samples from a pediatric dengue cohort representing all 4 serotypes in southern India. The dengue-positive panel consisted of 179 dengue real-time polymerase chain reaction (RT-PCR) positive samples from symptomatic children.

A High Malaria Prevalence Identified by PCR among Patients with Acute Undifferentiated Fever in India.

Background: Approximately one million malaria cases were reported in India in 2015, based on microscopy. This study aims to assess the malaria prevalence among hospitalised fever patients in India identified by PCR, and to evaluate the performance of routine diagnostic methods.

Methods: During June 2011-December 2012, patients admitted with acute undifferentiated fever to seven secondary level community hospitals in Assam (Tezpur), Bihar (Raxaul), Chhattisgarh (Mungeli), Maharashtra (Ratnagiri), Andhra Pradesh (Anantapur) and Tamil Nadu (Oddanchatram and Ambur) were included.

Norovirus Gastroenteritis in a Birth Cohort in Southern India.

Background: Noroviruses are an important cause of gastroenteritis but little is known about disease and re-infection rates in community settings in Asia.

Methods: Disease, re-infection rates, strain prevalence and genetic susceptibility to noroviruses were investigated in a birth cohort of 373 Indian children followed up for three years. Stool samples from 1856 diarrheal episodes and 147 vomiting only episodes were screened for norovirus by RT-PCR.

Characterization of hepatitis E virus from sporadic hepatitis cases and sewage samples from Vellore, south India.

Background: Hepatitis E virus (HEV) is endemic in India and causes epidemics and sporadic cases. However, the exact transmission route for sporadic hepatitis E remains unclear. This study investigated HEV in sporadic hepatitis cases and sewage samples, as sewage is the major source of contamination of water in developing countries.

Hepatitis E virus infections in swine and swine handlers in Vellore, Southern India.

Hepatitis E virus (HEV) in industrialized countries is zoonotically transmitted, and swine act as a major reservoir of HEV. Serum samples from 102 swine and plasma from 34 swine handlers in Vellore, India were tested by using a reverse transcription-polymerase chain reaction to detect and genotype HEV. We measured levels of IgG against HEV in swine handlers and in age and geographically matched controls from rural and urban populations in Vellore.

Investigation of an epidemic of Hepatitis E in Nellore in south India.

Objective: To determine the incidence of acute hepatitis because of hepatitis E virus (HEV) and the source of the epidemic in Nellore in south India in 2008.

Methods: Anti-HEV IgM ELISA and RT-PCR for HEV-RNA were carried out on blood and stool samples from patients with acute hepatitis presenting to different hospitals in the city. The city was divided into 33 clusters, and 20 families from each cluster were systematically interviewed to determine the incidence of hepatitis E in the city.

Seroprevalence of IgG antibodies to hepatitis E in urban and rural southern India.

Hepatitis E virus (HEV) is an important cause of sporadic and epidemic hepatitis E infection in northern India. Sera, collected from different age groups in rural (n=1144) and urban (n=1135) areas using a probability proportional to size survey, were tested using an ELISA for IgG antibodies. Antibodies increased with age in both populations, but the urban population had higher exposure in all age groups (Mann-Whitney U test, P<0.