Epidemiology of rotavirus diarrhea among children less than 5 years hospitalized with acute gastroenteritis prior to rotavirus vaccine introduction in India.

BACKGROUND: Rotavirus is an important cause of severe diarrhea requiring hospitalization, accounting for approximately 78,000 deaths annually in Indian children below 5 years of age. We present epidemiological data on severe rotavirus disease collected during hospital-based surveillance in India before the introduction of the oral rotavirus vaccine into the national immunization schedule. METHODS: The National Rotavirus Surveillance Network was created involving 28 hospital sites and 11 laboratories across the four geographical regions of India. From September 2012 to August 2016 children less than 5 years of age hospitalized for diarrhea for at least 6 h, were enrolled. After recording clinical details, a stool sample was collected from each enrolled child, which was tested for rotavirus antigen using enzyme immunoassay (EIA). Nearly 2/3rd of EIA positive samples were genotyped using reverse transcription polymerase chain reaction to identify the G and P types. RESULTS: Of the 21,421 children enrolled during the 4 years surveillance, 36.3% were positive for rotavirus. The eastern region had the highest proportion of rotavirus associated diarrhea (39.8%), while the southern region had the lowest (33.8%). Rotavirus detection rates were the highest in children aged 6-23 months (41.8%), and 24.7% in children aged < 6 months. Although rotavirus associated diarrhea was seen throughout the year, the highest positivity was documented between December and February across all the regions. The most common rotavirus genotype was G1P[8] (52.9%), followed by G9P4 (8.7%) and G2P4 (8.4%). CONCLUSIONS: There is high burden of rotavirus gastroenteritis among Indian children below 5 years of age hospitalized for acute diarrhea thereby highlighting the need for introduction of rotavirus vaccine into the national immunization program and also for monitoring circulating genotypes.

Diversity of rotavirus genotypes circulating in children < 5 years of age hospitalized for acute gastroenteritis in India from 2005 to 2016: analysis of temporal and regional genotype variation.

BACKGROUND: From 2016, the Government of India introduced the oral rotavirus vaccine into the national immunization schedule. Currently, two indigenously developed vaccines (ROTAVAC, Bharat Biotech; ROTASIIL, Serum Institute of India) are included in the Indian immunization program. We report the rotavirus disease burden and the diversity of rotavirus genotypes from 2005 to 2016 in a multi-centric surveillance study before the introduction of vaccines. METHODS: A total of 29,561 stool samples collected from 2005 to 2016 (7 sites during 2005-2009, 3 sites from 2009 to 2012, and 28 sites during 2012-2016) were included in the analysis. Stools were tested for rotavirus antigen using enzyme immunoassay (EIA). Genotyping was performed on 65.8% of the EIA positive samples using reverse transcription- polymerase chain reaction (RT-PCR) to identify the G (VP7) and P (VP4) types. Multinomial logistic regression was used to quantify the odds of detecting genotypes across the surveillance period and in particular age groups. RESULTS: Of the 29,561 samples tested, 10,959 (37.1%) were positive for rotavirus. There was a peak in rotavirus positivity during December to February across all sites. Of the 7215 genotyped samples, G1P[8] (38.7%) was the most common, followed by G2P[4] (12.3%), G9P[4] (5.8%), G12P[6] (4.2%), G9P[8] (4%), and G12P[8] (2.4%). Globally, G9P[4] and G12P[6] are less common genotypes, although these genotypes have been reported from India and few other countries. There was a variation in the geographic and temporal distribution of genotypes, and the emergence or re-emergence of new genotypes such as G3P[8] was seen. Over the surveillance period, there was a decline in the proportion of G2P[4], and an increase in the proportion of G9P[4]. A higher proportion of mixed and partially typed/untyped samples was also seen more in the age group 0-11 months. CONCLUSIONS: This 11 years surveillance highlights the high burden of severe rotavirus gastroenteritis in Indian children < 5 years of age before inclusion of rotavirus vaccines in the national programme. Regional variations in rotavirus epidemiology were seen, including the emergence of G3P[8] in the latter part of the surveillance. Having pre-introduction data is important to track changing epidemiology of rotaviruses, particularly following vaccine introduction.

Rotavirus gastroenteritis in Indian children < 5 years hospitalized for diarrhoea, 2012 to 2016.

BACKGROUND: In 2016, the Government of India introduced the oral rotavirus vaccine (ROTAVAC, Bharat Biotech, India) in 4 states of India as part of the Universal Immunization Programme, and expanded to 5 more states in 2017. We report four years of data on rotavirus gastroenteritis in hospitalized children < 5 years of age prior to vaccine introduction. METHODS: Children from 7 sites in southern and northern India hospitalized for diarrhoea were recruited between July 2012 and June 2016. Stool samples were screened for rotavirus using enzyme immunoassay (EIA). The EIA positive samples were genotyped by reverse-transcription polymerase chain reaction. RESULTS: Of the 5834 samples from the 7 sites, 2069 (35.5%) were positive for rotavirus by EIA. Genotyping was performed for 2010 (97.1%) samples. G1P[8](56.3%), G2P[4](9.1%), G9P[4](7.6%), G9P[8](4.2%), and G12P[6](3.7%) were the common genotypes in southern India and G1P[8](36%), G9P[4](11.4%), G2P[4](11.2%), G12P[6](8.4%), and G3P[8](5.9%) in northern India. CONCLUSIONS: The study highlights the high prevalence of rotavirus gastroenteritis in India and the diversity of rotavirus genotypes across different geographical regions. Pre- vaccine surveillance data is necessary to evaluate the potential change in admission rates for gastroenteritis and circulating rotavirus genotypes after vaccine introduction, thus assessing impact.

Clinical relevance of cagA and vacA and association with mucosal findings in Helicobacter pylori-infected individuals from Chennai, South India.

Helicobacter pylori is associated with a spectrum of severe gastrointestinal conditions. In this study, an attempt was made to correlate endoscopic mucosal patterns with H. pylori infection and examine the pathogenic potential of the strains. Among the 147 dyspeptic individuals studied, 42.2% were H. pylori infected. Association of H. pylori with type 3 and 4 mucosal patterns (P = 0.001) and intestinal metaplasia (P = 0.012) was seen. vacA was associated with histological (P = 0.014) and endoscopy findings (P = 0.009). Association of mucosal patterns with H. pylori infection could be useful for clinicians to decide on the need for eradication therapy.

Intussusception hospitalizations before rotavirus vaccine introduction: Retrospective data from two referral hospitals in Tamil Nadu, India.

BACKGROUND: The indigenous oral rotavirus vaccine Rotavac® was introduced into the public immunization system in India in 2016 and will be expanded in phases. This data will describe the epidemiology of intussusception in India in absence of rotavirus vaccination and will help in setting up or designing a safety monitoring system. METHODS: Medical records of intussusception cases between 2013 and 2016 in two major referral hospitals in Tamil Nadu, India were reviewed, and data on clinical presentation and management and outcome were collated. RESULTS: A total of 284 cases of intussusception were diagnosed and managed at the two centers of which 280/284 could be classified as level 1 by the Brighton criteria. Median age at presentation was 8 months (Inter Quartile Range, IQR 6-17.2) with a male to female ratio of 2.1:1. Over half (57.7%) required surgical intervention while the rest underwent non-surgical or conservative management. CONCLUSIONS: Retrospective data from referral hospitals is sufficient to classify cases of intussusception by the Brighton criteria. These baseline data will be useful for monitoring when rotavirus vaccination is introduced.

IL-21-dependent expansion of memory-like NK cells enhances protective immune responses against Mycobacterium tuberculosis.

Natural killer (NK) cells are traditionally considered as innate cells, but recent studies suggest that NK cells can distinguish antigens, and that memory NK cells expand and protect against viral pathogens. Limited information is available about the mechanisms involved in memory-like NK cell expansion, and their role in bacterial infections and vaccine-induced protective immune responses. In the current study, using a mouse model of tuberculosis (TB) infection, we found that interferon-gamma producing CD3-NKp46+CD27+KLRG1+ memory-like NK cells develop during Bacille Calmette-Guérin vaccination, expand, and provide protection against challenge with Mycobacterium tuberculosis (M. tb). Using antibodies, short interfering RNA and gene-deleted mice, we found that expansion of memory-like NK cells depends on interleukin 21 (IL-21). NKp46+CD27+KLRG1+ NK cells expanded in healthy individuals with latent TB infection in an IL-21-dependent manner. Our study provides first evidence that memory-like NK cells survive long term, expansion depends on IL-21, and involved in vaccine-induced protective immunity against a bacterial pathogen.

Expanded Indian National Rotavirus Surveillance Network in the Context of Rotavirus Vaccine Introduction.

OBJECTIVE: To extend a nation-wide rotavirus surveillance network in India, and to generate geographically representative data on rotaviral disease burden and prevalent strains. DESIGN: Hospital-based surveillance. SETTING: A comprehensive multicenter, multi-state hospital based surveillance network was established in a phased manner involving 28 hospital sites across 17 states and two union territories in India. PATIENTS: Cases of acute diarrhea among children below 5 years of age admitted in the participating hospitals. RESULTS: During the 28 month study period between September 2012 and December 2014, 11898 children were enrolled and stool samples from 10207 children admitted with acute diarrhea were tested; 39.6% were positive for rotavirus. Highest positivity was seen in Tanda (60.4%) and Bhubaneswar (60.4%) followed by Midnapore (59.5%). Rotavirus infection was seen more among children aged below 2 years with highest (46.7%) positivity in the age group of 12-23 months. Cooler months of September to February accounted for most of the rotavirus associated gastroenteritis, with highest prevalence seen during December to February (56.4%). 64% of rotaviru -infected children had severe to very severe disease. G1 P[8] was the predominant rotavirus strain (62.7%) during the surveillance period. CONCLUSION: The surveillance data highlights the high rotaviral disease burden in India. The network will continue to be a platform for monitoring the impact of the vaccine.

Profile and Trends of Rotavirus Gastroenteritis in Under 5 children in India, 2012 - 2014, Preliminary Report of the Indian National Rotavirus Surveillance Network.

OBJECTIVE: To estimate the burden of rotavirus-associated gastroenteritis in India. METHODS: Hospital based surveillance network was established, with clinical evaluation and laboratory testing for rotavirus among children aged below 5 years hospitalized with acute gastroenteritis. RESULTS: Between September 2012 and December 2014, stool samples from 10207 children were tested and rotavirus was detected in 39.6% of cases. Infections were more commonly seen among younger children (<2 years). Detection rates were higher during cooler months of September February. Among rotavirus infected children, 64.0% had severe or very severe disease. G1P[8] was the predominant rotavirus genotype (62.7%) observed during the surveillance period. CONCLUSIONS: Surveillance data highlights the high rotavirus disease burden and emphasizes the need for close monitoring to reduce morbidity and mortality associated with rotavirus gastroenteritis in India.

Interpretation of Rotavirus positivity Patterns Across India.

OBJECTIVE: To analyze variation in rotavirus-positivity using simple alternative statistical measures. METHODS: Hospital-based rotavirus surveillance among children admitted with acute gastroenteritis between 2005 and 2009. Prevalence, adjusted proportions and symmetrized index were calculated. RESULTS: Rotavirus prevalence was 40% (range 37% - 44%). Adjusted proportion analysis revealed higher level of deviation from annual prevalence in seasons (December to February and September to November); age groups (<12 months and 12-23 months) and regions (East and South). Analysis of symmetrized index revealed higher estimates of variation in all years, except in 2006. CONCLUSIONS: Proposed statistical measures are useful as refined measures to study extent of disease spread in surveillance programmes, aiding evaluation of the load and pattern of disease burden in different regions over time.

Intussusception in Children Aged Less than Five years.

OBJECTIVE: To enumerate the cases of intussusception in Chennai during 2012-2013, describe the clinical profile, outcomes of case management and highlight the importance of systematically collecting this data in lieu of rotavirus vaccine introduction in India. METHODS: Medical records of pediatric intussusception cases admitted in eight large hospitals in Chennai from July 2012 through June 2013 were retrospectively reviewed. Demographic and clinical data including diagnostic and treatment practices were obtained. Cases were categorized based on the diagnostic certainty criteria stipulated by the Brighton collaboration on intussusception. RESULTS: During the one year of study period, 205 cases of intussusception were diagnosed in 8 hospitals in Chennai city of India. The median age at presentation was 9 mo (Inter Quartile Range, IQR 6-14) with a male to female ratio of 1.8:1. The commonest site of intussusception was ileocolic (80.4 %). Most of the cases (59.8 %) were managed non-surgically. Direct surgical intervention was carried out in 26.5 % cases whereas in 11.8% of cases, surgery was required after failure of non-surgical measures. Median duration of hospital stay was 3 d (IQR 1-5). CONCLUSIONS: This study documents the case burden of intussusception among children in Chennai in a calendar year. Data on receipt of rotavirus vaccine was not available. The authors recommend collection of rotavirus vaccine data among all cases of intussusception in the country, and do retrospective analysis in other parts of the country and prospective surveillance in pediatric / immunization clinics to assess impact of rotavirus vaccine on intussusception rates in the post rotavirus vaccine introduction scenario.

Genotoxicity in agricultural farmers from Guntur district of South India--A case study.

BACKGROUND: Pesticides play an important role in controlling the pests on agricultural crops and thereby to increase the yield of agricultural produce. Farmers occupationally exposed to pesticides during spraying activities are more prone to genotoxicity than unexposed. AIM: To assess the genotoxicity in farmers, engaged in spraying complex mixture of pesticides in the cultivation of cotton crops. MATERIAL AND METHODS: A total number of 152 male subjects were selected randomly from Guntur district of Andhra Pradesh (AP), South India. The demographic particulars viz., personal habits, duration of exposure to pesticides, types of pesticides used were collected from the study subjects using an interview schedule. Among them 76 subjects were farmers and the remaining individuals served as unexposed or controls. Blood samples from these subjects were collected for assessing the genetic damage by chromosomal aberrations (CAs) test and micronucleus test (MNT). RESULTS: The results of the study indicated that CA was significantly higher with 2.8% in farmers who were exposed to pesticides when compared to unexposed (0.72%). However, there was a minor difference in MN with 0.13% and 0.12% between exposed and unexposed which was not statistically significant (p < 0.05). CONCLUSION: A correlation between CA frequency and exposure to benzene hexachloride (BHC) pesticide residue was observed.

Lot quality assurance sampling for monitoring immunization coverage in Madras City.

OBJECTIVE: To explore the usefulness of Lot Quality Assurance Sampling (LQAS) to identify divisions in a city that had immunization coverage levels of 80% for any of the four EPI vaccines. METHODS: Only 43 divisions were considered for the study, the stratification factor being the death rate. The hypothesis that 80% coverage is 'unacceptable' was stipulated. Critical value (the number of unimmunized children) was chosen as 3. A simple random sample of 36 children in the age-group 12-23 months was taken from each selected division. Since sampling frames of children were not available, a simple random sample of 36 households was selected. Immunization status of each child was assessed by interviewing the child's mother/guardian. If the number of unimmunized children exceeded 3, then the division was regarded having coverage level 80% and rejected. RESULTS: The coverage was classified as unacceptable(i. e., below 80%) in 19 divisions for Polio and DPT vaccines, in 26 divisions for Measles vaccine and in 4 divisions for BCG vaccine. The average time spent for undertaking the LQAS survey was 6 man-days per division. CONCLUSION: This study demonstrated the utility of the LQAS technique in identifying 'unsatisfactory' pockets in Madras City, when the overall coverage was satisfactory. The technique will have greater application with an increase in the number of large units (cities/districts) having an overall coverage of 90% or more.

A concurrent comparison of a WHO-recommended 30-cluster survey and a modified version of it under Indian conditions in the estimation of immunization coverages.

A concurrent comparison of the WHO 30-cluster sample survey method for estimating immunization coverages (DPT, Polio, BCG, Measles) and an Indian modification of (GOI) was undertaken in five districts in South India. The essential difference between the two methods is the manner in which the first household is selected in the chosen clusters. With the WHO method, it is chosen clusters. With the WHO method, it is chosen at random, whereas with the GOI method it is often close to the village centre. Estimates with the required degree of precision, i.e., 95% confidence limits of +/- 10 percentage points, were provided in 18 (90%) of 20 instances by the WHO method and in 19 (95%) by the GOI method, findings which are in accordance with expectation. The estimated coverages were, however, higher by the GOI method than by the WHO method in two districts, lower in one district, and in the remaining two districts there was no clear pattern. On the average, there was a suggestion that the GOI method yielded slightly higher coverages, but the differences were not statistically significant.

A comparison of a 30-cluster survey method used in India and a purposive method in the estimation of immunization coverages in Tamil Nadu.

A 30-cluster survey method that is employed for estimating immunization coverages by the Government of India (GOI) was compared with a Purposive method, to investigate whether the likely omission of SC/ST and backward classes in the former would lead to the reporting of higher coverages. The essential difference between the two methods is in the manner in which the first household is selected in the chosen first stage sampling units (villages). With the GOI method, it is often close to the village centre, whereas with the Purposive method it is always in the periphery or in a pocket consisting of SC/ST or backward classes. A concurrent comparison of the two methods in three districts in Tamil Nadu showed no real differences in the coverage with DPT and BCG vaccines. However, the coverage was consistently higher by the GOI method in the case of the Polio vaccine (by 1.5%, 3.1% and 5.3% in the 3 districts), and the Measles vaccine (by 4.8%, 13.3% and 13.9%); the average difference was 3.3% for Polio vaccine (p = 0.08) and 7.3% for Measles vaccine (p = 0.01).

Estimation of immunisation coverages in children by WHO 30-cluster survey.

A WHO 30-cluster survey for estimating immunisation coverages in infancy was undertaken in each of 5 districts in Tamil Nadu, strictly according to the specifications laid out in the WHO manual. The main aim was to examine whether the technique would provide estimates with the required degree of precision under Indian conditions. Of 60 sample survey estimates, 57 had the targeted degree of precision (i.e., 95% confidence limits of +/- 10 percentage points), which is in excellent agreement with expectation. The proportions of infants on whom immunisation was initiated, were very high for DPT vaccine (88-99%) and polio vaccine (85-99%); however, of those who had received the first dose, 23-39 per cent did not complete the 3-dose schedule. Estimated coverage with measles vaccine ranged from 15 to 54 per cent, while BCG coverage ranged from 53 to 97 per cent. Better health education regarding the need and correct age for immunisation, and more effective motivation at the time of administration of the first dose of DPT/polio vaccine, are recommended.