Foodborne Outbreak by Salmonella enterica Serovar Weltevreden in West Bengal, India.

Foodborne gastroenteritis outbreaks owing to Salmonella enterica serovar Weltevreden (Salmonella Weltevreden) represent a significant global public health problem. In the past two decades, Salmonella Weltevreden has emerged as a dominant foodborne pathogen, especially in South-East Asian countries. This report describes a community foodborne outbreak of gastroenteritis caused by Salmonella Weltevreden in August 2022 following consumption of panipuri from a street vendor in the Polba block in Hooghly district, West Bengal, India. This food item was consumed by 185 people, of whom 129 had acute watery diarrhea with other clinical symptoms and 65 of them were admitted to different District hospitals for treatment. Stool specimens collected from hospitalized cases were positive for S. enterica, and further serotyped as Salmonella Weltevreden. All the Salmonella Weltevreden strains possessed the Salmonella pathogenicity islands associated genes (invA/E, orgA, ttrc, ssaQ, mgtC, misL, spi4D), the enterotoxin (stn), and hyperinvasive locus gene (hilA). Except erythromycin, all the strains were susceptible for commonly used antimicrobials in the treatment of diarrhea. The XbaI-based pulsed-field gel electrophoresis analysis indicated that all the isolates responsible for the recent outbreak were similar, but diverged from other Salmonella Weltevreden that were previously reported in West Bengal. This report indicates that foodborne infection is a major public health concern in India and demands to strengthen capacity-building measures at the local health care levels for linking causative agents of outbreaks.

Diagnostic validation study of rapid urinary tract infection diagnosis kit at peripheral health facilities of West Bengal, India.

Patients reporting to the outpatient departments of peripheral health care settings in India with symptoms of urinary tract infection (UTI) receive one or the other antibiotic before culture confirmation and out of the total culture confirmed UTI cases, in less than one third cases the prescribed antibiotics matches to the antibiotic sensitivity test result. Hence, in this study, an indigenous point-of-care (POCT) rapid diagnostic kit (Rapidogram) for UTI was validated against conventional urine culture and sensitivity to understand its possible applicability at peripheral health care settings. This cross-sectional study was conducted during November 2021 to June 2022 in OPDs of two peripheral hospitals. A sample size of 300 was calculated using prevalence of urinary tract infection (UTI) as 33% for sensitivity and specificity using Buderer's formula. Urine specimens were collected following standard aseptic procedures from the recruited suspected UTI cases and transferred to laboratory maintaining the cold chain. The validation work up was done in two sections: lab validation and field validation. Out of 300 urine samples, 29 were found positive for the growth of UTI pathogen by both methods and 267 were found negative by both methods. Thus, the kit shows very high specificity (99.6%; 97.9-99.9%) and considerably high sensitivity (90.6%; 74.9-98.0%). We also observed higher PPV, NPV, test accuracy (> 96%). Diagnostic Odds Ratio and Youden index were respectively 2581 and 0.89. Clinical data showed that 44% of the suspected UTI cases were prescribed at least one antibiotic before urine test. Mostly they received Norfloxacin whereas the mostly identified organism E.coli was sensitive to Nitrofurantoin. In the context of absence of microbiology facility at peripheral setting and rampant empirical use of antibiotics in UTI, this highly specific and sensitive POCT for UTI may be used as it not only identifies the organism, also shows the antibiotic sensitivity pattern.

Existing Policies/Guidelines on the Environmental Dimension of Antimicrobial Resistance in India: An Insight into the Key Facets through Review and SWOT Analysis.

BACKGROUND: Antimicrobial resistance (AMR) is a multidimensional phenomenon. The environment acts as a mixing pot of drug-resistant bacteria from many sources such as pharmaceutical, biomedical, veterinary, and agricultural sectors. In this study, we analysed the existing AMR-related policies/guidelines/legislations in India in the above domains and how the current practices are being guided by them. METHODS: We used a convergent parallel mix method design. Quantitative data were collected through a review of policies/guidelines/legislations in the said domains and analysed using the SWOT tool parallelly supported by key informant interviews of domain-specific stakeholders. RESULTS: Altogether, 19 existing AMR policies/guidelines/legislations were identified. The existence of few policies/guidelines in each domain indicated the evolving environment for policy interventions. However, the lack of capacity among farmers, inadequate provision for structured capacity building, high cost of alternatives to antimicrobials, and lack of provision of incentivisation in case of crop failure were identified as the major weaknesses prevalent across the domains. Opportunities for policy refinements/the introduction of new policies are ample. However, easy access to antimicrobials and injudicious use imposes threats to AMR containment in all sectors. CONCLUSIONS: Despite having a few policies for the containment of AMR, their implementation witnesses challenge due to the lack of collaborative approaches, the existence of policies disjointed from ground reality, infrastructural issues, and the lack of capacity and resources.

Altered molecular attributes and antimicrobial resistance patterns of Vibrio cholerae O1 El Tor strains isolated from the cholera endemic regions of India.

AIMS: The present study aimed to document the comparative analysis of differential hypervirulent features of Vibrio cholerae O1 strains isolated during 2018 from cholera endemic regions in Gujarat and Maharashtra (Western India) and West Bengal (Eastern India). METHODS AND RESULTS: A total of 87 V. cholerae O1 clinical strains from Western India and 48 from Eastern India were analysed for a number of biotypic and genotypic features followed by antimicrobial resistance (AMR) profile. A novel polymerase chain reaction was designed to detect a large fragment deletion in the Vibrio seventh pandemic island II (VSP-II) genomic region, which is a significant genetic feature of the V. cholerae strains that have caused Yemen cholera outbreak. All the strains from Western India belong to the Ogawa serotype, polymyxin B-sensitive, hemolytic, had a deletion in VSP-II (VSP-IIC) region and carried Haitian genetic alleles of ctxB, tcpA and rtxA. Conversely, 14.6% (7/48) of the strains from Eastern India belonged to the Inaba serotype, polymyxin B-resistant, nonhemolytic, harboured VSP-II other than VSP-IIC type, classical ctxB, Haitian tcpA and El Tor rtxA alleles. Resistance to tetracycline and chloramphenicol has been observed in strains from both regions. CONCLUSIONS: This study showed hypervirulent, polymyxin B-sensitive epidemic causing strains in India along with the strains with polymyxin B-resistant and nonhemolytic traits that may spread and cause serious disease outcomes in future. SIGNIFICANCE AND IMPACT OF THE STUDY: The outcomes of this study can help to improve the understanding of the hyperpathogenic property of recently circulating pandemic Vibrio cholerae strains in India. Special attention is also needed for the monitoring of AMR surveillance because V. cholerae strains are losing susceptibility to many antibiotics used as a second line of defence in the treatment of cholera.

Distribution of virulence factors and its relatedness towards the antimicrobial response of enterotoxigenic Escherichia coli strains isolated from patients in Kolkata, India.

AIM: Enterotoxigenic Escherichia coli (ETEC) is one of the most widely recognized diarrhoeal pathogens in developing countries. The advancement of ETEC vaccine development depends on the antigenic determinants of the ETEC isolates from a particular geographical region. So, the aim here was to comprehend the distribution of virulence determinants of the clinical ETEC strains of this region. Additionally, an attempt was made to find any correlation with the antimicrobial response pattern. METHODS AND RESULTS: Multiplex PCR was employed to identify virulence determinants followed by confirmatory singleplex PCR. For observation of antibiotic response, the Kirby-Bauer method was used. Out of 379 strains, 46% of strains harboured both the enterotoxins ST and LT, whereas 15% were LT only. Among the major colonization factors (CFs), CS6 (41%) was the most prevalent followed by CFA/I (35%) and CFA/III was the lowest (3%). Among the minor CFs, CS21 (25%) was most prevalent, while CS15 showed the lowest (3%) presence. Among the non-classical virulence factors, EatA (69%) was predominant. ETEC strains harbouring CS6 showed resistance towards the commonly used drug Ciprofloxacin (70%). CONCLUSION: CS6 and elt+est toxin genes co-occurred covering 51% of the isolates. CS21 was found in most strains with est genes (43%). EatA was found to occur frequently when ST was present alone or with LT. CS6-harbouring strains showed an independent correlation to antimicrobial resistance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study would aid in identifying the commonly circulating ETEC isolates of Kolkata, India, and their prevalent virulence determinants. Knowledge of antibiotic resistance patterns would also help in the appropriate use of antibiotics. Furthermore, the study would aid in identifying the multivalent antigens suitable for region-specific ETEC vaccines with maximum coverage.

Increased human-animal interface & emerging zoonotic diseases: An enigma requiring multi-sectoral efforts to address.

Increased human-animal interfaces impose threats on human life by creating scope for the emergence and resurgence of many infectious diseases. Over the last two decades, emergence of novel viral diseases such as SARS, influenza A/H1N1(09) pdm; MERS; Nipah virus disease; Ebola haemorrhagic fever and the current COVID-19 has resulted in massive outbreaks, epidemics and pandemics thereby causing profound losses of human life, health and economy. The current COVID-19 pandemic has affected more than 200 countries, reporting a global case load of 167,878,000 with 2 per cent mortality as on May 26, 2021. This has highlighted the importance of reducing human- animal interfaces to prevent such zoonoses. Rapid deforestation, shrinking of boundaries between human and animal, crisis for natural habitation, increasing demands for wildlife products and threat of extinction compounded by biodiversity narrowing compel to increased human-animal conflict and contact. Large quantities of animal waste generated due to animal agriculture may also allow rapid selection, amplification, dissemination of zoonotic pathogens and facilitate zoonotic pathogen adaptation and hinder host evolution for resistance. Public health system faces challenges to contain such epidemics due to inadequate understanding, poor preparedness, lack of interdisciplinary approach in surveillance and control strategy and deficient political commitments. Because the management measures are beyond the purview of health system alone, policy-level adaptation in the transdisciplinary issues are required, emphasizing the engagement of multiple stakeholders towards wildlife protection, alternative land use, community empowerment for natural resource management and regulation on business of wildlife products to ensure comprehensive one health practice.

Genetic characterization and evolutionary analysis of norovirus genotypes circulating among children in eastern India during 2018-2019.

Noroviruses are significant etiological agents of acute gastroenteritis (AGE) across all age groups, especially in children under 5 years of age. Although the prevalence of norovirus infection is known to have increased in various countries, in India there are few reports pertaining to the norovirus disease burden. We investigated the epidemiology and molecular characteristics of noroviruses in children seeking health care at two hospitals in Kolkata, Eastern India. Faecal specimens were collected between January 2018 and December 2019 from 2812 children under 5 years of age with acute gastroenteritis. Noroviruses were detected in 6.04% (170/2812) of the samples, and 12.9% (22/170) of these were cases of coinfection with rotavirus. Among children (≤5 years), a higher infection rate (8.2%, n = 94/1152) was observed in the 6 to 12 month age group. GII.4 Sydney 2012 was the dominant norovirus capsid genotype (n = 75/90, 83.3%), followed by GII.3 (n = 10/90, 11.1%). Other capsid types GII.13 (n = 4/90, 4.4%) and GII.17 (n = 1/90; 1.1%) were also detected at low frequency. Phylogenetic analysis showed that the GII.P16 polymerase of strains in this region clustered with those of the phylogenetically distinct monophyletic clade of GII.P16 strains, whose members have been circulating worldwide since 2014. Inter-genotypic norovirus recombinants such as GII.P16-GII.3 (n = 10) and GII.P16-GII.13 (n = 4) were also observed among the circulating strains. In comparison to previous studies from eastern India, the present study shows a higher detection rate of norovirus infection in the paediatric population suffering from acute gastroenteritis. Continuous surveillance is required for predicting the emergence of novel genotypes and recombinant strains and for future vaccine development.

Genetic characterization and phylogenetic variations of human adenovirus-F strains circulating in eastern India during 2017-2020.

Human adenovirus-F (HAdV-F) (genotype 40/41) is the second-most leading cause of pediatric gastroenteritis after rotavirus, worldwide, accounting for 2.8%-11.8% of infantile diarrheal cases. Earlier studies across eastern India revealed a shift in the predominance of genotypes from HAdV41 in 2007-09 to HAdV40 in 2013-14. Thus, the surveillance for HAdV-F genotypes in this geographical setting was undertaken over 2017-2020 to analyze the viral evolutionary dynamics. A total of 3882 stool samples collected from children (≤5 years) were screened for HAdV-F positivity by conventional PCR. The hypervariable regions of the hexon and the partial shaft region of long fiber genes were amplified, sequenced, and phylogenetically analyzed with respect to the prototype strains. A marginal decrease in enteric HAdV prevalence was observed (9.04%, n = 351/3882) compared to the previous report (11.8%) in this endemic setting. Children <2 years were found most vulnerable to enteric HAdV infection. Reduction in adenovirus-rotavirus co-infection was evident compared to the sole adenovirus infection. HAdV-F genotypes 40 and 41 were found to co-circulate, but HAdV41 was predominant. HAdV40 strains were genetically conserved, whereas HAdV41 strains accumulated new mutations. On the basis of a different set of mutations in their genome, HAdV41 strains segregated into 2 genome type clusters (GTCs). Circulating HAdV41 strains clustered with GTC1 of the fiber gene, for the first time during this study period. This study will provide much-needed baseline data on the emergence and circulation of HAdV40/41 strains for future vaccine development.

SARS-CoV-2 seroprevalence among the general population and healthcare workers in India, December 2020-January 2021.

BACKGROUND: Earlier serosurveys in India revealed seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) of 0.73% in May-June 2020 and 7.1% in August-September 2020. A third serosurvey was conducted between December 2020 and January 2021 to estimate the seroprevalence of SARS-CoV-2 infection among the general population and healthcare workers (HCWs) in India. METHODS: The third serosurvey was conducted in the same 70 districts as the first and second serosurveys. For each district, at least 400 individuals aged ≥10 years from the general population and 100 HCWs from subdistrict-level health facilities were enrolled. Serum samples from the general population were tested for the presence of immunoglobulin G (IgG) antibodies against the nucleocapsid (N) and spike (S1-RBD) proteins of SARS-CoV-2, whereas serum samples from HCWs were tested for anti-S1-RBD. Weighted seroprevalence adjusted for assay characteristics was estimated. RESULTS: Of the 28,598 serum samples from the general population, 4585 (16%) had IgG antibodies against the N protein, 6647 (23.2%) had IgG antibodies against the S1-RBD protein, and 7436 (26%) had IgG antibodies against either the N protein or the S1-RBD protein. Weighted and assay-characteristic-adjusted seroprevalence against either of the antibodies was 24.1% [95% confidence interval (CI) 23.0-25.3%]. Among 7385 HCWs, the seroprevalence of anti-S1-RBD IgG antibodies was 25.6% (95% CI 23.5-27.8%). CONCLUSIONS: Nearly one in four individuals aged ≥10 years from the general population as well as HCWs in India had been exposed to SARS-CoV-2 by December 2020.

Determinants of optimum exclusive breastfeeding duration in rural India: a mixed method approach using cohort and content analysis design.

BACKGROUND: Despite established benefits, exclusive breastfeeding (EBF) rate remains poor in India. This study measured the rate of early initiation of breastfeeding and EBF up to 42 days postpartum period and the reasons associated with early interruption of it. METHODS: In this study we followed a cohort 319 mother-newborn dyads, on a scheduled day of each week for six postpartum weeks (42 postpartum days), during May 2017 - March 2019. We used standard maternal 24 h recall method to collect data on newborn feeding practices. Additionally, using content the analysis method, we analysed the data captured through open ended question on current breastfeeding practice and reasons to identify the sociocultural facilitators/barriers of exclusive breastfeeding . RESULTS: Of the retained 306 newborns, early initiation of breastfeeding rate was 60% (184/306), whereas, EBF rate was 47% (143/306). Mothers' educational level did not emerge as a risk for unsuccessful breastfeeding practices, whereas, father being not the major earner of the family (Relative risk [RR] 2.4; 95% Confidence interval [CI] 1.7,3.3), mothers who did not believe that effect of breastfeeding is longstanding (RR 1.8; 95% CI 1.3, 2.1) emerged as a risk for unsuccessful EBF practices. Lack of self-conviction about EBF among mothers; significant family members' influence; cultural beliefs; emerged as major socio-environmental barriers of early interruption of exclusive breastfeeding. Repeated counselling by the healthcare provider particularly focusing on exclusive breastfeeding, supportive family environment in terms of the elders being aware of the positive health outcomes of it, and prior positive experience emerged as the socio-environmental facilitators for successful EBF until 42 postpartum days. CONCLUSIONS: We conclude that the socio-environmental causes need to be addressed through the present healthcare delivery system for ensuring better infant feeding outcome.

SARS-CoV-2 antibody seroprevalence in India, August-September, 2020: findings from the second nationwide household serosurvey.

BACKGROUND: The first national severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurvey in India, done in May-June, 2020, among adults aged 18 years or older from 21 states, found a SARS-CoV-2 IgG antibody seroprevalence of 0·73% (95% CI 0·34-1·13). We aimed to assess the more recent nationwide seroprevalence in the general population in India. METHODS: We did a second household serosurvey among individuals aged 10 years or older in the same 700 villages or wards within 70 districts in India that were included in the first serosurvey. Individuals aged younger than 10 years and households that did not respond at the time of survey were excluded. Participants were interviewed to collect information on sociodemographics, symptoms suggestive of COVID-19, exposure history to laboratory-confirmed COVID-19 cases, and history of COVID-19 illness. 3-5 mL of venous blood was collected from each participant and blood samples were tested using the Abbott SARS-CoV-2 IgG assay. Seroprevalence was estimated after applying the sampling weights and adjusting for clustering and assay characteristics. We randomly selected one adult serum sample from each household to compare the seroprevalence among adults between the two serosurveys. FINDINGS: Between Aug 18 and Sept 20, 2020, we enrolled and collected serum samples from 29 082 individuals from 15 613 households. The weighted and adjusted seroprevalence of SARS-CoV-2 IgG antibodies in individuals aged 10 years or older was 6·6% (95% CI 5·8-7·4). Among 15 084 randomly selected adults (one per household), the weighted and adjusted seroprevalence was 7·1% (6·2-8·2). Seroprevalence was similar across age groups, sexes, and occupations. Seroprevalence was highest in urban slum areas followed by urban non-slum and rural areas. We estimated a cumulative 74·3 million infections in the country by Aug 18, 2020, with 26-32 infections for every reported COVID-19 case. INTERPRETATION: Approximately one in 15 individuals aged 10 years or older in India had SARS-CoV-2 infection by Aug 18, 2020. The adult seroprevalence increased approximately tenfold between May and August, 2020. Lower infection-to-case ratio in August than in May reflects a substantial increase in testing across the country. FUNDING: Indian Council of Medical Research.

Prevalence of SARS-CoV-2 infection in India: Findings from the national serosurvey, May-June 2020.

BACKGROUND & OBJECTIVES: Population-based seroepidemiological studies measure the extent of SARS-CoV-2 infection in a country. We report the findings of the first round of a national serosurvey, conducted to estimate the seroprevalence of SARS-CoV-2 infection among adult population of India. METHODS: From May 11 to June 4, 2020, a randomly sampled, community-based survey was conducted in 700 villages/wards, selected from the 70 districts of the 21 States of India, categorized into four strata based on the incidence of reported COVID-19 cases. Four hundred adults per district were enrolled from 10 clusters with one adult per household. Serum samples were tested for IgG antibodies using COVID Kavach ELISA kit. All positive serum samples were re-tested using Euroimmun SARS-CoV-2 ELISA. Adjusting for survey design and serial test performance, weighted seroprevalence, number of infections, infection to case ratio (ICR) and infection fatality ratio (IFR) were calculated. Logistic regression was used to determine the factors associated with IgG positivity. RESULTS: Total of 30,283 households were visited and 28,000 individuals were enrolled. Population-weighted seroprevalence after adjusting for test performance was 0.73 per cent [95% confidence interval (CI): 0.34-1.13]. Males, living in urban slums and occupation with high risk of exposure to potentially infected persons were associated with seropositivity. A cumulative 6,468,388 adult infections (95% CI: 3,829,029-11,199,423) were estimated in India by the early May. The overall ICR was between 81.6 (95% CI: 48.3-141.4) and 130.1 (95% CI: 77.0-225.2) with May 11 and May 3, 2020 as plausible reference points for reported cases. The IFR in the surveyed districts from high stratum, where death reporting was more robust, was 11.72 (95% CI: 7.21-19.19) to 15.04 (9.26-24.62) per 10,000 adults, using May 24 and June 1, 2020 as plausible reference points for reported deaths. INTERPRETATION & CONCLUSIONS: Seroprevalence of SARS-CoV-2 was low among the adult population in India around the beginning of May 2020. Further national and local serosurveys are recommended to better inform the public health strategy for containment and mitigation of the epidemic in various parts of the country.

Exploring Repurposing Potential of Existing Drugs in the Management of COVID-19 Epidemic: A Critical Review.

Despite high morbidity and mortality of ongoing coronavirus disease 2019 (COVID-19) pandemic, no specific therapy has been established till date. Though in vitro studies identified various molecules as possible therapies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), these findings call for substantiation by human studies. We conducted this review aiming at reporting evidences on therapies used so far globally for management of COVID-19 in clinical settings. We searched electronic databases as PubMed, Google Scholar, EMBASE and extracted 612 possible studies as on May 31, 2020. We included original studies of any epidemiological design done on human COVID-19 patients and measured clinical outcomes. Finally, following removal of duplicates and studies meeting exclusion criteria, we derived 22 studies, of which eight were clinical trials, seven were case reports and case series, and seven were observational studies. The most reported therapies were hydroxychloroquine (HCQ) (eight studies) and lopinavir/ritonavir (four studies). We conclude from the evidence generated so far that interferon combined with antivirals, remdesivir, umifenovir and favipiravir were mostly associated with better clinical outcomes. The therapeutic effect of HCQ was established initially by two clinical trials; one of them showing a reinforcing effect by azithromycin but subsequent studies did not elicit any effectiveness rather increased rate of adverse events was reported. Lopinavir/ritonavir was found beneficial when administered with interferon and ribavirin, but one clinical trial on its sole use proved contrary. As many clinical trials are in process, we expect to get concrete evidences on repurposing of existing drugs based on less biased, high powered studies.

First report of human rotavirus G8P[4] gastroenteritis in India: evidence of ruminants-to-human zoonotic transmission.

Group A rotaviruses are the major cause of childhood gastroenteritis worldwide. Due to close proximity of human and cattle in rural areas of developing countries like India, interspecies transmission or zoonotic transmission is a major source of rapid generation of reassortants and genetic or antigenic variants. Previously, many human group A rotaviruses were found with porcine or bovine characteristics from eastern and north-eastern India. In this study, four unusual human G8P[4] strains were identified which had artiodactyl-like origins. During an ongoing community based surveillance for epidemiological profiling of diarrheal pathogens, these unusual human group A rotavirus G8P[4] strains were detected from the stool samples of 3-14 months old children with acute diarrhea in Sonarpur, eastern India. Analysis of eleven complete and/or partial gene segments of these unusual G8P[4] strains were done by reverse transcription-PCR (RT-PCR) followed by nucleotide sequencing and phylogenetic analysis. The VP7 nucleotide sequences revealed a close phylogenetic relationship to the G8P[7] porcine strain D-1 and bovine strain KJ59-2 from South Korea. Whereas the VP4 gene segments were also related closely to human rotavirus prototype strain DS-1. Other nine gene segments of these G8P[4] rotaviruses were related closely to either animal or animal-derived rotavirus members of the DS-1-like family. These results suggest that origin of these G8P[4] strains might have been resulted from multiple reassortment events between artiodactyls and ruminant-derived reassortant human rotaviruses. To date, this is the first report of G8P[4] rotavirus from India and the first genomic analysis of G8P[4] strains from Asian continent.

Multi-center surveillance for pneumonia & meningitis among children (<2 yr) for Hib vaccine probe trial preparation in India.

BACKGROUND & OBJECTIVES: Severe clinical pneumonia and meningitis caused by Haemophilus influenzae type b in children less than 5 yr old is preventable by use of Hib vaccine. However, data on Hib burden in India are limited. To support an evidence-based decision for Hib vaccine introduction in India, a vaccine probe study was planned. This paper presents the results of the preparatory phase for such a study, which aimed to determine the feasibility of conducting a randomized vaccine probe study and to estimate the incidence of all causes of pneumonia and meningitis. The preparatory study included population- based, hospital-based and carriage surveillance. METHODS: Children aged 18-24 months and were enrolled at PGIMER, Chandigarh, CMC, Vellore and NICED, Kolkata, from July 2005 to December 2006. At the time of enrollment, parents were informed about the signs and symptoms of pneumonia and meningitis, and were encouraged to take the child to study hospitals for treatment. Hospitalized children less than two years of age suspected of having pneumonia and/or meningitis were enrolled in study hospitals, whether or not they were from the cohort population. Patients were examined clinically and received chest radiograph for suspected cases of pneumonia or lumbar puncture for suspected cases of meningitis. Blood culture was done for both pneumonia and meningitis patients. Cerebrospinal fluid (CSF) was tested for biochemistry, culture, latex agglutination test and polymerase chain reaction. Nasopharyngeal swabs were collected from healthy children less than 2 yr of age at immunization clinics to estimate Hib carriage. RESULTS: A cohort of 17,951 children were recruited for the population-based arm. The incidence of severe clinical pneumonia ranged from 2717 to 7890 per 100,000 child-years of observation; suspected meningitis ranged from 1971 to 2433 per 100,000 child-years of observation. In the hospital-based study 7/90 (7.8%), 29/98 (29.6%) and 38/181 (21.0%) of CSF samples with cell count > or =100 WBCs/mm(3); were purulent at Chandigarh, Kolkata and Vellore respectively. Of these purulent CSF samples, Hib was detected in 2, 6 and 11 cases, respectively. The Hib nasopharyngeal carriage prevalence ranged from 6.0 - 7.6 per cent. INTERPRETATION & CONCLUSIONS: Incidence of severe clinical pneumonia is comparable with other studies from India but that of suspected meningitis is higher. Although rates of Hib meningitis cannot be calculated from a hospital-based study, there is evidence of Hib meningitis in these study settings. Hib carriage prevalence indicates that Hib is present and circulating in these study areas. There is a significant burden of pneumonia and meningitis among children in India. Continued strengthening of laboratory capacity and bacterial surveillance systems are necessary.

HIV transmission potential among local and migrant factory workers in Kolkata, India.

Migrant workers in India play a key role in the spread of HIV. Kolkata is a common destination for workers, who may acquire infection and transmit it to their wives and/or other sexual partners. We investigated sexual relations and condom use by factory workers. Migrant and local factory workers were randomly selected from five wards of Kolkata. Information was collected about demographic and socio-economic characteristics, sexual relationships, condom usage, and perceptions and intent to use condoms. Condom use was very low in both groups of workers, particularly among migrants. Many married workers visited female sex workers but never used condoms. Few intended to use condoms, and if they did, it did not always translate into actual usage. There is great potential for transmission of HIV/sexually transmitted infections by these workers. Carefully designed intervention and education programs in the context of low literacy and cultural norms are urgently needed.

Evaluation of new-generation serologic tests for the diagnosis of typhoid fever: data from a community-based surveillance in Calcutta, India.

Although typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi, rapid and simple diagnostic serologic tests would be useful in developing countries. We examined the performance of Widal test in a community field site and compared it with Typhidot and Tubex tests for diagnosis of typhoid fever. Blood samples were collected from 6697 patients with fever for > or =3 days for microscopy, culture, and serologic testing and from randomly selected 172 consenting healthy individuals to assess the baseline Widal anti-Typhi O lipopolysaccharide antibody (anti-TO) and anti-Typhi H flagellar antibody (anti-TH) titers. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 3 serologic tests were calculated using culture-confirmed typhoid fever cases as "true positives" and paratyphoid fever and malaria cases as "true negatives". Comparing cutoff values for the Widal test, an anti-TO titer of 1/80 was optimal with 58% sensitivity, 85% specificity, 69% PPV, and 77% NPV. Sensitivity was increased to 67% when the Widal test was done on the 5th day of illness and thereafter. The sensitivity, specificity, PPV, and NPV of Typhidot and Tubex were not better than Widal test. There is a need for more efficient rapid diagnostic test for typhoid fever especially during the acute stage of the disease. Until then, culture remains the method of choice.