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.

The impact of the COVID-19 pandemic on health-care delivery system for other diseases and antimicrobial resistance threat in India.

India's health-care delivery is challenged with different inequalities and theelivery is challenged with different inequalities and the dual burden of communicable and noncommunicable diseases. Lockdown posed negative effects on the growth and economy of the country; simultaneously, some positive effects, like increased health consciousness and adoption of hygienic practices, were also there. Health-care delivery system faced tremendous challenges in diagnostics, therapeutics, infrastructure for inpatient care, and protection of health-care manpower. During this period, people chose to self medicate which in turn increased the threat of emergence of antimicrobial resistance. Due to shifting priority to COVID from other diseases, resources were shifted to COVID, affecting the management of other acute and chronic diseases. The launching of COVID-19 vaccination campaign showed some hope. However, despite the vaccination drive, strengthening infrastructure, and surveillance system, the devastating second wave could not be avoided due to the conglomeration of the crowd for pilgrimage, election campaign, and tourism in an unrestricted manner. It may be concluded that the fourth wave may be short lasting due to increased herd immunity.

Rationality of Prescriptions by Rational Use of Medicine Consensus Approach in Common Respiratory and Gastrointestinal Infections: An Outpatient Department Based Cross-Sectional Study from India.

BACKGROUND: Drug utilisation studies are relevant for the analysis of prescription rationality and are pertinent in today's context of the increasing burden of antimicrobial resistance. Prescriptions for patients with diarrhoea or Acute Respiratory Infection (ARI) have been analysed in this study to understand the prescription pattern among various categories of prescribers in two tertiary care centers. METHODS: This cross-sectional study was conducted from August 2019 to December 2020 in the medicine and pediatrics outpatient departments of two government teaching hospitals in West Bengal, India. A total of 630 prescriptions were evaluated against WHO standards. Prescriptions were assessed by a 'Rational Use of Medicine Consensus committee' approach. RESULTS: The Fixed Dose Combination (FDC) was used in half of the patients (51%). Both the generic prescription (23.3%) and adherence to hospital formulary rates (36.5%) were low. The antibiotics prescription rate was high (57%), and it was higher for diarrhoea than ARI. Deviations from the standard treatment guidelines were found in 98.9% of prescriptions. Deviations were commonly found with prescriptions written by the junior doctors (99.6%). CONCLUSION: Irrational prescribing patterns prevail in tertiary care centers and indicate the necessity of awareness generation and capacity building among prescribers regarding AMR and its unseen consequences.

Vertical Transmission Rate of Human Immunodeficiency Virus Exposed Twin Pregnancies and Associated Factors in West Bengal, India: a Retrospective Cohort Study.

Twin pregnancies are often associated with adverse obstetric outcomes. The mother-to-child transmission of the human immunodeficiency virus (HIV) in twin pregnancies has been less explored. Therefore, the present study aimed to determine the risk of vertical transmission of HIV in HIV-exposed twin pregnancies compared with that of singleton pregnancies and to explore the associated factors. We conducted a retrospective cohort study involving 348 HIV-exposed babies (58 twins and 290 singletons) through a systematic sampling from the program database of West Bengal, India, from April 2016 to March 2021. HIV vertical transmission rates were compared between single and twin live births. The effects of factors such as maternal age, timing of maternal HIV diagnosis, duration of antiretroviral treatment, mode of delivery, birth weight, and the sex of the baby were determined. The HIV transmission rate for twin pregnancies (15.5%) was significantly higher than that for single live births (5.5%) (adjusted odds ratio [OR] = 3.38 [1.17-9.69]). Among twin deliveries, maternal HIV diagnosis during the intrapartum and postpartum period was associated with HIV transmission (crude OR = 11.0, [2.2-54.9]). Perinatal HIV transmission is more common in twin pregnancies and is associated with the time of detection of maternal HIV. Therefore, early HIV detection and additional antiretroviral regimens should be considered for twin pregnancies.

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.

Epidemiology of major entero-pathogenic viruses and genetic characterization of Group A rotaviruses among children (≤5 years) with acute gastroenteritis in eastern India, 2018-2020.

AIMS: This study was carried out from January 2018 to March 2020 in Kolkata, eastern India to determine the prevalence rates and epidemiological patterns associated with the major viral agents of gastroenteritis among children ≤5 years of age. Molecular characterization of GARV, the predominant agent of viral gastroenteritis, was done to understand their genotype diversity. METHODS AND RESULTS: 1284 of 3157 stool samples (~40%) from children (≤5 years) with acute gastroenteritis tested positive for one or more enteric viruses with positivity rates 25.11%, 8.74%, 6.62% and 6.11% for GARV, HAdV-F, AstV and NoV respectively. Co-infection was observed in 5.31% of cases. Associated clinical/meteorological variables like age, sex, symptoms, temperature and precipitation were assessed to find any correlation between these and enteric virus infection rates. >70% of viral gastroenteritis cases were observed in 6-24 months' age group. GARV and AstV infection occurred mostly during cooler months while HAdV-F infection mostly occurred during warmer periods. No definite seasonality was observed for NoV infections. Clinical severity associated with GARV infection was higher compared to other enteric viruses. Genotyping of rotavirus positive samples revealed G3P[8] was the predominantly circulating GARV genotype throughout the study period. CONCLUSIONS: GARV remained the predominant viral agent of acute gastroenteritis among children though its prevalence rates in this region declined significantly compared to the previous years (2010-2016). The prevalence of other enteric viruses was below 10%. SIGNIFICANCE AND IMPACT OF STUDY: This study provides valuable insights regarding the current burden of viral gastroenteritis in Eastern India. The 2-year study in children will provide the baseline data for future surveillance studies in evaluating the impact of the introduced GARV vaccine on the overall prevalence of viral gastroenteritis.

Epidemiological drivers of mother to child HIV transmission in West Bengal, India: A retrospective cohort study.

BACKGROUND: HIV transmission through vertical route can be reduced to a large extent with combination of medical interventions. Apart from maternal HIV status several other epidemiological attributes determine this transmission dynamics.Objective: The objective of this study was to identify various associated factors that determine and modify the risk of HIV transmission from a mother living with HIV to her child.Materials and method: A retrospective cohort-study was conducted with 518 HIV-positive pregnant women with delivering live babies between April 2016 - September 2018. The HIV status of the children was ascertained with polymerase chain reaction. A number of socio-demographic and medical attributes were compared between HIV-positive (41) and HIV-negative babies (477) using bivariate and multivariate methods to identify disease modifying factors. RESULTS: Maternal HIV detection during the postnatal period (AOR = 11.2; 5.2 - 23.8), low birth weight (AOR = 2.7; 1.2 - 5.9), and vaginal delivery (AOR = 2.8; 1.01 - 7.7) were significantly associated with vertical transmission of HIV. Lower duration of maternal antiretroviral treatment and higher maternal age (>25 years) were also associated in bivariate analysis. CONCLUSION: The battery of PPTCT (Prevention of Parent to Child Transmission) interventions should be tailored in such a way to address all the epidemiological attributes influencing vertical transmission.

Socio-Demographic Correlates of HIV Sero-Discordance among Couples in West Bengal, India: a Cross Sectional Analysis.

Serodiscordant couples serve as potential sources of human immunodeficiency virus (HIV) transmission. Understanding the demographic dynamics of serodiscordant couples plays an important role in tailoring interventions to eliminate HIV infection. We conducted this cross-sectional analysis among 314 integrated counseling and testing centers in West Bengal, India, from April 2016 to March 2020. General individuals who were detected as HIV-reactive and whose spouses were also tested for HIV comprised the study population, in which a total of 8,740 couples were included. Sociodemographic variables were compared across concordant and discordant arms, as well as between male positive (M+ F-) and female positive (F+ M-) subgroups of serodiscordant couples. Among the couples studied, 35.2% (95% CI: 34.2-36.2%) were serodiscordant. Among serodiscordant couples, the proportion of M+ F- (86.1%) was significantly higher than that of F+ M- (13.9%). We observed that higher mean ages of couples, higher education, business and service occupations, and urban residence were significantly associated with the serodiscordance relationship (P < 0.05). A high mean age of couples and a low proportion of housewives were associated with the F+ M- subgroup. As approximately 35% of serodiscordant couples carry the risk of transmission to negative spouses, particularly in older age and urban residence, reorientation of HIV programs may be required to avert transmission in the future.

Prevalence of syphilis infection and associated sociodemographic factors among antenatal-care attendees in Meghalaya, India: Revisiting HIV Sentinel Surveillance data.

BACKGROUND: Despite relatively simple prevention and treatment, syphilis remains a major social and public health concern worldwide, particularly in developing nations. OBJECTIVE: To estimate the prevalence and to determine the sociodemographic factors associated with syphilis infection among antenatal-care (ANC) attendees in Meghalaya, India. MATERIALS AND METHOD: A facility-based cross-sectional study was conducted utilizing National HIV Sentinel Surveillance of Meghalaya, January-March 2017. Pregnant women aged 15-49 years (n = 3015) were recruited consecutively, interviewed, and tested for syphilis by Venereal Disease Research Laboratory test in eight selected ANC sites representing all districts of Meghalaya. RESULTS: Prevalence of syphilis was found to be 1.03 % (95% CI = 0.67-1.39) (31/3015). Prevalence was maximum among illiterates with gradual lowering of adjusted odds ratio (AOR) with improvement of education. Women whose husbands had no income were associated with higher risk (AOR = 4.97, 95% CI = 1.11-22.20) of syphilis. Significant risk (OR = 2.42, 95% CI = 1.02-5.74) was also observed with Jaintia Hills residents as compared to Garo Hills. CONCLUSIONS: As high prevalence of gestational syphilis was identified in Meghalaya along with important sociodemographic predictors, evidence to policy translation is required at state and national level to scale up prevention, screening, and management of syphilis.

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.

High Stillbirth Rate among Human Immunodeficiency Virus-Infected Pregnant Women in West Bengal, India: a Retrospective Cohort Study.

Human immunodeficiency virus (HIV) infection in pregnancy may result in adverse obstetric outcomes, such as stillbirth. The present study aimed to compare the stillbirth rate (SBR) in HIV-infected pregnant women with that in the general population, observing the year-wise trends of HIV infection-associated SBR and identifying possible associated exposures. A retrospective cohort study was conducted through the analysis of secondary data from 314 integrated counseling and testing centers across the state of West Bengal, India, from 2012 to 2020. A total of 3,478 HIV-infected pregnant women were followed up, and year-wise SBR trends were compared with that among all pregnancies of the state as per the latest available Sample Registration System report in India. A linear regression analysis of the year-wise trend in SBR was performed. T-test of two means and the relative risk (RR with 95% confidence interval) was conducted to identify the associations between different exposures and stillbirth. The SBR was significantly higher (26.7/1,000) in HIV-infected pregnancies than in all pregnancies (5/1,000) and was significantly reduced after the initiation of antiretroviral treatment (RR = 0.09: 0.05-0.16). Spouse testing for HIV (surrogate marker for familial involvement) (RR = 0.35: 0.20- 0.61) and maternal literacy (RR = 0.62: 0.40-0.97) were also found to be significantly effective in preventing stillbirth.

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.

Assessment of effectiveness of Japanese encephalitis vaccination in West Bengal, India using sample positivity rate as an alternate measure.

BACKGROUND & OBJECTIVES: Japanese encephalitis (JE), is a vaccine preventable mosquito borne arboviral disease. The State Health Department of West Bengal, India started a vaccination programme using live attenuated, single dose JE vaccine (SA-14-14-2) in children aged 1-below15 years since 2006 in five districts. The objectives were to compare Sample Positivity Rates (SPR) of Acute Encephalitis Syndrome (AES) cases for JE between vaccinated & unvaccinated districts and observe trend of SPR & Cumulative Incidence in vaccinated districts for three years. METHODS: The study was based on the analysis of surveillance data from all tested AES cases including confirmed JE (IgM ELISA) from all JE testing facilities existent in the state during the study period (2011-13). Calculation of Cumulative Incidence, Odds Ratio (OR) with 95% CI, Preventive Fraction and Chi Square for trend (for SPR) was done. Trend of incidence was assessed by linear regression. RESULTS: In three years, 5 vaccinated districts contributed 945 AES and 88 JE cases (SPR - 9.3%) compared to 1807 and 254 (SPR - 14.1%) JE cases in 14 unvaccinated districts. Effectiveness of vaccination was evident by gradual decline of Odds Ratio in favour of vaccinated districts. Vaccination effectiveness of 68% overall and 80% [OR = 0.20 (0.10 - 0.41)] in below 15 years were observed. Trend of SPR was found significantly declining in most of the vaccinated districts. INTERPRETATION & CONCLUSION: Significant reduction in sample positivity rate over three years in most of the vaccinated districts indicated that the vaccination programme had been gradually effective.

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.

Post-monsoon waterlogging-associated upsurge of cholera cases in and around Kolkata metropolis, 2015.

The Infectious Diseases and Beliaghata General Hospital, Kolkata, India witnessed a sudden increase in admissions of diarrhoea cases during the first 2 weeks of August 2015 following heavy rainfall. This prompted us to investigate the event. Cases were recruited through hospital-based surveillance along with the collection of socio-demographic characteristics and clinical profile using a structured questionnaire. Stool specimens were tested at bacteriological laboratory of the National Institute of Cholera and Enteric Diseases (NICED), Kolkata. Admission of 3003 diarrhoea cases, clearly indicated occurrence of outbreak in Kolkata municipal area as it was more than two standard deviation of the mean number (911; s.d. = 111) of diarrhoea admissions during the same period in previous 7 years. Out of 164 recruited cases, 25% were under-5 children. Organisms were isolated from 80 (49%) stool specimens. Vibrio cholerae O1 was isolated from 50 patients. Twenty-eight patients had this organism as the sole pathogen. Among 14 infants, five had cholera. All V. cholerae O1 isolates were resistant to nalidixic acid, followed by co-trimoxazole (96%), streptomycin (92%), but sensitive to fluroquinolones. We confirmed the occurrence of a cholera outbreak in Kolkata during August 2015 due to V. cholerae O1 infection, where infants were affected.

Dengue fever outbreak by more than one serotype in a municipal area of Kolkata, Eastern India.

A dengue outbreak struck Baranagar municipality area of North 24 Parganas district, West Bengal in July 2016. This study presents the epidemiological and virology findings of this outbreak. The outbreak started from 17 July and continued until 17th December. Total 1660 dengue cases (overall attack rate: 7/1000) and two deaths (case fatality rate: 1/1000) were reported. All age groups were affected. Out of the 213 blood samples collected from probable dengue cases and tested at Virus Unit, ICMR-National Institute of Cholera & Enteric Diseases (NICED), Kolkata, 163 (76%) tested seropositive through NS1 / IgM ELISA confirming dengue infection. DENV 1 was the predominant (53%, 44/83) serotype followed by DENV 2 (23%, 19/83), DENV 4 (15.6%, 13/83), DENV 3 (8.4%,7/ 83). Coexistence of dengue and chikungunya virus infection was detected. Major presentation of the confirmed dengue cases was fever with headache (95%), followed by arthralgia, myalgia, retro-orbital pain, abdominal pain, diarrhoea, and rash. Abundance of vector breeding spaces was observed in the area. Accordingly the health authorities were suggested to conduct frequent mass awareness campaigns involving community to reduce breeding sources during pre-monsoon and monsoon months. Further, adult mosquito control measures were also suggested throughout the year and inter-departmental coordination was recommended for prevention of such outbreaks in future.