A Rapidly-progressing Outbreak of Cholera in a Shelter-home for Mentally-retarded Females, Amta-II Block, Howrah, West Bengal, India

On 13 May 2010, a cluster of diarrhoeal disease cases was reported among the inmates of a shelter-home for mentally-retarded females in Parbaksi village of Howrah district in West Bengal, India. The outbreak was investigated to identify the aetiological agent and source of infection and to propose recommendations. A suspected case of cholera was defined as an acute onset of >3 loose watery stools in a female resident of the shelter-home since 1 May 2010. The demographic and clinical details were collected from the suspected case-patients, and the outbreak was described by time, place, and person. A retrospective cohort study was conducted to identify the risk factors associated with the illness. Of the 101 inmates, 91 (90%) developed diarrhoea, and three patients died (case fatality−3%). Four of the five stool specimens were positive for Vibrio cholerae O1 Ogawa. Drinking of water from the pond-connected tubewell (adjusted odds ratio=25.7, 95% confidence interval 2.7-236.4) was associated with the illness. Relocation of the pond-connected tubewell away from the groundwater tubewell, colour-coding of the tubewells meant for drinking purposes, and regular disinfection of the tubewells were recommended

Risk factors for malaria deaths in Jalpaiguri district, West Bengal, India: evidence for further action

BACKGROUND: In 2006, a cluster of malaria deaths in the highly endemic Jalpaiguri district, West Bengal, India, led to assignment of additional resources. Malaria deaths decreased, but continued to occur. A study was conducted to identify the risk factors for residual malaria deaths. METHODS: Malaria death was defined as a death from fever with microscopically confirmed Plasmodium falciparum among residents of Jalpaiguri during 2007–2008. For each case, three age-, sex- and locality-matched controls were recruited among microscopically confirmed falciparum malaria patients cured during the same period. Clinical and treatment information was abstracted from records. Information about knowledge about malaria, presence of bed nets and DDT spraying was collected through interviews of the close relatives of study subjects. Odds ratio (OR) were calculated using multivariate methods. RESULTS: 51 malaria deaths were matched with 153 controls, which did not differ by age (median: 35 versus 36 years) and proportion of males (63% versus 63%). On multiple logistic regression analysis, compared with survivors, malaria deaths were more likely to have been admitted with already existing complications [OR = 4.1, 95% confidence interval (CI) = 1.6–10)], treated at a private facility (OR = 3.7, 95% CI = 1.2–12), received treatment after 48 hours of fever onset (OR = 14, 95% CI = 2.9–64), received chloroquine (OR = 13.3, 95% CI = 3.7–47). Households of the deceased were also more likely to miss bed nets (OR = 6.3, 95% CI = 1.9–24) and DDT spraying (OR = 9.2, 95% CI = 2.8–31). CONCLUSION: Elimination of malaria deaths will require education of providers for prompt referral before complications, engagement of the private sector, community awareness for early treatment as well as scaled-up use of bed nets use and DDT. Use of newer generation anti-malarials must to be generalized

The 2010 Outbreak of Cholera among Workers of a Jute Mill in Kolkata, West Bengal, India

On 10 March 2010, an outbreak of diarrhoeal disease was reported among workers of a jute mill in Kolkata, West Bengal, India. The cluster was investigated to identify the agent(s) and the source of infection and make recommendations. A suspected case of cholera was defined as having >3 loose watery stools in a 24-hour period and searched for case-patients in the workers’ colony. The outbreak was described by time, place, and person, and a case-control study was conducted to identify the source of infection. Rectal swabs were collected from the hospitalized case-patients, and the local water-supply system was assessed. In total, 197 case-patients were identified among 5,910 residents of the workers’ colony (attack rate 3.33%). Fifteen of 24 stool samples were positive for Vibrio cholerae O1. The outbreak started on 7 March, peakedon 11 March, and ended on 16 March 2010. Compared to 120 controls, 60 cases did not differ in terms of age and socioeconomic status. Drinking-water from the reservoir within the mill premises was associated with an increased risk of illness [odds ratio: 26.7, 95% confidence interval (CI) 11.4-62.6) and accounted for most cases (population attributable risk percentage=82%, 95% CI 70.8-92.9). An outbreak of cholera occurred among workers of the jute mill due to contamination of the drinking-water reservoir. It occurred within a few days of re-opening of the mill after the workers’ strike. Health authorities need to enforce disinfection of drinking-water and regularly test its bacteriological quality, particularly before re-opening of the mill after the strike

Incidence, management, and reporting of severe and fatal Plasmodium falciparum malaria in secondary and tertiary health facilities of Alipurduar, India in 2009

Background & objectives: The proportion of malaria cases that are complicated and fatal are not well describedin India. Alipurduar sub-division of Jalpaiguri district in West Bengal is highly endemic for malaria. We constructeda retrospective cohort of severe malaria patients admitted in the secondary and tertiary care facilities in Alipurduarto determine the incidence, assess the management, and evaluate the reporting of severe and fatal malaria.Methods: We reviewed routine surveillance data and the case records of all the malaria patients admitted in allsecondary and tertiary care facilities, both public and private. We defined severe malaria cases as Plasmodiumfalciparum infection with clinical signs and symptoms of organ involvement in a resident of Alipurduar admittedduring January to December 2009. We compared clinical and demographic characteristics of severe malariacases that died with those who survived. We also reviewed human resources and laboratory facilities availablefor the treatment of severe malaria in these health facilities.Results: During 2009, 6191 cases of P. falciparum in Alipurduar were reported to the malaria surveillancesystem. We identified 336 (5.4%) cases of severe malaria among which 33 (9.8%) patients died. Four malariadeaths were also recorded from primary health centres. Only 17 of the 37 (46%) total deaths recorded werereported to the routine surveillance system. Most severe cases were males (65%), aged >15 years (72%), andnearly half were admitted to secondary care hospitals (48%). In multivariate analysis, the risk factors associatedwith death included increased delay fever onset and hospitalization, treatment in a secondary level hospital,younger age, and multi-organ involvement. The secondary level public hospital had too few physicians andnurses for supporting severe malaria patients as well as inadequate laboratory facilities for monitoring suchpatients.Conclusions: Severe and fatal malaria continue to burden Alipurduar and record keeping in health facilities waspoor. Many malaria deaths were not routinely reported even in the public sector. Improved surveillance andincreased human and laboratory resources are needed to reduce malaria mortalit

The 2010 Outbreak of Cholera among Workers of a Jute Mill in Kolkata, West Bengal, India

On 10 March 2010, an outbreak of diarrhoeal disease was reported among workers of a jute mill in Kolkata, West Bengal, India. The cluster was investigated to identify the agent(s) and the source of infection and make recommendations. A suspected case of cholera was defined as having 653 loose watery stools in a 24-hour period and searched for case-patients in the workers\u2019 colony. The outbreak was described by time, place, and person, and a case-control study was conducted to identify the source of infection. Rectal swabs were collected from the hospitalized case-patients, and the local water-supply system was assessed. In total, 197 case-patients were identified among 5,910 residents of the workers\u2019 colony (attack rate 3.33%). Fifteen of 24 stool samples were positive for Vibrio cholerae O1. The outbreak started on 7 March, peaked on 11 March, and ended on 16 March 2010. Compared to 120 controls, 60 cases did not differ in terms of age and socioeconomic status. Drinking-water from the reservoir within the mill premises was associated with an increased risk of illness [odds ratio: 26.7, 95% confidence interval (CI) 11.4-62.6) and accounted for most cases (population attributable risk percentage=82%, 95% CI 70.8-92.9). An outbreak of cholera occurred among workers of the jute mill due to contamination of the drinking-water reservoir. It occurred within a few days of re-opening of the mill after the workers\u2019 strike. Health authorities need to enforce disinfection of drinking-water and regularly test its bacteriological quality, particularly before re-opening of the mill after the strike

Five Pond-centred Outbreaks of Cholera in Villages of West Bengal, India: Evidence for Focused Interventions

In rural West Bengal, outbreaks of cholera are often centred around ponds that is a feature of the environment. Five investigations of laboratory-confirmed, pond-centred outbreaks of cholera were reviewed. Case-control odds ratios were approximated with relative risks (RRs) as the incidence was low. The environment was investigated to understand how the pond(s) could have become contaminated and could have infected villagers. The five outbreaks of cholera in 2004-2008 led to 277 cases and three deaths (median attack rate: 51/1,000 people; case fatality: 1.1%; median age of case-patients: 22 years; median duration: 13 days, range: 6-15 days). Factors significantly (p<0.05) associated with cholera in the case-control (n=4) and cohort investigations (n=1) included washing utensils in ponds (4 outbreaks of cholera, RR range: 6-12), bathing (3 outbreaks of cholera, RR range: 3.5-9.3), and exposure to pond water, including drinking (2 outbreaks of cholera, RR range: 2.1-3.2), mouth washing (1 outbreak of cholera, RR: 4.8), and cooking (1 outbreak of cholera, RR: 3.0). Initial case-patients contaminated ponds through washing soiled clothes (n=4) or defaecation (n=1). Ubiquitous ponds used for many purposes transmit cholera in West Bengal. Focused health education, hygiene, and sanitation must protect villagers, particularly following the occurrence of an index case in a village that has ponds

Report of dengue outbreak investigation in Jothinagar village, Thiruvallur district, Tamil Nadu, India, 2017: epidemiological, entomological, and geospatial investigations

Background: During July 2017 to August 2017, five cases of laboratory-confirmed dengue cases were reported from Jothinagar village, Tamil Nadu, India. The episode was investigated to confirm the existence of an outbreak and formulate appropriate recommendations for containment.Methods: The monthly occurrence of dengue cases from 2014 to 2017 was compared to confirm the outbreak. Additional blood specimens from 22 patients were sent for laboratory confirmation. We conducted active case search, eco-entomological survey, and geo-mapping of cases and Aedes breeding spots.Results: The occurrence of 36 cases of dengue in the village, previously free from the disease for the past 3.5 years, confirmed the outbreak. Twelve were laboratory-confirmed while the remaining 24 were probable cases. The attack rate was highest amongst females in the age group 11-15 years (10.8/100 population). Case fatality was zero. The house index, Breteau index, container index (CI) and pupal index was 37.7% (23/61), 54.1% (33/61), 16.7% (33/198) and 32.8% (20/61) respectively. Discarded tyres were the key productive containers (CI=28.36%). Geo-analysis suggested clustering of cases within 70 m of the Aedes breeding spots particularly within the central part of the village.Conclusions: Based on high entomological indices, an intensive vector elimination campaign was implemented with a special focus on managing discarded tyres. Geo-analysis can be incorporated in surveillance to identify clusters early for control measures.

Persistence of Diphtheria, Hyderabad, India, 2003–2006

During 2003–2006, diphtheria rates in Hyderabad, India, were higher among persons 5–19 years of age, women, and Muslims than among other groups. Vaccine was efficacious among those who received >4 doses. The proportion of the population receiving boosters was low, especially among Muslims. We recommend increasing booster dose coverage

Cholera Outbreak Linked with Lack of Safe Water Supply Following a Tropical Cyclone in Pondicherry, India, 2012

In the aftermath of a severe cyclonic storm on 7 January 2012, a cluster of acute diarrhoea cases was reported from two localities in Pondicherry, Southern India. We investigated the outbreak to identify causes and recommend control measures. We defined a case as occurrence of diarrhoea of more than three loose stools per day with or without vomiting in a resident of affected areas during 6-18 January 2012. We used active (door-to-door survey) and stimulated passive (healthy facility-based) surveillance to identify cases. We described the outbreak by time, place, and person. We compared the case-patients with up to three controls without any apparent signs and symptoms of diarrhoea and matched for age, gender, and neighbourhood. We calculated matched odds ratio (MOR), 95% confidence intervals (CI), and population attributable fractions (PAF). We collected rectal swabs and water samples for laboratory diagnosis and tested water samples for microbiological quality. We identified 921 cases and one death among 8,367 residents (attack rate: 11%, case-fatality: 0.1%). The attack rate was the highest among persons of 50 years and above (14%) and females (12%). The outbreak started on 6 January and peaked on the 9th and lasted till 14 January. Cases were clustered around two major leakages in water supply system. Nine of the 16 stool samples yielded V. cholerae O1 Ogawa. We identified that consumption of water from the public distribution system (MOR=37, 95% CI 4.9-285, PAF: 97%), drinking unboiled water (MOR=35, 95% CI 4.5-269, PAF: 97%), and a common latrine used by two or more households (MOR=2.7, 95% CI 1.3-5.6) were independently associated with cholera. Epidemiological evidence suggested that this outbreak was due to ingestion of water contaminated by drainage following rains during cyclone. We recommended repair of the water supply lines, cleaning-up of the drains, handwashing, and drinking of boiled water