A localised outbreak of Vibrio cholerae O139 in Kolkata, West Bengal.

BACKGROUND & OBJECTIVES: An explosive outbreak of diarrhoeal disease which occurred in the Baishnabghata, Patuli area of Kolkata Municipal Corporation during September 28 to October 12, 2000, was investigated by a team from the National Institute of Cholera and Enteric Diseases, Kolkata, to identify the causative agent and determine the antimicrobial susceptibility pattern. METHODS: Clinical and epidemiological data were collected from domiciliary cases and also from patients attending two medical camps that had been set up for the purpose. Stool and water samples were collected for isolation of diarrhoeagenic pathogens. RESULTS: A total of 710 cases of diarrhoea occurred with an attack rate of 7.1 per cent; majority were adults. All 6 faecal samples and 2 water samples collected, were positive for Vibrio cholerae O139. The strains were uniformly (100%) susceptible to the commonly used drugs for cholera such as tetracycline, norfloxacin, ciprofloxacin, co-trimoxazole and nalidixic acid but resistant (100%) to furazolidone and ampicillin. INTERPRETATION & CONCLUSION: This is the first localised outbreak of V. cholerae O139 in Kolkata since the devastating epidemic in 1992. Extensive chlorination of all water sources resulted in a dramatic decline of the outbreak. The appearance of resistance in V. cholerae O139 to furazolidone is a matter of great concern since this drug is used for the treatment of cholera in children and pregnant women.

An outbreak of Eltor cholera in Aizwal town of Mizoram, India.

During the months of May, June and through early part of July 1994, an unusual occurrence of severe dehydrating watery diarrhoea cases and deaths were reported from Aizwal town, the capital of Mizoram, a North-Eastern state of India. Vibrio cholerae 01 biotype Eltor, the causative agent responsible for this outbreak, was isolated from 50.0% of hospitalised cases. The disease affected older children and adults more (52.9%) than younger children below five years of age. Vibrio cholerae 01 strains isolated were uniformly resistant to furazolidone and co-trimoxazole, which are commonly advocated in the treatment of cholera specially in children of developing countries. Emergence of such resistant strain is alarming and is of great public health importance.

An El Tor cholera outbreak in Maldah district, West Bengal.

An outbreak of cholera occurred in Maldah district, West Bengal during July-August 1998. Attack rate was 34/1000. Cases were more (59.3%) amongst adults (> 15 years.). V. cholerae 01 biotype E1 Tor serotype ogawa was isolated as a single pathogen from 52.9% (9/17 samples examined). All V. cholerae strains belonged to phage type 2 (Basu and Mukherjee scheme) and type 27 (new phage type scheme). The strains were resistant to co-trimoxazole, furazolidone, ampicillin, streptomycin and nalidixic acid.

Maternal knowledge on risk behavioural practices and it's association with diarrhoea in a rural community of West Bengal, India.

Knowledge of rural mothers related to five diarrhoeagenic risk behaviours, identified in an earlier study, was ascertained. A high proportion of mothers (67%-79%) had knowledge about risk of bottle feeding, non-use of soap for cleaning feeding containers, storage of drinking water in wide-mouthed vessels and indiscriminate disposal of children's faeces. However, only around 31% of mothers were aware about danger of using pond water for cleaning feeding containers. Risk behavioural practices were less amongst mothers who had knowledge about them. Risk of diarrhoea amongst children of mothers having risk practice without knowledge as compared to those who utilised their knowledge to avoid risk practice was found significantly higher (p < or = 0.005) except for bottle feeding (p = 0.330). The results of this study indicate that children can be protected significantly from diarrhoea if mothers' diarrhoeagenic behaviours can be altered through educational intervention.

Value of faecal leucocyte count as an indicator of invasiveness in mucoid diarrhoea.

Importance of faecal leucocyte count as an indicator of invasiveness in mucoid diarrhoea was studied. A total of 290 faecal specimen, 170 from mucoid diarrhoea and 120 from watery diarrhoea were examined for faecal leucocyte count under high power field (hpf) from rural children below four years of age during the period from November 1992 to October 1995. Faecal leucocyte count > 10/hpf was noted in 45.9% of mucoid diarrhoea as against 19.2% of watery diarrhoea (p < 0.0001) samples. From faecal samples with > 10 faecal leucocyte count, invasive pathogens could be recovered in 19 (24.5%) to none of 23 patients with watery diarrhoea (p < 0.006 Fisher exact test). This sample test appears to be of value as an indicator of invasiveness in mucoid diarrhoea in the absence of culture facility.

Risk behavioural practices of rural mothers as determinants of childhood diarrhoea.

Maternal behaviours related to certain child care practices which possibly have a contributory role in causation of diarrhoea in children were studied. Comparison was made between behaviours of mothers in 108 families having diarrhoeal children (Case families) with mothers of 72 families having age and neighbourhood matched non diarrhoeal children (control families) using a logistic regression model. Five risk behaviours were identified and these are bottle feeding (OR-2.87; CI-1.30 to 6.34), non-use of soap for cleaning feeding container (OR-2.61; CI-1.30 to 5.23), water storage in wide-mouthed container (OR-2.75; CI-1.27 to 5.96), use of pond water for the same (OR-2.36; CI-1.15 to 4.84) and indiscriminate disposal of children's stool (OR-1.99; CI-0.97 to 4.08). Around 83 per cent of diarrhoeal families could be predicted using these five variables only. The first three of these five risk behaviours were responsible for occurrence of significantly higher incidence (3 or more episodes) of diarrhoea in the case families. All these risk behaviours are amenable to change if suitable intervention is initiated. The result of this study would be helpful in reducing diarrhoea associated morbidity to a substantial level.

Intestinal parasitism: a childhood problem in rural Bengal.

A study was undertaken to assess the parasitic infection rate in a rural community of West Bengal amongst children below four years of age suffering from gastrointestinal complaints. A total of 221 faecal samples were examined during November 1992 to April 1994. G. lamblia (17.2%) and E. histolytica (8.1%) were the predominant protozoas, whereas E. vermicularis (12.2%) and A. lumbricoides (8.1%) were found to be common amongst helminthic infection. A significantly lower infection rate was observed in children below one year (24.4 per cent) as compared to older age groups (66.4 per cent).

Implementation of ORT: some problems encountered in training of health workers during an operational research programme.

During an operational research study on implementation of oral rehydration therapy in a block of West Bengal, India, amongst a population of 2, 16,805, a total of 171 Community Health Guides and 152 Anganwadi Workers were initially trained for one working day by lectures and slides about diarrhoea case management at the community level. The training was evaluated after two months and found to be inadequate. The workers were then retrained with modern approach using a module (prepared in local language) as suggested by World Health Organisation. The level of retention of the imparted knowledge of Health Workers for different items 2-3 months after training with lectures and slides ranged between 5-25% except preparation of ORS which was 80%. With the use of modules, 47-98% of health workers could retain the same knowledge 3 months after the training. The knowledge thus acquired were sustained even after 12 months of training to a level which was still much better than that retained 2 months after training with slides and lectures. However some of the items like indication of use of Home Available Fluids, dosage of ORS and when to refer a diarrhoea case to health facility were more difficult to recall after one year. This possibly indicates need for in-service training of grassroot level health workers at suiTable interval.

Review on development and community implementation of oral rehydration therapy.

The review of the current status and implementation of Oral Rehydration Therapy at the community level have been presented in this communication with special emphasis on its development, ORS access rate, ORS use rate and home available fluids. The global ORS supply has gone up an increased eleven folds since 1981. Similarly the ORS access rate has also increase from 46% to 68% in 1991. However, the global ORS use rate was low (21%). The major constraints during ORT implementation which have been reported by several scientists are also discussed.

An operational study on implementation of oral rehydration therapy in a rural community of West Bengal, India.

An operational study of a 3-tier strategy for implementation of oral rehydration therapy (ORT) was conducted in a block of West Bengal with 216,825 population through the existing health services facilities. All the grassroot level, health workers including their supervisors at various levels were trained regarding the management of patients of diarrhoea with mild to moderate degree of dehydration, by ORT. Another block in the same district with similar demographic features where this intervention was not provided served as control. After 22 months of observation, it was evident that despite adequate training, the performance of Community Health Guides (CHGs) and Anganwadi Workers (AWWs) was not encouraging because of the low utilization of both home available fluids (32.0%) and oral rehydration solution (18.0%) in the study area. Similarly, diarrhoea associated mortality could not be reduced significantly. Lack of motivation and failure to maintain sustained level of skill by the CHGs and AWWs constitute the major bottlenecks for the successful implementation of the programme at the community level.

Report of an outbreak of diarrhoeal disease caused by cholera followed by rotavirus in Manipur.

An outbreak of acute diarrhoeal disease between August and October 1985 in 3 districts of Manipur state was investigated amongst 9,29,077 population at risk. The overall attack rate and case fatality rate were 0.2% and 0.9% respectively. Hospital records revealed that 58.8% of cases occurred amongst older children above 5 years of age. V.cholera was isolated from 25.3% of cases sampled. Interestingly, increased frequency in weekly admission of cases amongst children during first two years of life increased in the beginning of October when the original peak of diarrhoeal outbreak was about to decline. The October peak was caused by rotavirus which could be detected from 50.0% of diarrhoeal children in this age group. This possibly reflected beginning of the usual rotavirus diarrhoea season in the locality.

Multidrug resistant epidemic shigellosis in a village in west Bengal, 1984.

An out break of acute bacillary dysentery in a village called Dhamasin in Hooghly district of West Bengal was investigated during March 1984. Forty seven percent of families were affected. A total of 91 cases and 2 deaths occurred amongst 937 people giving an over all attack rate of 9.7% and a case fatality rate of 2.2 percent. Highest attack rate (22.7%) was observed in below one year age group. Multiple drug resistant Shigella dysentery type 1 strains were isolated for the first time from 6 out of 22 cases sampled at the domiciliary level. The organism was never isolated earlier during last ten years of surveillance in the infectious Diseases Hospital, Calcutta. Identification of nature of this outbreak and it's causative agent helped to realise the potentiality of extensive spread and paved the way for further investigations. Public health authorities were buffled as the rapid spread of the disease throughout the entire state of West Bengal could not be contained in spite of instituting all probable control measures on war footing.