An el tor cholera outbreak amongst tribal population in Tripura

An outbreak of acute diarrhoeal disease occurred in Dhalai and North Tripura district, Tripura during month of May 2004. An investigation was done to identify causative agent with anti microbial susceptibility pattern and to know the epidemiological feature. Overall attack rate and Case Fatality Rate (CFR) was 18.8%. and 6.9/1000 respectively. Vibrio cholerae O1 biotype El Tor, Ogawa was isolated as sole pathogen in 40% of hospitalized acute diarrhoea patient and from a water samples examined. The strains were sensitive to Tetracycline, Doxycycline, Norfloxacin, Ciprofloxacin, Chloramphenicol, and Azithromycin. Bad peridomestic sanitation, use of contaminated surface water along with low literacy, lack of personal hygiene, frequent movement might be the factor associated with persistence and spread of pathogen amongst tribal groups leading to outbreak of cholera.

Electron acceleration by a self-diverging intense laser pulse

Electron acceleration by a laser pulse having a Gaussian radial and temporal profile of intensity has been studied. The interaction region is vacuum followed by a gas. The starting point of the gas region has been chosen around the point at which the peak of the pulse interacts with the electron. The tunnel ionization of the gas causes a defocusing of the laser pulse and the electron experiences the action of a ponderomotive deceleration at the trailing part of the pulse with a lower intensity rather than an acceleration at the rising part of the laser pulse with a high intensity, and thus gains net energy. The initial density of the neutral gas atoms should be high enough to properly defocus the pulse; otherwise the electron experiences some deceleration during the trailing part of the pulse and the net energy gain is reduced. The rate of tunnel ionization increases with the increase in the laser intensity and the initial density of neutral gas atoms, and with the decreases in the laser spot size, which causes more defocusing of the laser pulse. The required initial density of neutral gas atoms decreases with the increase in the laser intensity and also with the decrease in the laser spot size.

Impact of zinc supplementation on diarrhoeal morbidity in rural children of West Bengal, India

AIM

To determine the role of zinc supplementation in reducing diarrhoeal morbidity in children.

METHODS

A randomized, double-blind, community-based intervention study was conducted in 280 rural children aged between 6 and 41 mo. Children were randomly allocated into three groups. One group received a daily dose of 10 mg zinc for 5 d wk(-1), another group received 50 mg zinc once weekly and the remaining group received placebo. Zinc was supplemented for 16 wk from November 1999. Diarrhoeal episodes were detected by weekly surveillance during the supplementation period.

RESULTS

Eighty diarrhoeal episodes were detected among 59 children in all 3 groups. The groups were compared with each other at baseline and as regard to the outcome variable (incidence of diarrhoea). The proportion of children suffering from diarrhoea during the period was significantly lower in the zinc-supplemented groups (15.8% in daily and 16.5% in weekly group) than in the placebo group (30.8%). The incidence of diarrhoea in the daily and weekly zinc-supplemented groups was 0.68 and 0.69 episodes child(-1) y(-1), and that in the placebo group was 1.67 episodes child(-1) y(-1) (relative risk 0.41, 95% confidence interval 0.24-0.71). Diarrhoeal incidence of < 4 d duration was found to occur significantly less often in the supplemented groups. There was no difference in diarrhoeal incidence between the daily and weekly zinc-supplemented children. There were no detected adverse reactions in any of the supplemented groups.

CONCLUSION

The study indicates that zinc supplementation is effective in reducing diarrhoeal morbidity when administered either daily or in a weekly schedule.

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.

Impact of vitamin A supplementation to rural children on morbidity due to diarrhoea

BACKGROUND AND OBJECTIVES

a number of studies have shown the association between vitamin A deficiency and the increased risk of diarrhoeal and other childhood morbidities and mortality. However, some studies have raised controversies regarding the reduction of the incidence of diarrhoea after vitamin A supplementation to children. This study was undertaken to evaluate the effectiveness of vitamin A supplementation to young rural children in reducing the incidence of diarrhoea.

METHODS

a double-blind randomized intervention trial was carried out amongst 404 rural children between 6-59 months of age to assess the impact of vitamin A supplementation on morbidity due to diarrhoea. Children aged 6-59 months were enrolled and allocated to receive either 200,000 or 50,000 IU of vitamin A and the same dose was repeated after six months. Morbidity due to diarrhoea was observed by twice-a-week household surveillance, during the subsequent one year of follow up. The incidence of diarrhoea was compared between the two supplemented groups. In addition, the overall incidence of diarrhoea n the two supplemented groups was also compared with the incidence observed during the year preceding supplementation.

RESULTS

the incidence of diarrhoea was similar in the two supplemented groups (Incidence Rate Ratio = 1.05. 95% C. I. 0.79-1.40). However, the overall incidence of diarrhoea among all the children in the two supplemented groups (0.56 episodes/child/year) was significantly lower than the incidence before supplementation (1.15 episodes/child/year). The Incidence Rate Ratio was 0.49 with 95% C.I 0.40-0.59.

INTERPRETATION AND CONCLUSIONS

the results of this study indicate that vitamin A supplementation in a dose of 200,000 IU, has no additional advantage over 50,000 IU, at least when the aim is to reduce the incidence of diarrhoea. For control of morbidity due to diarrhoea, vitamin A supplementation in a dose of 50,000 IU every six months appears to be adequate, cost effective and suitable for younger children.

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.

Isolation of Escherichia coli to detect faecal contamination of infants and their mothers in West Bengal

The present study was undertaken to gain insight into the sources of faecal contamination of infants in rural Bengal. It was carried out in three villages near Calcutta, India, from June 1993 to August 1995 among 148 infants and their mothers. Escherichia coli was used as an indicator of faecal pollution. A total of 725 samples, including hand rinsings of children and mothers, feeding utensils and leftover food were examined. The total isolation rate of faecal E. coli was 30%. The isolation rates from hands of children and mothers were 17% and 40% respectively. The germs from 30% of utensils and 59% of leftover food and drinks were recovered further. The study highlights the precarious hygiene in rural Bengal.

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.

Occurrence of diarrhoeal diseases in relation to infant feeding practices in a rural community in West Bengal, India

In a rural community-based prospective study, diarrhoea in relation to the feeding patterns of a cohort of infants was studied. A total of 148 infants between the ages of 0 and 2 months were enrolled and followed until the completion of 1 year of age. Survival analysis showed that by the fourth month of age exclusive breastfeeding dropped by 75%. The proportion of complementary breastfeeding increased from 18.6 to 52.9% during the same period and to 83.7% by the eighth month. This study clearly highlights the tendency for early switch over from exclusive breastfeeding to complementary breastfeeding. Early weaning was associated with an incidence rate ratio (IRR) of 3.02 (95% CI 1.043-8.802). The IRR of 3.02 and its confidence limits (1.043-8.02) suggest a significant protective effect of exclusive breastfeeding against diarrhoea in infants. The results of this study indicate that promotion of exclusive breastfeeding has a potential role to reduce the incidence of diarrhoea amongst infants. The findings of this study will be useful for Diarrhoeal Disease Control Programme in reducing diarrhoeal morbidity.

Epidemiological and clinical profiles of acute invasive diarrhoea with special reference to mucoid episodes: a rural community-based longitudinal study

A study was carried out in 3 villages near Calcutta, India, having a population of 5464, between August 1992 and December 1994. A cohort of rural children below 4 years of age was prospectively observed to determine the clinico-epidemiological aspects of mucoid diarrhoea and examine propensity to invasiveness. Overall, the incidence of diarrhoea was 1.7 episodes/child/year, and that of mucoid and bloody dysentery was 0.8 and 0.2 episodes/child/year, respectively. Children aged 6-11 months had a higher incidence of mucoid diarrhoea (1.3 episodes/child/year) and the peak season occurred in June and July. Multivariate analysis using logistic regression showed that mucoid diarrhoea and bloody dysentery were closely similar in both clinical and laboratory findings, including raised faecal leucocyte count (> 10/high power microscope field [hpf]). However, abdominal pain occurred more frequently in bloody dysentery than in mucoid diarrhoea. Faecal leucocyte count (> 10/hpf) can therefore be used as an indicator for invasiveness of mucoid diarrhoea at the community 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).

Epidemiology of Vibrio cholerae O139 with special reference to intrafamilial transmission in Calcutta

A total of 27 families of hospitalised patients (index case families) suffering from acute watery diarrhoea caused by Vibrio cholerae O139, and 14 neighbourhood families were bacteriologically screened for 4 consecutive days to determine the extent of V. cholerae O139 infection amongst healthy contacts and other suspected vehicles of transmission at the intrafamilial level. V. cholerae O139 was isolated from faeces of 14.6% of healthy contacts in index case families as compared to none in neighbourhood families (P = 0.002). The organism could be recovered from 3.7% of handwashings of contacts of index cases and also from stored drinking water (8.0%), open well water (28.6%), flies (3.8%) and pond water (25.0%) used by the index case families and none from neighbourhood families. The large number of asymptomatic infected persons indicate an epidemiological similarity to that of eltor cholera. The organisms may be carried on hands and may act as a potential source of infection to other inmates through contamination of stored drinking water, open wells etc. The results will be useful in formulating strategies for intervention of transmission of V. cholerae O139 at the community level.

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.

Prevalence of diarrhoeal diseases amongst tribals of Car Nicobar Island, India

In a cross sectional study of total 14514 tribal Nicobarese people of Car Nicobar Island, an union territory of India, situated in Bay of Bengal, morbidity, mortality and treatment practices of diarrhoeal diseases of under-five children were surveyed. The incidence of diarrhoea (0.2 episode/ch.year), Crude death rate (3.6/1000) and IMR (31/1000 live births) were exceedingly low as compared to SouthEast Asian Countries including mainland of India. ORS utilisation rate was high (41%) as compared to the National figure (12.0%). This is the first study of it's kind carried out in this island and amongst the Nicobarese tribe in India. A preliminary study carried out among the mothers of the hospitalised children indicated that protective behaviours like breast feeding, hand washing, use of chlorinated water and proper disposal of stool were regularly being practiced by the community traditionally. An in-depth study on risk factors of diarrhoea in this island can yield useful clue for describing the same.

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.

Epidemiology of campylobacteriosis in a cohort of rural population near Calcutta

Over a 2-year period, 25 families comprising of 181 individuals of all ages were longitudinally observed for the excretion of Campylobacter species. Faecal samples were taken from all persons with diarrhoea. Specimens were also taken from apparently healthy individuals and from domestic animals living within the confines of the study families at monthly intervals. The overall diarrhoea attack rate was 19 episodes per 100 person-years with peak incidence in the 1- to 4-year-old age group (76/100 person-years). Eight (11.5%) of the total episodes were campylobacter-associated and the overall rate of campylobacter positive diarrhoeal episodes were 2.2 per 100 person-years. Of the 1002 stool samples from healthy individuals 32 (3.2/100 samples) were positive for campylobacter. The organism was most frequently isolated from children under 1 year of age both during diarrhoeal episodes (11.5 per 100 person-years) and non-diarrhoeal (11.1 per 100 samples). Multiple infections in a family were rare. In 19.4% of the occasions one or more animals were campylobacter positive. However, only in 7.7% of these occasions was a human infection recorded within 1 month after the animal was found to be positive. The study showed that the epidemiology of campylobacteriosis in this community was distinct compared to that observed in developed countries.

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.

Studies on interventions to prevent eltor cholera transmission in urban slums

Transmission of eltor cholera infection in endemic communities continues without diminishing because of the absence of effective intervention measures. Two methods-chlorination of stored water and the use of a narrow-necked earthenware vessel (called a 'sorai') for storing the water-were found to be effective in reducing the transmission of infection among the family contacts of cholera patients. The cholera carrier rates in the chlorination and 'sorai' intervention groups were 7.3% and 4.4%, respectively, compared with 17.3% in the control group. The 'sorai' is cheap and was well accepted by the local communities; its narrow neck prevented the introduction of the hand and contamination of the stored water.

Contribution of lactic acid by the ampullary and isthmic parts of rabbit Fallopian tube under altered hormonal conditions

The capability of the ampullary and isthmic parts of the rabbit Fallopian tube to contribute lactic acid (LA) to the tubal lumen was examined using an in vitro method of study. In addition concomitant study was also made using the uterus. It was found that in the oestrous rabbit, the isthmus contributed LA at a higher rate than that of the ampulla; the uterine contribution was minimal. Ovariectomy reduced while exogenous oestrogen enhanced this ability in all the three tissues. In mated post-ovulatory rabbits the contributory efficiency of either tubal part changed and appeared to exhibit a peak value in the presence of the ovum; the uterus showed no such changes. This is discussed in relation to the ability of the egg to secure its energy source until it attained morula/the pre-blastocyst stage.

Differential response of the ampullary and isthmic cells to ovariectomy and estrogen treatment: an ultrastructural study

Ultrastructural response of the ciliated and secretory cells from the ampullary and isthmic parts of the oviduct was studied in ovariectomized and ovariectomized plus estradiol dipropionate (EDP) treated rabbits. Ovariectomy did not significantly affect the cilia in the ampullary epithelium; degenerative signs, however, appeared overtly in the isthmic cilia. EDP at either 1 microng/kg or 5 microng/kg doses raised the number of cilia/cell in either tubal segments. For comparable change isthmic cilia seemed to require a higher dosage of the estrogen. Ovariectomy led to the depletion of the secretory granules (SGs) from the secretory cells of either tubal segments. EDP at both the doses induced formation of the SGs; this is more remarkable in the isthmic cells. Merocrine type of secretions were observed from the secretory cells of either segments but only at the high dose of estrogen. The findings are discussed in the backdrop of current knowledge.

Incorporation of [U-C14-A1-glucose in vitro by different parts of the rabbit Fallopian tube and uterus

The in vitro incorporation of E1U-C14]-glucose by ampullary and isthmic segments of the Fallopian tube and the uterus was determined in the intact (estrous), ovariectomized, ovariectomized plus estrogen and ovarietcomized plus estrogen + progesterone treated rabbit. In the intact animal the ampulla incorporated glucose at a faster rate than the isthmus; uterine uptake is minimal. Ovariectomy reduced the rate of incorporation below normal values in all the tissues. EDP (estradiol dipropionate) administered to ovariectomized rabbit increased the incorporation rate. Progesterone antagonized the EDP-induced uptake. The relative rate and pattern of incorporation by the three tissues were, however, determined by the dosage of estrogen and the estrogen/progesterone ratio.