Typhoid fever: Control & challenges in India

Enteric fever is a common but serious disease that affects mostly children and adolescents in the developing countries. Salmonella enterica serovar Typhi remains responsible for most of the disease episodes; however, S. Paratyphi A has also been reported as an emerging infectious agent of concern. The control measures for the disease must encompass early diagnosis, surveillance and vaccine to protect against the disease. Sanitation and hygiene play a major role in reducing the burden of enteric diseases as well. The current status of diagnostics, the surveillance practices in the recent past and the vaccine development efforts have been taken into account for suggesting effective prevention and control measures. However, the challenges in all these aspects persist and cause hindrance in the implementation of the available tools. Hence, an integrative approach and a comprehensive policy framework are required to be in place for the prevention, control and elimination of typhoid fevers.

Evaluation of a rapid dipstick test for identifying cholera cases during the outbreak.

Background & objectives: Intermittent cholera outbreaks are major problem in many of the states of India. It is essential to identify cholera at the earliest for timely mobilization of public health responses and to abort the outbreaks. The present study was a part of a diarrhoeal outbreak investigation in Secunderabad, India, during May 2009 where the usefulness of Crystal VC rapid dipstick kit was assessed for detecting the aetiologic agent of the outbreak. Methods: Stool specimens were collected from 15 hospitalized patients with acute watery diarrhoea and analyzed for detection of cholera vibrios using Crystal VC rapid dipstick kit and the usefulness of the kit was determined by comparative analysis of the same set of specimens using both microbiological and real-time PCR (RT-PCR) based assays. Results: Detection of Vibrio cholerae O1 from 10 of 15 specimens was recorded using dipstick assay. Microbiological methods detected V. cholerae O1 positivity among 11 specimens. However, RT-PCR based assay showed all 15 specimens positive for the presence of V. cholerae O1. In addition, the same assay showed that the pathogen load in the dipstick as well as RT-PCR positive specimens ranged from 106 colony forming units (cfu)/ml or more. Interpretation & conclusions: Crystal VC kit had the potential to identify cholera cases in 10 min in field conditions without having good laboratory support. Therefore, dipstick kit may be considered as cholera detecting tool in diarrhoeal outbreak investigations. Specimens from clinically typical cholera cases, if negative by dipstick, should be reanalyzed by culture based methods.

Influence of relative humidity in Vibrio cholerae infection: A time series model.

Background & objectives : Spread of cholera in West Bengal is known to be related to its ecosystem which favours Vibrio cholerae. Incidence of cholera has not been correlated with temperature, relative humidity and rainfall, which may act as favourable factors. The aim of this study was to investigate the relational impact of climate changes on cholera. Methods : Monthly V. cholerae infection data for of the past 13 years (1996-2008), average relative humidity (RH), temperature and rainfall in Kolkata were considered for the time series analysis of Seasonal Auto-Regressive Integrated Moving Average (SARIMA) model to investigate relational impact of climatic association of V. cholerae infection and General Linear Model (GLM) for point estimation. Results : The SARIMA (1,0,0)(0,1,1) model revealed that monthly average RH was consistently linear related to V. cholerae infection during monsoon season as well as temperature and rainfall were non-stationary, AR(1), SMA(1) and SI(1) (P<0.001) were highly significant with seasonal difference. The GLM has identified that consistent (<10%) range of RH (86.78 ± 4.13, CV=5.0, P <0.001) with moderate to highest (>7 cm) rainfall (10.1 ± 5.1, CV=50.1, P <0.001) and wide (>5-10°C) range of temperature (29.00 ± 1.64, CV=5.6, P <0.001) collectively acted as an ideal climatic condition for V. cholerae infection. Increase of RH to 21 per cent influenced an unusual V. cholerae infection in December 2008 compared to previous years. Interpretation & conclusions : V. cholerae infection was associated higher RH (>80%) with 29°C temperature with intermittent average (10 cm) rainfall. This model also identified periodicity and seasonal patterns of cholera in Kolkata. Heavy rainfall indirectly influenced the V. cholerae infection, whereas no correlation was found with high temperature.

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.

The prescribing habits of doctors in a metropolitan city and economic consequences of such practices.

Four thousand prescriptions were studied to observe the prescription pattern and habit of the doctors practising in the city of Calcutta. Ten most common ailments were identified and their treatment and investigations were taken into account for judging the rationality of such action. Both, estimated rational prescription cost and actual cost of the prescription were determined to identify any cost variation between prescription written rationally and irrationally.

Severe cholera outbreak following floods in a northern district of West Bengal.

BACKGROUND & OBJECTIVES: An explosive epidemic of cholera in the district of Malda in the state of West Bengal, was induced by devastating floods resulting from overflowing of the two main rivers of the district, at the end of July 1998, affecting 15 blocks and 2 municipalities. Diarrhoeal outbreak occurred around the middle of August after receding of the flood waters. Within two weeks of its onset, the outbreak spread throughout the district. An investigation was conducted to understand the epidemiological characteristics, identify the etiological agent, rationalise clinical management and suggest control measures. METHODS: The team visited the Block Primary Health Centres, surrounding the affected villages and also the district hospital. Morbidity and mortality data were collected and 88 patients were interviewed and examined clinically. Epidemiological and clinical observations were recorded. Rectal swabs were collected from both hospitalised and domiciliary cases. RESULTS: During the period between August and October 1998, 16,590 cases were reported with 276 deaths (case fatality rate of 1.7%). Twenty one of 29 (72%) rectal swabs were positive for Vibrio cholerae O1, biotype ElTor, serotype Ogawa. All the strains were sensitive to tetracycline, norfloxacilin, ciprofloxacilin, gentamycin, chloramphenicol but resistant to furazolidine, co-trimoxazole, nalidixic acid, streptomycin and ampicilin. INTERPRETATION & CONCLUSIONS: Observations of the present study identified the epidemiological and clinical deficiencies in the management of the outbreak and recommendations were elaborated for its effective control.

Dr. P. C. Sen Memorial Award Paper. A study of HIV infection in thalassaemia patients of rural Bengal.

Thalassaemia patients receiving repeated blood transfusions are vulnerable to transfusion related infections. HIV infection is the most life threatening of them all. Blood being the most efficient mode of transmission of HIV, increases the risk of infection even further. Although the National AIDS Control programme has laid down stringent rules regarding blood safety, it remained to be seen whether they were being followed meticulously especially in rural areas. The present study was conducted to identify the HIV status of multi-transfused thalassaemia patients attending hospital blood banks of rural Bengal. Only 3 (0.9%) of the 330 thalassaemia patients examined were found to be HIV positive. Although the situation has not reached alarming proportions, yet appropriate control measures must be adopted on a mass scale to prevent further spread of the world wide pandemic.

Impact of nutrition education on health of the mother and newborn belonging to the poor urban slum community.

To find the nutritional knowledge among mothers of one child of the poor community and to relate status of education to the nutritional health of them and the newborn and to get a thorough knowledge on the impact of nutritional education, a comprehensive study was undertaken in an urban slum area. Nutritional grading was done through scoring system. There were 47 mothers (24.1%) out of 195 having normal nutritional grade and 37 mothers (19%) having severe nutritional grade. There were 80 mothers having 'no knowledge' on maternal nutrition. 'Adequate knowledge' was found in 31 cases. Mothers (n = 80) of 'no knowledge' delivered babies of average weight 2.3 kg whereas 'adequate knowledge' mothers gave birth to babies of average weight 2.9 kg.

Community perception about disaster preparedness and response programme in four states of India.

It is well felt that community participation, local planning, development of self reliance and manpower resource within the community itself can strengthen the effort of disaster preparedness and response. The present study was intended to bring out the salient features about perception and opinion of community leaders and community members about existing preparedness programme and appropriateness of mitigatory exercise against flood disaster in four eastern states of India viz. West Bengal, Bihar, Assam and Orissa. Many snags at the implementation level, in terms of co-ordination, directives, logistics and knowledge gap were noted, which should be dealt with due care for successful disaster preparedness programme.