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Biomedical subjects

K K Datta

Publications and source records attributed to K K Datta.

At least 19 recordsLinked to original sources

Widespread outbreaks of measles in rural Uttar Pradesh, India, 1996: high risk areas and groups.

OBJECTIVE: To describe outbreaks of measles which affected many districts in Uttar Pradesh (UP) during 1996. DESIGN: Outbreak investigations. SETTING: The state of Uttar Pradesh, India. METHODS: The reported data on measles morbidity, mortality and vaccine coverage from 1991 through 1996 were reviewed. Reported vaccine coverage levels were compared with the results of coverage surveys carried out in UP from 1992 through 1996. Line lists on measles cases were analyzed to ascertain the age, immunization status, geographical distribution, and age and sex-specific fatality ratios during the outbreaks. A community survey was organized in 7 affected villages to estimate vaccine effectiveness. RESULTS: Fifty one of 68 districts in UP reported 6922 measles cases and 281 deaths in 1996. The majority of cases and deaths occurred in June and July which are usually low transmission months. Overall cases fatality ratio (CFR) was 4.1%. CFRs were significantly higher in females and young children. The median age of cases was found to be below 5 years. There was heavy clustering of cases and deaths in rural areas. About 85% of the cases and virtually all the measles associated deaths occurred in unvaccinated children. Published documents on statewide coverage surveys revealed that the measles vaccine coverage levels ranged between 26% and 36% during 1992-96. Large gaps were found between reported coverage and survey results. Nevertheless, epidemiological studies indicated a vaccine effectiveness of more than 90%. CONCLUSIONS: The outbreaks occurred due to poor vaccine coverage levels and an inefficient surveillance system which failed to generate early warning signals. The study highlights the urgent need to raise the vaccine coverage levels rapidly in all districts to achieve measles control and prevent future outbreaks in UP.

Age Distribution↗

Acute sporadic viral hepatitis in urban population of a tribal district in Madhya Pradesh.

OBJECTIVE: To estimate the incidence of acute sporadic viral hepatitis and describe its epidemiology in an urban population. DESIGN: A retrospective community survey for jaundice cases. SETTING: Headquarter town of a tribal district, Bastar, in Madhya Pradesh state, India. METHOD: Trained paramedics surveyed about 51,643 population to detect cases of jaundice which occurred in the past one year. Cases were examined to collect clinical and epidemiological data. blood samples were drawn from all cases who had jaundice in the past 3 months for testing them for markers of viral hepatitis. RESULTS: Study estimated the annual incidence of jaundice cases as 244 (95% CI 201-287) per 100,000 population. Almost 95% jaundice cases occurred in summer and monsoon months. People from all socio-economic strata were affected. The incidence of jaundice was found to be the highest in children below 15 years of age (3.7 per 1000) which declined significantly with the increase in age (p = 0.0000). The overall incidence in two sexes was not different statistically (p = 0.7). Of 57 cases who had jaundice in the past 3 months, 19 (33%) were confirmed as having viral hepatitis. Hepatitis A and E combined together contributed 68% (13/19) of acute sporadic cases of viral hepatitis, whereas hepatitis B, C and D accounted for the remaining 32% of the cases. CONCLUSION: The study found the annual incidence of laboratory supported cases of viral hepatitis to be 81 (95 CI 57-106) per 100,000 population, which suggests that it is an important public health problem in India. Hepatitis A was much more prevalent than hepatitis E. Etiology of almost two-thirds of jaundice cases could not be established which require further community studies.

Acute Disease↗

Prevalence of North India of hepatitis B carrier state amongst pregnant women.

The study was undertaken to determine the hepatitis B carrier rate in North India along with the relative infectivity of the carriers. A total of 1,112 pregnant women were investigated for hepatitis B carrier state during their routine visits to antenatal clinics. All three tiers of the health care delivery system were included from four regions of North India. The sera were screened for the presence of hepatitis B surface antigen (HBsAg), hepatitis B "e" antigen (HBeAg), and antibody to hepatitis B "e" antigen (Anti-HBe) by third generation Macro ELISA tests. The average hepatitis B surface antigen carrier rate was 9.5%. The carriers were found to be of relatively low infectivity with HBeAg and Anti-HBe present in 12.0% and 25.3% of the HBsAg carriers respectively, and both these markers absent in 62.7%. It was concluded that in the past decade the hepatitis B endemicity in North India has probably increased, but the relative infectivity of the carriers remains the same.

Carrier State↗

Serological diagnosis of childhood tuberculosis by estimation of mycobacterial antigen 60-specific immunoglobulins in the serum.

SETTING: An ELISA assay based on mycobacterial antigen 60 (A60) for the estimation of specific immunoglobulins in the serum has been used successfully for the rapid diagnosis of tuberculosis in studies done predominantly in Western countries. In a recent Indian study, encouraging results were reported in adult tuberculosis. OBJECTIVE: To evaluate the utility of this ELISA test for rapid diagnosis of different clinical forms of tuberculosis in Indian children. DESIGN: ELISA test based on mycobacterial A60 was used to estimate specific IgM, IgA and IgG antibodies in the sera obtained from 452 cases of tuberculosis and 161 controls in the paediatric population of Delhi, India. RESULTS: Of the 161 controls, only 7.4% were positive for IgM, 4.3% for IgG, 3.7% for IgA and 8% when a combination of IgM and IgA was considered. Of 58 cases of definite pulmonary tuberculosis, 55.2% were positive for IgM, 32.7% for IgG, 36.2% for IgA and a high positivity of 72.4% was seen when IgA and IgM estimations were combined. The corresponding figures in 150 cases of definite extrapulmonary tuberculosis were 57.3%, 36.6%, 38% and 76.6%. A relatively weak serology was observed in 244 cases of probable tuberculosis. A very high positivity (95%) was seen in acid-fast bacilli-positive cases of tuberculosis. CONCLUSIONS: Our findings point to a very good specificity (92%) and a reasonably good sensitivity (75.5%) of the test when combined IgM and IgA antibody titres are considered in the diagnosis of childhood tuberculosis.

Antibodies, Bacterial↗

Chromoblastomycosis in India.

BACKGROUND: Chromoblastomycosis is reported for the first time from the states of Jammu-Kashmir and Bihar along with two additional cases from the states of Assam and Uttar Pradesh. The work carried cut on this disease in the Indian subcontinent is reviewed. METHODS: Relevant mycologic investigations, including direct microscopy, histopathology, and culture, were carried out to study the four cases. Treatment was given to two patients. RESULTS: The duration of the lesions varied from 5 to 32 years. In one case the lesion was a large erythematous plaque on the buttocks extending to the backs of the thighs, and in the others they were hypertrophic lesions on the extremities. Histopathologic study of specimens carried out in three patients revealed the causative organisms. On culture, Cladosporium carrionii was isolated in one and Fonsecaea species in the other three. The lesions in one patient were surgically excised and another patient responded well to a combined regimen of amphotericin B and 5-fluorocytosine. CONCLUSIONS: Although chromoblastomycosis is widely distributed in India, many patients remain undiagnosed due to a lack of proper facilities. Treatment is difficult and most patients are not able to afford the drugs prescribed for this condition.

Adult↗

Epidemiological considerations of the age distribution of measles in India: a review.

This paper reviews the Indian data on age distribution of measles prior to large scale immunization. In metropolitan areas, the median age was about 24 months and virtually all the cases were recorded in children under 5, whereas median age in most of rural studies was < 4-< 5 years and all the persons were not affected until 10 years of age. The situation was in between in other areas. Since less than 10 per cent of the cases occurred before 9 months of age, this age is appropriate for routine measles immunization. The results also suggested the choice of age groups to be immunized during measles mass campaigns; the upper age may be 3 years in metropolitan city, 10 years in rural areas, and 5 years in the rest of the population.

Age Distribution↗

Transplacental dilution of tetanus antitoxins in Delhi.

Maternal blood-cord samples from 171 women of middle socio-economic status who had been administered at least two doses of tetanus toxoid (TT), were assayed for tetanus antitoxins by passive haemagglutination (PHA) test. All the mother as well as cord samples had antitoxin titres > or = 0.015IU/ml, the generally accepted minimal protective level; 98 per cent of the mothers and 97 per cent of the newborns had levels > or = 0.125IU/ml. Transplacental dilution was observed in 45 per cent of the samples; the cord/maternal antitoxin ratio (C/M) of geometric mean titre (GMT) was found to be 0.72. The C/M ratio was not affected by the maternal age, parity, birth weight, and number of TT doses administered to mother. The study showed that tetanus antitoxins were diluted on the fetal side of circulation, but the protective levels of antitoxins were achieved in all the newborns as the mothers had received at least two doses of TT before delivery.

Adolescent↗

V. cholerae 01 outbreak in remote villages of Shimla district, Himachal Pradesh, 1994.

An outbreak of V. cholerae 01 occurred in remote villages of Rohru tehsil, district Shimla, Himachal Pradesh, during June-July 1994. Seven villages were affected. Overall attack rate was 16.4 per cent in surveyed villages. Attack rate in children < 5 was significantly high. Suspected source was spring water contaminated from open air defaecation. V. cholerae was resistant to co-trimoxazole and streptomycin.

Adult↗

Measles vaccine efficacy in India: a review.

Different workers have used different designs to assess effectiveness of live, further attenuated measles vaccine i.e., seroconversion studies, outbreak investigations, field trials and coverage survey methods. The results were often contradictory. We reanalyzed data from these studies to find out optimum vaccine efficacy (VE) and its determinants in the Indian context. Although nutritional status and sex of the subjects did not affect seroconversion rates, the rates were greater among initially seronegative and older children. Overall seroconversion rates in 9-11 months children ranged between 56 and 96%. Studies showing poor seroconversion had an inadequate sample size and/or technical flaws that detracted from the reliability of results. However, appropriately designed studies demonstrated seroconversion rates of more than 90% in 9-11 months children who were initially seronegative. Since 5-10% of 9-11 months old infants had persistent measles maternal antibody, measles vaccine may be around 85-90% effective in this age group. These results are in agreement with the findings observed in outbreak investigations. These outbreaks fulfilled all the criteria which are considered necessary for optimum estimation of VE in such settings; VE was found to be more than 90% in outbreak settings. Conversely, retrospective coverage surveys grossly under estimated VE (about 60%) which was probably due to misclassification of vaccination status of enrolled children. The surveys were undertaken in areas where immunization records were grossly incomplete and only few mothers retained immunization cards. Unfortunately, VE was also under estimated in field trials which were neither randomized nor blind, and no placebo injections were used in control children; many observations were on record which could explain the under estimation of VE. Reanalysis of data from different types of studies indicates that efficacy of measles vaccine given at 9-11 months of age is of the order of 85-90% in the Indian context.

Child, Preschool↗

Sensitivity of neonatal tetanus surveillance system in India.

OBJECTIVE: To estimate the sensitivity of neonatal tetanus (NNT) surveillance in India. DESIGN: A comparison of two sets of data obtained from NNT mortality surveys and routine surveillance system. METHODS: NNT mortality surveys were undertaken in 1981, 1989 and 1992 using 30 cluster sampling technique. The data on reported incidence of NNT through routine surveillance system was taken from the published documents of Health Ministry and WHO. RESULTS: In 1981, the incidence of disease in a national survey was estimated to be 4 and 16.4 per 1000 live births in urban and rural areas, respectively. Follow up surveys in 1989 and 1992 estimated the overall incidence as 4 and 1.74 per 1000 live births, respectively. Comparing the reported and estimated by surveys, around 10% of NNT cases were reported. CONCLUSIONS: There is an urgent need to strengthen the routine surveillance system which at present grossly under-reports the NNT incidence in India.

Humans↗

Epidemiology of endemic viral hepatitis in an urban area of India: a retrospective community study in Alwar.

In a community study during a reference period of 1 year, 192 cases of jaundice were detected in an urban population of 69,440 in Alwar, Rajasthan. Detected by paramedics and confirmed by physicians, these cases gave an annual incidence of 2.76 (95% CI: 2.37-3.15) per 1000 population. At least one of these patients died, giving a case fatality ratio of 0.6%. The jaundice cases occurred in all areas investigated, and affected all socioeconomic strata. About 94% of the affected families had only single cases. Although cases occurred throughout the year, more than 59% occurred during June-September, which are the summer and monsoon months. The incidence was highest (5.23 per 1000) among under-5-year-olds and declined progressively and significantly thereafter. Males had a higher incidence than females at all ages; the differences were not significant. Blood samples from 56 cases who had jaundice in the last 3 months of the reference period were tested for markers of viral hepatitis. Of these, 18 (32.1%), 1 (1.8%), 0, 2 (3.6%), and 4 (7.1%) were found to have hepatitis A, B, C, D and E, respectively. The etiology of the remaining 31 cases (55%) could not be established; previously, they would have been included in the NANB (non-A, non-B) category, inflating its proportion. Hepatitis A (HA) was the predominant type; being comparatively mild, it is perhaps underrepresented in hospital-based data. Many HA cases were in adults, which may be the beginning of an age shift of HA to the right owing to improvements in living standards of the study population. Five cases were carriers of hepatitis B virus (HBV), indicating the importance of HBV infection in India as well. Finally, the study found the annual incidence of laboratory-supported cases of viral hepatitis to be 1.24 (95% CI: 0.98-1.5) per 1000 population, which suggests that it is a major public health problem in India.

Adolescent↗

Profile of epidemic emergencies in India during 1991-95.

Epidemic emergencies have shown increasing trend in India and most parts of the country appear to be vulnerable to these emergencies. In this paper we present a profile of epidemic emergencies attended by the National Institute of Communicable Diseases in the last five years, to delineate aspects that will promote better preparedness and management. Water borne and water related disease epidemics constituted more than 70% of the epidemic emergencies in India. Non 01 cholera epidemics constituted one fourth of total cholera epidemics during 1991-95. Most of the hepatitis outbreaks were attributed to Non A Non B. The source of infection in majority of the cholera and jaundice epidemics was contaminated water. Dengue and resistant typhoid fever were among other emergencies reported during last five years. Some of these epidemic were reported to local health authorities as mysterious diseases due to lack of public health laboratory facilities. Encephalitis and encephalitis like epidemics in the form of Liquor poisoning and chronic Heat syndrome encephalopathy were also observed. The re-emerging disease epidemics like plague in Beed, Pneumonic plague in Surat and malaria in Rajasthan were also investigated during 1994. These observations indicate the weakness in the epidemiological and laboratory surveillance besides inadequacy in water management practices and other socio environmental reasons.

Disaster Planning↗

Unusual occurrence of cholera in Delhi during January 1994: epidemiological investigations.

Hundreds of laboratory-confirmed cholera cases occur every year in Delhi. However from 1965 through 1993, no cases of cholera nor carriers of Vibrio cholerae have been detected in the months January and February of all these years. Nevertheless, two cases occurred in January 1994. Both were children who acquired their infection locally. Six hundred fifty-eight rectal swabs collected from possible contacts were negative for V. cholerae. The next isolations could be made only in April, which is the usual beginning of the cholera season. The study suggests that cholera transmission can occur during the winter months in Delhi, but that it is not sustained.

Acute Disease↗

Virologic surveillance of poliomyelitis in Delhi.

OBJECTIVE: Virologic surveillance of poliomyelitis to monitor the transmission of wild polio virus in the community. STUDY AREA: All major hospitals of Delhi and surrounding area. METHODS: Stool samples were collected from 1221 cases of acute flaccid paralysis during 1992-1994 and were subjected to virus isolation on RD and HEp2 cell line. Viruses isolated were analyzed further by microneutralization test using polio and nonpolio antisera. The polio isolates were further characterized as vaccine or wild type using ELISA and probe technology. RESULTS: Out of the 1221 cases tested, virus was isolated in 57.4%. Among the virus positive cases, polio was isolated in 57% and in 43% non polio entero viruses were detected. The most prevalent was polio virus type 1. Most of the strains were wild type. CONCLUSION: Wild polio virus was prevailing in the community under study between the years 1992-1994.

Humans↗

Methods for estimating prevalence and incidence of senile cataract blindness in a district.

The problem of senile cataract blindness (SCB) is very acute in India, contributing to 80 per cent of total blindness. The national objective of reducing the prevalence of blindness from 1.49 per cent, during 1986-89 to 0.3 per cent by AD 2000 has necessitated the surgical correction of SCB to be the major activity. With the introduction of District Blindness Control Society (DBCS), there has been a substantial increase in the number of operations of SCB in those districts. However, in the absence of standard, feasible, simple and cost effective methods to estimate the prevalence and incidence of SCB, the DBCS may find it difficult to plan and execute its major activity in a realistic way. The paper suggests two such methods for the use by DBCS. Only five seemingly rational assumptions have been adopted for the purpose. The authors feel that proper field testing is required to be sure about the reliability and validity of these methods.

Adult↗

Immunity to diphtheria in women of childbearing age in Delhi in 1994: evidence of continued Corynebacterium diphtheriae circulation.

Blood samples from 171 full-term pregnant women (aged 18-38 years) of middle socioeconomic status from Delhi were tested for diphtheria antitoxins by indirect hemagglutination (IHA) test. History of primary immunization/clinical diphtheria during childhood was not ascertainable, but none had been revaccinated against diphtheria at any time. About 94% women had very high antitoxin titers (> or = 0.125 IU/ ml); none had antitoxin titer less than 0.015 IU/ml, the minimum protective level. The titers were uniformly high in all age groups. However, women having 2 or more children had significantly higher antitoxin titers than those having no or one child (p < 0.01). The results from this study and historical data on diphtheria in Delhi are compatible with continued transmission of C. diphtheriae in recent times in Delhi which is of sufficient magnitude to boost the antitoxin levels in adults, especially mothers having two or more children. The study highlights the need of increasing the immunization coverage with DPT among children to reduce the transmission of Corynebacterium diphtheriae.

Adolescent↗