Jaya Prakash Muliyil

Molecular and Spatial Epidemiology of Cryptosporidiosis in Children in a Semiurban Community in South India

ABSTRACT Cryptosporidium spp. are a leading cause of diarrhea in Indian children, but there are no data for prevalent species or subgenotypes. Genetic characterization of Cryptosporidium spp. by PCR-restriction fragment length polymorphism and spatial analysis of cases using Geographical Information Systems technology was carried out for 53 children with cryptosporidial diarrhea in an urban slum. The two most common species were C. hominis (81%) and C. parvum (12%). Other species identified were C. felis and C. parvum (mouse genotype). Five subgenotypes were identified at the Cpgp40/15 locus. Subgenotype Ia predominated among C. hominis isolates, and all C. parvum isolates were subgenotype Ic. C. hominis infection was associated with a greater severity of diarrhea. Sequencing of the Cpgp40/15 alleles of C. felis and C. parvum (mouse genotype) revealed similarities to subgenotype IIa and C. meleagridis, respectively. Space-time analysis revealed two clusters of infection due to C. hominis Ia, with a peak in February 2005. This is the first study to demonstrate space-time clustering of a single subgenotype of C. hominis in a setting where cryptosporidiosis is endemic. Molecular characterization and spatial analysis have the potential to further the understanding of disease and transmission in the community.

Comparative Study of the Epidemiology of Rotavirus in Children from a Community-Based Birth Cohort and a Hospital in South India

ABSTRACT Rotavirus gastroenteritis is the major cause of severe dehydrating diarrhea in children worldwide. This study compares rotavirus diarrhea in 351 children in a community-based cohort and 343 children admitted to a hospital during the same period. Clinical information and fecal specimens were obtained during diarrheal episodes. Fecal samples were screened for VP6 antigen, and the positive samples were G and P typed by reverse transcription-PCR. Rotavirus was detected in 82/1,152 (7.1%) episodes of diarrhea in the community and 94/343 (27.4%) cases in the hospital. The median age of affected children (7.5 versus 10.5 months) and the mean severity of symptoms (Vesikari score, 7.6 ± 3.4 versus 11 ± 2.5) were lower in the community. A larger proportion of children in the community were breast-fed than were children admitted to the hospital (73% versus 34.8%). In the community, the genotypes identified in symptomatic patients, in order of frequency, were G1 (36.5%), G10 (17.1%), G2 (15.9%), and G9 (7.3%) and mixed infections (7.3%). The most common G-P combinations were G1P[8], G2P[4], G1P[4], and G10P[11]. The distribution of G types from hospitalized children was G1 (46.8%), G9 (19.1%), G2 (8.5%), G10 (1.1%), and 4.3% mixed infections. The most common G-P combinations were G1P[8] and G9P[8]. This study documents significant genetic heterogeneity of rotaviruses in the community and the hospital. G10P[11] strains resembling a vaccine candidate strain caused disease in the community, indicating the need for careful epidemiological studies as well as safety studies for the vaccine candidates.

Prevalence of intestinal parasites in rural Southern Indians

objective    To determine the prevalence of intestinal protozoal and helminthic infection in a rural population.method  Seventy‐eight members of 15 families from a village were studied. Stool samples from all subjects were examined on alternate days for one month.results  The overall prevalence rate of various parasitic infections was 97.4%, with only 2 of 78 subjects not excreting parasites in any of their 15 samples. Eighteen (23.1%) persons had only one type of parasite, while 58 (74.3%) excreted multiple parasites. Giardia and Cryptosporidium were the commonest protozoan infections, affecting 42/78 (53.8%) and 31/78 (39.7%), respectively. Hookworm infestations were the commonest helminthic infections, seen in 48/78 (61.5%). Based on excretion patterns, the asymptomatic individuals could be divided into 2 groups of infrequent and frequent excretors, indicating that the host response may determine the level of parasite replication in the gut.

Infant morbidity in an Indian slum birth cohort

Objective: To establish incidence rates, clinic referrals, hospitalisations, mortality rates and baseline determinants of morbidity among infants in an Indian slum. Design: A community-based birth cohort with twice-weekly surveillance. Setting: Vellore, South India. Subjects: 452 newborns recruited over 18 months, followed through infancy. Main outcome measures: Incidence rates of gastrointestinal illness, respiratory illness, undifferentiated fever, other infections and non-infectious morbidity; rates of community-based diagnoses, clinic visits and hospitalisation; and rate ratios of baseline factors for morbidity. Results: Infants experienced 12 episodes (95% confidence interval (CI) 11 to 13) of illness, spending about one fifth of their infancy with an illness. Respiratory and gastrointestinal symptoms were most common with incidence rates (95% CI) of 7.4 (6.9 to 7.9) and 3.6 (3.3 to 3.9) episodes per child-year. Factors independently associated with a higher incidence of respiratory and gastrointestinal illness were age (3–5 months), male sex, cold/wet season and household involved in beedi work. The rate (95% CI) of hospitalisation, mainly for respiratory and gastrointestinal illness, was 0.28 (0.22 to 0.35) per child-year. Conclusions: The morbidity burden due to respiratory and gastrointestinal illness is high in a South Indian urban slum, with children ill for approximately one fifth of infancy, mainly with respiratory and gastrointestinal illnesses. The risk factors identified were younger age, male sex, cold/wet season and household involvement in beedi work.

Neonatal Infection with G10P[11] Rotavirus Did Not Confer Protection against Subsequent Rotavirus Infection in a Community Cohort in Vellore, South India

BACKGROUND Various observational studies have suggested that neonatal rotavirus infection confers protection against diarrhea due to subsequent rotavirus infection. We examined the incidence of rotavirus infection and diarrhea during the first 2 years of life among children infected with the G10P[11] rotavirus strain during the neonatal period and those not infected with rotavirus. METHODS Children were recruited at birth and were followed up at least twice weekly. Stool samples, collected every 2 weeks for surveillance and at each episode of diarrhea, were screened by enzyme-linked immunosorbent assay and were genotyped by polymerase chain reaction. RESULTS Among 33 children infected neonatally with G10P[11] and 300 children not infected with rotavirus, there was no significant difference in the rates of rotavirus-positive diarrhea (rate ratio [RR], 1.05 [95% confidence interval [CI], 0.61-1.79]), moderate or severe rotavirus-positive diarrhea (RR, 1.42 [95% CI, 0.73-2.78]), or asymptomatic rotavirus shedding (RR, 1.25 [95% CI, 0.85-1.83]). CONCLUSION Neonatal G10P[11] infection with a strain resembling a vaccine candidate did not confer protection against subsequent rotavirus infection or diarrhea of any severity in this setting.

Polymerase chain reaction in the detection of an ‘outbreak’ of asymptomatic viral infections in a community birth cohort in south India

Asymptomatic enteric infections are important where sequelae or protection from subsequent illness is an outcome measure. The use of reverse transcription-polymerase chain reaction (RT-PCR) to identify asymptomatic enteric infections in a birth cohort followed for rotaviral infections in a south Indian urban slum is reported. Of 1191 non-diarrhoeal samples from 371 children collected in May-June 2003, 22 (1.9%) were positive by ELISA. A total of 147 (40.6%) of 362 samples tested by VP6 RT-PCR were positive. In those samples that could be typed, a high diversity of G types including G1, G2, G4, G8, G9 and G10, and a high proportion (34.4%) of mixed infections were detected. Noroviruses were identified in 6/28 (21.4%) samples tested. The identification of infections undetectable by conventional techniques indicates the importance of the use of sensitive diagnostic techniques in research studies. Asymptomatically infected children may also act as a source of infection for other susceptible hosts.

Congenital rubella syndrome and rubella in Vellore, South India

Rubella, a mild, vaccine-preventable disease, can manifest as congenital rubella syndrome (CRS), a devastating disease of the fetus. To emphasize the inadequacy of the existing rubella vaccination programme in India, we evaluated epidemiological evidence of rubella virus activity with data available from a tertiary-care centre. The proportion of suspected CRS cases that were laboratory confirmed increased from 4% in 2000 to 11% in 2008. During the same period, 329 clinically suspected postnatal rubella cases were tested of which 65 (20%) were laboratory confirmed. Of women (n=770) of childbearing age, 12·5% were susceptible to rubella.

Retrospective cohort study comparing neonatal outcomes of women treated with glyburide or insulin in gestational diabetes: a 5-year experience in a South Indian teaching hospital.

OBJECTIVE To assess the effectiveness of glyburide in preventing complications of gestational diabetes in neonates as compared to insulin. MATERIALS AND METHODS Information from birth register, maternal and neonatal records were obtained. Five hundred and seventy-seven gestational diabetics with moderate hyperglycemia i.e., with highest fasting plasma glucose value of ≤130 mg/dl and/or highest post-prandial value of ≤250 mg/dl treated with insulin or glyburide were included from a cohort of 769 women needing additional therapy to initial diet therapy during a 5-year period. Thus neonatal outcomes of 303 women treated with insulin and 274 women treated with glyburide were compared. RESULTS Baseline plasma glucose levels in the group treated with insulin were higher. The mean birth weight (SD) of the neonates in women treated with insulin was 3021.3 g (604.19) as compared to 3104.6 g (499.35, P = 0.07) in the group treated with glyburide. Neonatal outcomes such as hypoglycemia (4.9%, 3.6%, P = 0.44), hypocalcemia (1.3%, 0.7%, P = 0.48), polycythemia (1.7%, 0.7%, P = 0.31), macrosomia (11.6%, 8.7%, P = 0.26), congenital anomalies (2.1%, 2.3%, P = 0.87), birth trauma (1.4%, 1.2%, P = 0.79) were similar in both groups. Neonates of women treated with insulin were more likely to have hyperbilirubinemia (11.5%, 6.5%, P = 0.03). CONCLUSION Neonatal outcomes of women treated with glyburide were comparable to those in women treated with insulin. More number of neonates of mothers treated with insulin had hyperbilirubinemia compared to neonates of mothers treated with glyburide (11.5%, 6.5% P = 0.03).

Rotavirus and other Diarrheal Disease in a Birth Cohort from Southern Indian Community.

ObjectiveTo describe the incidence, severity and etiology of diarrheal disease in infants and young children residing in an urban slum community in Southern India.SettingThree contiguous urban slums in Vellore, Tamil Nadu.Participants452 children participating in a birth cohort study on diarrheal disease; 373 completed three years of follow-up.Outcome measuresDiarrheal incidence (obtained by twiceweekly home visits) and severity (assessed by the Vesikari scoring system), and etiological agents associated with diarrhea (through examination of stool specimens by bacteriologic culture, rotavirus enzyme immunoassay, PCR for norovirus and microscopy for parasites).ResultsA total of 1856 diarrheal episodes were reported in 373 children. The overall incidence rate of diarrhea was 1.66 episodes per child year for three years, with 2.76 episodes per child year in infancy. The incidence peaked during the months of July and August. Severe diarrhea formed 8% of the total episodes. Rotavirus was the most common pathogen detected, being identified in 18% of episodes. Good hygiene status resulted in 33% protection against moderate-to-severe diarrhea.ConclusionsThis study highlights the burden of diarrheal disease and the important etiological agents of childhood diarrhea in Southern India. Promotion of hygienic behavior through health education may help reduce diarrheal incidence in this and similar communities.