Symptomatic and Asymptomatic Cryptosporidium Infections in Children in a Semi-Urban Slum Community in Southern India

Ajjampur, Sitara S. R.; Sarkar, Rajiv; Sankaran, Premi; Kannan, A.; Menon, Vipin; Muliyil, Jayaprakash; Ward, Honorine; Kang, Gagandeep

doi:10.4269/ajtmh.2010.09-0644

Cited by 55 publications

(44 citation statements)

References 31 publications

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“…Previous studies have shown that Cryptosporidium is an important cause of gastroenteritis in children in developing countries (45)(46)(47); in the recent GEMS, around 10% of diarrhea cases in children younger than 2 years were attributed to Cryptosporidium (3). In our study, Cryptosporidium was detected in 30% of children with diarrhea versus 11% of asymptomatic children, and 25% of patients had Cryptosporidium detected with C T values below the cutoff of 35, indicating a causative role.…”

Section: Discussionmentioning

confidence: 99%

Real-Time PCR Threshold Cycle Cutoffs Help To Identify Agents Causing Acute Childhood Diarrhea in Zanzibar

et al. 2014

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f Molecular assays might improve the identification of causes of acute diarrheal disease but might lead to more frequent detection of asymptomatic infections. In the present study, real-time PCR targeting 14 pathogens was applied to rectal swabs from 330 children aged 2 to 59 months in Zanzibar, including 165 patients with acute diarrhea and 165 asymptomatic control subjects. At least one pathogen was detected for 94% of the patients and 84% of the controls, with higher rates among patients for norovirus genogroup II (20% versus 2.4%; P < 0.0001), rotavirus (10% versus 1.8%; P ‫؍‬ 0.003), and Cryptosporidium (30% versus 11%; P < 0.0001). Detection rates did not differ significantly for enterotoxigenic Escherichia coli (ETEC)-estA (33% versus 24%), ETEC-eltB (44% versus 46%), Shigella (35% versus 33%), and Campylobacter (35% versus 33%), but for these agents threshold cycle (C T ) values were lower (pathogen loads were higher) in sick children than in controls. In a multivariate analysis, C T values for norovirus genogroup II, rotavirus, Cryptosporidium, ETEC-estA, and Shigella were independently associated with diarrhea. We conclude that this real-time PCR allows convenient detection of essentially all diarrheagenic agents and provides C T values that may be critical for the interpretation of results for pathogens with similar detection rates in patients and controls. The results indicate that the assessment of pathogen loads may improve the identification of agents causing gastroenteritis in children.

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Section: Discussionmentioning

confidence: 99%

Real-Time PCR Threshold Cycle Cutoffs Help To Identify Agents Causing Acute Childhood Diarrhea in Zanzibar

et al. 2014

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“…Previous studies in the same community have shown a high burden of childhood cryptosporidiosis. 31,32 …”

Section: Introductionmentioning

confidence: 99%

Risk Factors for Cryptosporidiosis Among Children in a Semi Urban Slum in Southern India: A Nested Case-Control Study

Sarkar

Kattula

Francis

et al. 2014

The American Society of Tropical Medicine and Hygiene

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Abstract. The risk factors for acquisition of cryptosporidial infection in resource-poor settings are poorly understood. A nested case-control study was conducted to assess factors associated with childhood cryptosporidiosis (detected by stool polymerase chain reaction) in an endemic, Indian slum community using data from two community-based studies with 580 children followed prospectively until their second birthday. Factors were assessed for overall cryptosporidiosis (N = 406), and for multiple (N = 208), asymptomatic (N = 243), and symptomatic (N = 163) infections, respectively. Presence of older siblings (odds ratio [OR] = 1.88, P = 0.002) and stunting at 6 months of age (OR = 1.74, P = 0.019) were important risk factors for childhood cryptosporidiosis. Always boiling drinking water before consumption, the use of a toilet by all members of the family, and maternal age 23 years were protective. These results provide insights into acquisition of childhood cryptosporidiosis in settings with poor environmental sanitation, contaminated public water supply systems, and close human-animal contact. Disease control strategies will require a multifaceted approach.

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“…Previously, we investigated the clinical features and molecular and spatial epidemiology of cryptosporidiosis in a birth cohort of children in a semiurban slum community in South India (2,3). The most common species identified in diarrheal stool samples from these children was C. hominis, with gp40/15 subtype Ia predominating.…”

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Serum IgG Response to Cryptosporidium Immunodominant Antigen gp15 and Polymorphic Antigen gp40 in Children with Cryptosporidiosis in South India

Ajjampur

Sarkar

Allison

et al. 2011

Clin. Vaccine Immunol.

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The surface-associated glycopeptides gp40, one of the most polymorphic Cryptosporidium antigens, and gp15, one of the most immunodominant Cryptosporidium antigens, are putative vaccine candidates because they mediate infection in vitro and induce immune responses in vivo. We evaluated antibody responses to these antigens before and after the first episode of symptomatic cryptosporidiosis in 51 children from a birth cohort study in an area in South India where Cryptosporidium is endemic and a major cause of parasitic diarrhea. IgG levels to gp15 and to homotypic and heterotypic gp40 antigens were measured in pre-and postdiarrheal sera by enzyme-linked immunosorbent assay (ELISA). There was a significant IgG response to gp15 (P < 0.001) following the first episode of cryptosporidial diarrhea. Using a general additive model, we determined the estimated time of the peak IgG response to gp15 to be 9.3 weeks (confidence interval, 5.2 to 13.4) following the diarrheal episode. In a subset of 30 children infected with Cryptosporidium hominis subtype Ia, there was a significant difference in IgG responses to homotypic C. hominis Ia and to heterotypic Cryptosporidium parvum II gp40 antigens (P ‫؍‬ 0.035). However, there was also a significant correlation (P ‫؍‬ 0.001) in the responses to both antigens in individual children, suggesting that while responses are in part subtype specific, there is significant cross-reactivity to both antigens. This is the first report of the characterization of immune responses to cryptosporidiosis in Indian children and the first study to investigate human immune responses to the polymorphic gp40 antigen. However, further studies are needed to determine whether immune responses to these antigens are protective against subsequent infections.

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Symptomatic and Asymptomatic Cryptosporidium Infections in Children in a Semi-Urban Slum Community in Southern India

Cited by 55 publications

References 31 publications

Real-Time PCR Threshold Cycle Cutoffs Help To Identify Agents Causing Acute Childhood Diarrhea in Zanzibar

Real-Time PCR Threshold Cycle Cutoffs Help To Identify Agents Causing Acute Childhood Diarrhea in Zanzibar

Risk Factors for Cryptosporidiosis Among Children in a Semi Urban Slum in Southern India: A Nested Case-Control Study

Serum IgG Response to Cryptosporidium Immunodominant Antigen gp15 and Polymorphic Antigen gp40 in Children with Cryptosporidiosis in South India

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