Cryptosporidium parvum is a leading pathogen in children in developing countries. To investigate whether early postnatal malnutrition leads to heavier C. parvum infections, we assessed intestinal adaptation and parasite load in suckling mice during the first 2 wk of life, analogous to the first postnatal yr in humans. Undernutrition was induced by daily C57BL6J pup separation from lactating dams. Half of the pups were separated daily, for 4 hr on day 4, 8 hr on day 5, and for 12 hr from day 6 until day 14. On day 6, each pup received an oral inoculum of 10 5 to 10 7 parasites in 10-25 μl of PBS. Littermate controls received PBS alone. Stools were assessed from days 8, 11, and 14 for oocyst counts. Mice were killed on day 14, 8 days postinoculation, at the peak of the infection. Ileal and colon segments were obtained for histology, real-time and reverse transcriptase PCR, and immunoassays. Villus and crypt lengths and cross-sectional areas were also measured. Undernourished and nourished mice infected with excysted 10 6 or 10 7 oocysts exhibited the poorest growth outcomes compared with their uninfected controls. Nourished 10 6 -infected mice had comparable weight decrements to uninfected undernourished mice. Body weight and villi were additively affected by malnutrition and cryptosporidiosis. Hyperplastic crypts and heavier inflammatory responses were found in the ilea of infected malnourished mice. Undernourished infected mice exhibited greater oocyst shedding, TNF-α and IFN-γ intestinal levels, and mRNA expression compared to nourished mice infected with either 10 5 or 10 6 oocysts. Taken together, these findings show that Cryptosporidium infection can cause undernutrition and, conversely, that weanling undernutrition intensifies infection and mucosal damage.Cryptosporidiosis, first described by Tyzzer (1907) in the gastric glands of infected mice (Tzipori and Ward, 2002), has emerged as an increasingly recognized public health threat. Cryptosporidium spp. have been identified in watery diarrhea of patients with HIV and other immunocompromised patients and in large human outbreaks of diarrhea in both developed and developing parts of the world (Harp, 2003;Ramirez et al., 2004;Houpt et al., 2005). Furthermore, the long-term impact of cryptosporidial infection has been increasingly recognized in impoverished settings around the world (Checkley et al., 1997;Guerrant, 1997;Checkley et al., 1998 protozoan is adapted to survive and spread in the environment (Dillingham et al., 2002;Karanis et al., 2007).Crowded households with inadequate sanitation further aggravate the likelihood of the infection spreading from person to person (Newman et al., 1999;Caccio and Pozio, 2006). The lack of adequate treatment or prevention for high-risk groups for this chlorine-resistant food-and waterborne protozoan adds to the difficulties controlling cryptosporidial infections (Smith and Corcoran, 2004).Impoverished household environments and water contamination tremendously increase the risk of exposure to waterborne pathogen...

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Worldwide, contaminated drinking water poses a major health threat, particularly to child development. Diarrhoea represents a large part of the water-related disease burden and enteric infections have been linked to nutritional and growth shortfalls as well as long-term physical and cognitive impairment in children. Previous studies detailed the frequency of infection and the consequences for child health in a shanty town in north-east Brazil. To determine the frequency of contaminated water, we measured faecal contamination in primary drinking water samples from 231 randomly selected households. Risk for contamination was compared across source and storage types. Nearly a third of the study households (70/231: 30.3%) had contaminated drinking water; the source with the highest frequency of contamination was well water (23/24: 95.8%). For tap water, the type of storage had a significant effect on the susceptibility to contamination (x 2 ¼ 12.090; p ¼ 0.007). The observed pattern of contamination demonstrated the relative potential contributions of both source and storage. With evidence that supports the inclusion of source and storage in water quality surveys, this study, like others, suggests that contaminated drinking water in storage vessels may be an important factor for the documented diarrhoea disease burden in the Brazilian shanty town.