Epidemiology and Molecular Relationships of Cryptosporidium spp. in People, Primates, and Livestock from Western Uganda

Abstract

Background Cryptosporidium is one of the most common parasitic diarrheal agents in the world and is a known zoonosis. We studied Cryptosporidium in people, livestock, and non-human primates in the region of Kibale National Park, Uganda. Land use change near the park has resulted in fragmented forest patches containing small, remnant populations of wild primates that interact intensively with local people and livestock. Our goal was to investigate risk factors for Cryptosporidium infection and to assess cross-species transmission using molecular methods. Methodology/Principal Findings Diagnostic PCR revealed a prevalence of Cryptosporidium of 32.4% in humans, 11.1% in non-human primates, and 2.2% in livestock. In the case of humans, residence in one particular community was associated with increased risk of infection, as was fetching water from an open water source. Although 48.5% of infected people reported gastrointestinal symptoms, this frequency was not significantly different in people who tested negative (44.7%) for Cryptosporidium , nor was co-infection with Giardia duodenalis associated with increased reporting of gastrointestinal symptoms. Fecal consistency was no different in infected versus uninfected people or animals. DNA sequences of the Cryptosporidium oocyst wall protein gene placed all infections within a well-supported C. parvum / C. hominis clade. However, the only two sequences recovered from primates in the core of the park's protected area fell into a divergent sub-clade and were identical to published sequences from C. parvum , C. hominis , and C. cuniculus , suggesting the possibility of a separate sylvatic transmission cycle. Conclusions/Significance Cryptosporidium may be transmitted frequently among species in western Uganda where people, livestock, and wildlife interact intensively as a result of anthropogenic changes to forests, but the parasite may undergo more host-specific transmission where such interactions do not occur. The parasite does not appear to have strong effects on human or animal health, perhaps because of persistent low-level shedding and immunity.

Laboratory utility of coproscopy, copro immunoassays and copro nPCR assay targeting Hsp90 gene for detection of Cryptosporidium in children, Cairo, Egypt

“…Using PCR, different Cryptosporidium prevalence rates were reported in Egypt (Hassan et al 2002;El-Mohamady et al 2006;El-Shazly et al 2007;El-Hamshary et al 2008;El-Settawy and Fathy 2012) and worldwide (Morgan et al 1998;Khurana et al 2012;Salyer et al 2012), in Egypt the prevalence ranged from 10.7 to 25.5 %. The difference in the reported prevalence may be attributed to differences in study population, demographic, behavioral, environmental and socioeconomic factors, diagnostic methods, time of the study (summer vs. winter), nutritional status of the children, and educational level of parents (AL-Hindi et al 2007).…”

“…Due to its higher sensitivity, PCR-based methods were nominated by many authors (Jex et al 2008;Salyer et al 2012) and the present study as the gold standard test. a In order to obtain lab use, priority values were multiplied by the ranks given for each attribute for every diagnostic technique, sum up was given in total Microscopy and copro immunoassays were of prefect specificity with 100 % specificity and PPV.…”

“…Challenge to incomparable sensitivity of PCR (Salyer et al 2012) is the reliable extraction of Cryptosporidium copro-DNA from oocyst stage in stools. This requires a cell disruption; include thermal treatment; boiling, and freezethaw cycles, chemical and/or mechanical treatment.…”

“…Recently, PCR based methods for the laboratory diagnosis of cryptosporidiosis were developed and showed excellent specificity and sensitivity, compared with antigen detection, and microscopy (Salyer et al 2012).…”

Low sensitivity of the ImmunocardSTAT® Crypto/Giardia Rapid Assay test for the detection of Giardia and Cryptosporidium in fecal samples from children living in Libreville, Central Africa

“…However, it has been shown that C. spp. is not restricted to immunocompromised hosts, it is also found in immunocompetent individuals (Nchito et al 1998;Gatei et al 2006;Salyer et al 2012). This parasite frequently infects children, in which it may have adverse effects on nutritional outcomes, affecting intestinal absorption, nutrition, and childhood development (Checkley et al 1997;Mondal et al 2009;Mølbak et al 1997).…”