Epidemiology and Molecular Characterization of Cryptosporidium spp. in Humans, Wild Primates, and Domesticated Animals in the Greater Gombe Ecosystem, Tanzania

Abstract

Cryptosporidium is an important zoonotic parasite globally. Few studies have examined the ecology and epidemiology of this pathogen in rural tropical systems characterized by high rates of overlap among humans, domesticated animals, and wildlife. We investigated risk factors for Cryptosporidium infection and assessed cross-species transmission potential among people, non-human primates, and domestic animals in the Gombe Ecosystem, Kigoma District, Tanzania. A cross-sectional survey was designed to determine the occurrence and risk factors for Cryptosporidium infection in humans, domestic animals and wildlife living in and around Gombe National Park. Diagnostic PCR revealed Cryptosporidium infection rates of 4.3% in humans, 16.0% in non-human primates, and 9.6% in livestock. Local streams sampled were negative. DNA sequencing uncovered a complex epidemiology for Cryptosporidium in this system, with humans, baboons and a subset of chimpanzees infected with C. hominis subtype IfA12G2; another subset of chimpanzees infected with C. suis; and all positive goats and sheep infected with C. xiaoi. For humans, residence location was associated with increased risk of infection in Mwamgongo village compared to one camp (Kasekela), and there was an increased odds for infection when living in a household with another positive person. Fecal consistency and other gastrointestinal signs did not predict Cryptosporidium infection. Despite a high degree of habitat overlap between village people and livestock, our results suggest that there are distinct Cryptosporidium transmission dynamics for humans and livestock in this system. The dominance of C. hominis subtype IfA12G2 among humans and non-human primates suggest cross-species transmission. Interestingly, a subset of chimpanzees was infected with C. suis. We hypothesize that there is cross-species transmission from bush pigs (Potaochoerus larvatus) to chimpanzees in Gombe forest, since domesticated pigs are regionally absent. Our findings demonstrate a complex nature of Cryptosporidium in sympatric primates, including humans, and stress the need for further studies.

Prevalence and Determinants of Cryptosporidium Infection in an Underdeveloped Rural Region of Southwestern China

“…Previous studies also found that raising cattle, especially calve, was a risk factor for human Cryptosporidium infection. 3,31 In this area, cattle usually graze on the nearby hills away from human settlements, thus human-cattle contacting is less frequent. Horses, cats, and dogs are primarily infected with host-specific Cryptosporidium species or genotypes, and therefore, the actual risk of zoonotic transmission of these animals may be low.…”

Occurrence of Cryptosporidium spp. in wild animals living in the Cascavel city park, Paraná, Brazil

“…Out of the total of 31 analyzed stool samples, 18 (58.06%) were positive, results much higher than those found by other authors in different parts of the world, ranging from 0.5 to 27% (SAK et al, 2013;. SALYER et al, 2012;PARSONS et al, 2015;EKANAYAKE et al, 2006). These authors claim that environmental changes caused by man and the use of these means by humans and animals provide a transmission of parasitic infection between wild and domestic animals and man.…”

Association of Anthropogenic Disturbances and Intestinal Parasitism in Ecuadorian Mantled Howler Monkeys, Alouatta palliata aequatorialis

“…Both zoonotic transmission of pathogens and composition of parasite communities in mammals have been linked to human disturbances, as previously outlined [Patz et al, 2000;Chapman et al, 2005;Puttker et al, 2008;Zommers et al, 2013;Helenbrook, 2014;Parsons et al, 2015; reviewed by Han et al, 2016]. In particular, parasite species richness and prevalence of several intestinal parasites have been reported to be higher in selectively logged and forest fragments compared to primary habitat Salzer et al, 2007;Trejo-Macías et al, 2007;Schwitzer et al, 2010]; however, there are several cases where no effect was found -particularly as it relates to primates [Kowalewski and Gillespie, 2009;Young et al, 2013].…”