Global Distribution, Public Health and Clinical Impact of the Protozoan PathogenCryptosporidium

Abstract

Cryptosporidium spp. are coccidians, oocysts-forming apicomplexan protozoa, which complete their life cycle both in humans and animals, through zoonotic and anthroponotic transmission, causing cryptosporidiosis. The global burden of this disease is still underascertained, due to a conundrum transmission modality, only partially unveiled, and on a plethora of detection systems still inadequate or only partially applied for worldwide surveillance. In children, cryptosporidiosis encumber is even less recorded and often misidentified due to physiological reasons such as early-age unpaired immunological response. Furthermore, malnutrition in underdeveloped countries or clinical underestimation of protozoan etiology in developed countries contribute to the underestimation of the worldwide burden. Principal key indicators of the parasite distribution were associated to environmental (e.g., geographic and temporal clusters, etc.) and host determinants of the infection (e.g., age, immunological status, travels, community behaviours). The distribution was geographically mapped to provide an updated picture of the global parasite ecosystems. The present paper aims to provide, by a critical analysis of existing literature, a link between observational epidemiological records and new insights on public health, and diagnostic and clinical impact of cryptosporidiosis.

Cryptosporidiosis in HIV/AIDS Patients in Kenya: Clinical Features, Epidemiology, Molecular Characterization and Antibody Responses

“…The distribution of Cryptosporidium species varies from country to country and even from one region to another 50 ; the majority of the patients in this study were infected with C. hominis followed by C. parvum species. This is consistent with a previous study on HIV-infected children in Kenya, in whom C. hominis and C. parvum were the main species identified with prevalence rates of 87% and 9%, respectively.…”

Enteric Protozoa in the Developed World: a Public Health Perspective

“…Most animals are not infected with human-pathogenic species and thus play no role in zoonotic transmission of cryptosporidiosis. However, zoonotic transmission from direct contact with infected animals or their feces (55,89,345,476) or indirectly through the consumption of contaminated water (63,66,327,476) can occur. The small size and subtle staining characteristics of Cryptosporidium spp.…”

Waterborne outbreaks of cryptosporidiosis

“…However, whether, given improved drinking water quality and reduction in Cryptosporidium risk since then [18], this permanent blanket advice remains necessary there is currently under review. Also of great concern are the longer term sequelae of infection in both the general population and in malnourished children in whom, even following asymptomatic infection, reduced cognitive function and failure to thrive have been reported (reviewed by Putignani and Menichella [19]). Even in non-immune compromised people, there is some evidence to suggest there may be different long term health effects depending on infecting species: for example, those cryptosporidiosis patients infected with C. hominis (but not C. parvum) were more likely to report joint pain, eye pains, headaches and fatigue in the two months following infection than controls HeAltH rIsks from wAter AnD new cHAllenges for tHe future [20].…”