Human Cryptosporidiosis: An insight into Epidemiology, Modern Diagnostic Tools and Recent Drug Discoveries

Cryptosporidiosis is an emerging food and water borne zoonotic disease, which is caused by genus Cryptosporidium . The first  Cryptosporidium  spp. was isolated from mice in 1907 and gained importance when it was found in an HIV positive patient. It usually causes self-limiting diarrhea in young children and immunocompetent patients. However, it may lead to chronic diarrhea with life threatening condition in immunocompromised patients. Other complications related to this transmittable infection may include respiratory problems, skin rashes and headache. HIV/AIDS patients are highly susceptible host for this parasite.  Cryptosporidium parvum  and  Cryptosporidium hominis  are the known pathogenic species, prevalent among humans and they are being transmitted through contaminated food and water. Usually, the diagnosis of  Cryptosporidium  spp. is dependent on microscopic technique in many countries, which has a low sensitivity and specificity leading to false positive results. However, for a step forward to successful epidemiological studies, advanced techniques (Serological and DNA-based) provide us the better ways of diagnosis with more sensitivity and specificity. Furthermore, no antiparasitic drug has found to be effective against Cryptosporidium  spp. except Nitazoxanide which is FDA-approved and effective only when administered along with antiretroviral therapy. In this regard, present review summarizes the various epidemiological studies conducted around the globe along with modern diagnostic tools and the suitable treatment available now a days. This systemized review will help the scientists to better understand all the aspects of cryptosporidiosis at one platform which may help in designing surveillance studies through selection of sensitive diagnostic techniques. The new drugs mentioned in this review may also help to better control this parasite in humans, especially immunocompromised individuals.