Avian Cryptosporidiosis And Its Zoonotic Significance In Asia

Cryptosporidium is regarded as one of the neglected, zoonotic, food and water-borne protozoal pathogens. Cryptosporidium species (C.) have been reported from more than 30 species of domestic, wild and captive birds. Human interaction with birds may cause zoonotic spread of Cryptosporidium spp., leading to high morbidities and even mortalities in both immune-competent and immune-compromised individuals. The research data from 16 Asian countries indicate highly variable prevalence of avian cryptosporidiosis ranging 8-35% approximately. The data on human cryptosporidiosis outbreak cases in the US during 2009-2017 has shown an increase of 12.8% per annum. A similar or even worse trend may be expected in developing nations. Based on critical analysis of current millennial data (2000-2019) from Asia, the reported zoonotic prevalence of cryptosporidiosis was approximately 1.5-7, 5.2, 8.3, 8.5, 9-20, 11, similar to 11, 11.8, and 38.25% in Iran, Malaysia, Jordan, Saudi Arabia, Pakistan, China, Lebanon, India and Egypt, respectively. Research on metagenomics and eco-biology of Cryptosporidium is providing valuable insights into potential vaccine candidates against the disease globally. Strict biosecurity, disinfection, filtration, hand sanitisation, and overall adequate hygienic measures can effectively prevent infection with the hardy cryptosporidial oocysts at commercial and household levels. The bottle-necks for Cryptosporidium spread in birds and humans need to be identified and adequately addressed. The purpose of this review is to highlight avian cryptosporidiosis including epidemiology, transmission dynamics, associated risk factors, and their prevention, diagnostics with streamlined efforts in strengthening health-care surveillance systems and therapeutics, along with its zoonotic impact across the Asian continent.