Mycobacteria affect both man and animals. The three major pathogenic species include M. tuberculosis, M. bovis and M. africanum. These three cause tuberculosis. However, there are Mycobacteria that do not cause tuberculosis but have the ability to cause disease in humans and animals, the most common being Mycobacterium avium complex, which consists of M. avium and M. intracellulare. Non tuberculosis Mycobacteria are highly resistant to chlorination as a way of treatment, they can therefore be found in piped water, write Leclerc H. et al in Microbial Waterborne Pathogens, chpt1.
Crptosporidium parvum It is important to note that this parasite came about as a result of the AIDS epidemic. Crptosporidium parvum is one of the major leading causes of diarrhoea in most developing countries. Like the salmonella, it is found in communal swimming pools, hospitals, surfaces of untreated water, areas where there is poor hygiene like refugee camps, IDP camps, daycare centers and hospitals. Infection occurs through drinking water that is already contaminated. The oocysts are very tiny but thick walled and the are resistant to chlorination.
In AIDS patients, the pathogens have proven to be life threatening. Because their immune systems have been compromised, the diarrhoea is usually more severe and lasts longer than that of the healthy person. In an AIDS patient it lasts for more than 2 weeks while in a formerly healthy patient the maximum period is two weeks. According to Manatsathit et al, in Journal of Gastroentology, the most common pathogen that causes diarrhoea is cryptosporidium and since there is no effective treatment for the disease, they might have it
for life and, in patients who are in the late stage of AIDS it usually attacks their pulmonary systems leading to death (Manatsathit et al, p535). Because of the cysts resistance to chlorination, filtration and flocculation helps in their removal from drinking water. Cyclospora cayetanensis Like cryptosporidium, this also causes a gastroenteric disease known as cyclosporiasis. In a formerly healthy person, the illness lasts up to seven weeks while in an AIDS patient the period is usually longer; about four months. Cyclosporiasis is characterized
by nausea, abdominal cramps, anorexia and watery diarrhoea…these symptoms are similar to those of cryptosporidiosis. Like the cryptosporidium oocysts, Cyclospora oocysts are also resistant to chlorination. Therefore, the same methods of water treatment which are filtration and flocculation are used to get rid of the oocysts from drinking water. Again, like in the case of the Cryptosporidium, Cyclospora came about as a result of AIDS. Study also shows that fruits and legumes are hosts for the pathogen, they should therefore be properly cleaned before being eaten.