[Human cryptosporidiosis and Cryptosporidium spp. in Haiti].

Contamination by water-born infectious diseases is closely linked to urban slums conditions such as overcrowding and high level of faecal pollution by animal and human excreta. In this environment, cryptosporidiosis is a major cause of acute diarrhoea in children and chronic persistent diarrhoea in AIDS patients, resulting in increased morbidity and mortality in both populations. The aims of this study conducted in Port-au-Prince, Haiti were to: (i) determine the frequency of Cryptosporidium infection in two populations of patients with diarrhoea, children and AIDS patients, and the existence of Cryptosporidium carriage in healthy adults living in close contact with them; (ii) identify by molecular genotyping the Cryptosporidium species involved; and (iii) evaluate the viability of Cryptosporidium oocysts isolated from human stools. From January 2000 to January 2001, 158 of 1529 diarrhoea stool samples collected from 93 patients with diarrhoea, 57 adults followed at Centres GHESKIO and 36 children admitted at the University Hospital in Port-au-Prince contained Cryptosporidium oocysts (10.3%). The majority of adult patients (98%) were HIV-infected whereas the majority of children (81%) tested negative for HIV. Cryptosporidium was documented in only 1/102 healthy persons living in contact with Cryptosporidium infected patients and infection was with the same genotype as that of the contact patient. Among the 69 Cryptosporidium isolates studied for genotyping, three species were identified: C. hominis (59%), C. parvum (38%) and C. felis (3%). The two C. felis cases are the first reported from AIDS patients in the Caribbean. Most of the children regardless of their HIV status were infected with C. hominis (72%), whereas AIDS patients were more likely to be infected by either human or animal genotypes. These data confirm that immunocompromised individuals are susceptible to a wide range of Cryptosporidium spp. Viability of Cryptosporidium oocysts were determined in an experimental mouse model for 17/18 specimen studied including in 12/13 C. hominis, 4/4 C. parvum and 1/1 C. felis. Infectivity in newborn mice was found to be dose-dependent and more effective with C. parvum than the other two genotypes. Cryptosporidiosis remains a frequent hazard for both AIDS patients and young children in Haiti because of poor hygiene, particularly contaminated water and overcrowded conditions associated with urban slums.