Mauritania lies between West-Central Africa where human cystic echinococcosis (CE) is considered extremely rare and West Maghreb where CE accounts for a real public health problem. Until 1992, Mauritania was considered as human CE-free even through CE seemed well known in livestock. In 1992, the introduction of ultrasonography led to the diagnosis of the first human CE cases. In 1997, a veterinary study revealed that dogs living around Nouakchott were commonly infected by Echinococcus granulosus. To assess E. granulosus transmission and to identify the most relevant animal reservoir responsible for human CE emerging in Mauritania, a simultaneous eco-epidemiological and molecular biology approach was performed. The fieldwork included sample collection and investigation of relationship between intermediate hosts, definitive hosts and humans. Typing of E. granulosus strains was performed using comparison of polymerase chain reaction (PCR)-amplified DNA sequences with one nuclear (BG 1/3) and 2 mitochondrial (COI, NDI) targets. Results show that the 'camel' strain is actually infectious to humans and circulates between intermediate hosts including camels and cattle. It is suggested that preventive measures at slaughtering places could reduce human contamination.

Recent studies of Echinococcus granulosus molecular strain typing have enabled a better understanding of the transmission cycle of cystic echinococcosis. There have been many publications in this area but there is a need for the evaluation of these tools. We have attempted to respond to this need in our study, which assessed 8 DNA fragments of 40 E. granulosus cysts from North Africa. Parasitological material was collected from 5 types of intermediate hosts, in 5 different countries. The primers chosen to amplify DNA targets were defined either in nuclear DNA, or in mitochondrial DNA. After amplification, PCR products were sequenced. The sequences obtained were aligned and comparisons were made within the group and with GenBank sequences. Whether the target was nuclear or mitochondrial, the same 2 main groups of genotypes were found. The first one, the 'sheep' strain, was found in the human, sheep and cattle samples collected in North Africa. The second one, the 'camel' strain, was found in the camel cysts and cattle and human cysts from Mauritania. These findings further confirm the congruence of the data given by the nuclear and the mitochondrial genome.