We studied the parasitization by Anisakis spp. in European hake (Merluccius merluccius) of 40–52 cm from the Atlantic off north-west Africa and the Mediterranean off southern Spain. Infection parameters differed: The fish from the Atlantic showing a prevalence of 87.97% and a mean intensity of 4.69, while, in those from the Mediterranean, these were 41.27% and 1.73, respectively. In both samples the two-third larval stage types were isolated: Anisakis simplex sensu lato and Anisakis larvae type II, with prevalence of 85.71% and 30.83% in fish from the Atlantic and 41.27% and 1.59% for those from the Mediterranean, respectively. In both samples, the prevalence of larvae in viscera was clearly higher than in the muscle tissue. We also observed an increase in parasitization with increasing host length, those ≥ 46 cm having the highest prevalences (94.87% for those from the Atlantic and 58.33% for those from the Mediterranean; p<0.03).

Summary: The current situation of endemic malaria in Mauritania is not clear since, in most health centres, suspected malaria cases are not confirmed by parasitological analysis and diagnosis is based on clinical symptoms alone. To obtain reliable data about malaria in this country, thin and thick blood smears were taken from patients with symptoms compatible with the illness, who attended two hospitals: Polyclinic of Nouakchott, which serves one‐third of the country's population, where a malaria infection rate of 18.5% (77 of 446) was recorded; Plasmodium falciparum caused 61.85% of these, P. vivax 35.5% (28/77). In Kaedi Regional Hospital, provincial capital of the endemic Gorgol region, a prevalence of 25.49% (106 of 416) was recorded, with P. falciparum as the sole pathogenic species. Of the 77 cases of malaria diagnosed in Nouakchott, nine (seven of P. falciparum and two of P. vivax) were considered as endemic to the city. These cases were all children under 8 years of age except for one adult who had never left the capital, and this is the first time that cases endemic to this city have been detected.