Jean Dupouy-Camet

Acquired and congenital toxoplasmosis are frequently complicated by ocular toxoplasmosis. The diagnosis relies on clinical aspects, response to specific treatment and results of biological assays. The incidence and the prevalence of this complication are difficult to establish precisely and depend on the prevalence of the parasite infection in the general population, and are affected by factors such as type of exposure to the parasite, genetic backgrounds of the parasite and the host, and type of immune response elicited by the parasite. Les toxoplasmoses acquises ou congénitales sont fréquemment compliquées par des lésions oculaires. Le diagnostic de ces complications se fonde sur les aspects cliniques, la réponse au traitement spécifique et les résultats des analyses biologiques. L’incidence et la prévalence de ces complications sont difficiles à établir avec précision et dépendent de la prévalence de la parasitose dans la population générale et sont affectées par le type d’exposition au parasite, par la génétique de l’hôte et du parasite et par la réponse immune induite chez l’hôte par le parasite.

Three confirmed and three suspected cases of trichinellosis have been reported in France with onset of symptoms in March 2009, linked to consumption of smoked warthog ham in Senegal.

Tapeworms of the genus Diphyllobothrium (Cobold, 1858) are widely distributed all around the world and some of them are agents of human diphyllobothriasis. Approximately 50 species have been described within the Diphyllobothrium genus but only 13 are human pathogens. Species identification by using morphological criteria is very difficult. We determined the value of 18S ribosomal RNA gene, internal transcribed spacer (ITS) and cytochrome c oxidase subunit 1 gene (COI) sequences to differentiate between Diphyllobothrium isolates. Sequences from 18 isolates (larvae or adults) of D. latum, D. nihonkaiense, D. ditremum, D. dentriticum and D. stemmacephalum species were obtained. COI region sequences analysis was clearly more discriminative than those of the ITS1 and 18S rRNA and was a useful tool for identifying specimens.

Trichinellosis is an important and under-recognized food-borne zoonosis in Southeast Asia. After 30 years of no reports, a small outbreak was described in Central Lao PDR (Laos) in 2003. Here we report a large outbreak of at least 650 estimated patients in Udomxay (northern Laos) in June 2005. Trichinella ELISA assays on serum from 133 patients and Western blot assays on 16 patients were positive in 67.6% and 81.2%, respectively. No deaths were recorded. Consumption of uncooked or fermented pork at funeral and wedding ceremonies was the main source of infection. Larvae of Trichinella spiralis were found in 1 of 11 local pigs not involved in this outbreak. The results suggest that trichinellosis may be an under-recognized but important endemic disease in Laos and reinforces the need to urgently implement veterinary and educational programs.

Diphyllobothriasis is contracted by consuming raw or undercooked freshwater fish and is still present on the shores of lake Leman. The aim of this study was to evaluate the prevalence of Diphyllobothrium latum plerocercoid larvae in Perca fluviatilis from this lake. Four to 10% of perch fillets examined in November 2003, February 2004, April 2004 and January 2005, were infested with D. latum larvae. The identification of the larvae was confirmed by PCR and sequencing of the 18S rDNA.

We evaluated industrially prepared Western blot strips designed to avoid the cross-reactions observed with indirect immunofluorescence and enzyme-linked immunosorbent assays used for the serodiagnosis of trichinellosis. The antigen preparations were crude extracts of Trichinella spiralis . The Western blot profile characteristic of trichinellosis was characterized by comparing 60 sera from patients infected by Trichinella to 11 sera from healthy subjects, 51 sera from patients with other proven parasitic diseases (cysticercosis, schistosomiasis, strongyloidosis, fascioliasis, toxocariasis, liver amebiasis, anisakiasis, filariasis, toxoplasmosis, hydatidosis, or malaria), and 23 sera from patients with autoantibodies. Specific 43- to 44-kDa and 64-kDa bands were obtained with all of the sera from 51 patients with acute trichinellosis, in 4 out of 9 patients at the early stages of the disease, and in only 1 control patient, who had suspected anisakiasis and in whom trichinellosis could not be ruled out by muscle biopsy.