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Biomedical subjects

D Fontenille

Publications and source records attributed to D Fontenille.

At least 109 records · Page 6Linked to original sources
PubMed1990

[Serological surveillance of West Nile virus infection in a village of the Central Highlands in Madagascar].

A serological survey on the frequency of West Nile virus antibodies has been carried out in a village near Antananarivo. IgG antibodies were searched for by enzyme-linked immunosorbent assay on 460 sera collected in December 1988 and on 494 sera collected in July 1989. The prevalence of West Nile virus antibodies varied from 13.4% to 21.8% between the beginning and the end of the rainy season. Seroconversion was observed in 14.7% of 354 paired serum samples collected in December and July which had been negative in December. The distribution of seropositive samples in the hamlets, and their frequency in relation to the presence of domesticated animals were analysed. Results show that West Nile virus circulates in the human population of the central highlands of Madagascar, which might account for the pseudo-influenza pathology observed in the region.

Adolescent↗
PubMed1989

[Bacterial, viral and parasitological study of a population of Chaerophon pumila bats in Anjiro, Madagascar].

This bacterial, viral and parasitical study of the insect eater bats Chaerophon pumila allowed to isolate, from stools of 88 of them, 115 bacterial strains to Enterobacteriaceae family: some of them were identified as very atypical, rare or potentially pathogenic for man. From salivary glands, brain and blood, 13 viral strains were also isolated: 8 of them were less identified as Dakar-bat virus. Any parasite was observed.

Animals↗
PubMed1989

[Transmission cycles of the West-Nile virus in Madagascar, Indian Ocean].

Virological, serological and entomological research conducted in Madagascar since 1975, reveal the wide-spread presence of West-Nile virus on the island. This arbovirus has been isolated from humans, parrots and egrets. Vectors belong to the genus Culex (e.g. Cx. decens, Cx. quinquefasciatus, Cx. antennatus, Cx. univittatus), however the virus has also been isolated from Aedes and Anopheles. Serological tests carried out on over 1,600 human and almost 1,000 animal sera, revealed that human beings could be infected throughout the island. Other potential vertebrate hosts, apart from birds, are oxen and bats. Insectivores, rodents and lemurs are probably involved in the transmission cycles only to a very small extent.

Animals↗
PubMed1989

[Transmission cycles of arboviruses in Madagascar].

Some arboviruses are highly pathogenic for Men or animals. Arboviruses epidemiological patterns in Madagascar were determined by entomological, serological, and virological surveys. We listed potentials arboviruses vectors in Madagascar. Entomological results generated by us during five years, as well as prior to, are shown. We caught more than 150,000 hematophagous arthropods, belonging to 107 species at least. 3 of these species were new. 4183 inoculation pools were done. We studied serollogically (by HI test) samples collected from 563 animals and 626 Men. Our data, in agreement with others collected from 1965 to 1982, demonstrate that arboviruses circulate in the whole island. Positive reactions were obtained mainly with Flavivirus, in particular with West-Nile. Nine various arboviruses, including dengue-2 virus isolated from an individual having travelled to La Réunion, have been isolated. Dakar-Bat and Mengo virus have been observed. We studied transmission cycles of the following viruses: Babanki, West-Nile, Rift Valley Fever, Crimean-Congo Hemorrhagic Fever, MMP 158, Ngari, Perinet and Andasibe; the last 2 being endemics. In relation to Madagascar biogeographic characteristics (long-term isolation, scarce communications, high endemicity, and low vertebrate density), we evaluated the risk of potential introduction and amplification of various arboviruses (dengue, yellow fever, japanese encephalitis, Sindbis and Chikungunya). The risk is very high for dengue due to the presence of susceptible mosquitoes strains while the virus circulates in East Africa and in the Indian Ocean area. This risk seems to be very low for yellow fever, and intermediate for other arboviruses.

Animals↗
PubMed1989

[Entomological results of the malaria program of the Pasteur Institute in the Malagasy Highland Plateaux in 1987-1988].

An entomological survey carried out between october 1987 and july 1988 in Manarintsoa, a village 30 Km West of Antananarivo, shows that An. gambiae s.l. and An. funestus are both vectors of malaria. The sporozoite rate was estimated at 0.71%, and the annual risk about 2 infectious bites per person. In all, more than 16,000 mosquitoes, belonging to at least 15 species, were caught over a period of 294 nights.

Animals↗
PubMed1989

[The presence of the Culex (Culex) neavei mosquito in Madagascar, its relevance in the transmission of arboviruses].

A study was made of 25 male and 43 female mosquitoes belonging to the Culex (Culex) univittatus group, from different localities in Madagascar, Indian Ocean. This showed that Culex neavei Theobald, 1906 is present on the island, at least in the Tsiroanomandidy region. As demonstrated previously, Cx. univitatus Theobald, 1901 is also present. Because of the presence of some atypical forms, firm identifications was made only in males according to the structure of the leaflet of the sub-apical lobe of the gonocoxite. The relevance of the presence of Cx. neavei to the epidemiology of West Nile and Babanki viruses in Madagascar is discussed.

Animals↗
PubMed1989

[Malaria in 1988 in a village of the Malagasy Highland Plateaux. Epidemiological findings].

In 1988, the Malaria Research Unit of the Madagascar Pasteur Institute settled an out-patients clinic in Manarintsoa, a village of the Highland Plateaux where epidemic malaria appeared recently. 2776 consultants presented between January and June. In addition, the 200 schoolchildren were examined thrice. For each individual, clinical examination and thick and thin blood smears were performed. In the out-patients, parasite rates were above 50% each month and in each age group; the mean parasite rate being 74%. Splenomegaly rates were above 60% in individuals less than 15 years of age, and around 20% in adults. In schoolchildren, parasite and splenomegaly rates are consistently above 50%. Gametocyte indexes were 7.5% and 7% in May and October, respectively. Plasmodium falciparum is the most encountered species (in 85% of the cases), but P. vivax and P. ovale are also present. P. malariae is very rare. Early diagnosis and adequate therapy were very effective against mortality. During the high transmission time, monthly mortality rates varied from 12% before our arrival to 0.66% after. The number of malaria attacks was estimated at 2 per man and per year. In this area of unstable malaria, presence of fever appears to be of poor predictive value of the malaria infection. Systematic chloroquine therapy of fevers would be adapted to only 43% of the cases.

Adolescent↗
PubMed1989

[Tick-borne relapsing fever in Madagascar: an eradicated disease?].

Since about thirty years, no relapsing fever due to Borrelia duttoni is recorded from Madagascar. A survey was conducted in the formerly endemic area, between Soalala and Majunga, in order to collect data on possible cases and to look if the vector, Ornithodoros moubata is still present. No mention of the disease was recorded; all Ornithodoros seem to have completely disappeared in the area, without any clear reason. However, a few O. moubata specimens were recorded from piggeries in Mahasolo, 150 km west of Tananarive, outside the endemic area.

Animals↗
PubMed1989

Biology and distribution of Aedes albopictus and Aedes aegypti in Madagascar.

The biology and distribution of the 2 Malagasy Stegomyia species, Aedes aegypti and Aedes albopictus, is updated and reported. Aedes aegypti is present in the western and southern regions and Ae. albopictus in the east and on the high plateau. Some unusual locations are noted. The ranges of Ae. albopictus and Ae. aegypti on Madagascar overlap only slightly. Aedes aegypti is present in the west and in the south, while the Ae. albopictus distribution area is in the east and on the central high plateau. Climatic factors (number of dry months, annual rainfall and temperature), rather than competitive interactions, appear to be the major determinants of the distribution of these species. Aedes aegypti is just slightly anthropophilic, contrary to Ae. albopictus. Babanki virus and MMP 158 virus were isolated from Ae. aegypti; no virus has been isolated from Ae. albopictus.

Aedes↗
PubMed1989

[Arbovirus transmission cycles in Madagascar].

Some arboviruses are highly pathogenic for Men or animals, Arboviruses epidemiological patterns in Madagascar were determined by entomological, serological, and virological surveys. We listed potentials arboviruses vectors in Madagascar. Entomological results generated by us during five years, as well as prior to, are shown. We caught more than 150,000 hematophagous arthropods, belonging to 107 species at least. 3 of these species were new. 4183 inoculation pools were done. We studied serologically (by HI test) samples collected from 563 animals and 626 Men. Our data, in agreement with others collected from 1965 to 1982, demonstrate that arboviruses circulate in the whole island. Positive reactions were obtained mainly with Flavivirus, in particular with West-Nile. Nine various arboviruses, including dengue-2 virus isolated from an individual having travelled to La Réunion, have been isolated. Dakar-Bat and Mengo virus have been observed. We studied transmission cycles of the following viruses: Babanki, West-Nile, Rift Valley Fever, Crimean-Congo Hemorrhagic Fever, MMP 158, Ngari, Perinet and Andasibe; the last 2 being endemic. In relation to Madagascar biogeographic characteristics (long-term isolation, scarce communications, high endemicity, and low vertebrate density), we evaluated the risk of potential introduction and amplification of various arboviruses (dengue, yellow fever, japanese encephalitis, Sindbis and Chikungunya). The risk is very high for dengue due to the presence of susceptible mosquitoes strains while the virus circulates in East Africa and in the Indian Ocean area. This risk seems to be very low for yellow fever, and intermediate for other arboviruses.

Animals↗
PubMed1988

[Arboviroses in the region of Nosy-Bé, Madagascar. Serologic and entomologic data].

Since 1977, the Pasteur Institute of Madagascar has been studying, during six surveys, the arboviruses of Nosy-Be area, in the north-west of Madagascar. 47.2% out of 271 human sera and 11.3% out of 151 sera of Lemurs, tested for antibodies to 16 arboviruses by the haemagglutination inhibition test, are positive. The results show an important prevalence of Flaviviruses. West Nile and Dengue 1 viruses were probably circulating some years before the surveys. Antibodies against Sindbis and Rift Valley Fever viruses, were found only in few subjects. Bunyamwera and California groups of virus are absent. The rate of positive Lemurs is weak, particularly in Lemur macaco macaco. Flaviviruses are the most frequent. 12,262 haematophagous diptera (11,965 Culicidae belonging to 40 species) were caught. Aedes aegypti and Aedes albopictus are both present. Arbovirus isolation attempts from 394 mosquito pools failed; only Mengo virus was isolated from four pools of Eretmapodites quinquevittatus and one pool of Aedes (Skusea) sp.

Animals↗
PubMed1988

[Arbovirus infections on the island of Nosy-Be; serologic and entomologic findings].

Since 1977, the Pasteur Institute of madagascar has been studying, during six surveys, the arboviruses of Nosy-Be area, in the north-west of Madagascar. 47.2 p. 100 out of 271 human sera and 11.3 p. 100 out of 150 animal sera (mostly from Lemurs), tested for antibodies to 16 arboviruses by the haemagglutination inhibition test, are positive. The results show an important prevalence of Flaviviruses. West-Nile and Dengue 1 viruses were probably circulating some years before the surveys. Antibodies against Sindbis and Rift Valley Fever viruses, were found only in few subjects. Bunyamwera and Tahyna viruses are absent. The rate of positive Lemurs is weak, particularly in Lemur macaco species. Flaviviruses are the most frequent. 12262 haematophagous diptera (11965 Culicidae belonging to 40 species) were caught . Aedes aegypti and Aedes albopictus are both present. Arbovirus isolation attempts from 394 mosquito pools failed; only Mengo virus was isolated from four pools of Erethmapodites quinquevittatus and one pool of Aedes (Skusea) sp.

Animals↗
PubMed1988

[Hemorrhagic fever viruses in Madagascar].

The authors remind, what are the viral haemorrhagic fevers, and explain the situation in Madagascar. The viruses of Crimée-Congo haemorrhagic fever, Rift valley fever and haemorrhagic fever with renal syndrome are present in Madagascar. There is no real proof about the presence of Dengue viruses. The yellow fever viruses have never been stown off. It seems that there was not diagnosed outbreak of haemorrhagic fever, since the beginning of our century.

Animals↗
PubMed1987

[A one-year collection of Culicidae in illuminated traps in the park around the Pasteur Institute of Madagascar in Tananarive].

Culicidae captures by light traps have been done, during one year and at regular intervals in the Madagascar Pasteur Institute's park in Tananarive. 3,350 individuals representing twenty species have been caught. Results show a great specific wealth, inter and intraspecific variations in space and time and this, particularly in relation with rain. Culex quinquefasciatus is in a widely commanding position. The Madagascar Pasteur Institute's park can be considered, by number of present species, as representative of Culicidae fauna of the Tananarive's country.

Animals↗