[Bancroftian filariasis in Madagascar: persistent endemicity]. / La filariose de Bancroft à Madagascar: une endémie persistante.

A major study was conducted to determine the prevalence of Bancroftian filariasis in 9 health districts located mainly on the east and north coast of Madagascar between 1995 and 1997. The study population included 2524 people 10 years or older. On the east and north coast, the incidence of microfilarial carriers varied depending on location from 7 p. 100 to 47 p. 100 in men and 3 p. 100 to 33 p. 100 in women. The highest incidences, i.e., around 33 p. 100 in both sexes, were observed in the southeastern districts of Ifanadiana, Manakara, and Vangaindrano. In the other districts on the east coast, the highest rates occurred mainly in men, i.e., 47 p. 100 in Vavatenina, 33 p. 100 in East Feneriva, and 33 p. 100 in Mahanoro. Only two districts on the west coast were studied, i.e., Marovoay where the incidence was zero and Ankazoabo where the prevalence was 4 p. 100 for men and 3 p. 100 for women. The results are compared with those of a study carried out in 1958. At 16.22 p. 100, chronic morbidity is relatively common in men but less disabling, i.e. mainly scrotal and member elephantiasis and hydroceles. Chronic morbidity was only 2.26 p. 100 in women, i.e. mainly member elephantiasis. Control of Bancroftian filariasis may be achievable by targeted use of drug prophylaxis and bednets in zones of high prevalence.

[KAP study (knowledge-attitude-practice) on seafood poisoning on the southwest coast of Madagascar]. / Etude CAP (connaissance-attitude-pratique) sur les intoxications par consommation d'animaux marins sur le littoral sud-ouest de Madagascar.

In June and July 1996, a knowledge, attitude and practice survey concerning seafood poisonings was conducted in Tuléar Province, 41 villages spread along 300 km of cost, with some 34,000 inhabitants, were included in the survey. 84 seafood poisonings after fish, shark and turtle meals occurred during the period 1931 to 1995; 14 of them were responsible of deaths. The family of toxic fishes are Clupeidae, Tetraodontidae, Scaridae and Siganidae. Sphyrna lewini is the shark species the most often responsible for poisonings. Three turtle species are involved in poisonings: Eretmochelys imbricata, Chelonia mydas and Dermochelys coriacea. Clinical patterns were related to marine toxins. Although the communities were aware of the risks, there was no change in seafood meal practice. Preventive measures are not very often used. Practical techniques to detect toxins, although very simple, are not systematically carried out. For a better understanding of the seafood poisoning risk in Madagascar, a retrospective survey in the villages located in coastal areas all around Madagascar was to be carried out in 1997. An eco-toxicological survey will likewise probably be organised in an Indian Ocean regional approach.

[Seafood poisoning in Madagascar: current state of knowledge and results of a retrospective study of the inhabitants of coastal villages]. / Intoxications par consommation d'animaux marins à Madagascar.

In 1996 and 1997, a knowledge, attitude and practice survey concerning seafood poisonings was conducted in 560 villages spread along the Madagascar coasts, gathering 585,000 people. 175 serious and 205 mild seafood poisonings after fish, shark and turtle meals occured during the period 1930 to 1996. Squales (mainly Sphyrnidae and Cacharinidae familiesi) are the most often responsible of serious poisoning (48% of episodes), then other fishes (37%), and mainly of the Clupeidae family (herrings, sardinels), then marine turtles (11%), with Eretmochelys imbricata and Chelonia mydas, and finally crabs (4%). Neurological symptoms are predominant in squale poisonings, neurological symptoms associated with gastrointestinal symptoms are present in 50% of all kind of seafood poisoning episods. Most of episods incame on the East Coast (mainly Toamasina and Antisiranana Region) and on the South-West Coast (Toliara Region). Mild seafood poisonings are spread along all the Coasts but central East Coast; fishes are the most often responsible (41% of episodes). Gastro-intestinal symptoms are the most conmon. More than 50% of t interviewed people knows about poisoning risks with some kind of marine animals, but less than 20% practice preventive measures such as giving a piece of fished animal to a domestic animal before eating. These results are used to plan a comprehensive epidemiological surveillance and control programme.

Urban epidemic of bubonic plague in Majunga, Madagascar: epidemiological aspects.

After an absence of 62 years, an epidemic of plague occurred in the harbour city of Majunga (Madagascar) from July 1995 to March 1996, following sporadic cases in March and May 1995. By 15 March 1996, 617 clinically suspected cases of bubonic plague had been notified. Laboratory testing was carried out for 394 individuals: 60 (15.2%) were confirmed to have bubonic plague and 48 (12.2%) were considered as presumptive cases. The incidence was significantly higher in males in all age groups and in both sexes in the 5-19 age group. Twenty-four deaths were related to plague, but early treatment with streptomycin has confirmed its effectiveness insofar as the case-farality ratio was only 8.7% among confirmed and presumptive cases admitted to hospital. The difficulty of clinically diagnosing bubonic plague was affirmed. The disease met favourable conditions through the poverty and low level of hygiene prevalent in most parts of Majunga.

[Annual risk of tuberculosis infection in Madagascar: study from 1991 to 1994]. / Le risque annuel d'infection tuberculeuse à Madagascar: étude réalisée de 1991 à 1994.

This article reports the results of a national tuberculin skin test survey of childhood age group. The survey period was from december 1991 to june 1994. For the calculation of annual risk of tuberculous infection, 1544 schoolchildren, aged 6 to 10 years old, without scare related to BCG, were included. The antigen used was tuberculin PPD Mérieux; in order to define a mode of positivity, this tuberculin was first tested with 250 confirmed pulmonary tuberculous patients: the mode was 16mm. With the hypothesis of a cut-off point of positivity at 14 mm, the prevalence of tuberculous infection was found at 9.6% (with a confidence interval of 1.6%); then, the annual risk of tuberculous infection was calculated at 1.21% (from 1% to 1.42%). With the hypothesis of a mode at 16 mm, the prevalence of tuberculous infection was found at 10.2% (with a confidence interval of 2.3%); then, the annual risk of tuberculous infection was calculated at 1.29% (from 0.97% to 1.59%). Considering separately two age groups, the annual risk was 1.25% for 6-8 years old children and 1.32% for 9-10 years old children. In conclusion, the authors stress the important constraints in the achievement of such a survey in developing countries. Though the difficulties that arised, the standardised methodology used in this survey gives reliable information. These results could be compared with those of future surveys using the same methodological approach.

[Intoxication by marine animal venoms in Madagascar (ichthyosarcotoxism and chelonitoxism): recent epidemiological data]. / Intoxications par animaux marins vénéneux à Madagascar (ichtyosarcotoxisme et chélonitoxisme): données épidémiologiques récentes.

If seafood poisonings are well documented in the Pacific region, they are not often reported in the Indian Ocean. In Madagascar, fishermen and people living in coastal areas are traditionally aware of seafood poisonings. Mass intoxications were described in the sixties, including lethal cases following sardine ingestion. From 1989 to 1993, 28 ichtyosarcotoxism cases, mainly ciguatera occurring in children, were reported in Tulear hospital. From July 1993 to May 1996, nine seafood poisoning outbreaks occurred in coastal villages after turtle, shark and sardine meals. Clinical symptoms were related to marine toxins. For turtle intoxications, gastro-intestinal symptoms are the most frequently seen (acute stomatitis, dysphagia, vomiting and diarrhea), with case fatality rates around 7%. For shark intoxications, the most frequent symptoms were neurologic (paresthesia specially peribuccal and extremities), and gastro-intestinal (diarrhea and vomiting), with specific case fatality rates varying from 0% to 30%. For sardine intoxication, symptoms were gastro-intestinal (vomiting) and neurologic (paresthesia), and from the two intoxicated people one died. Two previously unknown biotoxins were isolated from the liver of a shark responsible for a mass poisoning, namely carchatoxins. For the turtles, the search of chelonitoxin is under way. For the sardines, clupeotoxin was isolated. Because of the frequency and the gravity of collective seafood poisonings occurring in recent years, the Ministry of Health has implemented a Seafood Poisoning National Control Programme. This programme is based on three major strategies: the setting of an epidemiological surveillance network, the prevention of the communities through educational programmes, and the development of research on marine eco-environment.

[Role of Anopheles funestus in the transmission of malaria in the south of Madagascar (Ampanihy district)]. / Rôle d'Anopheles funestus dans la transmission du paludisme dans le Sud de Madagascar (District d'Ampanihy).

The authors reported the results of paludometric and entomological studies carried-out for two years: 1995-1996 in two localities: Ampanihy and Ankilimivory located in the South of Madagascar. These studies followed a suspect malaria epidemic in Ankilimivory in June and July 1994; the population plasmodic index was of 45%. In April 1995, this data was of 35% in Ampanihy and of 15% in Ankilimivory. Entomological studies carried out in April 1996 allowed to find Anopheles funestus in Ankilimivory and Anopheles gambiae l. s. in the two localities. Both the endemicity of malaria and the role of A. funestus had to be taken into account in the southern part of Madagascar. Until now, rare epidemics in this area were thought to occur only when climatic conditions were favorable, mainly during the rainy season. However, other factors, linked with the development could also facilitate the upset of epidemics, e.g.: irrigation programmes.

[Preliminary results in the clinical, epidemiological and parasitological study of Bancrofti filariasis in Madagascar]. / Résultats préliminaires de l'enquête épidémio-clinique et parasitologique sur la filariose de Bancroft à Madagascar.

In 1958, a large study on the distribution of Bancroft filariasis was set up in Madagascar. In order to update these data, the authors have studied in the same areas the parasitological and clinical prevalence of Bancroft filariasis. Here are the preliminary results of this study, concerning 1862 people, aged 10 years and more. The mean prevalence rate of microfilaria-carriers was of 22.9%, and the average parasitic density was of 3.6 parasits/20 microliters of blood. The prevalence rate of chronic clinical symptoms was of 14.7% for men (elephantiasis, hydroceles, chyluria) and of 2% for women (elephantiasis). These were usually mild symptoms, which very little impact on way of life.

Fatal mass poisoning in Madagascar following ingestion of a shark (Carcharhinus leucas): clinical and epidemiological aspects and isolation of toxins.

In November 1993, 188 people were admitted to hospital after eating the meat from a single shark (Carcharhinus leucas) in Manakara, a medium-sized town on the south-east coast of Madagascar. This shark and its meat had no unusual characteristics. The attack rate was about 100%. The first clinical signs appeared within 5-10 hr after ingestion. The patients presented with neurological symptoms almost exclusively, the most prominent being a constant, severe ataxia. Gastrointestinal troubles, like diarrhoea and vomiting, were rare. The overall case mortality ratio was close to 30% among the 200 poisoned inhabitants. There were no reports of previous similar poisonings in this area, and fishermen in Manakara usually eat this kind of shark without problems. Bacteriological and chemical causes were eliminated. Two liposoluble toxins were isolated from the liver and tentatively named carchatoxin-A and -B, respectively. They were distinct from ciguatoxin in their chromatographic properties.

[Difficulties in the realization and implementation of a national survey on the Annual Risk of Tuberculosis Infection in Madagascar]. / Difficultés dans la réalisation et l'exploitation d'une enquête nationale sur le Risque Annual d'Infection tuberculeuse à Madagascar.

The authors describe on the basis of their own experience, the difficulties that may arise during the achievement of a nationwide survey of the Annual Risk of Tubercular Infection and the analysis of the results. They stress the need of a close methodology at all stages of the survey, from conception to analysis, in order to get reliable and comparative results.

[A malaria epidemic in the south of Madagascar?]. / Une épidémie de paludisme dans le sud de Madagascar?

Authors record the results of entomological and paludometric studies which were run on July 1994 in Ampanihy (Southern Madagascar), since an epidemic of malaria occurred in that region. Although the risk of epidemic malaria is described in the Southern Madagascar, paludometric indexes found in these surveys are pertinent with a mesoendemic malaria. The entomological survey found. A gambiae complex and A. funestus. Complementary surveys are proposed to improve the knowledge of the epidemiology of malaria in this area.

[Study of malaria vectors in the south-west of Madagascar]. / Contribution à l'étude des vecteurs du paludisme dans le sud ouest de Madagascar.

The authors describe the results of an entomological study run in December 1994 in the little town of Bezaha (South-Western Madagascar). The observed entomological indexes are those of an intensive malaria transmission area. The authors suggest to organize a longitudinal entomological survey along with a clinical and parasitological study. They also point out the fact that they found two microfilariae Wuchereria bancrofti in an Anopheles funestus female.

[Fatal ichthyosarcotoxism after eating shark meat. Implications of two new marine toxins]. / Ichtyosarcotoxisme mortel après consommation de requin. Mise en cause de deux nouvelles toxines marines.

A fish poisoning involving 188 hospitalizations occurred in November 1993, in Manakara, a middle-sized town on the south-east coast of Madagascar, following the ingestion of shark. A single shark was involved in this poisoning and was identified as Carcharinus leucas. There was no unusual characteristic of this shark or its meat. The attack rate was about 100%. First clinical signs appeared within five to ten hours after ingestion. The patients presented neurological symptoms almost exclusively, the most prominent being a constant, severe ataxia. Gastrointestinal troubles, like diarrhoea and vomiting were rare. The overall case-fatality ratio was close to 30% among the 200 poisoned inhabitants. Search for similar poisoning previously reported in this area was negative, and fishermen in Manakara usually eat that kind of shark without mistrust. Bacteriological and chemical origins were eliminated. Two liposoluble toxins were isolated from the shark liver and tentatively named carchatoxin-A and -B respectively. They were distinct from ciguatoxin in chromatographic properties.

[Mass food poisoning after eating sea turtle in the Antalaha district]. / Intoxication alimentaire collective par consommation de tortue de mer dans le district d'Antalaha.

In December 1994, a mass food poisoning through ingestion of turtle affected about 60 persons, on the north-eastern coast of Madagascar. The prevailing clinical signs were digestive (nausea, vomiting, dysphagia, acute stomatitis) and might persist during several weeks. The poisoning attack rate was 48% with a lethality of 7.7%. Such accident, even if rare in Madagascar, requires a structured organization to control sea products poisoning and to set up adequate prevention measures.

[Evolution of Plasmodium falciparum drug sensitivity in Madagascar from 1982 to 1993 and operational consequences]. / Evolution de la chimiosensibilité de Plasmodium falciparum a Madagascar de 1982 a 1993 et conséquences operationnelles.

Madagascar was one of the first African countries with reported chloroquine drug resistance of P. falciparum. Suspected as early as 1975, it was confirmed in 1981. Hereafter, regular tests in vivo and in vitro have been performed and allow for a study of drug resistance development. In 742 standard in vivo tests at the dose of 25 mg/kg of chloroquine that were executed between 1983 and 1993, R I resistance levels could be found in 8.5% of cases, R II was found in 8.2%. No resistance at R III levels was detected. The overall situation for in vitro is equally favorable. In 406 tests 78% of samples proved sensitive. The investigations undertaken by the Pasteur Institute of Madagascar, by the Institute for Tropical Medicine and Epidemiology in Paris and by the Unit of Epidemiological Surveillance within the Malagasy Ministry of Health raise a number of questions: Taking to account the various causes for imprecision in measurement and in evaluation (variations in parasite density, microscopic detection levels, bio-availability of the drug) of the groups of R I and R II how significant are the variations observed in numbers and proportions of resistance levels R I and R II? How important are the effects of auto-medication? Can they be correctly evaluated by Bergquist's test? How explain the low level of drug resistance in a country close to East Africa, in which chemoprophylaxis has been widely practiced and in which insufficient dosage for treatment is common? The absence of R III resistance in vivo permit for chloroquine to remain the first line treatment for malaria in Madagascar.(ABSTRACT TRUNCATED AT 250 WORDS)

[Clinical epidemiology of plague in Madagascar (current data)]. / Epidémiologie clinique de la peste à Madagascar (Données actuelles).

After a recall of the epidemiological cycle of plague, the authors describe the course of this disease from 1989 to 1992. Out of 2676 pathological samples suspected of plague, 2105 biological examinations were carried out. 312 cases were confirmed and 335 considered as probable. 93% of those positive cases come from the plague triangle located in the Central Highlands and delimited by Ambatondrazaka, Miarinarivo and Fianarantsoa and they occur during the rainy season (November to March). However, an outbreak of urban epidemics is possible on the coast during the cold season. The most frequent clinical form had been bubonic plague (90%). Plague did not much concern young children and men are affected more often than women. Clinically, toxi-infectious syndrome, lymph node reaction and hemoptoïc spits can be noted. The 1989-1992 results are compared with those of the two previous studies.

[Epidemiological stratification of malaria in Madagascar]. / Stratification épidémiologique du paludisme à Madagascar.

Madagascar is considered as a sub-region of the Afrotropical geographical Region in spite of the high endemicity of 95% of the invertebrates. Nevertheless the three malaria vectors An. gambiae s.s., An. arabiensis and An. funestus are quite similar to those of the continental Africa. This support the hypothesis of their recent introduction. Plasmodium falciparum is the dominant parasite but the prevalence of P. vivax is not negligible. It is linked to the Asian component of the human population. P. malariae and P. ovale are of minor importance. The main epidemiological "facies" of Africa are found in Madagascar. The equatorial facies on the East Coast is characterized by a high transmission all year long. In the tropical facies on the West Coast transmission is seasonal (7 months at least). In both areas, malaria is stable and the inhabitants acquire a high immunity before the age of ten; most of the severe cases touch children below 10. The three vectors can be found but An. gambiae s.s. is dominant. In the exophilic southern facies the transmission is seasonal (two to four months). The only vector is An. arabiensis. Malaria is unstable and severe epidemics occur during the years of high rainfall. All age groups are vulnerable because the population is not immune in the Plateaux facies above 1,000 m., malaria is unstable. Severe epidemics occurred in 1987-1988. The vectors are An. Arabiensis and An. funestus. The occurrence of P. falciparum on the Plateaux seems linked to the development of irrigation of rice farming in the XIXth century. Most of the anopheles breeding places on the Plateaux are dependent on rice cultivation. Urban development has brought the inhabitants of the suburbs in close contact with rice fields. Despite the high number of anopheline bites the number of malaria cases remains by far lower than in the neighbouring rural areas. Regional migrations inside the island bring non-immune populations, from the south and the plateaux, in highly malarious areas of the coast, where the migrants are exposed to high risk. In spite of 40 years of uncontrolled use, chloroquine can still cure most, if not all, of malaria cases. Control measures appropriated to the different areas of Madagascar are discussed.

Epidemiologie du paludisme sur les hautes terres malgaches depuis 1878

Le paludisme est decrit sur les cotes malgaches depuis le XVIe siecle; mais la premiere epidemie liee a l'introduction de plasmodium falciparum n'est survenue sur les hautes terres qu'en 1878. La deuxieme epidemie; de 1896; a permis l'installation d'une transmission endemique jusqu'a la compagne d'eridication des annees 1950. L'arret progressif des activites antipaludiques dans les annees 1970 a permis une reinfestation progressive des hautes terres et la survenue d'une epidemie meurtriere de 1986 a 1988 qui redevient endemique depuis 1989. Ces trois epidemies ont en commun une repartition geographique heterogene; un mode de transmission instable et une tres forte morbidite-mortalite