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J Julvez

Publications and source records attributed to J Julvez.

At least 37 records · Page 2Linked to original sources
PubMed1997

[The progress of malaria in sahelian eastern Niger. An ecological disaster zone].

The south eastern part of the Republic of Niger was ecologically damaged by the dryness since 1971. Rainfall decreased by 30 to 40% as compared to 1961-70 and lake Chad retreated 100 km to the south. Now it does not reach any more the Republic of Niger. Malaria studies have been carried out in urban and suburban places in Zinder and in the Diffa area at the extreme east. In Zinder parasitic indexes (PI) after the rainy season were around 30% to 10% according to the situation of the corner in respect with surface waters during the rains. In dry season the index fell to 3%. In Diffa in a part of the city at high risk because lining the Komadougou river, PI was only 6.7% in October after the rains. Before 1970 PI recorded in Niamey were up to 50%. In Diffa area they were of 49% in N'Guigmi and 32% in Bosso, ecologically similar to Diffa. Obviously there was a sharp decrease of malaria which could be due to the disappearance of An. funestus after 1970. It was one of the main malaria vectors. Its larvae were developing in pools remaining after the rains with heavy standing vegetation. These breeding sites have been destroyed by both dryness and human activities. Now the area has became hypoendemic and is suitable for epidemic because population has not much immunity. A surveillance system for epidemic control should be settle.

Animals↗
PubMed1997

[Eco-epidemiology of malaria in Niamey and in the river valley, the Republic of Niger, 1992-1995].

The Niger valley is an original ecosystem in the Sahelian belt. For more than 25 years it has been affected by dryness and rainfall decreased by more than 30% as compared to the period 1950-1960. Moreover the demography has sharply increased and the capital town Niamey grew by 10% a year. The Niger valley including Niamey has about 1 million inhabitants. Three sites have been selected to study the status of malaria and its evolution for the last 30 years: Niamey, Karma 40 km on the N.W. on the river and the nearby fossil valley of Fatay-Karma. In the sixties the malaria vectors were An. gambiae, An. arabiensis et An. funestus. The last species was no more harvested after 1970 because its breeding places have been destroyed on the combined action of dryness and human activities. In Niamey, parasite index was very low in the dry season but grew by 5 to 10 times during the rainy season to reach 50% in certain corners. The highest plasmodic index (PI) were recorded along the river banks where vectors are found all the year long. It decreases in the central part of the city and becomes very low in some peripheral suburban settlements. This situation is quite different of most of the cities of the area where prevalence decrease from outskirts to city centre. The serology confirms these points. In Karma, along the Niger and despite a perennial transmission, the PI removes low as well as the malaria antibodies, probably because of the self use of antimalarial drugs by the population. In Fatay-Karma the PI of 23.9% after the rainy season drops to 6% in the dry one. In data prior to 1970 the PI was over 60%, reaching 89% in young children of Niamey suburbs. Obviously it has strongly decreased. It is very likely that this is due partly to the disappearance of An. funestus after the drought.

Adolescent↗
PubMed1997

[Serological study of rickettsia infections in Niamey, Niger].

Rickettsioses is a possible alternative to presumptive diagnosis of malaria. A serologic study was carried out in 1994 to determine the prevalence of rickettsioses in children under 5 years of age from three different areas of Niamey, Niger. Indirect immunofluorescent assays using the micromethod were performed with antigens for Rickettsia conori, Rickettsia mooseri, and Coxiella burneti. Results were read from a positive threshold of 1/160 up to 1/640. Out of a randomized population of 177 children 35 were positive for at least one antigen: 17.5% for Rickettsia conori, 15.8% for Rickettsia mooseri, and 9.6% for Coxiella burneti. The incidence of positivity for Rickettsia mooseri and Coxiella burneti. was significantly higher in an area where contact between people and animals was particularly close. This high rate of positivity is in agreement with previous reports in other countries in West Africa and suggests that close contact between man and rickettsiae is common. Although dogs carry ticks in Niger, direct contact with Rickettsia conori is probably the most mode of transmission. Rodents like Cricetomys gambianus and Rattus norvegicus carry Rickettsia mooseri and goats and sheep which are often kept in the courtyards of buildings carry Coxiella burneti. The recently identified species Rickettsia africae could be transmitted by other vectors such as cattle ticks.

Animals↗
PubMed1996

[Seroepidemiology of toxoplasmosis in Niamey, Niger].

A seroepidemiological survey of toxoplasmosis was carried out in Niamey, Niger, in 1992. Three hundred and seventy-one sera from 200 females and 171 males were tested by indirect immunofluorescence assay for IgG. Using a cut-off value of 12 UI, 67 sera (18%) were positive. In this group detection of specific IgM by ELISA with immunocapture revealed 8 positive sera (11.9%). Seroprevalence of specific IgG was not correlated with ethnic origin or sex but did increase with age from 6.9% in subjects under 5 years to 34.9% in subjects 50 years and over. These findings are comparable with those from previous studies in similar climates and confirm that the prevalence of toxoplasmosis is higher in humid coastal regions than dry desert areas.

Adolescent↗
PubMed1994

[Seroepidemiology of toxoplasmosis on Mayotte (Comores Archipelago)].

A seroepidemiological survey of toxoplasmosis was carried out on Mayotte Island. Detection of IgG was performed on 871 samples from 509 females and 362 males by indirect immunofluorescence assay. Using a cut-off value of 12 UI (1/16), 734 sera (84.3%) were found to be positive. Assays for specific IgM which were carried out only in positive subjects detected IgM in 13 people (1.5%). Comparison between different ethnic groups showed significantly higher rates of seroprevalence in villages with latrines. This finding is attributed to the use of fresh water for bathing and dish washing. It has been hypothesized that use of salt water for these purposes lessens the rate of contamination by destroying Toxoplasma gondii oocysts.

Adolescent↗
PubMed1994

[Historical epidemiology of bancroftian filariasis in southwest islands of the Indian Ocean].

Bancroftian filariasis arose in the South-West Indian Ocean Islands with human settlements. During the XIXe century, most of the islands were infected but the prevalence and clinical features of the disease were different from an Island to an other. The vectors are Cx. quinquefasciatus, An. gambiae, An. arabiensis, An. funestus. Even if Culex are proven vectors most of the transmission is due to anophelines. The introduction of the parasite was followed by an explosion of the diseases with dramatic clinical features. But since the beginning of the century the disease retreats. Whatever this is due to malaria vector control and specifies chemoprophylaxis or is linked to the rise of life standard is still a subject of debate.

Animals↗
PubMed1992

[Specifics of the epidemiology of urinary schistosomiasis in Mauritius].

Early observations on this disease were made in Mauritius by Chapotin (1812) before the discovery of Schistosoma haematobium. Bulinus cernicus, the snail intermediate host, one of the nine species within the B. forskali group, is restricted to the island and the disease is not occurring in the neighbouring islands of La Reunion and Rodrigues. Under laboratory conditions, the snail susceptibility to the Mauritian strain of S. haematobium has been demonstrated. But the infection rate of the snail remains very low and the transmission of the disease is sporadic except in three foci. Its occurrence is not linked with agriculture or irrigation but is closely related to other man/water contacts in the rivers. Without clinical significant signs, the disease, quite different of the historic description, is largely underestimate. The snail is well adapted to the climatic conditions on Mauritius with a remarkably resistance to long drought periods. In fact, distribution of snail and evolution of population size fluctuate dramatically. Canalization and drainage of rivers, streams and marches since the beginning of malaria outbreak, widespread use of pesticides during the antimalaria spraying campaigns, only overhead irrigation, permanent maintenance of the lined canal system, induced many ecological constraints to possible snail habitats. Without animal reservoir of infection, control of urinary schistosomiasis or even its eradication looks feasible through a large school case-finding eventually associated with mollusciciding activities in the main foci.

Animals↗
PubMed1992

[Diversity of malaria in the Sahelo-Saharan region. A review apropos of the status in Niger, West Africa].

The concept of epidemiologic facies of malaria underlines the diversity in the expression of the disease in areas where important ecological variations interfere largely with transmission. Niger is quite a border region between the afrotropical fauna from the south and the Palearctic fauna from the north. The last one filters through the mountains where it maybe represents a relic of ancient paleoclimates. Annual variations of the northern limit of Anopheles arabiensis, in the Sahelo-Saharan region including some oasis, are related to temporary breeding places produced by seasonal rainfall, after estivation during the dry season or after a long migration with the wind. An. gambiae s.s is present in the south and along the Niger river, with An. funestus, even till Zinder. The northern limit of An. nili is the Niger river. The permanent variations of the environment induce great differences in the level of transmission between an intermediate stable situation in the south to an unstable one in the north. Epidemic outbreaks appear some years in vulnerable populations. The implementation of a malaria program supposes to take account of the various eco-epidemiologic situations all over the country. Even if mortality and morbidity became lower, natural precaution in some groups of people must be preserved.

Adolescent↗
PubMed1990

[Seroepidemiologic evaluation of malaria in Mayotte (Comoro archipelago) 1984-1988].

In the context of a research programme on the immunology of malaria in the islands of the south-west of the Indian Ocean, seroepidemiological studies by means of sampling surveys have been carried out annually in Mayotte Island (Comoro Archipelago) from 1984 to 1988. Apart from the transient character of the increases in rates in the wake of the epidemic outbreak of 1984, the evolution of the antibody geometric mean reciprocal titre (GMRT) by age reveals a negativation of population at large, fast only in the younger age-group. At such a high level of negativation, the GMRT does not lend itself to interpretation. In the older age-groups the negativation becomes so slow as to render a yearly periodicity too short to show differences. The correlation between GMRT and age that persisted over the five-year period suggests that the evolution of the rates according to age follows a predetermined model. The epidemiological interpretation of purely serological data, except for a general indication of the trend, is however difficult, specially in an archipelago where the levels of malaria transmission are not the same in the different islands, but where inter-island migration is quite important.

Adolescent↗
PubMed1990

[Inventory of fresh water snails in Mayotte, Comoro Islands].

No trematodosis is known at the present time in Mayotte despite the close historical relationships between the Mayotte Archipelago and the neighbouring island of Madagascar, which is heavily infested. It is noteworthy that no intermediate host has been described in previous studies in Mayotte. An inventory of fresh water snails was performed from 1985 to 1988, in 53 experimental stations during the rainy and the dry seasons: 3,940 snails of eight different species were collected and further identified. The sole occurrence of Lymnaea natalensis constitutes a new record in Mayotte where there are now 14 different species of fresh water snails. According to the role of Lymnaea natalensis as a vector of Fasciola gigantica, particularly in Madagascar, the veterinary control of cattle importation into Mayotte is of great interest.

Animals↗
PubMed1990

[The cost of a campaign against malaria. General considerations].

Malaria is yet one of the major tropical problems and the technical evolution of the malaria campaigns since 90 years is a witness of its complexity. The cost of a programme against malaria, including house spraying, case finding with chemotherapy and chemoprophylaxis for pregnant women, must allow a long-term (10 years) mobilization of resources. In Mayotte island (Comoro archipelago), the cost of the malaria campaign was, in 1987, about 6 US $ by inhabitant. Without man power cost, the house spraying needed 3 US $ by inhabitant, 0.2 US $ for Entomology and Parasitology Laboratories, 0.1 US $ for chemoprophylaxis, case finding and treatment. Apart from the frequency of house spraying which depends on epidemiological features (whole year or seasonal transmission), the integration of activities looks to be the major argument for the optimization of this cost.

Animals↗
PubMed1990

[Historical epidemiology of malaria in the archipelago of the Mascarenes (Indian Ocean)].

The Mascarenes Islands (Mauritius, Rodrigues and Reunion) have been for the last few centuries a place of rest and convalescence for sailors, soldiers and inhabitants of the other regions of the Indian Ocean affected by "intermittent fevers". In the middle of the nineteenth century a severe and deadly malaria epidemic occurred first in Mauritius and then in Reunion Island. It took a century to bring the disease under control, but this has in no way diminished the risk of its re-introduction. Comparative study of the way the disease appeared and got established in these two islands and not in the adjoining ones (Rodrigues, Chagos, Seychelles) leads us to formulate the hypothesis that massive deforestation for sugar cane cultivation created a favourable environment for the implantation of the malaria vector, the african origin of which is beyond doubt. The evolution of the environment, subjected to natural catastrophe (cyclones) and to human activities (often as a consequence of economic development) has exerted pressure on the vector which in a way gives an answer of the development of the disease over time. This study highlights the importance of epidemiological analysis of the history of major communicable diseases not only in the cognitive context but also in predicting probable public health problem arising from environmental modifications.

Animals↗
PubMed1989

Integrated malaria control achieves results in Mayotte.

A malaria control campaign in the island territory of Mayotte has achieved remarkable success owing to the integration of activities with the general health service and to the high degree of decentralization practised.

Animals↗
PubMed1988

[Malaria in the islands of the Comoro archipelago. Historical and geophysical aspects. Epidemiologic considerations].

Located on the maritime road to India, important harbour during slavery period, Comoro Archipelago was therefore free of malaria in the XVIIth century in spite of the presence of infected persons. In the XIXth century, malaria became endemic in Mayotte, Mohéli and Anjouan but only at the beginning of the XXth century in Grande Comore. The origin of vectors and main parasite, P. falciparum, are african. After quite a "natural" evolution, the situation is the same in these islands (continual high transmission) except Mayotte where a malaria programme is performed since 1976. But the historical differences, island by island, in the outbreak of malaria suggest various ecological balance which would be underlined by antimalarial activities.

Animals↗
PubMed1987

[Effectiveness of mass chemotherapy campaigns with diethylcarbamazine on blood microfilaria of Wuchereria bancrofti in Mayotte].

An evaluation of the microfilarial index has been carried out in a randomised population, during April and May 1986, to determine the efficacy of long course mass chemotherapy. A single dose of DEC at 6 mg/kg was distributed to the whole population of the island, every 4 months, in 1985 and 1986. The survey was done three months after the treatment. 1,307 thick blood films have been collected in night-time. The prevalence of microfilaremia was 1.9% as compared with 17.1% in 1981 in the conditions. The control measures were considered as quite satisfactory, and it was decided to continue mass chemotherapy together with vector control.

Animals↗
PubMed1987

[Epidemiology of malaria and the antimalarial campaign in Mayotte (Comoro archipelago, Indian Ocean). Development of the situation between 1976 and 1986. Outlook].

Up to 1976 an integrated malaria control programme has been carried out in Mayotte island. By 1980, there was a drastic reduction of the number of the malaria cases and of the plasmodic index (below 1%). But in 1984, an uprise of cases and a consistent increase of the plasmodic index was observed throughout the island (up to 10%). It is supposed to be due to the laxity in malaria control measures. Immediately a reinforcement of all aspects of malaria control measures was undertaken. Every house is sprayed four times a year with fenitrothion (2 g/m2). Chemical and biological ("guppy" fishes) larviciding measures were extensively applied throughout the island together with simple environmental measures like filling peridomestic breeding sites. Mass chemoprophylaxis was gradually decreased and is now only applied for pregnant women according to the W.H.O. recommendations. Presumptive treatment of febrile cases is generalized before laboratory confirmation. The surveillance of malaria prevalence is a continuous process both active and passive but, every year, a randomized parasitical and serological survey is carried out in a sample of representative villages. In 1986 there was only 3 indigenous cases observed despite the introduction of numerous carriers from neighbouring infected countries. It appears that pertinent control can reduced or may be eliminate malaria transmission in a short period of time. But the maintenance of the malaria clearance in the local, ecological and geographical context need a continuation of the control measures at least for the near future, as the population has lost most of its immunity and has become highly vulnerable to malaria.

Humans↗