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J F Molez

Publications and source records attributed to J F Molez.

At least 37 records · Page 2Linked to original sources
PubMed1995

[The utilization of molecular biological tools in the study of malaria transmission: example of programs conducted in Senegal].

Some informations about malaria transmission, which has until nox difficult to get, can be obtained thanks to the use of molecular biology tools, PCR mainly. In Senegal, we use that technique to solve two kinds of problems: -Identification of species of the Anopheles gambiae complex: PCR technique is useful compared to other diagnostic methods (chromosome pattern, DNA probes, etc.) because it enables quickly and simply identification of captured anopheles from the DNA contained in their legs. The rest of the mosquito is tested by circumsporozoite protein antigen ELISA and blood meal ELISA. The data obtained are used to determine distribution, cycles, trophic preferences and comparative vectorial capacities of Anopheles gambiae, Anopheles arabiensis and Anopheles melas. -Identification in a mosquito blood meal of the individual bitten: we propose to evaluate factors (weight, age, sex, location of bedroom, etc.) which could explain why individuals are more, or less, bitten by a Plasmodium vector. Genetic typing is used on inhabitants'leukocytes DNA and on the leukocyte DNA extracted from the blood meal of resting anopheles. Through the high degree of polymorphism of three (AAAG)n microsatellites markers, we hope, using PCR, to attribute each blood meal to one individual. Statistical analysis will be used to identify attractivity factors and to determine more precisely the inoculation rates for each group rather than the classical rate calculated with male adults volunteers.

Adult↗
PubMed1995

[Malaria and rice growing in the Senegal River delta (Senegal)].

An epidemiological survey of malaria was carried out from September 1992 to November 1994 in three villages located in the Senegal river delta, two villages growing rice in irrigated fields and one practicing traditional rain water agriculture. Entomological observations showed that Anopheles pharoensis is the main anopheline species caught in the area with a high population density in the rice growing villages. The population density of species of the An. gambiae complex, represented by An. gambiae s.s., An. arabiensis and An. melas is low. Agressivity rates and anthropophlic indexes of An. pharoensis females are high but their parity rates are low. The malaria transmission is weak and was not perceptible in the area as shown by the negative results obtained with the ELISA tests and the examination of salivary glands. Parasitological indexes, malaria morbidity and incidence rates are low and are in agreement with the entomological data. In the Senegal river delta, irrigation has, on the whole, increased the An. pharoensis density but both malaria transmission and incidence rates did not rise.

Agriculture↗
PubMed1994

[Anopheles of Senegal. An annotated and illustrated list].

Twenty species of Anopheles are presently known from Senegal. An. gambiae, An. arabiensis, An. pharoensis, An. rufipes and An. ziemanni have an extensive distribution. Probably because of climatic change, An. funestus is no more found in some areas and An. paludis tend to disappear. An. melas is located in coastal areas. The other species, namely An. coustani, An. brohieri, An. brunnipes, An. domicola, An. flavicosta, An. freetownensis, An. hancocki, An. maculipalpis, An. nili, An. pretoriensis, An. squamosus and An. wellcomei, are mainly found in southern Senegal. Only An. gambiae, An. arabiensis and An. funestus are of epidemiological significance as vectors of malaria and bancroftian filariasis. Twelve arboviruses have been isolated from eight Anopheles species. Each Anopheles species is illustrated and an identification key is given.

Animals↗
PubMed1994

[Placental infections with Plasmodium in an endemic zone. Risk factors].

A survey has been carried out during eight months in the hospital of Bobo-Dioulasso (Burkina Faso) in view to observe the infection of the placentas by Plasmodium and their risk factors. One thousand forty pregnant women were included. Infection rates were 6.5% during the low transmission season and 24.5% during the high transmission season. P. falciparum was present in all the infections. Thirty eight per cent of the women under 18 years old and 26% of the primigravidae were infected. The mean difference in birth weights between the newborn babies of primigravidae with infected or non-infected placentas was 275 g. The regular visits to antenatal clinics, a high level of education and sufficient income were linked with a low level of placental infection. The use of bed nets was linked with a low level of placental infections even after suppression of the other socio-economic data. These observations are discussed in view of an action against malaria in endemic areas.

Adolescent↗
PubMed1993

High human malarial infectivity to laboratory-bred Anopheles gambiae in a village in Burkina Faso.

The malarial infectivity of an African village population was tested by selecting a demographically representative sample of individuals for study, regardless of parasitemia or gametocytemia. The infectivity of this population people to laboratory-bred mosquitoes was investigated using membrane feeding techniques. Tests on 322 subjects (greater than four years of age) indicated that approximately 48.4% were capable of infecting mosquitoes. There were similar proportions of infectious individuals among gametocyte carriers (52.5%) and nongametocyte carriers (46.6%). All age groups appeared to contribute equally to this infective reservoir. Most of the infections resulted in low oocyst loads (1.8 oocysts) on the midgut of the positive mosquitoes and only a few mosquitoes per batch were infected (11.5%). A previous entomologic survey estimated 90 infected bites/person/year and a low parity index in Anopheles gambiae (< 60%) as well as in An. funestus (< 40%), the two main malaria vectors in this region. This low parity index could indicate a low life expectancy for infected mosquitoes and could therefore explain an inoculation rare lower than expected considering the high degree of infectivity of the human population studied.

Adolescent↗
PubMed1989

[Iterative placental infection by P. falciparum during 2 successive pregnancies in Bobo-Dioulasso (Burkina-Faso)].

A young woman living in a malaria endemic area in West Africa, was contaminated twice with placental infection by Plasmodium falciparum, in two successive pregnancies. No parasites were observed on blood smears both in mother peripheral blood and in cord blood. A parasitemia was described in the intervillous space in the placental. The first placental infection was attributed to a febrile illness ten days before the end of gestation. No reliable symptoms of malaria were found for the second infection. Treatment for fever during pregnancy were given, at 6 and 9 months for the first gestation, and at 4 months for the second gestation. Investigations are correlated with the age of the two placental infections, the second infection is a very young and synchronous parasitemia. No foetal diseases, no low birth weight o congenital malaria were observed on newborns during the both gestations.

Adult↗
PubMed1981

Enzyme typing of Plasmodium falciparum from African and some other Old World countries.

Freeze-dried and freshly cultured isolates of Plasmodium falciparum from different countries have been examined for variation in six enzymes, GPI, PGD, LDH, GDH, ADA and PEPE, using starch gel electrophoresis. Variant forms of each enzyme occur. For most enzymes, similar forms occur in isolates from different parts of the world, although differences in frequencies of each form are found. LDH-2 has been found only in African isolates. PEPE variants vary markedly in their frequency between East and West Africa, although further work is needed to confirm this finding.

Adenosine Deaminase↗
PubMedDate not supplied

Population genetics of abnormal haemoglobins in Burkina Faso, west Africa.

The gene frequencies of haemoglobin A (HbA), HbS and HbC were studied in Burkina-Faso (BF) and in a neighbouring region of Niger, Ayorou. The frequency of HbS was higher in the Sahel region, (northern part of BF and Ayorou) than in the Savanna region. The reverse was true for the HbC gene. The major findings of this study are: (a) confirmation of a peak of HbC gene frequency in the central region of BF (Mossi plateau); (b) a possible negative correlation between the frequencies of HbS and HbC-Cavalli-Sforza and Bodmer have observed that this correlation is at a significantly different level from that expected because of the allelic relationship between HbS and HbC; (c) comparison with the data collected by Livingstone shows a modification in the fitness of the different genotypes in the last thirty years: AS individuals have a lower and AA and SS a higher fitness. Our data favour a partial selection relaxation in this region.

Burkina Faso↗
PubMedDate not supplied

[Myths concerning malarial transmission among Amazonian Indians and their relation with 2 types of transmission encountered in the Amazonian forest].

Among the Indians Desana's (Tukano amerindians) in the Upper Rio Negro, the interseasonal variation of the malarial fevers were associated with two myths (localised in two distinguishable places). One myth associates the malarial with the rivers which contain "malaria pots". Conception based on an observation of localised water collection in the banks and the rocky rapids ("banks and rocky's fever"). The transmission and the anophelian density present variation between the seasons in relation to the river's level. Another myth associates malarial fevers in the forest, with the song of a frog ("fever's frog") and the flowering and fructification of a tree (Poaqueira sericea Thul.). There is in South America a particular type of forest malaria, known as "Bromelia malaria" and denounced in human and/or simian transmission. This forest malaria is transmitted by the a sub-genus anopheles (Kerteszia) which larval breeding are areal in the canopy. The breeding places are found in the forest in the epiphyte bromeliads. To understand this type of transmission, we must take reference to the previous endomological data at the Upper Oyapock Wayâpi (Tupi amerindians). This Bromelia malaria could fluctuated according larval density variation, related to washing of epiphytes (end of the rainy season) or to their flowering (end of the dry season). The "fever's frog" myth collected at the Desana's in the Upper Rio Negro can be related to the existence of Bromelia malaria in this amazonian habitat. These myths showed the perfect adaptation of the amerindians to their environment and their complete knowledge of the neotropical forest.

Animals↗
PubMedDate not supplied

[A case of a combination heterozygote with hemoglobin K Woolwich and hemoglobin C (Hb Kw/HbC) discovered in Bobo-Dioulasso (Burkina Faso)].

During a study on malaria in pregnant women in Burkina Faso, the authors gave a particular attention to the hemoglobin of a mother and her new-born child (blood of cord) and they noticed an hemoglobin migrating before the HbA which was identified by isoelectric focusing (IEF). The child is a composite HbK/HbC heterozygote. A survey was carried out to check the transmission of such a K Woolwich hemoglobin within the family of the mother. Out of 40 people, 17 got HbKw. A noticeable anemia was found in HbKw/HbC heterozygote. The authors tried to identified a possible thalassemia. There was little probability for an association of a minor alpha-thalassemia in the absence of Bart's hemoglobin in the blood of the cord (IEF test) and there was no associated beta-thalassemia.

Adult↗
PubMedDate not supplied

[Epidemic of yellow fever in the southeastern region of Upper Volta (October-December, 1983). Epidemiological study. Preliminary results].

An epidemic of yellow fever raged during the last three months of 1983 in South East of Upper Volta. It spread on about ten thousand square kilometers, in a bushy savanna area, affecting only populations living in contact with forest galleries, belonging especially to the peul ethnical group. The transmission of the virus was effected by sylvatic vectors, essentially Aedes furcifer. Serological tests showed that about 50 % of the population living in contact with forest galleries was affected, that is to say 15.000 to 17.500 people. The average death rate on the whole area was 4 % (800 to 1.700 deaths); the lethality rate was estimated between 6 and 10 % of affected people. On the whole, 54 strains of yellow fever virus were isolated from human blood samples, and 26 strains from batches of mosquitoes. We called this epidemic "intermediate sylvatic epidemic". The epidemic quickly decreased in the sylvatic area, owing to climatic conditions. A mass campaign of vaccinations prevented it from spreading to near urban centres. On this particular case, the thermostability on field of the vaccine 17D provided by the Institute Pasteur of Dakar was proved to be effective.

Adolescent↗
PubMedDate not supplied

[Retrospective study on the mortality of children under 5 in a rural district of the region of Brazzaville (People's Republic of Congo). I. Rate and causes of mortality].

A retrospective study of 1,003 children permits us to identify precisely rates and causes of mortality in children under 5 years old in a rural holoendemic malaria area of the People's Republic of the Congo. The mortality rates are distinctly lower than those generally observed in tropical Africa. Infant mortality (0-1 year) was found to be 71%, mortality 13%, early neonatal mortality (0-7 days) 41% and mortality between 1-5 years, 49%. Main causes of mortality are those related to pregnancy (prematurity, obstetrical pathology) and with infectious diseases particularly measles. On the other hand, no death seems to be attributable directly to malaria in this study.

Age Factors↗
PubMedDate not supplied

[Plasmodium falciparum and drepanocytic gene in Popular Republic of Congo. I. Prevalence of malaria and drepanocytic trait among school children in Brazzaville area (author's transl)].

From 1978 to 1979, 5 surveys, among schoolchildren, were carried out during the rainy season in the neighbourhood of Brazzaville (R.P. Congo): 3 in PK 45 village (northern part of the capital), 2 in Djoumouna village (southern part), and 1 in "Talangai" (a suburb of the capital). 868 exams (plasmodic and splenic index fitted with hemoglobin composition [Hb AA or Hb AS]) were done. It appeared that 19,6% of schoolchildren examined were heterozygous sicklers (AS). This percentage confirmed the previous results from other authors in different countries of Central Africa. On the other hand, in spite of an intense transmission, both plasmodic and splenic index were, on the average, relatively low (24,5 and 24,8% respectively). Plasmodium falciparum was largely predominant (95,3% of infections) but P. ovale and P. malariae were also found (1,9% for each species). From our study no obvious "protecting effect" can be attributed to sickle cell trait because plasmodic index of children AA and AS were similar (23,8 and 27,6% respectively). A slight decrease of splenic index was noticed in AS in regard to AA (19,4 and 26.1% respectively). It is difficult to consider this no significative regression as a definitive proof of a premunition stronger in AS than in AA. Effectively some splenic infarctus are well known to be a regular physiopathological process occurring in homozygous SS but often in heterozygous AS too. In such highly endemic and stable malaria area the problem of a suitable antimalaria strategy remains to be solved.

Adolescent↗