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Biomedical subjects

D Richard-Lenoble

Publications and source records attributed to D Richard-Lenoble.

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

Hepatitis B, C, D, and E markers in rural equatorial African villages (Gabon).

Serologic markers of hepatitis B virus (HBV), including HBV DNA, and of hepatitis delta virus were measured in three villages in Gabon. Of 303 subjects studied, 19% were carriers of hepatitis B surface antigen (HBsAg); 8.5% of these had anti-delta antibodies. No difference among the three villages was observed. All HBV DNA carriers were children less than 11 years of age. In the 2-9-year-old group, 71% of the HBsAg-positive children tested were HBV DNA carriers. These results indicate that HBV prevalence is high in Gabon and emphasize the importance of horizontal transmission of HBV in Africa. Antibodies to hepatitis C virus, assessed in one of the three villages, were found with a prevalence of 35% with a second generation enzyme-linked immunosorbent assay (ELISA) and 24% with a third generation ELISA. None of 35 subjects tested for antibodies to hepatitis E virus was positive.

Adolescent↗
PubMed1995

[Cutaneous candidiasis due to Candida parapsilosis occurring in the course of idiopathic aplastic anemia].

Candida parapsilosis is a very common and saprophytic fungus. Its pathogenic role has been reported in intensive care units after invasive instrumentations. We report a case of dermal candidiasis due to Candida parapsilosis occurring in an immunocompromised patient suffering from aplastic anemia treated with corticosteroids. The histopathological aspect was non specific, showing a polymorphous granulomatous reaction in the middermis. Findings of periodic acid-Schiff and Grocott-Gomori stains revealed a large number of pseudohyphae and spores. Candida parasilosis was cultured from a skin biopsy. The route of skin infection is discussed: direct inoculation or septic localization after fungemia.

Adrenal Cortex Hormones↗
PubMed1994

Nontyphoidal salmonellal septicemia in Gabonese children infected with Schistosoma intercalatum.

Relapses of enteric fever induced by Schistosoma intercalatum have been observed to occur in central Africa. In Libreville, Gabon, 70 children (ages, 2.1-15.9 years) who were seronegative for human immunodeficiency virus and were hospitalized for septicemic salmonellosis underwent rectal biopsy for diagnosis of S. intercalatum infection. A nontyphoidal Salmonella species was isolated from 53 of the 70 patients: Salmonella typhimurium in 14 cases; Salmonella enteritidis in 7 cases; Salmonella galiema in 4 cases; Salmonella arizonae in 3 cases; and other species in 25 cases. Schistosomal eggs were present in the rectal mucosa of 48 (90.6%) of these 53 patients, in 11 (64.7%) of 17 patients with septicemia due to Salmonella typhi or Salmonella paratyphi, and in 21 (38.2%; P < .001) of 55 controls. Clinical symptoms were not different among patients coinfected with S. intercalatum and nontyphoidal Salmonella vs. those with enteric fever. Treatment with antibiotics induced apyrexia only after administration of antiparasitic therapy in 30 patients. These data strongly suggest interactions between S. intercalatum and Salmonella in infected children with clinically severe nontyphoidal salmonellal septicemia.

Adolescent↗
PubMed1994

Evaluation of Onchocerca volvulus-specific IgG4 subclass serology as an index of onchocerciasis transmission potential of three Gabonese villages.

The major objective of this study was to evaluate the usefulness of IgG4 ELISA and Western blot analysis, using a crude extract of Onchocerca volvulus adult worms as antigens, for diagnosing onchocerciasis in a Gabonese paediatric population with mixed filarial infections. The subjects had loaisis, streptocercosis or mansonellosis in addition to onchocerciasis. Control sera from loaisis or mansonellosis subjects residing outside the endemic zone were used to provide the cut-off point for positive results. The IgG4 ELISA had a specificity of 96% but a lower sensitivity of 78.7%. It detected 25 onchocerciasis cases out of 65 individuals who were negative on parasitological examination. Furthermore, the ELISA provided a more accurate picture of onchocerciasis transmission in a village with very low skin microfilarial load. A 27.5-kD antigen was identified on Western blots as a marker of onchocerciasis. The paediatric population provided a reliable window for assessing the parasitologic and serologic parameters in the three villages with disparate levels of onchocerciasis transmission.

Adolescent↗
PubMed1993

[Bilharziasis caused by Schistosoma intercalatum, a recent and forgotten form of schistosomiasis].

Schistosoma intercalatum schistosomiasis is confined to the western regions of equatorial Africa. It is often asymptomatic but it produces microscopic lesions in the intestine (mainly the rectum), the liver and the genital organs of both men and women, the latter lesions being more insidious and insufficiently explored. Its treatment, like that of other schistosomiases, consists of one course of praziquantel. Naturally, S. intercalatum may be hybridized with S. haematobium in Gabon and Cameroun which are the two countries where the two parasites coexist.

Animals↗
PubMed1993

Elevated antifilarial IgG4 antibody levels in microfilaremic and microfilaridermic Gabonese adults and children.

Immunologic analyses of sera from 47 selected individuals living in a mixed filariasis transmission zone in Gabon were carried out. Onchocerca volvulus, Loa loa, Mansonella streptocerca, and M. perstans are transmitted in this region. Based on parasitologic findings and age, the 47 individuals were stratified into four groups: microfilaria negative (Mf-) children (3-15 years old), Mf- adults (> 15 years old), microfilaria positive (Mf+) children and Mf+ adults. For descriptive purposes, the term microfilaria positive refers to individuals with skin and blood microfilariae. Antifilarial antibody titers were determined using an enzyme-linked immunosorbent assay with Dipetalonema viteae antigens. In general, children had higher titers of IgG antibodies than adults. For the IgG1, IgG2, and IgG3 subclass responses, both age and microfilarial status appeared to be important variables since Mf- children consistently had the highest titers whereas Mf- adults had the lowest titers. For the IgG4 antifilarial response, only the microfilarial status was an important variable. All Mf+ individuals had significantly higher levels of IgG4 antibody than Mf- individuals. Pooled sera of Mf- and Mf+ individuals reacted with similar O. volvulus antigens on Western blots. Control sera of individuals who did not reside in the study area, but who had single infections with L. loa or M. perstans, did not react with any O. volvulus antigens.

Adolescent↗
PubMed1993

[Evaluation of 3 tests applied in the immunological diagnosis of hepatic amebiasis in Gabon].

The diagnosis of hepatic amoebiasis is not always easy. In case of suspicion of hepatic amoebiasis in an endemic area, the patient is immediately treated with a 5-nitroimidazole. Immunological diagnosis is indispensable. After a comparative study of BLA, IHA and IFA reactions, the BLA test has shown to be well adapted to the context of a country with insufficient sanitary infrastructure. The BLA test is easily performed and enables rapid detection of antibodies. The result obtained in about 5 minutes allows to adjust the therapeutic conduct.

Adolescent↗
PubMed1992

[Parasitemia in Plasmodium falciparum malarial attacks in children].

In order to evaluate the predictive value of parasitaemia, this parameter was measured on admission in 69 Gabonese children aged from 3 to 13 years hospitalized for Plasmodium falciparum malarial attacks. Fourteen of these children had cerebral malaria, 5 had isolated convulsions and 50 had uncomplicated attacks. The parasitaemia values measured were compared with those found in asymptomatic children of the same age range carrying trophozoites. There were no significant differences in mean parasitaemia count between the 3 types of malarial attack, and only the asymptomatic carriers had significantly lower counts. However, the wide scattering of individual values within each group indicated that simple measurement of parasitaemia is not discriminative enough to predict the course of malarial attacks in children living in endemic regions. In particular, malarial attacks with very low or very high parasitaemia value are possible, but similar values are found in asymptomatic carriers.

Adolescent↗
PubMed1992

[Malaria and hemoglobin S: interactions in African children].

Among 300 cases of Plasmodium falciparum malaria attacks explored in Gabon, the proportion of homozygous (SS) or heterozygous (AS) sickle-cell patients was 6.2 percent in 206 ordinary attacks and 3.2 percent in 94 cerebral malaria attacks, and 23.2 percent in the general population. On the other hand, asymptomatic carriage, as detected in 98 children by thin blood films in school screening, was as frequent in the SS or AS infantile population as in the general population. These data show that haemoglobin S protects effectively, although not entirely, against severe attacks of P. falciparum malaria. The incidence of anaemia and vaso-obstructive crisis in malaria-infested sickle-cell patients suggests that subclinical carriage of haematozoa may worsen the course of sickle-cell disease, and this must be taken into account when planning treatment.

Adolescent↗
PubMed1992

Efficacy, safety and acceptability of halofantrine in the treatment of acute Plasmodium falciparum malaria in African children (Gabon).

Halofantrine chlorhydrate 2 per cent suspension was given to 50 children (mean age 6.2 years in a dose of 8 mg/kg three times a day as a single day treatment. The children were born and lived in Gabon, where malaria transmission is continuous. They all had acute Plasmodium falciparum malaria. The children were kept in hospital for 5 days, and regularly followed over a 15-day period. The 50 children were cured and efficacy was evaluated as good in 44 cases, and excellent in six cases, as judged by improvement in their clinical signs and parasitaemia. Two criterias were considered in the evaluation of efficacy: clearance of parasitaemia (mean day 4), fever clearance (mean hour 24). There were two cases of persistences of parasites at day 15 with a very low parasitaemia rate. Tolerance to halofantrine was good from a clinical and biological point of view. Acceptability was excellent in all cases. Halofantrine 2 per cent suspension is a good alternative in the treatment of acute Plasmodium falciparum malaria in children, especially with the present situation of multidrug-resistant strains in Central Africa.

Acute Disease↗
PubMed1992

Influence of intestinal parasitism on lactose absorption in well-nourished African children.

Hydrogen breath tests were performed in Gabon (Central Africa) after a loading dose of lactose in 67 well-nourished African children (50 with intestinal parasites and 17 unparasitized) and in 18 unparasitized young adults. All had normal nutritional status, and none had diarrhea or digestive symptoms. Parasites that were found included Ascaris lumbricoides in 76% of the parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16%, and Necator Americanus in 14%. A similar proportion of parasitized (64%) or unparasitized (62.8%) subjects were lactose malabsorbers. Giardia infection was associated with a higher, but not significantly different, proportion of lactose intolerance (10 of 12, 83.3%). The presence of infection with A. lumbricoides or T. trichiura did not increase the percentage of lactose malabsorption. These data indicate that a decrease of lactase activity in well-nourished African children is not related to the presence or the importance of Ascaris or other intestinal parasites if the nutritional status is normal.

Animals↗
PubMed1992

[Seroepidemiological study of toxoplasmosis in Libreville, Gabon].

A sero-epidemiological survey of toxoplasmosis has been carried out in 1178 subjects residing in urban and suburban areas of Libreville, Gabon. Two techniques were used: Pastorex toxo of the Institut Pasteur and ISAGA of bioMérieux. The acquisition of antibodies occurs at an early age, from the age of six months on. After the age of 15 years, the age of procreation, the prevalence is 68%. Between the ages of 15 and 19 years, 19% have IgM. The risk for toxoplasmosis acquired during pregnancy is not to be neglected. It decreases between the ages of 20 and 30 years. The most probable source of contamination is the reservoir from the soil. No difference between the sexes was observed.

Adult↗
PubMed1992

[Toxoplasmosis in Gabon. Results of a seroepidemiological investigation].

A toxoplasmosis sero-epidemiological inquiry was effected with 2,324 sera collected from Libreville, Lébamba, Makokou, Lastourville and Woleu-Ntem. All the sera were first screened through Pastorex toxo (Diagnostics Pasteur). Those with more 8 IU/ml and 267 sera with less 8 IU/ml were then assayed by ISAGA (bioMerieux) for IgM. The results of ISAGA must be interpreted with carefulness for natural agglutinins are frequent in this population. The acquisition of immunity is precoce and more of 60% have a serology positive from ten years old. There was no difference between sex.

Adolescent↗
PubMed1992

[Decreased intraepithelial lymphocytes in the intestinal mucosa in children with malnutrition and parasitic infections].

In Gabon, 15 children aged 13 to 36 months admitted for malnutrition with chronic diarrhea underwent a small bowel biopsy for detection of parasites in the duodenal contents and histologic evaluation of the intestinal mucosa. In every case, intraepithelial lymphocyte counts (IELC) were under the lower limit of normal for children and adults, regardless of whether or not parasites were found. Partial villous atrophy was a consistent finding. Proportion of lymphocytes among intraepithelial cells was 7.4% in the 6 children with no parasitic infection, 7.9% in the children with giardiasis, and 8.1% in the children with strongyloidiasis. Appropriate treatment of the parasitic infections was quickly followed by resolution of the diarrhea in the nine patients with demonstrable intestinal parasites. These data should be compared with the well documented lymphocyte function anomalies associated with protein-calory malnutrition. The fall in IELC and lack of response to local anigenic stimulations are features of malnutrition.

Atrophy↗