Malaria epidemiology in the province of Moyen Ogoov, Gabon

In the course of epidemiological and immunological baseline studies parasitological surveys were conducted, in 1992, in three localities situated in our near rain forest in the area of Lambaréné, Gabon, western Central Africa. Anopheles gambiae s.s. and A. funestus are considered to be the main vectors of malaria. The three localities represent strata with obvious differences in the intensity of malaria transmission. The lowest parasite rates were recorded in the village around the Albert-Schweitzer-Hospital where environmental sanitation and easy access to diagnostic and therapeutic facilities afford a fair measure of malaria control. The villages of Bellevue and Tchad show a much higher prevalence of Plasmodium falciparum, followed by P. malariae and P. ovale. In all three villages parasite rates and geometric mean parasite densities of P. falciparum showed the age pattern typical for areas with stable, hyperendemic malaria. Analysis by season showed the period of the long rains to be the epidemiologically calmest while the dry season and even more the short rainy season produced an increase of parasite rates and densities. In Tchad, the most affected of the three villages, the parasite rates in female adults were significantly lower than in male adults. This was accompanied by lower parasite densities in female adults.

[Digestive cryptosporidiosis in young children in an urban area in Gabon]

A 27 month epidemiological survey of cryptosporidiosis in stools was conducted in 288 Gabonese children aged between 0 and 2 years (mean 10.2 months). By at least one of two staining techniques, acid-fast and direct immunofluorescence, the rate of infection was determined to be 24%. The rate was 28% in cases of acute diarrhea, in striking contrast with the low prevalence of 14.8% in uninjured gastroenteritus subjects (p < 0.05). The notion of asymptomatic carriers was clearly demonstrated. The maximum of 34.4% was observed for infants aged between 6 and 12 months (p < 0.02). In cases of malnutrition, this rate increased to 31.8%, whereas it was 16.8% in eutrophic children (p < 0.01). For the rainy and dry seasons, it was 31.7% and 19.4%, respectively (p < 0.02). Water is emerging as an important vehicle for the transmission and spread of Cryptosporidium sp. in tropical areas.

Intestinal parasites of sympatric gorillas and chimpanzees in the Lopé Reserve, Gabon

A coprological survey of intestinal parasites of wild chimpanzees (Pan t. troglodytes) and western lowland gorillas (Gorilla g. gorilla) was carried out in the Lopé Reserve in central Gabon. Most samples (69%) were positive but the prevalence of intestinal parasites in the 61 gorilla samples (84%) was higher than in the 66 chimpanzee samples (56%). At least 11 species of parasite were observed: six protozoan, one trematode and at least four nematodes. Six of the species were found in gorillas and chimpanzees but the remainder only occurred in chimpanzees. All but one parasite occurred at low prevalences. Entodiniomorph ciliates, which occurred frequently in both ape species (particularly in gorillas) in the Lopé survey and in all previous coprological surveys of wild apes, may be symbionts involved in cellulose digestion. The dietary and behavioural strategies of wild primates that serve to reduce infection by pathogenic parasites are reviewed.

Protein C activity in Gabonese children with sickle cell disease

Protein C levels were determined in 40 Gabonese children with sickle cell disease, in the steady state and during vasoocclusive crisis. In comparison with 40 healthy controls matched for age and sex, there was a significant decrease in protein C activity in the patients, although no difference was found between protein C levels in the steady state and during crisis.

Immunologic responses to soluble exoantigens of Plasmodium falciparum in Gabonese children exposed to continuous intense infection

The development of antidisease immunity in children infected with Plasmodium falciparum is thought to be related to their immunologic responses to certain soluble parasite-derived exoantigens. We have assessed both cellular and humoral responses to these antigens in a cross-sectional study of a cohort of Gabonese schoolchildren who live in an area where malaria is holoendemic and perenially transmitted, in an attempt to identify immunologic markers of this early developing protective immunity. Concurrent parasitemia was found to have a significant influence on lymphoproliferative and antibody responses to the exoantigens. Individuals with higher levels of parasitemia had significantly lower proliferative and IgG isotype responses. Higher concentrations of specific IgG1 and IgG3, in particular, were associated with lower or no parasitemia, suggesting a possible protective role for these isotypes, whereas the level of IgM antibodies showed a trend towards higher concentrations in those with parasitemia, perhaps indicative of an exoantigen-induced T cell-independent response. Cytokine responses were unaffected by either the presence or the intensity of parasitemia and were dissociated from both proliferative and antibody response to the exoantigens. However, the mitogen-stimulated production of tumor-necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL)-6 was positively correlated with the corresponding lymphoproliferative responses. At the individual level, mitogen-stimulated TNF-alpha, interferon-gamma, IL-2, and IL-6 responses were positively correlated, as were mitogen- and exoantigen-induced TNF-alpha. The results are discussed in the light of current knowledge of immune responses to the exoantigens and the development of protective immunity to P. falciparum.

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.

Hepatitis C virus genotype 4 is highly prevalent in central Africa (Gabon)

Following a survey of hepatitis C virus (HCV) infection recently carried in central Africa (Gabon), we cloned and sequenced PCR products of the 5' non-coding and capsid-encoding regions of HCV RNA from three randomly selected HCV RNA-positive Gabonese subjects. In the capsid-encoding region, the identity between the three Gabonese isolates was 91 to 98%. The three Gabonese sequences showed a divergence of 11 to 17% from published HCV genotypes I to IV (1a, 1b, 2a and 2b) isolates and of 6 to 11% from HCV genotype 4 isolates. Thus the Gabonese isolates, termed HC-G, belong to HCV genotype 4. Based on the sequences of the three isolates, a specific probe (cpsG) was designed to detect the HC-G genotype in 30 randomly selected anti-HCV-positive Gabonese subjects, 14 of whom were HCV RNA-positive. Analysis with cpsG showed that 10 of 14 of the HCV RNA-positive subjects were infected by the HC-G genotype. HC-G is therefore highly prevalent in the HCV RNA-positive Gabonese population. The availability of these Gabonese sequences should facilitate the design of specific serological tests for African HCV isolates.

Demographic factors associated with HTLV-1 infection in a Gabonese community

An epidemiological study of human T-lymphotropic virus type 1 (HTLV-1) and syphilis has been carried out in a multiethnic community of seven neighbouring villages located in eastern Gabon on 1240 subjects over 5 years old (82.7% of the population in this age range). Antibodies to HTLV-1 (anti-HTLV-1) were detected by ELISA with confirmation by Western Blot and antibodies to syphilis by Venereal Diseases Research Laboratory assay with confirmation by the Treponema pallidum haemaglutination assay. The prevalence rate of anti-HTLV-1 was 8.5% and increased from 3.7% in the 5-14 years age group to 23.8% in the over 60 years age group. Logistic regression showed that the positivity for anti-HTLV-1 was associated with age, ethnic group and sex (higher prevalence in females). The seroprevalence rate of syphilis was 8.2%. Seropositivity for syphilis and HTLV-1 were related but age was a confounding variable in this relationship. This study showing a highly heterogeneous distribution of HTLV-1 in a geographically limited area suggests the role of environmental and behavioural factors in HTLV-1 transmission.

White piedra and Trichosporon species in equatorial Africa. III. Identification of Trichosporon species by slide agglutination test

Fifty-two Trichosporon strains isolated from Gabonese female patients 15-60 years, were studied. The identity of these strains was established by two different methods: the method proposed by Guého et al. (1992), based on mycological criteria, and a slide agglutination method performed with monospecific antisera prepared in our laboratory. The final results show a perfect correlation between the two methods, which allowed us to identify 25 strains of T. mucoides, 21 strains of T. inkin and seven strains of T. asahii. The results of the agglutination tests performed with 24-h-old subcultures grown on Sabouraud glucose agar are available in less than 15 mins. In the light of these results, it appears that this method, which is rapid and easy to perform and reproduce, may readily be used in hospital laboratories. In addition, this method allowed us to verify the presence of antigens common to the genera Cryptococcus and Trichosporon, which were easily shown by the use of crude sera. The fact that the anti-Trichosporon monospecific sera lose their capacity to agglutinate Cryptococcus neoformans proves their high specificity.

White piedra and Trichosporon species in equatorial Africa. I. History and clinical aspects: an analysis of 449 superficial inguinal specimens

White piedra is a hair infection characterized by nodules composed of fungal elements which envelop the hair shaft. Classically, this infection was considered to be produced by an asexual yeast-like fungus, Trichosporon beigelii. At present, in accordance with studies carried out previously, this species is subdivided into six newly defined distinct species (T. asahii, T. ovoides, T. inkin, T. mucoides, T. asteroides and T. cutaneum), all belonging to the class Basidiomycetes. Although widespread, white piedra has not previously been described in tropical regions of Africa. The present study, carried out in Libreville (Gabon), an equatorial region of Africa, shows that the incidence of this infection is quite high (18% of 449 inguinal specimens) in the female population aged 15-60 years, with a predominance in young patients (15-44 years). The relationship between the clinical manifestations and the specific hair lesions is also detailed. Three species belonging to the genus Trichosporon were identified: T. mucoides, T. asahii and T. inkin.

White piedra and Trichosporon species in equatorial Africa. II. Clinical and mycological associations: an analysis of 449 superficial inguinal specimens

Eighty-one of 449 Gabonese female patients examined were found to be positive for genitopubic white piedra. The association with trichobacteriosis is frequent (53 cases), and mostly seen with inguinal intertrigo. Fifty-two strains belonging to the genus Trichosporon were isolated from genital hairs as well as from inguinal intertrigo lesions. These strains were identified in accordance with previously defined morphological and biochemical criteria. Three species were recognized: T. mucoides (25 strains), T. inkin (20 strains) and T. asahii (seven strains). Their macroscopic and microscopic morphological properties, as well as their ability to reduce tetrazolium, were determined. In addition, the study of the clinical and pathogenic associations in which each of these strains was involved revealed some of their particular properties.

[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.

High level of hepatitis C endemicity in Gabon, equatorial Africa

To assess the prevalence of hepatitis C virus (HCV) infection, a community-based study was performed in eastern Gabon on 1172 subjects over 5 years of age. The prevalence of antibodies to HCV (anti-HCV) detected using second-generation enzyme-linked immunosorbent assay (ELISA) and confirmed by an immunoblot assay (RIBA 2), was 6.5%. Anti-HCV prevalence increased with age but was related to neither sex nor ethnic group. Among 30 subjects with positive ELISA results, 14 had HCV viraemia as shown by the polymerase chain reaction (11/12 RIBA positive, 2/15 RIBA negative, 1/3 RIBA indeterminate). We conclude that HCV is highly endemic in western equatorial Africa and that a high proportion of the population may be viraemic.

Population-based study of serum hepatitis B virus DNA in Gabon

The prevalence of serum hepatitis B virus (HBV) deoxyribonucleic acid (DNA) was measured in a Gabonese community at high risk for HBV infection. Among 698 subjects 5 to 24 years old, the prevalence of HBsAg was 11.1% vs. 57.9% for anti-HBs and 7.2% for anti-HBc alone. The prevalence of HBeAg among HBsAg-positive subjects was 26.5% vs. 59.5% for anti-HBe. The prevalence of HBV DNA tested by a hybridization spot test was 2.1% in the overall population and 18.7% among HBsAg-positive subjects. HBV DNA was found in 15 of 21 HBeAg-positive subjects but in none of the subjects positive for anti-HBe or negative for both HBeAg and anti-HBe. HBV DNA was not detected in any HBsAg negative subjects. The prevalence of HBV DNA decreased with age. This low prevalence of HBV DNA contrasts with the high level of endemicity in the study population.

Blood transfusion as a major risk factor for HTLV-I infection among hospitalized children in Gabon (Equatorial Africa)

To study the risk factors for HTLV-I infection of African infants living in a high seroprevalence area, a survey was conducted among hospitalized children and their mothers in Franceville, southern Gabon. A total of 610 children (6 months to 14 years old) from 555 families and 434 mothers participated in the study. HTLV-I seroprevalence was 7.1% in the mothers and 2.8% in the children. No increase by age was observed in the children. Significantly more children with sickle cell anemia (11 of 57, or 19.2%) were infected than others (1%) (Fisher's exact test p < 0.001). Of the 13 seropositive infants (C+) whose mothers were tested, six (43%) had a seropositive mother (M+) [p < 0.001, prevalence ratio (PR) 10.12, 95% CI 3.40-30.35, attributable risk (AR) 0.55]. Risk factors for nonmaternally acquired HTLV-I infection were previous blood transfusion (Fisher's exact test p < 0.001, PR 15.74, CI 5.20-47.60, AR 0.71) and hospital admission. In a hospitalized pediatric population in Gabon mother-to-child transmission and blood transfusion (because of sickle cell disease) were equally implicated in HTLV-I infection. Control of HTLV-I infection in children in Africa requires prevention of both vertical and transfusion-associated transmission, which may be exceedingly difficult in developing countries.

[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.

Non-Hodgkin lymphoma in Gabon and its relation to HTLV-I

A case-control study was performed in Libreville, Gabon, to determine whether a relationship can be established between the relatively high proportion of non-Hodgkin lymphoma (NHL) among all cancer cases and the high seroprevalence rate of HTLV-I observed, and to discover whether cases of adult T-leukemia/lymphoma (ATLL) related to HTLV-I exist in Gabon. From November 1987 to April 1989, a total of 32 patients with NHL were recruited; 6 were infants with Burkitt's lymphoma and 26 were adults with NHL. Each patient was matched with 2 asymptomatic controls for age, sex and ethnic group. HTLV-I serology was done by ELISA and Western blot. Comparison of the groups was done by chi-square analysis. None of the 6 infants with Burkitt's lymphoma and none of their controls had antibodies to HTLV-I. Of the 26 patients with NHL, 7 (26.9%) had HTLV-I antibodies. Among the 52 controls, the HTLV-I rate was 13.4% (n = 7). There was no difference between cases and controls (Fisher's exact test, p = 0.16). Among the 26 NHL, 4 cases fitted the criteria of ATLL and were HTLV-I-positive; 3 others who were positive for HTLV-I were a woman with lymphoblastic gastric NHL and 2 old men with an unclassified lymphoma. From the results of this limited series it is not possible to state that there is an association between NHL and HTLV-I infection. Nevertheless, cases of ATLL related to HTLV-I are reported from this area. Based on the HTLV-I seroprevalence rates reported in Gabon, the estimated incidence rate of ATL among seropositive people in Gabon appears much lower than in Japan. Different explanations can be proposed, but under-diagnosis of ATLL is probably one of the main factors.

[Ankylosing spondylarthritis: first case described in Gabon]

The first case of ankylosing spondylitis described in Gabon is reported here. The patient was a 32 years old and presented an advanced typical form. Test for HLA-B27 was negative. The rarity of this disease among black Africans is explained by the low prevalence of the antigen.

[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.

An epidemiological study of a Schistosoma intercalatum focus in south-east Gabon

A Schistosoma intercalatum focus in south-east Gabon was studied between July 1989 and July 1990. Among the 356 permanent residents in the village, 354 provided stool specimens and 101 (28.5%) were excreting eggs (geometric mean of egg density = 101.4 eggs/g, with a range of 1-3200). The pattern of prevalence and intensity of infection with age showed the curve usually found in schistosomiasis, i.e. increasing during the first 2 decades of life and then gradually decreasing. The analysis by stepwise logistic regression of factors shown to be important in determining infection in other schistosomiasis clearly demonstrated the significant and independent effects of both age and water contact on infection by S. intercalatum. These similarities with other schistosomal infections could indicate that similar immune mechanisms were operating. Urine from 284 subjects, of whom 90 were egg excreters, was tested for circulating antigen by enzyme-linked immunosorbent assay using a Schistosoma genus-specific monoclonal antibody (Sm 10.27.12). The test was positive for 90 subjects but only 35 of these were egg excreters. Although S. intercalatum is usually considered of low pathogenicity in man, this study showed a relationship between egg excretion and both splenomegaly and lower haemoglobin levels, even after taking into account the confounding presence of Plasmodium falciparum.

[Epidemiologic and clinical aspects of child tuberculosis in Gabon. Retrospective study of 47 cases]

Forty-seven pediatric cases of tuberculosis seen over three years in a department of general pediatrics are reviewed. The main epidemiological and clinical features were studied. Yearly incidence approximated 1.42% in the department. In most instances the source of contamination was not identified. Most patients had not been immunized according to recommendations. Early immunization should be performed and followed by routine tests for vaccine-induced immunity during the first two years.

[The practice of pediatric oncology in a general pediatric service in Black Africa. The experience of the hospital center of Libreville (Gabon)]

From 1984 through 1990, 41 children with malignant diseases were admitted to the department of general pediatrics of 6,700 patients. The department had 40 beds including ten for neonates. Patients often sought medical advice only late in the disease. In many cases, solutions can be found to the problems raised by the treatment of these patients in a tropical area with no specialized facilities. However, this treatment is a significant burden for both the physicians and the families and new, adapted solutions are needed.

[Recurrent extra-uterine pregnancies. 63 cases treated at the Hospital Center of Libreville from 1985 to 1989]

Ectopic implantation of the fertilised ovum, whether for the first time or as a recurrence, is not uncommon in this department. In a study in the Libreville Hospital group from 1985 to 1989, the authors found 828 cases of ectopic pregnancy (EP) including 63 recurrences, i.e. 7.61 per cent. These recurrences most often involved young women (26 per cent of cases) and nullipara (30%). The chief common etiology for the first occurrence remained tubal infection (57.28 per cent of cases). Treatment consisted most often of radical macrosurgery because of the advanced state of tubal disease, thus leading to the permanent sterilisation of 48 patients, i.e. 71.2 per cent of recurrences. Nineteen patients had a history of previous conservative surgery, including 8 homolateral recurrences (43 per cent). Reducing the incidence of such pathology essentially involves the prevention of gynecological infections, and in particular sexually transmitted diseases, as well as the possibility of early diagnosis of EP. Despite the fact that it seriously compromises the subsequent fertility of these young patients, total salpingectomy remains the treatment of choice for avoiding recurrences.

Prevalence and type of infertility in Gabon

The prevalence and type of infertility based on the WHO criteria were determined in a rural and semi-rural population in south-eastern Gabon. The prevalence rate of infertility in the rural population was 5.7% for primary infertility and 20.0% for secondary infertility. In the semi-rural area, 3.0% suffered from primary infertility and 22.4% from secondary infertility. Pregnancy wastage and home delivery were risk factors for secondary infertility. An evaluation of the WHO criteria for fertility surveys was made.

[Diagnostic problems with cerebral vascular accidents in Gabon]

This retrospective study covers a period of eleven years (1977-1988). It concerns 365 patients who developed a cerebrovascular accident or stroke and originated from different provinces of Gabon. The authors report their experiences in order to emphasize the diagnostic problems and the need of computerized tomography.

Malignant lymphomas in Gabon (equatorial Africa): a morphologic study of 72 cases

A retrospective morphologic analysis was conducted on 72 malignant lymphomas collected in Gabon, a country of the equatorial area in Africa. Non-Hodgkin's lymphomas (NHLs) were by far the most frequent type of lymphoma, representing 67 cases (93%); only five patients (7%) had Hodgkin's disease. Non-Hodgkin's lymphomas were classified according to two modern systems (Kiel and Working Formulation). The age distribution of NHL patients was bimodal, with the highest peak in the 0 to 14 years age group (these cases were almost exclusively associated with Burkitt's lymphomas), and with the second highest peak in the 55 to 64 years age group. The male to female ratio was 2.5:1, and the overall median age was 44 years. According to the Working Formulation, the NHL cases were composed of one follicular lymphoma (1.5%), 55 diffuse lymphomas (82%), and 11 miscellaneous lymphomas (16.5%). Burkitt's lymphoma was the most frequent NHL (17 cases; 25.4%), followed by diffuse large cell lymphoma (15 cases; 22.4%) and immunoblastic lymphoma (nine cases; 13.4%). Consequently, high-grade NHL formed the largest group (28 cases; 42%), intermediate-grade NHL formed the next largest group (21 cases; 31.3%), and low-grade NHL formed the smallest group (seven cases; 10.4%). These data are compared with series from developed and developing countries, and the observed differences in distribution of the histologic subtypes of malignant lymphoma are discussed.

Prevalence of HTLV-I and HTLV-II infection in Gabon, Africa: comparison of the serological and PCR results

A cluster sampling survey was performed in 1989 in Libreville, Gabon, to determine HTLV-I and HTLV-II prevalence and to compare the efficacy of polymerase chain reaction (PCR) and serology in detecting HTLV-I and HTLV-II infections. A total of 322 sera from adults were tested by ELISA and by Western blot (WB). The WB patterns were interpreted according to WHO criteria and those of the manufacturer. PCR analysis using primer pairs in the gag and pol region, with a specific probe for HTLV-I and HTLV-II, was performed on the lymphocytes of the 322 adults. In addition, 134/322 samples were re-tested with tax primers, in a second laboratory. Using WHO criteria, 8/322 (2.5%) samples were positive on WB and 25 were indeterminate; with the criteria of the kit, 26/322 (8.1%) were positive and 7 were indeterminate by WB. By PCR, 13 (4%) samples were positive, including 12 for HTLV-I (3.7%) and one for HTLV-II (0.3%). All 8 seropositive samples (by the WHO criteria) were positive by PCR, as were 4 out of 25 indeterminate samples. Only one out of 289 seronegative samples was positive by PCR. In contrast, only 12/26 positive samples by the kit criteria were confirmed by PCR. These results confirm the relatively high HTLV-I/II seroprevalence observed in Gabon. HTLV-I infection is preponderant, but HTLV-II is also present. The WHO criteria for WB give a better fit with PCR results than the kit criteria for WB. In the absence of a specific confirmatory test and based on the uncommon "seronegative" HTLV-I/II infection, the indication for PCR appears limited to the positive WB samples (to differentiate HTLV-I and II infection) and to the indeterminate WB samples.

[Eclampsia at the Hospital Center of Libreville. 53 cases among 41,285 deliveries from 1985 to 1989]

Eclampsia is a serious complication at the end of pregnancy. This retrospective study over a 5-year period at the Libreville CHU hospital shows that the incidence of 0.12 p. cent is comparable to the incidence fond in other countries at a similar level of development. Promoting causes include youth of the patients, twin births, the "cold" season, the lack of follow-up after prenatal consultations. The consequences are increased maternal and perinatal death. Cesarean section remains the best way of dealing with an attack of eclampsia and improves both maternal and fetal prognosis. It is possible to eliminate, or at least reduce, the number of cases by developing conscientious and regular prenatal consultations.

Cytokines in the pathogenesis of malaria: levels of IL-I beta, IL-4, IL-6, TNF-alpha and IFN-gamma in plasma of healthy individuals and malaria patients in a holoendemic area

A longitudinal study was conducted between October 1989 and February 1990 in a malaria holoendemic area of Gabon to determine the plasma concentration of various cytokines in individuals continuously exposed to infection with malaria parasites. No cases of severe malaria were seen and fever was the main presenting symptom of clinical malaria. Parasite rates were highest in children 6-9 years old but clinical malaria was seen essentially in children below 6 years of age. The incidence of clinical malaria was highest in November and February corresponding to the beginning and end of heavy rains respectively. Parasite rates did not show any seasonal variations. Overall, there was no seasonal variation in plasma cytokine levels but both IL-6 and IL-4 levels were highest in February. Plasma concentration of TNF-alpha and IFN-gamma were higher in parasitaemic than aparasitaemic individuals and donors who had clinical malaria had higher levels of TNF-alpha, IFN-gamma and IL-6 than asymptomatic parasitaemic donors. There was a negative correlation between age of the individual and the concentration of plasma TNF-alpha and IFN-gamma suggesting that the production of these cytokines could be modulated by repeated malarial infections. Asymptomatic parasitaemic children 5-7 years of age had higher levels of plasma TNF-alpha than clinically similar children below or above this age group suggesting that refractoriness to the clinical effects of TNF-alpha may be an important factor in the ability of these children to resist clinical malaria.(ABSTRACT TRUNCATED AT 250 WORDS)

[First appearance of monkey pox in human beings in Gabon]

The authors report on the first coming out in Gabon of human monkey-pox. Four children in the same family were simultaneously attacked. In one of the two fatal cases, diagnosis of monkey-pox was confirmed by the isolation of the virus. In the three other cases, diagnosis was based on clinical and epidemiological findings. The coming out of monkey-pox in Gabon squares with sporadic coming out of this zoonosis observed in the humid tropical forests of west and Central Africa. Two fatal cases presented some symptoms of hemorrhagic fever and cutaneous symptoms did not dominate the clinical feature. As a consequence of it, monkey-pox has to be envisaged in similar cases. The attack of liver and spleen in man has not been documented up till now, as it has been for monkeys. Classical diagnosis is based on the isolation of the virus from a cutaneous lesion. In the present case, the virus was isolated from a blood sample. Epidemiological study did not reveal any interhuman transmission evidence, nor the source of infection.

[Intestinal parasites and lactose malabsorption]

Breath-test was performed for diagnosis of lactose malabsorption in 50 Gabonese children of normal nutritional status, aged 5 to 15 years, with parasites in stools, but without diarrhoea or digestive symptoms. Control group was unparasitized and consisted of 17 children and 18 young adults living in the same area. Parasites discovered by stool examination were Ascaris lumbricoides in 76% of parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16% and Necator Americanus in 14%. Children were given a 10 g lactose load and adults 20 g. Lactose malabsorption was discovered in 64% of parasitized patients and in 63% of unparasitized. Ten of 12 (83.3%) of Giardia infected children had a lactose malabsorption (no significant difference). These data show that decrease of lactase activity in African children is not related to the presence or to the importance of intestinal parasitism, except for Giardia infestation, if nutritional status is normal.

[Specific serologic reactions in the cerebrospinal fluid in congenital syphilis and therapeutic implications]

In a study carried out in Gabon, antibodies against the treponema were looked for in the cerebrospinal fluid (CSF) in 13 children with active congenital syphilis (presence of specific IgM antibodies) and in 7 children with positive serologic reactions reflecting transplacental passage of maternal antibodies. Serologic reactions used included the VDRL test, the TPHA test, and the FTA-ABS IgG and IgM tests. Among the 13 children with syphilis, 7 had a positive FTA-ABS IgG test in the CSF; positivity of this test was not correlated with severity of clinical features, CSF protein levels or CSF cytologic findings. The TPHA test was positive in only four children and the VDRL test was consistently negative. These findings are similar to those reported in another group of patients with meningeal involvement proven by the demonstration of IgM in the CSF using recent techniques. Passage of antibodies into the CSF is possible (1 case in this study) but for safety patients with specific IgG in the CSF should be given penicillin in a dosage that provides treponema-killing levels in situ (100,000 U/kg/d). Use of this dosage is recommended whenever sensitive techniques for CSF analysis are not available.

[The sequela of peri-hepatitis due to Chlamydia trachomatis (Fitz-Hugh-Curtis syndrome) seen during an ectopic pregnancy]

Between January 1st and May 31 1989, there were 31 cases of perihepatic adhesions (Fitz-Hugh-Curtis syndrome) about 90 ectopic pregnancies (rate: 34 p. cent). The Chlamydia's serology is positive at 1/64 level in 97 p. cent of cases and at 1/256 level in 72 p. cent. Only three cases are not allied with pelvic disease. Peri-splenitis accompanies severe hepatitis (3 cases) and no perinephritis was observed in this study. The authors emphasize the wish to explore perihepatic space in all pelvic surgery. In the department of Gynecology and Obstetrics at the University Hospital of Libreville, increased the rate of ectopic pregnancy (1 for 44 deliveries), this coincides with the increased prevalence to Chlamydia trachomatis infection (81 p. cent ectopic pregnancies and 63 p. cent deliveries). This situation creates a new and greater problem of health in sub-Saharan Africa.

[Indications for cesarean section and their outcome at the Hospital Center in Libreville]

Over a 16-year period and 113,739 deliveries, the rate of caesarean sections in the Department of Gynecology-Obstetrics of the Centre Hospitalier of Libreville (Gabon) reaches 1.79 p. cent. Since 1985, there is a highly significant (p less than 0.001) of that rate reaching 2.33 p. cent. A comparative study of two 4-year periods (1981-1984 and 1985-1988) permits to analyze the evolution of caesarean sections. The increase is the result of an improved diagnosis of the pathology during pregnancy, especially pre-eclampsia (6.2 p. cent of indications), a better obstetrical monitoring in pelvic deliveries (7 p. cent) and screening of fetal distress (11 p. cent). The indications remain stable in mechanical dystocias and placenta praevia (40 p. cent) and for scarred uterus (19 p. cent) the rate of which remains at 1 p. cent of the deliveries. The decreased rate of perinatal mortality which has benefited from the improvement of the quality of care is not directly related to the increased rate of caesarean sections: in Africa, caesarean sections are still performed in harmful conditions for saving the mother. Maternal mortality remains high (160 of 100,000 NB) and the mortality of caesarean sections is 9 for 1,000, with only 4 p. 1,000 related to the C. section itself and not to the pathology requiring the procedure. The mortality of caesarean section is 5 times higher than that of vaginal deliveries. Caesarean sections results in uterine ruptures during subsequent pregnancies (2 p. cent of scarred uterus). The increased of caesarean sections may only be considered within the scope of concomitant improvement of prenatal monitoring, obstetrical monitoring and neonatal medicine.

[Epidemiologic aspects of malaria in Gabon]

The authors report the results of 3 sample surveys carried out in Libreville, Ngounié and Haut-Ogooué Provinces to evaluate the main malarial indexes among 0 to 15 years old children in Gabon. These investigations would suggest that malaria is mesoendemic in the three areas. The systematic presumptive antimarial treatment of fever attacks is widely used in Libreville but not so frequent in rural areas.