Clinical trial of beta-arteether versus quinine for the treatment of cerebral malaria in children in Yaounde, Cameroon.

One hundred and two children aged 0-10 years with cerebral malaria (Blantyre coma score of 2 or less) were randomly treated either with intramuscular arteether (3.2 mg/kg on Day 0, followed by 1.6 mg/kg on Days 1 to 4) or intravenous (i.v.) quinine dihydrochloride (20 mg of the salt/kg, followed by 10 mg of the salt/kg every 8 hr up to Day 6). Treatment with oral quinine sulfate (10 mg/kg every 8 hr) was substituted for i.v. quinine when the patient was able to take oral medicine. All patients were followed up in the hospital for 7 days; thereafter, they were treated as outpatients on Days 14, 21, and 28. Mortality rate, the main efficacy parameter, was 11.8% lower in the arteether treatment group than in the quinine group (15.7% versus 27.4%); however, the difference was not significant (P = 0.25). Means for fever clearance time, coma resolution time, and parasite clearance time were similar in the 2 treatment groups (42.2 +/- 34.9 hr; 34.8 +/- 18.8 hr, and 46.3 +/- 28.5 hr, respectively for arteether, versus 45.0 +/- 26.7 hr; 30.3 +/- 18.9 hr, and 40.7 +/- 18.9 hr, respectively, for quinine). At 28 days, the cure rates were 73.2% and 64.9% for the arteether and quinine treatment groups, respectively. Arteether is safe and therapeutically at least as effective as quinine for the treatment of cerebral malaria in children in Cameroon. Because of its ease of administration, arteether appears to be suited for use in the rural zones where monitoring facilities do not exist.

Impact of Schistosoma haematobium infection and of praziquantel treatment on anaemia of primary school children in Bertoua, Cameroon.

There is some debate as to the extent to which Schistosoma haematobium haematuria may be the cause of anaemia. Our goal was to evaluate the impact of a single 40 mg kg-1 dose of praziquantel on anaemia. Since praziquantel does not reduce the hookworm intensity of infection (a major cause of anaemia in children in the area) changes in the prevalence of anaemia in the study population should be due only to the elimination of S. haematobium. Seven hundred and seventy-one primary schoolboys from Bertoua (East Cameroon) were divided into four groups: high infection, moderate infection treated with praziquantel or placebo, and non-infected. Haemoglobin concentrations of the children were determined at the onset of the study and 6 months after the praziquantel intervention. Mean haemoglobin concentrations were not significantly different for no infection or for mild or heavy infection by S. haematobium. A factorial analysis of variance using S. haematobium intensity of infection, malaria and intestinal parasite infections and age as independent variables and haemoglobin concentration as the dependent variable show that only age and malaria infection show a significant relationship with haemoglobin concentration. Despite treatment with praziquantel, all the children in the treatment groups had lower mean haemoglobins 6 months after intervention. A factorial analysis of variance using age, malaria infection and the treatment category as independent variables and the difference in haemoglobin concentration as the dependent variable shows that only malaria infection showed a significant relationship with haemoglobin concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

[Periportal fibrosis in Schistosoma mansoni schistosomiasis. An ultrasonographic study in the area of Nkolbisson (Cameroon)]. / Fibrose périportale dans la schistosomiase à Schistosoma mansoni. Une étude ultrasonographique dans le foyer de Nkolbisson (Cameroun).

PURPOSE: The appearance of Symmers' periportal fibrosis (SPF) is considered a major event in the natural history of Schistosoma mansoni infection, because of the risk of portal hypertension and subsequent intestinal hemorrhage. Ultrasonography has been found useful in the assessment of this lesion. We undertook the present study to determine the prevalence of SPF in Nkolbisson (near Yaoundé), where previous studies had shown Schistosoma mansoni infection to be endemic. METHODS AND MATERIALS: 147 patients more than 15 years old (mean age: 32 years) were prospectively studied during a 3 month period. 107 subjects (51 male, and 56 female) were excreting Schistosoma mansoni eggs in the stools (mean egg output = 336 egg/g), and 40 controls had a negative stool exam. A medical history, a physical examination, and an abdominal ultrasound examination were performed on each subject. The degree of SPF was graded according to Homeida's scale. RESULTS: 39 Subjects (24 male, 15 female) with positive stool examination had SPF giving a prevalence rate of 37%, while it was found to be 5% for controls. 28 patients had mild fibrosis (grade I), 7 patients had moderate fibrosis (grade II), and 4 patients had severe fibrosis (grade III). Higher prevalence rates of SPF were associated with longer duration of infection and very high egg outputs (> 1,000 egg/g). The positive predictive value of hepatomegaly or splenomegaly for the presence of SPF was 0.52, and the negative predictive value 0.69. CONCLUSION: We conclude that SPF affects a significant proportion of infected patients and ultrasonography is a valuable tool in the study of this lesion in our patients.

[Value of rectoscopy in the diagnosis of Schistosoma mansoni bilharziasis. Study at Nkolbisson-Cameroon]. / Intérêt de la rectoscopie dans le diagnostic de la bilharziose a Schistosoma mansoni. A propos d'une étude réalisée à Nkolbisson--Cameroun.

The aim of this study was to investigate endoscopically and histologically rectal mucosa complications in bilharzia patients. Coprology using KATO's technique was carried out in 1406 school children aged 4 to 18 years. 134 (9.53%) were infested. Among the infested school children and the sample population, a random selection of 80 school children (40 infested and 40 of sample population) was made, in whom rectoscopy and biopsy of rectal mucosa were carried out. The lesions found were classified on endoscopic and histologic basis. The prevalence of the disease 9.53% appears to be in constant regression. Inflammatory lesions are more common in bilharzia patients. Histology facilitated the unveiling of a specific rectitis in 72.5% bilharzia patients and 12.5% of the sample population. This study confirm the effectiveness of the several bilharzia eradication campaigns carried out in the Nkolbisson area. Rectoscopy with biopsy of the rectal mucosa should be reserved to symptomatic patients, in whom many coprologies have turned out negative.

[Morbidity and histo-endoscopic study of Schistosoma mansoni bilharziasis in Nkolbisson (Cameroon)]. / Morbidité et étude histo-endoscopique de la bilharziose a Schistosoma mansoni a Nkolbisson (Cameroun).

This study confirms the efficiency of bilharzia eradication campaigns at Nkolbisson. The authors recommend rectal mucosa biopsy of symptomatic patients in whom several investigations have turned out negative.

The impact of Schistosoma haematobium infection and of praziquantel treatment on the growth of primary school children in Bertoua, Cameroon.

Our objective was to determine in a Cameroonian school population the effect of mild to moderate S. haematobium infection intensity on growth and development of children before and 6 months after praziquantel treatment. Previous studies have yielded contradictory results. Children from Bertoua schools were divided into four study groups: heavily infected (> 500 eggs 10 ml-1), moderately infected (1-499 eggs 10 ml-1) treated with praziquantel, a similar group treated with placebo, and an uninfected control group. Anthropometric measures--height for age per cent median (HAPM), and weight for age per cent median (WAPM)--were significantly higher among the uninfected children. Stepwise regression analysis showed that S. haematobium and Ascaris infections were the strongest predictors of the HAPM with hookworm and malaria infections playing a lesser role. Post treatment comparison of the praziquantel treatment group and the placebo group showed no significant differences for the anthropometric indicators except for mid-arm circumference. Longer observations of growth after treatment as well as monitoring of the rate of reinfection would be necessary to understand better the effect of S. haematobium on growth.

Distribution of hookworm infection in Cameroon.

Prevalence of hookworm infection was measured in Cameroon during a national survey carried out for a schistosomiasis research project. The survey provided a representative sample of the 10-19 year age group for each one of the 49 administrative divisions. Prevalences were low in the Extreme North province with a sahelian climate. Prevalences were high in the provinces with an equatorial climate except for the Centre province which is more developed. Regions with tropical Cameroonian climate, which receive a very heavy rainfall, showed the highest prevalences. Urbanized areas had lower infection rates than rural areas. It should not be assumed that hookworm prevalence is uniformly high throughout a tropical country. Since hookworm distribution shows wide variations, large control programmes should start with a thorough evaluation of the situation.

Estimation of the number of cases of schistosomiasis in a country: the example of Cameroon.

An estimate of the number of schistosomiasis infections in Cameroon was based on a statistically representative national prevalence survey carried out in the entire country. The number of cases of infection by Schistosoma haematobium was estimated to be 393,900, and 419,600 for S. mansoni, a total of 813,500. Taking into account the dual infections the total number of cases was 719,100 (95% confidence interval: 392 900-1 027,800). A current World Health Organization estimate extrapolating from the results of limited epidemiological surveys showed 2,239 591 cases for Cameroon, an estimate 3.1 times higher than the more accurate estimate based on the national survey. Schistosomiasis being a focal disease, prevalences observed in limited foci are not representative of regional prevalences. Prevalence survey data in the literature are biased toward reporting only positive results. Therefore extrapolations made on limited surveys may lead to an overestimation of the number of cases of schistosomiasis.

Schistosoma mansoni eggs in urine.

S. mansoni eggs show a preferential localization in stools with localization in urine being unusual. The factors that influence the appearance of S. mansoni in urine have not been studied extensively. The data presented here were collected during a schistosomiasis survey conducted in the northern provinces of Cameroon and a longitudinal community survey in Douloumi. As expected, the majority of individuals infected with S. mansoni had eggs in their stools. However, this is not always the case. Under special epidemiologic conditions, very high S. haematobium prevalence and much lower S. mansoni prevalence, urinary localization may become dominant. Individuals with high intensities of infection by S. mansoni do not have a higher probability for having S. mansoni in urine (there is no 'spill over').

Ascariasis and trichuriasis in Cameroon.

A national survey of Ascaris lumbricoides and Trichuris trichuria was carried out in Cameroon on more than 22,000 children from a random sample of 512 schools. Prevalence rates of both A. lumbricoides and T. trichuria infection were very low in the tropical zone (below 5%). They increased markedly in the equatorial zone, Guinea-type climate, to 60-85% for A. lumbricoides and 85-95% for T. trichuria. In the equatorial zone with Cameroon-type climate, prevalences were slightly lower: 50-70% for A. lumbricoides and 70-90% for T. trichuria infections. Environmental conditions are the main factors explaining these differences. Other factors (altitude, population density and urbanization) were not important. The entire population of villages selected from distinct climatic zones of Cameroon were also examined. The age group distribution of A. lumbricoides and T. trichuria infections indicated acquisition early in life, reaching a peak in early childhood, followed by a stable prevalence rate.

Distribution and preservation of Schistosoma mansoni eggs in stools.

Thirty-eight stool samples were preserved with sodium azide, 5 mg g-1 of stool. Results show that after 12 weeks, all the samples with S. mansoni eggs remained positive with good egg morphology. Egg counts show an average decrease of about 20%. Given the logistic advantages provided by using a small quantity of dry preservative this method is acceptable for mass prevalence surveys where sensitivity is not critical. The distribution of eggs in the stool was studied in 10 samples. Results showed no significant differences between centre and surface of the stools.

Human schistosomiasis in Cameroon. I. Distribution of schistosomiasis.

The status of schistosomiasis in Cameroon was examined in a nationwide survey of 5th grade schoolchildren. Five hundred twelve schools were surveyed; 19,524 urine and 22,166 stool samples were examined. The 3 northern provinces, which comprised 29% of the population, had 87% of all urinary and 82% of all intestinal cases. These provinces have a low seasonal rainfall. The presence of temporary bodies of water and of molluscan intermediate hosts adapted to this environment permits intense transmission of schistosomiasis haematobium and mansoni. In the rest of the country, the distribution of Schistosoma haematobium and S. mansoni was highly focal. S. intercalatum endemic areas were restricted to the equatorial forest and were small with low prevalences and intensities.

Detection of IgE antibodies in onchocerciasis. Possibility of using allergens from Dipetalonema viteae extracts that cross-react with allergenic determinants in crude extracts of Onchocerca volvulus.

The present study reports the presence of Onchocerca volvulus specific IgE in the sera obtained from onchocerciasis patients. About 70% of onchocerciasis patients showed a raised level of O. volvulus specific IgE compared to patients infected either with other human filarids (Loa loa, Wuchereria bancrofti, Brugia malayi) or with other helminths (Schistosoma mansoni, Ascaris lumbricoides, Fasciola hepatica). The O. volvulus specific IgE level was significantly higher in patients exhibiting 'gale filarienne' than in microfilaremic patients or in endemic controls. The total IgE level was significantly raised in the serum samples of all groups of subjects from endemic areas compared to European controls. There was no significant increase in the level of IgE in the onchocerciasis sera when O. volvulus antigen was replaced by the antigens from various helminths in the present assay system (radioallergosorbent test). However, there was a clear evidence of the presence of cross-reacting allergens in the crude extracts from adults of O. volvulus and Dipetalonema viteae (a rodent filarial parasite) because there was a significant reduction in IgE level in onchocerciasis sera following absorption with either O. volvulus or D. viteae sorbents. Moreover, the IgE antibodies in onchocerciasis patients sera recognized the allergens which were present in the somatic extracts of O. volvulus and D. viteae as revealed by radiolabelled anti-IgE.

Detection of circulating antigens in onchocerciasis.

This report describes the presence of circulating Onchocerca volvulus antigens (COA) in sera of patients with onchocerciasis. By using a double diffusion immunoelectrophoresis method, COA could be detected in 24 of 77 sera analyzed (31%). In contrast, when more sensitive assays such as the radioimmunoprecipitation-PEG assay or sandwich radioimmunoassay were used to detect COA, about 75% of the sera from O. volvulus-infected patients were found positive; moreover, a highly significant correlation between the two assays was observed. The parasite specificity of the COA was demonstrated directly by identity reaction with a component of O. volvulus somatic antigens. COA was never found when hyperimmune antisera against other parasite antigenic extracts were used instead of anti-O. volvulus hyperimmune serum. However, when anti-O, volvulus hyperimmune serum was used against sera obtained from patients infected with various other helminths we found a cross-reactivity between COA and the circulating antigens of other human filarids (Wuchereria bancrofti, Loa loa, Brugia malayi), but not with other nematode or trematode parasites (Ascaris lumbricoides, Schistosoma mansoni, Fasciola hepatica). Further immunoelectrophoretic studies demonstrated one precipitin are localized in the cathodic region which seemed specific for COA, which raises the possibility of preparing a monospecific hyperimmune serum to circumvent cross-reactivities.

Carence en iode et reproduction chez les femmes de l'Adamaoua

La malnutrition est aggravee par les deficiences en oligo-elements et l'une des formes les plus connues est la carence en iode qui donne des troubles divers. Cette carence atteint environ 160 millions de personnes en Afrique contre 300 millions en Chine; 200 millions en Inde; 100 millions en Indinesie; 60 millions en Amerique et quelques millions de cas en Europe. Les troubles dus a la carence en iode (TDCI) sont un probleme general qui touche 12de la population mondiale. Au Cameroun; l'enquete nationale sur les TDCI montre que 6 millions de personnes sur 11 millions sont atteintes; de meme que toutes les 10 provinces mais a des taux differentes de prevalence. Ainsi une forte endemicite est signalee a l'Extreme-Nord (Doukoula 75); au Nord-Ouest (64a Oshie et 59a Jakiri); dans l'Adamaoua (45dans Vina); dans Ouest (58dans le Noun) et une endemicite moindre dans l'Est (14a Batouri)