Quantitative determination of circulating anodic and cathodic antigens in serum and urine of individuals infected with Schistosoma intercalatum.

Circulating anodic and cathodic Schistosoma antigens (CAA and CCA) have been determined by enzyme immunoassays in serum and urine of 60 individuals infected with S. intercalatum in Equatorial Guinea. The median egg output was 29 eggs/g of faeces (range 3-840). The egg output strongly correlated with concentrations of serum CAA (p = 0.47) and urine CAA (p = 0.42) (P < 0.001 for both); the later 2 quantities were also correlated with each other (p = 0.44, P < 0.001). All except 3 infected individuals had detectable amounts of serum CAA and/or urine CCA, a sensitivity of 95% for these 2 tests combined. Urine CAA was detected in 43% of patients. Serum CCA was detected in all infected individuals; however, no significant correlation was obtained between serum CCA levels and egg output in the stools of individual patients. This is the first study to demonstrate CCA in specimens of patients infected with S. intercalatum. The detection of CCA in urine is a new, non-invasive diagnostic method for S. intercalatum infection.

Integration of disease control programmes.

In Equatorial Guinea the structures of the Trypanosomiasis Control Programme and the primary health care network are being used by the country's campaign against schistosomiasis. The benefits--and considerable difficulties--of this endeavour are discussed in the present article.

Effect of repeated targeted mass treatment with praziquantel on the prevalence, intensity of infection and morbidity due to Schistosoma intercalatum in an urban community in equatorial Guinea.

A longitudinal community-based study was carried out in order to evaluate the impact of repeated selective population chemotherapy with praziquantel on the epidemiology of an urban focus of Schistosoma intercalatum in the city of Bata, capital of the Continental Region of Equatorial Guinea. Three surveys were undertaken in January of 1988, 1989 and 1990, determining parasitological prevalence, intensity of infection and morbidity and applying repeated targeted mass treatment. One dose of praziquantel (40 mg/kg body weight) was given one week after treatment with mebendazole (100 mg every 12 hours for 3 days). A reduction of the overall prevalence by S. intercalatum of 69.9% and 79.3% in the first and second year respectively was found. Persons showing high parasite burden suffered a reduction of 95.7%. The cure rate (no more eggs in stool) was between 90% and 98.9%. A significant decrease of signs and symptoms was observed. No important side effects were detected. This study shows the positive action of praziquantel in reducing prevalence, intensity of infection and morbidity due to S. intercalatum, above all in the case of a high human population participation response. Cure rates obtained being similar to the ones observed using the same drug in Schistosoma mansoni and Schistosoma haematobium.

Endemic human paragonimiasis in Equatorial Guinea. Detection of the existence of endemic human paragonimiasis in Equatorial Guinea as a result of an integrated sanitary programme.

Between February and April 1990 the first five cases of human paragonimiasis, tentatively due to Paragonimus africanus, have been detected in Equatorial Guinea, thanks to the normal activities of the National Schistosomiasis Project and its coordination with the National Tuberculosis Project.

[Control of human African trypanosomiasis in Luba in equatorial Guinea:evaluation of three methods]. / La lutte contre la trypanosomiase humaine africaine dans le foyer de Luba en Guinée équatoriale: bilan de trois méthodes.

The object of this study was to (a) reduce the prevalence of sleeping sickness by serological testing, parasitological examination, and treatment of every infected person; (b) determine the maximum acceptable interval between serological surveys; and (c) define the impact of vector control, using monopyramidal non-impregnated traps, on the transmission. For this sero-parasitological survey, the focus in Luba was divided into three zones as follows: Epicentre A (with high prevalence, 27.5%), Epicentre B (with average prevalence, 8.3%), and Peripheral C (with moderate prevalence, 3.0%). Differences in the prevalence rates in the Epicentres and Peripheral zone permitted the use of three different approaches for control and epidemiological follow-up of the disease: (1) Serological examination of the entire population was carried out by the indirect immunofluorescent antibody test (IFAT), with six-month intervals in Epicentres A and B and once a year in the Peripheral zone C. (2) DIAGNOSIS AND TREATMENT: all IFAT seropositives were examined in Luba hospital for parasites, and every parasitologically confirmed patient was treated according to the WHO protocol of 1983. Another serological test (CATT) was applied to cases in which trypanosomes were not present and if this was positive, the CSF was examined. Cases with parasites and abnormal CSF were treated with melarsoprol, and those with a normal CSF received pentamidine. CATT-negative and parasite-negative cases were considered to be false-positives by IFAT and free of the disease. (3) Vector control: 74 monopyramidal traps (18 traps per km2) were set up in Epicentre A. The flies captured were collected once a month and sent to the programme's laboratory where they were identified and counted.(ABSTRACT TRUNCATED AT 250 WORDS)

Urban epidemiology of Schistosoma intercalatum in the city of Bata, Equatorial Guinea.

In a cross sectional study, 1221 individuals were enrolled to determine the urban epidemiology of Schistosoma intercalatum in the city of Bata, Equatorial Guinea. Bulinus forskalii was the only intermediate host for schistosomes found in the study areas. The only Schistosoma species detected in faeces was S. intercalatum. However, no Schistosoma eggs were found in urine. The overall prevalence of S. intercalatum infection was 21.2%. Although infected subjects were found in all age groups, peak prevalence and highest parasite load occurred in 5-14 years old children. But only 38 individuals (3.1%) had infection with more than 400 eggs per gram faeces. Thirty out of these (78.9%), were children between 5 and 14 years of age. In the heavily infected subjects (greater than 400 eggs/g. faeces) highly significantly more diarrhoea with microscopic and macroscopic blood in stool was present (p less than 0.0001).

African trypanosomiasis and S. intercalatum infection in Equatorial Guinea: comparative epidemiology and feasibility of integrated control.

The integration of schistosomiasis control with the activities of different endemic disease control or health programmes has been endorsed by a WHO Expert Committee on the Control of Schistosomiasis (WHO 1985). Endemic countries face increasing economic and manpower constraints which limit the coverage and effectiveness of control activities. Integration would be expected to optimize available resources for control. The feasibility of integration can be assessed by a comparative evaluation of: the epidemiology and distribution of the health problems; the techniques and methodology of control; and the requirements for maintenance and their relative health importance. This report presents a preliminary assessment of trypanosomiasis and schistosomiasis in Equatorial Guinea. The background and implementation of the operational national trypanosomiasis control programme are summarized. Population-based epidemiological investigations undertaken by the staff of the trypanosomiasis control programme are reported from a rural village and an urban suburb of Bata, Equatorial Guinea. The distribution and morbidity of S. intercalatum are compared, the public health importance of S. intercalatum is reviewed and the feasibility of integration of control of trypanosomiasis and schistosomiasis are assessed.