Prevalence; diversite antigenique et multiplicite d'infections de Plasmodium falciparum en milieu scolaire au centre de la Cote d'Ivoire

Une etude a ete conduite a Taabo - village; localite rurale du centre de la Cote d'Ivoire; situee a proximite d'un gra n d lac artificiel. Les objectifs etaient (i) de determiner le taux d'endemicite du paludisme; la diversite antigenique et la multiplicite des infections a Plasmodium falciparum au sein d'ecoliers; et (ii) de comparer la performance du diagnostic microscopique a celle de la reaction de polymerisation en chaine (PCR). Au total; 424 eleves ages de 5 a 15 ans ont eu des examens de sang au microscope et par PCR. La multiplicite d'infection a porte sur 196 (46;2) d'entre eux. L'indice plasmodique detecte au micro s c o p e est de 54;7et de 83;9par PCR. Les typages genotypiques determines par le polymorphisme des longueurs de fragments de restriction du gene respon sable des proteines de surface-2 du mero zoite (m s p 2); ont revele 86;5de cas d'infections multipes; avec une moyenne geometrique de 3;87 genotypes par individu positif. Une correlation positive significative a ete obtenue entre a multiplicite et les densites parasitaires au sein du groupe d'age 5-6 ans. 50 genotypes dont six observes pour la premiere fois ont ete denombres puis classes en familles de tailles similaires FC27 (n=26 ; 52) et 3D7 (n=24 ; 48). Compare a la PCR; la microscopie a montre une sensibilite et une specificite respectivement de 81;3et 88;2. Nos donnees sont discutees au regard d'etudes similaires en Afrique sub-saharienne et ailleurs; et peuvent servir de base a long terme pour l'evaluation d'impact des grands amenagements d'eau sur la prevalence; la diversite antigenique et la multiplicite des infections a P. fal c i p a ru m

Repartition de la morbidite dans trois communautes nomades du Chari-Baguirmi et du Kanem; Tchad

Within the framework of an multidisciplinary research and action program; morbidity patterns were assessed in three nomadic communities; i.e.; Fulani; A rab cattle bre e d e rs and A rab camel breeders; l iving in Chari - B ag u i rmi and Kanem; Chad. This is the first data about the health of Chadian nomadic pastoralists who account for approximately 6of the total population. A total of 1092 women; men and children were interviewed and examined in the course of three surveys carried out by a physician during the dry and rainy season. Nomads reporting no health problems were rare. Tuberculosis was suspected in 4;6of adults after clinical examination and bronchopulmonary disorders in children less than five years of age. Febrile diarrhea was more prevalent during the wet season when access to clean drinking water was more difficult. Simple malaria was rarely diagnosed in Arabs during the dry season. In contrast simple malaria was frequent in Fulani who stay inthe vicinity of Lake Chad during the dry period. Protein-energy malnutrition was observed in only 3 of 328 children younger than 15 years of age

Taux sérique de rétinol chez les femmes nomades pastoralistes tchadiennes en relation avec la teneur en rétinol et en carotène dans le lait de leur bétail

Dans le cadre d'une étude sur le statut sanitaire des pasteurs nomades et de leur bétail exécutée en étroite colla-boration entre les services de santé publique et vétérinaire tchadiens,le taux de rétinol sérique humain a été analysé en cor-rélation avec celui contenu dans le lait du bétail. Parmi les femmes examinées (n = 99),43% (IC95% 33 - 54 %) étaient défi-c i t a i resen rétinol (tauxde0,35µmol/Là0,7µmol/L) et 17% (IC95% 10 -26%) sévèrement défi c i t a i resen rétinol (tauxinféri e u rà0,35µmol/L). Aucunedesfemmesinterrogées(n=87)n'indiquaituneconsommation defruitset seulesdeux avaientconsommédeslégumesfraisau coursdesdern i è res 24 heures. Lelait était donc pratiquement la seule source devitamineA pour ces popu-lations. Parmi le bétail,les chèvres (n=6) avaient les taux moyens de rétinol les plus élevés dans leur lait (329 ± 84 µg/kg),sui-vies des bovins (n=25; 247 ± 32 µg/kg) et des dromadaires (n=12; 120 ± 18 µg/kg). Les concentrations de rétinol dans le sérumhumain dépendaient de manière significative de la concentration de rétinol dans le lait du bétail (pente partielle 0,23; inter-valle de confiance de 95% 0,008 - 0,47). Notre étude confirme que le lait de chèvre et de vache est une source importante devitamine A chez les pasteurs nomades. Par ailleurs,la promotion de la consommation de légumes verts,de fruits et de sup-pléments vitaminés reste nécessaire pour lutter contre les carences en vitamine A

Premiers isolements de mycobacteries tuberculeuses chez l'homme et l'animal au Tchad

This report describes the first successful isolation and identification of mycobacterial infection in humans and animals of Chad. All mycobacterial strains from human specimens were M. tuberculosis and strains from animal specimens (cattle) were M. bovis. None of the 10 of M. tuberculosis strains tested for antibiotic resistance were multidrug resistant. Due to the intrinsic resistance of M. bovis to pyrazinamide and the growing number of tuberculosis cases in HIV-infected people in Africa and elsewhere; more information on the potential of M. bovis for human infection is needed to guide disease control policy

Approche novatrice des vaccinations en sante publique et en medecine veterinaire chez les pasteurs nomades au Tchad: Experiences et couts

The purpose of this report is to describe a network of public health care workers; veterinarians and nomadic pastoralists that was set up in Chad to increase vaccination coverage to nomadic children and women who had rarely been va c c i n ated befo re. The objectives of the project we re to provide human vaccination in conjunction with existing ve t e ri n a ry serv ices; to evaluate the feasibility and limitations of such campaigns; to determine wh at other services could be provided concurrently; and to estimate the savings for public health care cases in comparison with carrying out vaccination separately. In a s e ries of 12 vaccination campaigns in the Chari-Baguirmi and Kanem distri c t s ; more than 2100 children; 2100 women and 52000 c attle we re fully immu n i ze d. These results confirmed the feasibility of joint campaigns in nomadic settings and provided important experience for improving organization. Information-Education-Communication (IEC) campaigns adapted to the realities of the pastoral setting were an important factor in mobilizing nomadic pastoralists for attendance at vaccination clinics. The savings in logistics costs (i.e. ; personnel; transportation and cold chain costs ex cluding vaccine costs) was 15in Gre d aya where 3 out of 6 campaigns were carried out together with veterinarians and 4in Chaddra/Am Dobak where only 1 out of 6 campaigns was carried out in conjunction with veterinarians. The cost per fully immunized child (FIC) was considerably higher in Chaddra/Am Dobak than Gredaya (EUR 29.2 vs. EUR 11.5). The joint vaccination campaign approach is innovative; appreciated by nomadic pastoralists and less expensive than separate vaccination. By using the mobility of veterinarians in remote zones far from health care facilities; vaccination can be provided to nomadic children and women in countries with limited resources

Artemether, an effective new agent for chemoprophylaxis against shistosomiasis in China: its in vivo effect on the biochemical metabolism of the Asian schistosome.

Conventional drug chemotherapy against human schistosomiasis currently relies on treatment with praziquantel to eliminate adult schistosome worm pairs. The use of praziquantel for control purposes is limited, however, by high rates of post-treatment re-infection with subsequent parasite egg deposition and host end-organ damage. Artemether, a methyl ether derivative of the anti-malarial drug quinghaosu, was discovered recently to also have anti-schistosomal properties. Because artemether selectively targets the larval migratory stages of the parasite, known as schistosomulae, it blocks the development of ovipositing adult schistosome worm pairs in the vasculature. On this basis, we have since shown in clinical trials conducted in China that artemether has proven benefit as an agent for chemoprophylaxis. In vivo studies using laboratory animals suggest that artemether causes damage to the tegument and musculature of schistosomulae. Artemether may exert its helminthotoxic effect through synergy with hemin or related heme-containing compounds. Schistosomes recovered from artemether treated laboratory animals have increased glycogen phosphorylase activity, but decreased glucose uptake. These findings may account for their decreased glycogen content, relative to schistosomes recovered from untreated laboratory animals. The artemether-damaged schistosomes also have decreased activities of a number of enzymes and enzyme systems, including glycolysis. This might suggest common pathways by which artemether may target human parasites that live in the bloodstream.

Field activity cost estimates for the first 3 years of the World Bank Loan Project for schistosomiasis control in China.

The World Bank Loan Project for schistosomiasis in China commenced field activities in 1992. In this paper, we describe disease control strategies for levels of different endemicity, and estimate unit costs and total expenditure of screening, treatment (cattle and humans) and snail control for 8 provinces where Schistosoma japonicum infection is endemic. Overall, we estimate that more than 21 million US dollars were spent on field activities during the first three years of the project. Mollusciciding (43% of the total expenditure) and screening (28% of the total) are estimated to have the most expensive field activities. However, despite the expense of screening, a simple model predicts that selective chemotherapy could have been cheaper than mass chemotherapy in areas where infection prevalence was higher than 15%, which was the threshold for mass chemotherapy intervention. It is concluded that considerable cost savings could be made in the future by narrowing the scope of snail control activities, redefining the threshold infection prevalence for mass chemotherapy, defining smaller administrative units, and developing rapid assessment tools.