Transmission of human immunodeficiency virus type 1 through breast-feeding: how can it be prevented?
One-third to two-thirds of maternal transmission of human immunodeficiency virus type 1 (HIV-1) infection to breast-fed infants can be attributed to ingestion of breast milk. The presence of HIV-1 as cell-free and as cell-associated virus in milk has been documented. Several substances in breast milk may be protective against transmission, including maternal anti-HIV antibodies, vitamin A, lactoferrin, and secretory leukocyte protease inhibitor. The portal of virus entry in the infant's gastrointestinal tract is unknown but may involve breaches in mucosal surfaces, transport across M cells, or direct infection of other epithelial cells, such as enterocytes. Timing of transmission of HIV-1 during lactation should be further clarified. An early rebound of plasma viremia after withdrawal of antiretrovirals was recently detected. This rebound may reduce the benefit of antiretroviral prophylaxis when women breast-feed their infants. Interventions should be viewed from the public health perspective of risks of infant morbidity and mortality associated with breast-feeding versus risks from formula-feeding. (+info)
Increasing the utilization of cost-effective health services through changes in demand.
Attaining efficiency in a health care system with a budget constraint involves increasing the utilization of the most cost-effective services. This can be achieved by adjustments to prices, cost curves, or demand curves. In this paper, the potential for demand curve adjustments is examined by selecting two apparently cost-effective services (prenatal care and childhood immunization against tuberculosis), and analyzing the factors explaining their utilization. Data from recent household surveys in Burkina Faso and Niger are used. A multivariate analysis of utilization employs income, price, and taste variables. Utilization is highly sensitive to the distance which must be travelled to the health facility, a price, and taste variables. Utilization is highly sensitive to the distance which must be travelled to the health facility, a price variable. Members of certain ethnic groups tend to use the services less, other things being equal. The importance of demand-side factors like ethnicity points to certain kinds of policy interventions like information, education and communication activities which could increase the utilization of cost-effective services. (+info)
Research note: price uncertainty and the demand for health care.(3/443)
Dirt and diarrhoea: formative research in hygiene promotion programmes.
Investment in the promotion of better hygiene for the prevention of diarrhoeal diseases and as a component of water and sanitation programmes is increasing. Before designing programmes capable of sustainably modifying hygiene behaviour in large populations, valid answers to a number of basic questions concerning the site and the intended beneficiaries have to be obtained. Such questions include 'what practices favour the transmission of enteric pathogens?', 'what advantages will be perceived by those who adopt safe practices?' and 'what channels of communication are currently employed by the target population?' A study of hygiene and diarrhoea in Bobo-Dioulasso, Burkina Faso, used a mixture of methods to address such questions. This paper draws on that experience to propose a plan of preliminary research using a variety of techniques which could be implemented over a period of a few months by planners of hygiene promotion programmes. The techniques discussed include structured observation, focus group discussions and behavioural trials. Modest investment in such systematic formative research with clear and limited goals is likely to be repaid many times over in the increased effectiveness of hygiene promotion programmes. (+info)
Performance of village pharmacies and patient compliance after implementation of essential drug programme in rural Burkina Faso.
After implementation of a nation-wide essential drug programme in Burkina Faso a prospective study was undertaken consisting of non-participant observation in the health centre and in the village pharmacy, and of household interviews with the patients. The study covered all general consultations in nine health centres in three districts over a two-week period as well as all client-vendor contacts in the corresponding village pharmacies; comprising 313 patients in consultations and 498 clients in eight village pharmacies with 12 vendors involved in dispensing 908 drugs. Additionally patients were interviewed in their households. Performance and utilization of the village pharmacy: 82.0% of the drugs prescribed in the health centres were actually dispensed at the village pharmacy, 5.9% of the drugs were not available at the village pharmacy. Wrong drugs were dispensed in 2.1% of cases. 41.3% of the drugs dispensed in the village pharmacy were bought without a prescription. Differences are seen between the district and are put in relation to different onset of the essential drug programme. Patient compliance: Patients could recall the correct dosage for 68.3% of the drugs. Drug taking compliance was 63.1%, derived from the pills remaining in the households. 11.5% of the drugs had obviously been taken incorrectly to such an extent that the occurrence of undesired drug effects was likely. The study demonstrates the success of the essential drug programme not only in performance but also in acceptability and utilization by the population. (+info)
Isolation and characterization of Desulfovibrio burkinensis sp. nov. from an African ricefield, and phylogeny of Desulfovibrio alcoholivorans.
A sulfate-reducing bacterium, strain HDvT (T = type strain), was isolated from an anoxic ricefield soil. Cells were Gram-negative, non-sporulating curved rods motile by means of a single polar flagellum. Cytochrome c3 and desulfoviridin were present. In the presence of sulfate, glycerol, 1,2- and 1,3-propanediol, dihydroxyacetone, pyruvate, lactate, fumarate, maleate, malate and succinate were incompletely oxidized mainly to acetate. Sulfite, thiosulfate, elemental sulfur, fumarate, maleate and malate were utilized as alternative electron acceptors. In the absence of added electron acceptors, pyruvate, fumarate, maleate, malate and dihydroxyacetone were fermented. The DNA base composition was 67 mol% G + C. The phylogenetic, phenotypic and physiological characteristics of strain HDvT indicate that it is a new species of the genus Desulfovibrio, for which the name Desulfovibrio burkinensis sp. nov. is proposed; the type strain is HDvT (= DSM 6830T). Phylogenetic analysis confirmed that Desulfovibrio alcoholivorans was a distinct species supporting the previously published phenotypic data. (+info)
Population biology of human onchocerciasis.
Human onchocerciasis (river blindness) is the filarial infection caused by Onchocerca volvulus and transmitted among people through the bites of the Simulium vector. Some 86 million people around the world are at risk of acquiring the nematode, with 18 million people infected and 600,000 visually impaired, half of them partially or totally blind. 99% of cases occur in tropical Africa; scattered foci exist in Latin America. Until recently control programmes, in operation since 1975, have consisted of antivectorial measures. With the introduction of ivermectin in 1988, safe and effective chemotherapy is now available. With the original Onchocerciasis Control Programme of West Africa coming to an end, both the new African Programme for Onchocerciasis Control and the Onchocerciasis Elimination Programme for the Americas, rely heavily on ivermectin self-sustained mass delivery. In consequence, the need for understanding the processes regulating parasite abundance in human and simuliid populations is of utmost importance. We present a simple mathematical framework built around recent analyses of exposure- and density-dependent processes operating, respectively, within the human and vector hosts. An expression for the basic reproductive ratio, R0, is derived and related to the minimum vector density required for parasite persistence in localities of West Africa in general and northern Cameroon in particular. Model outputs suggest that constraints acting against parasite establishment in both humans and vectors are necessary to reproduce field observations, but those in humans may not fully protect against reinfection. Analyses of host age-profiles of infection prevalence, intensity, and aggregation for increasing levels of endemicity and intensity of transmission in the Vina valley of northern Cameroon are in agreement with these results and discussed in light of novel work on onchocerciasis immunology. (+info)
Insecticide-treated curtains reduce the prevalence and intensity of malaria infection in Burkina Faso.
A large, randomized controlled trial to investigate the impact of insecticide-treated curtains (ITC) on child mortality was conducted in an area of seasonal, holoendemic malaria in Burkina Faso. 158 communities totalling some 90,000 people were censused and grouped into 16 geographical clusters, 8 of which were randomly selected to receive ITC in June-July 1994, just prior to the rainy season. In September-October 1995, at the peak period of malaria transmission, a cross-sectional survey was conducted in 84 of the villages. A random sample of 905 children aged 6-59 months was identified and visited. 763 children (84%) were present at the time of the visit and recruited into the study. Mothers were asked about fever in the past 24 h, the child's temperature was taken, and a sample of blood collected to identify and quantify malaria infections and to measure haemoglobin (Hb) levels. Children protected by ITC were less likely to be infected with Plasmodium falciparum (risk ratio = 0.92; 95% CI 0.86, 0.98) or P. malariae (risk ratio = 0.42, 95% CI 0.19, 0.95). The mean intensity of P. falciparum infections was lower among children protected by ITC (899 vs. 1583 trophozoites/microliter; P < 0.001), while the mean Hb level was 0.4 g/dl higher (P < 0.001). While we found no evidence that ITC had an impact on the prevalence of malaria-associated fever episodes, the confidence intervals around our estimates of the impact of ITC on malaria morbidity were wide. We conclude that widespread implementation of ITC in this area of high malaria transmission led to a modest reduction in the prevalence of malaria infection and to a more substantial reduction in the intensity of these infections which caused increased Hb levels. We were unable to demonstrate any impact of ITC on malaria morbidity, but the wide confidence intervals around our point estimates do not preclude the possibility of a substantial impact. (+info)