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Distribution and density of tsetse flies (Glossinidae: Diptera) at the game/people/livestock interface of the Nkhotakota Game Reserve human sleeping sickness focus in Malawi
No full textIn large parts sub-Saharan Africa, tsetse flies, the vectors of African human or animal trypanosomiasis, are, or will in the foreseeable future, be confined to protected areas such as game or national parks. Challenge of people and livestock is likely to occur at the game/livestock/people interface of such infested areas. Since tsetse control in protected areas is difficult, management of trypanosomiasis in people and/or livestock requires a good understanding of tsetse population dynamics along such interfaces. The Nkhotakota Game Reserve, an important focus of human trypanosomiasis in Malawi, is a tsetse-infested protected area surrounded by a virtually tsetse-free zone. The abundance of tsetse (Glossina morsitans morsitans) along the interface, within and outside the game reserve, was monitored over 15 months using epsilon traps. A land cover map described the vegetation surrounding the traps. Few flies were captured outside the reserve. Inside, the abundance of tsetse at the interface was low but increased away from the boundary. This uneven distribution of tsetse inside the reserve is attributed to the uneven distribution of wildlife, the main host of tsetse, being concentrated deeper inside the reserve. Challenge of people and livestock at the interface is thus expected to be low, and cases of trypanosomiasis are likely due to people and/or livestock entering the reserve. Effective control of trypanosomiasis in people and livestock could be achieved by increasing the awareness among people of dangers associated with entering the reserve
Phlebotomus argentipes seasonal patterns in India and Nepal
No full textThe current control of Phebotomus argentipes (Annandale and Brunetti), the vector of Leishmania donovani (Laveran and Mesnil), on the Indian subcontinent is base on indoor residual spraying. The efficacy of this method depends, among other factors, on the timing and number of spraying rounds, which depend on the P. argentipes seasonality. To describe P. argentipes' seasonal patterns, six visceral leishmaniasis (VL) endemic villages, three in Muzaffarpur and three in Sunsari districts in India and Nepal, respectively, were selected based on accessibility and VL incidence. Ten houses per cluster with the highest P. argentipes density were monitored monthly for 15-16 mo using Center for Disease Control and Prevention light traps. Minimum and maximum temperature and rainfall data for the months January 2006 through December 2007 were collected from the nearest available weather stations. Backwards stepwise regression was used to generate the minimal adequate model for explaining the monthly variation in P. argentipes populations. The seasonality of P. argentipes is similar in India and Nepal, with two annual density peaks around May and October. Monthly P. argentipes density is positively associated with temperature and negatively associated with rainfall in both study sites. The multivariate climate model explained 57% of the monthly vectorial abundance. Vector control programs against P. argentipes (i.e., indoor residual spraying) should take into account the seasonal described here when implementing and monitoring interventions. Monitoring simple meteorological variables (i.e., temperature, rainfall) may allow prediction of VL epidemics on the Indian subcontinent
From project aid to sustainable HIV services: a case study from Zambia
No full textINTRODUCTION: Sustainable service delivery is a major challenge in the HIV response that is often not adequately addressed in project implementation. Sustainable strategies must be built into project design and implementation to enable HIV efforts to continue long after donor-supported projects are completed. Case description This paper presents the experiences in operational sustainability of Family Health International's Zambia Prevention, Care and Treatment Partnership in Zambia, which is supported by the US President's Emergency Plan for AIDS Relief through United States Agency for International Development (October 2004 to September 2009). The partnership worked with Zambia's Ministry of Health to scale up HIV clinical services in five of the country's nine provinces, reaching 35 districts and 219 facilities. It provided technical and financial support from within the ministry's systems and structures. By completion of the project, 10 of the 35 districts had graduated beyond receiving ongoing technical support. Discussion and evaluation By working within the ministry's policies, structures and systems, the partnership was able to increase the ministry's capacity to add a comprehensive HIV service delivery component to its health services. Ministry structures were improved through renovations of health facilities, training of healthcare workers, procurement of essential equipment, and establishment of a quality assurance plan to ensure continued quality of care. The quality assurance tools were implemented by both the ministry and project staff as the foundation for technical graduation. Facilities that met all the quality criteria for more than six months were graduated from project technical support, as were districts where most supported facilities met the criteria. The district health offices then provided ongoing supervision of services. This predetermined "graduation" exit strategy, with buy in of the provincial and district health offices, set the stage for continued delivery of high-quality HIV services. CONCLUSIONS: Achieving operational sustainability in a resource-limited setting is feasible. Developing and institutionalizing a quality assurance/quality improvement system is the basis on which facilities and districts can move beyond project support and, therefore, sustain services. Quality assurance/quality improvement tools should be based on national standards, and project implementation should use and improve existing health system structure
Effect of applying a treatment threshold in a population. An example of pulmonary tuberculosis in Rwanda
No full textPurpose Clinicians often think treatment thresholds should be adapted to the setting. We intended to explore the effect in terms of harm because of false negatives and true and false positives of the application of a treatment threshold for pulmonary tuberculosis from a patient's perspective at different prevalence levels in a developing country. Methods In a cohort of 300 patients with chronic cough, we estimated the prevalence of pulmonary tuberculosis, and the sensitivity and specificity of key predictors with latent class analysis (LCA). We computed the post-test probability of individual patients based on these data. With disease- and treatment-related mortality and morbidity, and without cost or regret, we calculated the break-even point of disease probability where treating versus not treating resulted in similar total harm from the patient's perspective. We estimated the total harm of applying this threshold to the cohort, and to hypothetical settings with different disease prevalence. Results The threshold was computed at 0.026, suggesting treatment for all patients of the cohort. Hypothetically lowering the prevalence showed that the lowest total harm in the cohort always coincides with this threshold, but that numbers of treated patients drop considerably. Conclusion For pulmonary tuberculosis a decision threshold solely based on utilities without cost or regret leads to a very low threshold. The lowest total harm is found always at this disease probability, irrespective of the distribution of the patients. Although these findings might suggest an excess prescription at reference level, this is not the case in settings with lower prevalenc
Terrestrial small mammals as reservoir of Mycobacterium ulcerans in Benin
No full textMycobacterium ulcerans (MU), the causative agent of Buruli ulcer (BU), is considered an environmental pathogen. Different mycobacteria were detected in 68 (12%) out of 565 small mammals collected in BU endemic areas in Benin. Although MU was not found, we suggest more research on MU in African (small) mammal
Knockdown resistance in Anopheles vagus, An. sinensis, An. paraliae and An. peditaeniatus populations of the Mekong region
No full textBACKGROUND: In the Mekong region (Vietnam, Cambodia and Laos), a large investigation was conducted to assess the susceptibility of Anopheles species against DDT and pyrethroids. In this study, the resistance status of the potential malaria vectors An. vagus, An. sinensis, An. paraliae and An. peditaeniatus was assessed. METHODS: Bioassays were performed on field collected unfed female mosquitoes using the standard WHO susceptibility tests. In addition, the DIIS6 region of the para-type sodium channel gene was amplified and sequenced and four allele-specific PCR assays were developed to assess the kdr frequencies. RESULTS: In Southern Vietnam all species were DDT and pyrethroid resistant, which might suggest the presence of a kdr resistance mechanism. Sequence-analysis of the DIIS6 region of the para-type sodium channel gene revealed the presence of a L1014S kdr mutation in An. vagus, An. sinensis and An. paraliae. In An. peditaeniatus, a low frequency L1014S kdr mutation was found in combination with a high frequency L1014F kdr mutation. For pyrethroids and DDT, no genotypic differentiation was found between survivors and non-survivors for any of these species. In the two widespread species, An. vagus and An. sinensis, kdr was found only in southern Vietnam and in Cambodia near the Vietnamese border. CONCLUSIONS: Different levels of resistance were measured in Laos, Cambodia and Vietnam. The kdr mutation in different Anopheles species seems to occur in the same geographical area. These species breed in open agricultural lands where malaria endemicity is low or absent and vector control programs less intensive. It is therefore likely that the selection pressure occurred on the larval stages by insecticides used for agricultural purpose
Access to maternal and perinatal health services: lessons from successful and less successful examples of improving access to safe delivery and care of the newborn
No full textSummary The huge majority of the annual 6.3 million perinatal deaths and half a million maternal deaths take place in developing countries and are avoidable. However, most of the interventions aiming at reducing perinatal and maternal deaths need a health care system offering appropriate antenatal care and quality delivery care, including basic and comprehensive emergency obstetric care facilities. To promote the uptake of quality care, there are two possible approaches: influencing the demand and/or the supply of care. Five lessons emerged from experiences. First, it is difficult to obtain robust evidence of the effects of a particular intervention in a context, where they are always associated with other interventions. Second, the interventions tend to have relatively modest short-term impacts, when they address only part of the health system. Third, the long-term effects of an intervention on the whole health system are uncertain. Fourth, because newborn health is intimately linked with maternal health, it is of paramount importance to organise the continuum of care between mother and newborn. Finally, the transfer of experiences is delicate, and an intervention package that has proved to have a positive effect in one setting may have very different effects in other setting
