Demographic surveillance and health equity in sub-Saharan Africa.

Accurate data are always needed to inform health policy, but are especially critical in tackling health inequities. The growing number of field research stations in sub-Saharan Africa are well-placed to generate relevant data and so support health policy action. Over the past 60 years, demographic surveillance systems have been crucial research tools for the evaluation of health interventions aimed at reducing socioeconomic differentials in mortality and morbidity in sub-Saharan Africa. The bulk of such work has been carried out by field research sites, often operating in remote, resource-constrained settings. The present paper reviews what we have learned since the pioneering work carried out in the field sites of Pholela (South Africa) and Niakhar (Senegal). It then focuses on current efforts to address health equity through INDEPTH, the international network of field sites with continuous demographic evaluation of population and their health in developing countries.     

Impact of Hepatitis B Virus Infection,Non-alcoholic Fatty Liver Disease,and Hepatitis C Virus Co-infection on Liver-Related Death among People Tested for Hepatitis B Virus in British Columbia: Results from a Large Longitudinal Population-Based Cohort Study

Data on the contribution of hepatitis B virus (HBV) infection and related comorbidities to liver-related mortality in Canada are limited. We assessed the concurrent impact of HBV infection, non-alcoholic fatty liver disease (NAFLD), and hepatitis C virus (HCV) coinfection on liver-related deaths in British Columbia (BC), Canada. We used data from the BC Hepatitis Testers Cohort (BC-HTC). We used Fine–Gray multivariable sub-distributional hazards models to assess the effect of HBV, NAFLD, and HCV coinfection on liver-related mortality, while adjusting for confounders and competing mortality risks. The liver-related mortality rate was higher among people with HBV infection than those without (2.57 per 1000 PYs (95%CI: 2.46, 2.69) vs. 0.62 per 1000 PYs (95%CI: 0.61, 0.64), respectively). Compared with the HBV negative groups, HBV infection was associated with increased liver-related mortality risk in almost all of the subgroups: HBV mono-infection (adjusted subdistribution hazards ratio (asHR) of 3.35, 95% CI 3.16, 3.55), NAFLD with HBV infection, (asHR 12.5, 95% CI 7.08, 22.07), and HBV/HCV coinfection (asHR 8.4, 95% CI 7.62, 9.26). HBV infection is associated with a higher risk of liver-related mortality, and has a greater relative impact on people with NAFLD and those with HCV coinfection. The diagnosis and treatment of viral and fatty liver disease are required to mitigate liver-related morbidity and mortality.     

Child morbidity and mortality following vitamin A supplementation in Ghana: time since dosing, number of doses, and time of year.

OBJECTIVES: The impact of large-dose vitamin A supplementation given at intervals of 4 months on child mortality and morbidity was examined according to the time interval since dosing, number of doses received previously, and time of year. METHODS: Two double-blind, randomized, placebo-controlled trials of large doses of vitamin A administered at intervals of 4 months were conducted in adjacent populations in northern Ghana. RESULTS: While vitamin A supplementation significantly reduced the overall incidence of severe illnesses (especially diarrhea with dehydration), clinic attendances, hospital admissions, and mortality, there was no evidence that the impact of each dose of vitamin A was related to the number of doses the child had received previously. There was no evidence that the effectiveness of the supplement waned over the 3 to 5 months between doses. The impact on mortality did not differ significantly by the month in which the supplement had been given. CONCLUSIONS: In the study population, there was no evidence that an interval between doses of less than 4 months would have had a greater impact on severe morbidity or mortality, and the effectiveness of supplementation did not vary by time of year.     

Severe anemia in young children after high and low malaria transmission seasons in the Kassena-Nankana district of northern Ghana

Malaria and anemia accounted for 41% and 18% respectively of hospital deaths in the Kassena-Nankana district of northern Ghana during 1996. We measured hemoglobin (Hb), malaria prevalence, and anthropometric indices of 6--24-month-old infants and young children randomly selected from this community at the end of the high (May-October, n = 347) and low (November-April, n = 286) malaria transmission seasons. High transmission season is characterized by rainfall (the equivalent of 800-900 mm/yr.), while the remaining months receive less than 50 mm/yr. Severe anemia, defined as Hb < 6.0 g/dL, was 22.1% at the end of the high transmission season compared to 1.4% at the end of the low transmission season (Odds Ratio [OR] = 20.1; 95% CI: 7.1-55.3). Parasitemia was 71% and 54.3% at these time points (OR = 2.1; 95% CI: 1.5-2.9). Nutritional anemia appeared to have little impact upon this seasonal difference since anthropometric indices were comparable. Although the relative contributions of other causes of severe anemia were not assessed, repeated malaria infections may be a primary determinant of severe anemia among infants and young children during the high transmission season.     

外源性一氧化氮对创伤愈合过程中一氧化氮合酶表达及瘢痕形成的影响

目的:应用组织化学、免疫组织化学及计算机辅助图像分析方法,观察外源性一氧化氮在创伤愈合过程不同时间,对一氧化氮合酶表达和胶原形成的影响,探讨其在促进创伤愈合和抑制病理性瘢痕形成中的机制。方法:实验于2004-09/2006-03在河北省人民医院整形烧伤外科及河北省人民医院临床医学研究中心完成。以硝普钠为一氧化氮供体,将60只大鼠随机分为对照组及硝普钠0.5,1,2,4mmol/L组,每组12只,通过建立大鼠创伤模型,并分别在创面局部应用50g/L葡萄糖溶液、0.5,1,2,4mmol/L硝普钠,观察及测量创伤后3,7,10,14d的肉芽组织生长情况、一氧化氮合酶的表达情况和肉芽组织中羟脯氨酸含量。结果:60只大鼠全部进入结果分析。①形态学观察:对照组于创伤后14d可完全愈合;硝普钠0.5mmoL/L组及1mmoL/L组肉芽组织生长良好,且愈合时间较对照组提前三四天;硝普钠2mmoL/L组及4mmoL/L组愈合情况不良,完全愈合时间延迟,皮肤张力较低,炎症反应明显。②一氧化氮合酶蛋白表达:大鼠皮肤创伤后角质形成细胞、汗腺、毛囊和骨骼肌细胞以及创伤后肉芽组织的炎症细胞、成纤维细胞、血管内皮细胞均不同程度的表达一氧化氮合酶蛋白。对照组在第3天和第14天分别呈现一氧化氮合酶阳性颗粒表达高峰,而硝普钠各组仅在第7～10天出现表达一氧化氮合酶阳性高峰,呈先增加后减少的趋势。③羟脯氨酸含量:对照组从创伤后第3,7,10,14天羟脯氨酸含量进行性增加[依次为(1.637±0.127),(2.250±0.169),(2.420±0.201),(2.908±0.241)mg/g];硝普钠0.5mmol/L组在创伤后第3,7天羟脯氨酸含量低于对照组[(1.435±0.147),(1.766±0.211)mg/g,P<0.05或P<0.01],而在第10天和第14天羟脯氨酸含量均高于对照组[(3.128±0.240),(3.437±0.239)mg/g,P<0.01];硝普钠1mmol/L组和2mmol/L组在第10天和第14天的羟脯氨酸含量明显高于对照组[(1mmol/L组:(3.244±0.245)(3.582±0.282)mg/g,P<0.01;硝普钠2mmol/L组:(3.666±0.263),(4.301±0.268)mg/g,P<0.01);硝普钠4mmol/L组仅在创伤后第3天表现比对照组多[(1.912±0.139)mg/g,P<0.01),其余均与对照组水平相近。结论:局部应用外源性一氧化氮具有显著的促修复作用,主要体现在伤后第7～10天,小剂量的一氧化氮促进创面愈合的作用远远大于大剂量一氧化氮。     

Accelerating reproductive and child health programme impact with community-based services: the Navrongo experiment in Ghana

OBJECTIVE: To determine the demographic and health impact of deploying health service nurses and volunteers to village locations with a view to scaling up results. METHODS: A four-celled plausibility trial was used for testing the impact of aligning community health services with the traditional social institutions that organize village life. Data from the Navrongo Demographic Surveillance System that tracks fertility and mortality events over time were used to estimate impact on fertility and mortality. RESULTS: Assigning nurses to community locations reduced childhood mortality rates by over half in 3 years and accelerated the time taken for attainment of the child survival Millennium Development Goal (MDG) in the study areas to 8 years. Fertility was also reduced by 15%, representing a decline of one birth in the total fertility rate. Programme costs added 1.92 US Dollar per capita to the 6.80 US Dollar per capita primary health care budget. CONCLUSION: Assigning nurses to community locations where they provide basic curative and preventive care substantially reduces childhood mortality and accelerates progress towards attainment of the child survival MDG. Approaches using community volunteers, however, have no impact on mortality. The results also demonstrate that increasing access to contraceptive supplies alone fails to address the social costs of fertility regulation. Effective deployment of volunteers and community mobilization strategies offsets the social constraints on the adoption of contraception. The research in Navrongo thus demonstrates that affordable and sustainable means of combining nurse services with volunteer action can accelerate attainment of both the International Conference on Population and Development agenda and the MDGs.     

Gate-keeping and women's health seeking behaviour in Navrongo,northern Ghana

Among the Kassena-Nankana of northern Ghana, compound heads and husbands impede women's prompt access to modern health care. This paper shows that such gate-keeping systems have a negative effect on child survival. To investigate the social construction of compound-based gate-keeping systems, the authors relied on a series of qualitative interviews conducted in the Kassena-Nankana district These data reveal that whilst compound heads are gate-keepers for spiritual reasons, husbands play such role for economic reasons. But more important, this article presents health interventions that are on trial in Navrongo (northen Ghana) and how they undermine such gate-keeping systems.