War, famine and excess child mortality in Africa: the role of parental education.
(33/1130)BACKGROUND: Civilian-targeted warfare and famine constitute two of the greatest public health challenges of our time. Both have devastated many countries in Africa. Social services, and in particular, health services, have been destroyed. Dictatorial and military governments have used the withholding of food as a political weapon to exacerbate human suffering. Under such circumstances, war and famine are expected to have catastrophic impacts on child survival. This study examines the role of parental education in reducing excess child mortality in Africa by considering Tigrai-Ethiopia, which was severely affected by famine and civil war during 1973--1991. METHODS: This study uses data from the 1994 Housing and Population Census of Ethiopia and on communities' vulnerability to food crises. Child mortality levels and trends by various subgroups are estimated using indirect methods of mortality estimation techniques. A Poisson regression model is used to examine the relationship between number of children dead and parental education. RESULTS: Although child mortality is excessively high (about 200 deaths per 1000 births), our results show enormous variations in child mortality by parental education. Child mortality is highest among children born to illiterate mothers and illiterate fathers. Our results also show that the role of parental education in reducing child mortality is great during famine periods. In the communities devastated by war, however, its impact was significant only when the father has above primary education. CONCLUSIONS Our findings suggest that both mother's and father's education are significantly and negatively associated with child mortality, although this effect diminishes over time if the crisis is severe and prolonged. The policy implications of our study include, obviously, reducing armed conflict, addressing food security in a timely manner, and expansion of educational opportunities. (+info)
Association between vitamin A status and lung function level in children aged 6--9 years in Wukro wereda, Northern Ethiopia.
(34/1130)BACKGROUND: In developing countries, studies using morbidity recalls to evaluate the benefits of vitamin A on respiratory health in children under 6 years of age have been inconclusive. This relationship has not been examined in older children. Spirometric measurements, an objective means of assessing respiratory health, require the subject's collaboration and have been successfully used in children over 6 years of age. This report describes a cross-sectional analysis of the relationship between lung function and vitamin A status in an area endemic to vitamin A deficiency. METHODS: The data on which this report is based were gathered prior to the implementation of a prospective trial of the effect of vitamin A supplementation on lung function level in Northern Ethiopia. Vitamin A status was assessed by the Modified Relative Dose Response (MRDR) method and lung function assessed by spirometry in 702 rural children aged 6--9 years. Demographic, personal health, household, environmental and socioeconomic data were gathered by questionnaire. RESULTS: In children with low vitamin A reserve, the unadjusted forced expiratory volume in one second (FEV(1)) was 48.8 ml (P = 0.006) lower than in those with adequate reserve. This difference was 23.1 ml (P = 0.04) when adjusted for age, gender and height and 14.1 ml (P = 0.20) when adjusted for children's demographic, general health, lung function and household-related characteristics. CONCLUSION: Although these findings suggest that vitamin A plays a relatively minor role in determining FEV(1) level, interpretation is limited by the cross-sectional design. Further clarification of its role requires a trial of vitamin A supplementation. (+info)
Effect of misclassification of causes of death in verbal autopsy: can it be adjusted?
(35/1130)BACKGROUND: Verbal autopsy (VA) is an indirect method of ascertaining cause of death from information about symptoms and signs obtained from bereaved relatives. This method has been used in several settings to assess cause-specific mortality. However, cause-specific mortality estimates obtained by VA are susceptible to bias due to misclassification of causes of death. One way of overcoming this limitation of VA is to adjust the crude VA estimate of cause-specific mortality fractions (CSMF) using the sensitivity and specificity of the VA tool. This paper explores the application of sensitivity and specificity of VA data obtained from a hospital-based validation study for adjusting the effect of misclassification error in VA data obtained from a demographic surveillance system. METHOD: Data from a multi-centre validation study of 796 adult VA, conducted in Tanzania, Ethiopia and Ghana, were used to explore the effect of distribution of causes of death in the validation study population and the pattern of misclassification on the sensitivity and specificity of VA. VA estimates of CSMF for six causes (acute febrile illness, diarrhoeal diseases, TB/AIDS, cardiovascular disorders, direct maternal causes and injures) were obtained from a demographic surveillance system in Morogoro Rural District in Tanzania. These were adjusted for misclassification error by using sensitivity and specificity values of VA obtained from the validation study in a model proposed for correcting the effect of misclassification error in morbidity prevalence surveys. RESULTS: Sensitivity and specificity of VA differed between the three validation study sites depending on the distribution of causes of death. These differences were explained by variations in the level and pattern of misclassification between sites. When these estimates of sensitivity and specificity were applied to data from the demographic surveillance system with a comparable structure of causes of death the difference between crude and adjusted VA estimates of CSMF ranged from 3 to 83%. CONCLUSION: Estimates of sensitivity and specificity obtained from hospital-based validation studies must be used cautiously as a de facto 'gold standard' for adjusting the misclassification error in CSMF derived from VA. It is not possible to use sensitivity and specificity estimates derived from a location-specific validation study to adjust for misclassification in VA data from populations with substantially different patterns of cause-specific mortality. (+info)
A case study of using artificial neural networks for classifying cause of death from verbal autopsy.
(36/1130)BACKGROUND: Artificial neural networks (ANN) are gaining prominence as a method of classification in a wide range of disciplines. In this study ANN is applied to data from a verbal autopsy study as a means of classifying cause of death. METHODS: A simulated ANN was trained on a subset of verbal autopsy data, and the performance was tested on the remaining data. The performance of the ANN models were compared to two other classification methods (physician review and logistic regression) which have been tested on the same verbal autopsy data. RESULTS: Artificial neural network models were as accurate as or better than the other techniques in estimating the cause-specific mortality fraction (CSMF). They estimated the CSMF within 10% of true value in 8 out of 16 causes of death. Their sensitivity and specificity compared favourably with that of data-derived algorithms based on logistic regression models. CONCLUSIONS: Cross-validation is crucial in preventing the over-fitting of the ANN models to the training data. Artificial neural network models are a potentially useful technique for classifying causes of death from verbal autopsies. Large training data sets are needed to improve the performance of data-derived algorithms, in particular ANN models. (+info)
Prevalence of vitamin A deficiency in children aged 6-9 years in Wukro, northern Ethiopia.
(37/1130)OBJECTIVE: To determine the prevalence of vitamin A deficiency in children aged 6-9 years in northern Ethiopia. METHODS: A cross-sectional study was carried out and the data were analysed for 824 (61.5%) of 1339 eligible children for whom there was complete information on biochemical vitamin A status, dietary vitamin A intake, ocular examination for xerophthalmia, and anthropometry. FINDINGS: The prevalence of xerophthalmia was 5.8%; serum retinol levels were below 0.35 mumol/l and between 0.35 and 0.70 mumol/l in 8.4% and 51.1% of the children respectively. The liver vitamin A reserve (modified relative dose response ratio > or = 0.06) was low in 41.0% of the children. CONCLUSION: The high prevalence of severe vitamin A deficiency in children aged 6-9 years indicates the need to reevaluate the practice of targeting vitamin A supplementation programmes on children under 6 years of age in areas where vitamin A deficiency is endemic. (+info)
Has oral fluid the potential to replace serum for the evaluation of population immunity levels? A study of measles, rubella and hepatitis B in rural Ethiopia.
(38/1130)OBJECTIVE: To assess the suitability of using oral-fluid samples for determining the prevalence of immunity to vaccine-preventable infections. METHODS: Paired blood and oral-fluid samples were obtained from 853 individuals of all ages from a rural Ethiopian community. Oral fluid around the gums was screened for measles- and rubella-specific antibodies using enhanced IgG antibody capture (GAC) enzyme-linked immunosorbent assays (ELISAs), and for anti-HBc antibodies using a prototype GACELISA. IgG antibodies in serum to measles, rubella and HBc were determined using commercial ELISAs. FINDINGS: Relative to serum, oral fluid assay sensitivity and specificity were as follows: 98% and 87% for measles, 79% and 90% for rubella, and 43% and 87% for anti-HBc. These assay characteristics yielded population prevalence estimates from oral fluid with a precision equal to that of serum for measles (all ages) and rubella (ages < 20 years). CONCLUSION: Our results suggest that oral fluid could have the potential to replace serum in IgG antibody prevalence surveys. Further progress requires assessment of variation in assay performance between populations as well as the availability of standardized, easy to use assays. (+info)
Short report: Detection of borrelia (relapsing fever) in rural Ethiopia by means of the quantitative buffy coat technique.
(39/1130)The diagnosis of louse-borne relapsing fever is commonly made on the basis of the detection of Borrelia spirochetes on Giemsa-stained thin blood films. In the present study, we used acridine orange-coated quantitative buffy coat (QBC) tubes, centrifugation, and fluorescence microscopy to detect Borrelia. Between July and August 1998, we used the QBC technique to diagnose 7 patients with borreliosis who visited a rural clinic in southwest Ethiopia. In laboratory studies that used Borrelia burgdorferi as a model, we detected spirochetes at concentrations as low as 10 organisms/mm3, whereas the number of positive readings assessed by means of stained blood films fell significantly at dilutions below 3,263 organisms/mm3. The greater sensitivity of the QBC technique is important in areas where Borrelia is endemic, as in the Horn of Africa. It may also prove useful in evaluating relapsing fevers in travelers. (+info)
Fcgamma receptor polymorphisms in populations in Ethiopia and Norway.
(40/1130)Seventy-seven healthy Ethiopians were genotyped for polymorphisms in the immunoglobulin G Fc receptors (FcgammaR) FcgammaRIIa, FcgammaRIIIa and FcgammaRIIIb, including the SH allele. The genotype and allele frequencies were compared with those of 96 healthy Norwegians. Ethiopians had higher frequencies of the SH-FcgammaRIIIb (P = 0.001), FcgammaRIIIa-158 V (P = 0.026) and FcgammaRIIIb-Na2 (P = 0.046) alleles. The genotype distributions of FcgammaRIIa, FcgammaRIIIa and FcgammaRIIIb, however, did not differ significantly from those of the Norwegians. The data were also compared with those reported from studies on other ethnic groups. The variation of different polymorphisms both within and between ethnic groups may influence differences in the incidence rates of infectious and autoimmune diseases. (+info)