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Gail Davey

Publications and source records attributed to Gail Davey.

7 recordsLinked to original sources

Podoconiosis: a tropical model for gene-environment interactions?

Podoconiosis (endemic non-filarial elephantiasis) is a geochemical disease occurring in individuals exposed to red clay soil derived from alkalic volcanic rock. It is a chronic, debilitating disorder and a considerable public health problem in at least 10 countries in tropical Africa, Central America and northern India. Only a small proportion of individuals exposed to red clay develop disease and familial clustering of cases occurs, so we tested the hypothesis that disease occurs in genetically susceptible individuals on exposure to an environmental element in soil. Using multiple statistical genetic techniques we estimated sibling recurrence risk ratio (lambda(s)) and heritability for podoconiosis, and conducted segregation analysis on 59 multigenerational affected families from Wolaitta Zone, southern Ethiopia. We estimated the lambda(s) to be 5.07. The heritability of podoconiosis was estimated to be 0.629 (SE 0.069, P=1x10(-7)). Segregation analysis showed that the most parsimonious model was that of an autosomal co-dominant major gene. Age and use of footwear were significant covariates in the final model. Host genetic factors are important determinants of susceptibility to podoconiosis. Identification of the gene(s) involved will lead to better understanding of the gene-environment interactions involved in the pathogenesis of podoconiosis and other complex multifactorial conditions.

Age of Onset↗

Economic costs of endemic non-filarial elephantiasis in Wolaita Zone, Ethiopia.

BACKGROUND: Endemic non-filarial elephantiasis or podoconiosis is a chronic and debilitating geochemical disease occurring in individuals exposed to red clay soil derived from alkalic volcanic rock. It is a major public health problem in countries in tropical Africa, Central America and North India. OBJECTIVE: To estimate the direct and the average productivity cost attributable to podoconiosis, and to compare the average productivity time of podoconiosis patients with non-patients. METHODS: Matched comparative cross sectional survey involving 702 study subjects (patients and non-patients) supplemented by interviews with key informants in Wolaita Zone, southern Ethiopia. RESULTS: Total direct costs of podoconiosis amounted to the equivalent of US$ 143 per patient per year. The total productivity loss for a patient amounted to 45% of the total working days per year, causing a monetary loss equivalent to US$ 63. In Wolaita zone, the overall cost of podoconiosis exceeds US$ 16 million per year. CONCLUSIONS: Podoconiosis has enormous economic impact in affected areas. Simple preventive measures (such as use of robust footwear) must be promoted by health policy makers.

Adolescent↗

Use of acetaminophen and the risk of self-reported allergic symptoms and skin sensitization in Butajira, Ethiopia.

BACKGROUND: Studies in developed countries suggest that acetaminophen use is associated with increased risk of asthma, but it is unclear whether this association is causal. OBJECTIVE: To determine the relation among acetaminophen use, asthma, and allergy, and to explore potential biases in acetaminophen use, in a developing country population. METHODS: We surveyed 7649 adults and children from Butajira, Ethiopia, collecting data on self-reported symptoms of allergic disease, skin sensitization to Dermatophagoides pteronyssinus and cockroach, acetaminophen use, and potential confounders. We then collected detailed data on indications for acetaminophen use and reasons for aspirin avoidance in a nested follow-up study. RESULTS: Allergic symptoms increased significantly with frequency of acetaminophen use, with odds ratios in those using >3 tablets in the past month relative to none 1.89 (95% CI, 1.51-2.36) for wheeze, 2.14 (1.72-2.67) for nocturnal shortness of breath, 2.52 (1.99-3.20) for rhinitis, and 1.90 (1.39-2.61) for eczema. Cockroach sensitization was also more common in the highest acetaminophen category (odds ratio, 1.40; 95% CI, 1.10-1.79), but D pteronyssinus sensitization was not. Less than 1% of participants with asthma or wheeze in our nested study reported avoidance of aspirin because of asthma symptoms. None volunteered using acetaminophen to treat allergic symptoms. CONCLUSION: There is a dose-related association between acetaminophen use and self-reported allergic symptoms in this population that is not a result of aspirin avoidance, reverse causation, or other bias. Acetaminophen may therefore be involved in the etiology of asthma and allergic disease.

Acetaminophen↗

Prevalence of podoconiosis (endemic non-filarial elephantiasis) in Wolaitta, Southern Ethiopia.

The survey was undertaken to establish the point prevalence of overt podoconiosis (endemic non-filarial elephantiasis) in Wolaitta zone, Southern Ethiopia, and also to determine whether age- or sex-related prevalence differences exist. A cross-sectional survey was performed during May-September 2001 among 33 678 residents of 4210 households randomly selected from all seven woredas (administrative districts) of Wolaitta zone. Trained data collectors administered a simple questionnaire and examined household residents for signs of podoconiosis. Of the residents 1890 had overt signs of podoconiosis. The mean zonal prevalence weighted for the woreda size was 5.46%. Most of cases (64%) occurred in the economically productive age groups (16-45 years). The male:female ratio was 1:0.98, reflecting the gender ratio of the zone. Podoconiosis is an important chronic public health problem affecting both men and women in areas of irritant soil. Further research is necessary to establish the economic effects of the condition.

Adolescent↗

Overall HIV-1 prevalence in pregnant women over-estimates HIV-1 in the predominantly rural population of Afar Region.

The appropriateness of sentinel sero-surveillance based upon ante-natal clinic (ANC) attendees to estimate HIV-1 prevalence in the general population has been questioned. In Ethiopia, where the population is heterogeneous and where economic and practical barriers to ANC attendance exist, problems of extrapolation may be exacerbated. We planned an unlinked anonymous sero-survey which included data on basic population characteristics to investigate whether sero-surveillance data from ANCs in Afar Region might be taken to represent the situation among the general population of the Region. 371 pregnant women attending Dubti Hospital and Assayta Health Centre were tested for HIV-1 (using a single ELISA test) and active syphilis (RPR test). Socio-demographic characteristics were collected for each woman. Of the women tested, 278 (75%) were 28 years of age or younger. Two hundred eighty (76%) were urban residents and 237 (64%) described themselves as being of Amhara ethnicity. Overall, 73 (19.7%) were HIV-1 positive, but prevalence was three times higher among the 237 women of Amhara ethnicity compared to the 112 of Afar ethnicity (24.9% vs 8.0%, p < 0.001), and almost three times higher for urban compared to rural residents (23.2% vs 8.8%, p < 0.001). Positive RPR results were strongly associated with HIV-1 infection (OR 3.37, 95% CI 1.47-7.71). According to the Demographic and Health Survey (DHS) 2000, only 4.5% of the population of Afar Region is of Amhara ethnicity, and 7.8% urban residents. We have demonstrated that basing ANC sero-surveillance in urban areas of Afar Region over-samples urban residents of Amhara ethnicity and yields a major over-estimation of overall HIV-1 prevalence for the Region. Reliable estimation of HIV-1 prevalence in Afar Region will require more flexible strategies that permit sampling of rural Afar residents.

AIDS Serodiagnosis↗

Association between migraine and asthma: matched case-control study.

BACKGROUND: Earlier studies have suggested a link between asthma and severe headache, and also between migraine and wheezing illness. Recent analysis have also shown an increase of asthma among cases with a prior history of migraine but without a history of hay fever, allergic rhinitis or eczema. AIM: To examine whether there is an association between migraine and asthma in the United Kingdom. DESIGN OF STUDY: Matched case-control study using the General Practice Research Database (GPRD). SETTING: Practices in the United Kingdom providing data on 5,110,619 patients to the GPRD. METHOD: The subjects were the patients with one or more diagnoses of migraine plus treatment for migraine. Each case was matched by general practice, sex, and age, with one control who had never been given a diagnosis of migraine. Case and control groups were compared for prevalence of asthma, chronic obstructive pulmonary disease, respiratory symptoms treated with inhalers or hay fever. Investigations were carried out to determine whether the association between migraine and asthma was stronger among patients with hayfever or those without hayfever, and whether patients with migraine had an increased prescription of other (non-migraine and non-asthma) medications. RESULTS: Among 64 678 case-control pairs, the relative risk of asthma in patients with migraine was 1.59 (95% CI = 1.54 to 1.65) among definite cases, and 0.75 (95% CI = 0.67 to 0.83) among those whose selection as case included beta-blocker prophylaxis. Among definite migraine cases, relative risks of chronic obstructive pulmonary disease, respiratory symptoms, eczema, and hay fever (pollinosis), were all raised (at 1.22, 1.85, 1.55, and 1.67, respectively). The association between migraine and asthma was stronger in patients without a diagnosis of hay fever, than in those with hayfever (relative risk = 1.32 and 1.19, respectively). The relative risk of prescription for a range of non-migraine, non-asthma medications was raised, the exception being anti-diabetic medication. CONCLUSION: This large case-control study provides evidence for an association between migraine and asthma. Frequent attendance at a general practice surgery may confound this association. However, if the association is real, its elucidation may help the understanding of disease mechanisms shared by migraine and asthma.

Asthma↗