HIV infection, seasonality and younger age predicting incident Bell’s palsy among black South Africans

BACKGROUND: Although South Africa (SA) is facing a high prevalence of HIV infection, there is no literature from this region on a link between Bell’s palsy and HIV. The aim of this study was to identify the occurrence of Bell’s palsy in relation to demographics, seasons and HIV status among black South Africans. METHODS: This retrospective cohort was conducted among adult black patients, without Bell’s palsy in 2003, presenting to the neurology outpatients department at Dr. George Mukhari Academic hospital, Pretoria, South Africa, between 2004 (study baseline) and 2012 (end test). Gender, age, HIV status, and seasons were potential predictors of Bell’s palsy using Cox regression model and Kaplan Meier curves. RESULTS: From the baseline of 1487 patients, 20.9% (n = 311) experienced Bell’s palsy onset by the end of the study. In univariate analysis, male gender (RR = 2.1 95% CI 1.7–2.5; P < 0.0001), age less than 30 years (RR = 2.9 95% CI 2.4–3.6; P < 0.0001), HIV seropositivity (RR =2.9 95% CI 2.3–4.9; P < 0.0001). The highest incidence in winter (30.3% n = 136/450) vs. incidences during other seasons with Intermediate values during Summer (25.3% n = 136/450) and Autumn (20.7% n = 64/308) and the lowest incidence in Spring (23.7% n = 16/353) P < 0.0001) were predictors of Bell’s palsy. In multivariate analysis at adjusting for gender, the most significant and independent predictors of incident Bell’s palsy were HIV seropositivity (HR = 6.3 95% CI 4.8–8.3; P < 0.0001), winter (HR = 1.6 95% CI 1.2–2.1; P < 0.0001) vs. other seasons, and younger age < 30 years (HR = 7.1 95% CI 5.6–9.1; P < 0.0001) vs. older age groups. CONCLUSION: Seasonality, younger age and HIV positivity are important and independent risk factors of Bell’s palsy. Education and awareness programs on the possible effects of HIV and seasons on the development of Bell’s palsy are necessary. This would lead to a better understanding and even a possible development of avoidance measures for this condition amongst young black South Africans.