115 (0.012–0.6) for ages 30–39, HR = 0.2 (0.043–0.79) for people older than 39, when compared with people younger than 30]. Smoking was significantly associated with an increased risk of contracting malaria [HR = 4.93(1.27–27.86)]. Fewer smokers complied with pretravel recommendations regarding the use of chemoprophylaxis,

but the association was not statistically significant (p = 0.083). To further explore if the association of smoking with risk of malaria is due to this possible confounding we performed a multivariate analysis by a Cox proportional hazard regression analysis which included only smoking and chemoprophylaxis. In this model smoking remained to be a statistically significant risk factor for malaria while chemoprophylaxis was not statistically significant (data not see more shown). There was no evidence that country of origin and alcohol consumption were risk factors for malaria (Table 1). The protective effect of age and living in high-level floors remained significant in multivariate analysis, while the Torin 1 effect of smoking and being a male was only marginally significant (Table 2). Incidence of malaria in the workers that did not

take the recommended chemoprophylaxis was 20 cases/100 person-years while for the workers reporting that they were taking prophylaxis it was only four cases/100 person-years. This association was not statistically significant [incidence rate ratio = 0.2 (0.005–1.35), p value = 0.087]. The effect of chemoprophylaxis was not significant and therefore not included in the final Cox proportional hazard regression model. Of the workers not using chemoprophylaxis, 84% did use chemoprophylaxis initially, upon arrival in Equatorial Guinea, but chose to discontinue it prematurely. The most common reasons given for withdrawing chemoprophylaxis were self-reported side effects of treatment and fear of long-term consequences of antimalarial drugs. Although 68% of hospital employees had received pretravel consultation about mosquito-bite avoidance and chemoprophylaxis, compliance with such Calpain measures was generally

poor. Only 11 workers (10.6%) reported applying mosquito repellent on a daily basis and 56 (54.9%) did not use repellent at all. Similarly, only 13 workers (12.7%) reported wearing long sleeves after dusk at all times, while 60 (58.8%) never used any barrier clothing at all. None of the workers used insecticide-impregnated nets, perhaps believing that air-conditioned rooms with screened windows provided sufficient protection. No significant association was found between the use of mosquito repellents and barrier clothing, and the risk of acquiring malaria (Table 1). The spatial distribution of malaria cases was somewhat unexpected. Mapping malaria cases according to different floors within the buildings led to an interesting observation: nearly all healthcare workers who had contracted malaria lived on the ground floor.