Occupational health risks due to shipboard cockroaches

Objectives In various investigated populations, sensitization to cockroaches was observed in 8% of screened subjects from temperate climatic zones and in 36% of those from tropical zones. Because of the numerous hiding places and food storages aboard a ship the crews can be highly exposed to cockroaches. The aim of this study is to assess the prevalence of sensitization to cockroaches and potentially associated health risks in seafarers. Methods In July 2005, a total of 145 seamen sailing under the German flag were recruited from a medical surveillance program for a cross-sectional study (response 95.4%). A standardized interview and a skin prick test (SPT) with nine common inhalant allergens and a cockroach extract (Blatella germanica) were performed. In cockroach-sensitized seafarers total and cockroach-specific IgE was measured and lung function tests conducted. Results In total, 39 seamen (26.9%) were cockroach-sensitized according to SPT results. Presence of cockroach sensitization in seamen from the tropical zone (37.3%) was significantly higher than in seamen from the temperate zone (21.3%) (odds ratio 2.20, 95% confidence interval 1.04–4.66). The prevalence of sensitization to any of the other nine common allergen mixtures tested was lower (between 2.1 and 12.4%). Neither current or past cockroach exposure on board nor cumulative cockroach exposure and time since last cockroach exposure were associated with cockroach sensitization. Among cockroach SPT-positive seamen, cockroach-specific IgE was detected in 52.8%. Five out of 37 (13.5%) SPT-positive seamen exhibited an obstructive ventilation pattern. The prevalence of work-related atopic symptoms was 9.0% (n = 13). These symptoms were not related to cockroach sensitization. Conclusion The high prevalence of sensitization to cockroaches among seamen in the presented study emphasizes the strong sensitization potency of these insects. Longitudinal studies and bronchial cockroach challenge tests are necessary to assess the clinical relevance of cockroach sensitization aboard a ship in more detail.