Frequency of typhoon occurrence accounts for the Poisson distribution of human leptospirosis cases across the different geographic regions in the Philippines

• Main Authors: Derick Erl P. Sumalapao, Benjamin Kyle M Del Rosario, Lara Beatrice L. Suñga, Catherine C Walthern, Nina G Gloriani
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2019-01-01
• Series: Asian Pacific Journal of Tropical Medicine
• Subjects: human leptospirosis; typhoon; poisson distribution; philippines
• Online Access: http://www.apjtm.org/article.asp?issn=1995-7645;year=2019;volume=12;issue=1;spage=38;epage=42;aulast=Sumalapao

Objective: To study the distribution of human leptospirosis cases across the different geographic regions in the Philippines in 2015-2017 and to determine the relationship between the frequency of typhoon occurrence and human leptospirosis cases. Methods: Information on the frequency of leptospirosis cases and typhoon occurrence across the different regions in the Philippines from 2015 to 2017 was retrieved from the databases of the Department of Health and the Philippine Atmospheric, Geophysical, and Astronomical Services Administration, respectively. Descriptive measures on the prevalent cases and occurrence of typhoons across the different regions were summarized. Linear regression analysis was employed to establish the functional relationship between leptospirosis cases and typhoon occurrence. The distribution of human leptospirosis cases was assessed using the Poisson distribution. Results: The frequency of typhoon occurrence accounted for the significant linear variation in the geographic distribution of human leptospirosis cases in the Philippines (P<0.001). Moreover, the human leptospirosis cases obeyed a Poisson distribution (λ=6.89, P<0.001). Conclusions: The Philippines has frequently experienced severe weather perturbations such as typhoons resulting in flooding and subsequently increasing the risk of transmitting bacterial infections including leptospirosis. Information obtained regarding the determinants and distribution of human leptospirosis will provide better understanding of the disease propagation for subsequent design of optimal disease prevention measures, appropriate resource allocation, effective control strategies, and necessary public health programs.