Philippine E-Journals

Global Patterns in Spatial Expansion of Dengue Serotype-I in Response to Increasing Surface Temperature

Rhoniel Ryan J Ymbong | Jake Joshua C Garces

 

Abstract:

Dengue is a mosquito-borne viral infection (DENV serotypes 1-4) that imposes a serious health and economic burden in tropical and sub-tropical countries around the world. Increasing atmospheric temperature had changed the dynamics of the mosquito habitats and, thereby, influences distribution of these mosquito vectors. We examined the increase in the number of countries within the regions of Asia, Africa, and America’s reporting laboratory confirmed dengue cases caused by DENV-1 as a response to increasing global surface temperature difference. Data on the number of countries with confirmed reports of dengue (Messina et al. 2014) and surface temperature difference (General Circulation Model) were subjected to scatter plots and linear regression. There were 113 recorded countries across three regions (America=44, comprising the North and South; Africa=28; and Asia=41) reporting dengue incidence from 1943 to 2013, of which 98 countries (America=41; Africa=20; and Asia=37 with the inclusion of Australia) reported confirmed dengue cases caused by DENV-1. Findings suggest that the effect of temperature to the expansion of dengue varies dramatically in certain groups of country. Here, we explore three patterns (PAT) of expansion response where 1) continuous increase in temperature results into a continuous increase in the number of countries with dengue cases (PAT-A), 2) initial increase in temperature results into increase in the number of countries with dengue cases but subsequent increase in temperature results in the decline of dengue expansion (PAT-B), and 3) initial increase in temperature results into higher rate of dengue expansion but continued increase slows it down (PAT-C). PAT-A represented the majority of these countries, including 10 out of 11 countries in Southeast Asia. These results are in congruence with the past studies that supports dengue expansion to be temperature-dependent.