Impacts of El Niño Southern Oscillation and Indian Ocean Dipole on dengue incidence in Bangladesh

Abstract

Dengue dynamics are driven by complex interactions between hosts, vectors and viruses that are influenced by environmental and climatic factors. Several studies examined the role of El Niño Southern Oscillation (ENSO) in dengue incidence. However, the role of Indian Ocean Dipole (IOD), a coupled ocean atmosphere phenomenon in the Indian Ocean, which controls the summer monsoon rainfall in the Indian region, remains unexplored. Here, we examined the effects of ENSO and IOD on dengue incidence in Bangladesh. According to the wavelet coherence analysis, there was a very weak association between ENSO, IOD and dengue incidence, but a highly significant coherence between dengue incidence and local climate variables (temperature and rainfall). However, a distributed lag nonlinear model (DLNM) revealed that the association between dengue incidence and ENSO or IOD were comparatively stronger after adjustment for local climate variables, seasonality and trend. The estimated effects were nonlinear for both ENSO and IOD with higher relative risks at higher ENSO and IOD. The weak association between ENSO, IOD and dengue incidence might be driven by the stronger effects of local climate variables such as temperature and rainfall. Further research is required to disentangle these effects.

Emerging Role of Zika Virus in Adverse Fetal and Neonatal Outcomes

“…Global climate changes are increasingly linked to the emergence and spread of infectious diseases (145)(146)(147). Although in the case of ZIKV this hypothesis needs to be further explored, it has been speculated that ENSO influenced the spread of DENV in the region (148)(149)(150). Congruently, recent ZIKV epidemic foci in South America overlap regions that experienced the most marked effects on climate caused by ENSO (144).…”

Effects of climatic and social factors on dengue incidence in Mexican municipalities in the state of Veracruz

“…5,6,15,31,32 Dengue transmission in warm and humid regions of México has been shown to be a strongly associated with ENSO and weather variables. 8,9,12,14 Less is known about the relation with cultural and social factors (social backwardness, the lack of water access and the use of uncovered water tanks not using mosquitoes nets, the lack of health services and health education), which also play an important role in the prevalence of the disease.…”

“…2,3 Local climate and the El Niño-Southern Oscillation (ENSO) play a key role in the ecology and biology of mosquito vectors and the viruses they transmit, and consequently have a strong influence on the risk of dengue transmission. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Precipitation changes may create larger or new habitats for mosquito larva, increasing vector populations. 7,[20][21][22][23] Ambient temperatures influence rates of mosquito larval development, 24,25 adult biting activity, 26 27 the gonotrophic cycle, 28 and reduction of the extrinsic incubation period.…”

Infección por virus del Zika en el embarazo, impacto fetal y neonatal

“…Esto coincide con lo reportado en la actualidad donde 75 a 80% de los pacientes infectados son asintomáticos 10 . Se podría interpretar como si el virus del Zika se hubiese quedado latente o dormido en el tiempo y ahora ha sido despertado por factores como el cambio climá-tico, el fenómeno del Niño [11][12][13][14][15] , los cuales han generado condiciones excepcionales en el Noreste de Sur América, donde en el segundo semestre de 2015, se registraron las temperaturas más calientes acompañadas de grandes sequías. Este fenómeno ha contribuido a la expansión Infectología al Día geográfica del vector, al igual que su supervivencia y replicación viral, además de incrementar la tasa de alimentación por la mosquita 16,17 .…”