Abstract
Malaria is one of the most widespread communicable diseases in the southeast regions of Iran, particularly the Chabahar County. Although the outbreak of this disease is a climate-related phenomenon, a comprehensive analysis of the malaria-climate relationship has not yet been investigated in Iran. The aims of this study are as follows: a) analyzing the seasonal characteristics of the various species of the infection; b) differentiating between number of patients during El Niño and La Niña and also during the wet and dry years. The monthly malaria statistics collected from twelve health centers were firstly averaged into seasonal scale and then composited with the corresponding data of the ground-based meteorological records, Southern Oscillation Index (SOI), and the satellite-based rainfall data. The proper statistical tests were used to detect differences in the number of patients between El Niño and La Niña and also between the adopted wet and dry episodes. Infection rate from the highest to the lowest was associated with summer, autumn, spring, and winter, respectively. Plasmodium falciparum, P. vivax, and the other species were responsible for 22%, 75%, and 3% of the sickness, respectively. The outbreak of P. falciparum/P. vivax occurs during autumn/summer. Due to the malaria eradication programs in urban areas, infection statistics collected from the rural areas were found to be more climate-related than that of urban regions. For rural/urban areas, the infection statistics exhibited a significant decline/increase during El Niño episodes. In autumn, spring, and winter, the patient number has significantly increased/decreased during the dry/wet years, respectively. These relationships were, however, reversed in summer.
Highlights
Malaria is a leading life-threatening mosquito-borne parasitic disease across the globe, accounting for up to 212 million cases and 429 000 deaths in 2015(1)
Temperature and relative humidity in Chahbahar station were matched with the El Niño and La Niña years to construct the El Niño-Southern Oscillation (ENSO) composites for each variable
Since rainfall time-series in Chahbahar are affected by frequent near zero and sporadic torrential rain, the presented ENSO-rainfall relationships could change over time for winter, spring and summer, when these relationships are not strongly significant
Summary
Malaria is a leading life-threatening mosquito-borne parasitic disease across the globe, accounting for up to 212 million cases and 429 000 deaths in 2015(1). Malaria control programs initiating from 1945 resulted in eradication/significant suppression of the disease in the northern/southern parts of the country by 1977, respectively[3]. The El Niño-Southern Oscillation (ENSO) is a natural phenomenon described by periodic warming of the ocean surface between the eastern and western parts of the equatorial Pacific Ocean. Recent studies have shown that ENSO in conjunction with variations in the sea surface temperatures over tropical and extra-tropical water bodies induces a significant impact on precipitation variability and climate change in Iran and West Asia[16,17,18,19,20]. After analyzing the spatio-temporal distribution of the disease, the relationships between the infection statistics and some important climate indices the El Niño-Southern Oscillation (ENSO) and rainfall were investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
