Watch the Weather: Disease in Uganda put on a Climate Timeline

By Nicole C. Little

Out of a total 57 million global deaths in 2008, 36 million, or 63%, were due to non-communicable diseases (NCDs). Comparatively, it is estimated to be that NCDs are only responsible for 27% of mortalities in Uganda. In Uganda, the amount of deaths due to injury are roughly about 33% less than the global average. Therefore, the large remaining portion of deaths in Uganda can be attributed to communicable, maternal, neonatal, and nutritional diseases. Prevalence of these diseases are often correlated with environmental and behavioral factors. In regards to behavior, malnutrition and unsafe sex are the leading causes for communicable diseases which include nutritional deficiency, diarrhea, lower respiratory infections, and HIV. Leading non-injury, non-NCD deaths caused by environmental factors include air-borne illnesses, air pollution issues as well as WaSH (Water and Sanitation Hygiene.)

Mosquito transmitted diseases as well as Neglected Tropical Diseases (NTDs) are predominant in Uganda. NTDs are bacterial and parasitic diseases. In developed countries, they are almost eradicated through health care. However, in less developed countries this is not the case; they are still quite prevalent. These diseases primarily affect low-income areas. Although they usually are not the primary cause of death, they tend to contribute to a shortened life span. They can also lower a person’s quality of life by causing disfigurement, life-long disability, lower economic activity and social stigmas. If expressed in disability-adjusted life years, NTD’s are accounted as an equivalent burden to malaria, and a quarter of the burden from HIV. Some of these diseases include ebola, leprosy, foot and mouth diseases, diarrhea, and worms. Mosquito transmitted diseases include malaria, yellow fever, west nile, and dengue fever. There are many innovations and simple methods used for mosquito bite prevention opposed to mosquito prevention. Other prevention mechanisms include education, improving WaSH facilities and homes.

 A lot of the diseases mentioned flourish in the tropical climate of Uganda. With a long wet season and hot yearly temperatures that range between 70 to 80 degrees Fahrenheit, this climate is prone to disease cultivation, especially tropical diseases. The wet season lasts from March to November with a slight decrease in precipitation from May to August. With increased water sources, ground water cover, and penetration during wet months, water-borne illnesses spread at a faster pace, soil borne illnesses can move through the soil and contaminate greater areas, and mosquitoes gain more breeding grounds. The remaining dry months from December to February allow temperatures to rise to peak heat. During these months more respiratory diseases emerge due to air-borne diseases and pollution.

A case study done on the plague (Yersinia pestis infection) in Uganda proved the case for using climate as a predictor for disease. In the study, they found:

“Climate and weather influence the occurrence, distribution, and incidence of infectious diseases, particularly those caused by vector-borne or zoonotic pathogens. Thus, models based on meteorological data have helped predict when and where human cases are most likely to occur. Such knowledge aids in targeting limited prevention and control resources and may ultimately reduce the burden of diseases”

The study showed data of temperature, rainfall, and relative humidity to correlate with the plague directly.

“Using an ensemble of meteorological datasets and model-averaging techniques we find that the number of suspected cases in the West Nile region was negatively associated with dry season rainfall (December-February) and positively with rainfall prior to the plague season. “

One of the biggest challenges to this study to be aware of is the lack of high quality, in situ meteorological data. This is an unfortunate paradox of present times for these vulnerable countries who could benefit greatly from these methods.

Uganda lies in the El Nino Southern Oscillation, which causes more extreme weather events. Diseases are directly correlated to amplified epidemics during the oscillation period. El Nino years cause greater health risks in Uganda due to increased rainfall and temperatures. In 1997, a malaria outbreak that was 3 times the rate of preceding years occurred. Uganda has also seen major outbreaks of Cholera, a water borne illness, as well as large outbreaks of Rift Valley Fever during El Nino. On top of disease spread, El Nino’s flooding and unpredictable weather destroys crops along with many homes.

Finally, it is important to note that El Nino is a fair prediction of the effects of climate change in Uganda, reflecting the current trends happening. Floods, droughts, hail storms, rain, high temperatures, receding water levels, increased disease, loss of major crops, and landslides are dangers the country may soon face. Through design of the build environment, partnered with other divisions of health and epidemiology, disease prevention and resilience must become a priority.