A Study of Weather Related Respiratory Diseases in Eco-climatic Zones

We study the temporal pattern of selected respiratory diseases and the influence of specific weather parameters on their morbidity in two eco-climatic zones in Nigeria for the period 19962006. Out of 2,056 and 2,647 cases of respiratory diseases (bronchial asthma, bronchopneumonia, lobar pneumonia, bronchiolitis, cardiac asthma, pulmonary tuberculosis, sinusitis, tonsillitis and upper respiratory tract infection) reported in Humid-forest (Ile-Ife) and Derived-savanna (Ilorin), respectively, 60% and 48% for each region respectively occurred in subjects of age less than ten years. Whereas, for patients aged 80 years and above it accounted for 1.2% and 1.7% in respective zones. There is a significant (p<0.01) variation in the morbidity pattern of respiratory diseases among age groups at each location. Males in humid forest and derived savanna reported respectively about 56.7% and 59.0% of the specific respiratory diseases. Out of all the respiratory diseases considered, bronchial asthma, lobar pneumonia, sinusitis and tonsillitis are statistically significant with weather variables in humid forest (Ile-Ife) while bronchial asthma, bronchopneumonia, cardiac asthma and lobar pneumonia are statistically significant with maximum air temperature (p < 0.05) in derived savanna (Ilorin). Further analysis showed that maximum air temperature accounted for 46.6% (r=0.68) and 43.3% (r=0.66) of bronchial asthma (p< 0.05) at humid forest and derived savanna, respectively. Similarly, air temperature explained 39.1%, 39.8% and 43.8% of bronchopneumonia, cardiac asthma and lobar pneumonia occurrence in derived savanna respectively. Relative humidity accounted for 36.3% of tonsillitis morbidity and in combination with wind speed, explained 82.1% of lobar pneumonia in humid forest. Maximum temperature and wind speed accounted for 69.3% of the occurrence of sinusitis at humid forest. The study advocates the importance of inclusion of thermal environment into monitoring and surveillance of respiratory diseases transmission.