The Role of Weather in the Spread of Lassa Fever in Parts of Northern Nigeria

Abstract

This study employed multiple regression analysis to evaluate the impact of weather variables (relative humidity, rainfall amount and maximum temperature) on the reported number of Lassa fever cases and to assess the strength of relationship between same for thirteen states in northern Nigeria (Adamawa, Bauchi, Jigawa, Borno, Kaduna, Katsina, Kano, Kebbi, Sokoto, Taraba, Yobe, Zamfara and Gombe states) over a five-year period (2016-2020). Secondary data on Lassa fever disease and weather variables were described on a weekly basis from the data base of the Nigeria Centre for disease control (NCDC) as well as weather variables from the National Aeronautics Space Administration, U.S.A. (NASA).  The study seeks to establish the role of weather in the occurrence of Lassa fever in parts of Northern Nigeria and also to evaluate the impact of these weather variables on the occurrence of the disease. The study reveals that these weather variables accounted for 70% (r2=0.70) of the cases of Lassa fever reported in Northern Nigeria. It occurred all year round but cases peaked during the dry months, from December to March where relative humidity is low and rainfall amount small. At confidence level of 0.05, there was a significant (p=0.000) strong positive correlation of r=0.83 between Lassa fever cases and weather variables. Of the three weather parameters, maximum temperature had a weak positive and insignificant (p=0.3) relationship with Lassa fever while relative humidity and rainfall had strong and moderate negative relationships of r = -0.7 and r = -0.5 respectively which were both significant at (r2=0.000).  In conclusion, there is need to cultivate sufficient preparedness strategies in order to cope with the burden to ensure general wellbeing of people resident in these affected areas using these weather parameters.