The pattern of variation between diarrhoea and malaria coexistence with corresponding risk factors in, Chikhwawa, Malawi: a bivariate multilevel analysis

Developing countries face a huge burden of infectious diseases, a number of which co-exist. This paper estimates the pattern and variation of malaria and diarrhea coexistence in Chikhwawa, a district in Southern Malawi using bivariate multilevel modelling with Bayesian estimation. A probit link was employed to examine hierarchically built data from a survey of individuals (n = 6,727) nested within households (n = 1,380) nested within communities (n = 33). Results show significant malaria [σ²_ul = 0.901 (95% CI : 0.746,1.056) ] and diarrhea [σ²_ul = 1.009  (95% CI : 0.860,1.158) ] variations with a strong correlation between them [r_u^(1,2) = 0.565 ] at household level. There are significant malaria [σ²_v1 = 0.053 (95% CI : 0.018,0.088) ] and diarrhea [σ²_v2 = 0.099 (95% CI : 0.030,0.168 ] variations at community level but with a small correlation [r_v^(1,2) = 0.124 ] between them. There is also significant correlation between malaria and diarrhea at individual level [r_e^(1,2) 0.241]. These results suggest a close association between reported malaria-like illness and diarrheal illness especially at household and individual levels in Southern Malawi.