A case-control study of risk factors for Haemophilus influenzae type b disease in Navajo children

To understand the potential risk factors and protective factors for invasiv e Haemophilus influenzae type b (Hib) disease, we conducted a case-control study among Navajo children less than two years of age resident on the Nava jo Nation. We analyzed household interview data for 60 cases that occurred between August 1988 and February 1991, and for 116 controls matched by age, gender, and geographic location. The Hib vaccine recipients were excluded from the analyses. Conditional logistic regression models were fit to exami ne many variables relating to social and environmental conditions. Risk fac tors determined to be important were never breast fed (odds ratio [OR] = 3. 55, 95% confidence interval [CI] 1.52, 8.26), shared care with more than on e child less than two years of age (OR = 2.32, 95% CI = 0.91, 5.96); wood h eating (OR = 2.14, 95% CI = 0.91, 5.05); rodents in the home (OR = 8.18, 95 % CI = 0.83, 80.7); and any livestock near the home (OR = 2.18, 95% CI = 0. 94, 5.04).