CD4 and Opportunistic infection: ART: Antiretroviral therapy; BMI: Body Mass Index; CD4: Cluster Differentiation 4; CPT: Cotrimoxazole preventive therapy; DIC: Deviance Information Criterion; E.C: Ethiopian Calendar; FMOH: Federal Ministry of Health; HIV: Human Immune Deficiency Virus; IPT: Isoniazid preventive therapy; MRN: medical registration number; OCC: Other Comorbid Condition; OIs: Opportunistic Infections; PLWHIV: People Living With Human Immune Deficiency Virus; RBC: Red Blood Cell; TB: Tuberculosis; UNAIDS: The Joint United Nations Program on HIV/AIDS; WBC: White Blood Cell; WHO: World Health Organization.