Bulletin of the World Health Organization

Economic evaluation of delivering Haemophilus influenzae type b vaccine in routine immunization services in Kenya

Angela Oloo Akumu, Mike English, J Anthony G Scott, Ulla K Griffiths

Volume 85, Number 7, July 2007, 511-518

Table 1. Parameters for estimating burden of Hib disease in Kenya before and after vaccine introduction

Parameter Base case value Range used in uncertainty analysis Ref.
2004 birth cohort 1 322 000 – 24
Pentavalent & DTP+hep B vaccine coverage of 3rd dose 73% 70–75% 24
Types of Hib disease:
Meningitis of total invasive Hib disease 54% 52–56% 11
Non-meningitic invasive disease of total invasive Hib disease 46% – 11
Hib pneumonia:Hib meningitis cases 5:1 SD 0.5 5–7
Hib invasive disease hospital incidence:
Before Hib vaccine introduction 66 49.6–81.6 11
After Hib vaccine introduction 7.60 1.6–22.3 11
Access to health care for children < 5 years with Hib disease:
Hospital care 50% 30–70% 12,13
Outpatient care 25% 15–35% 12,13
No access to formal care 25% 15–35% 12,13
Case fatality rates for children < 5 years:
Hib meningitis + hospital treatment 17% 7–44% 16,25
Hib meningitis & non-meningitis invasive Hib disease + outpatient treatment 63% 40–90% 26
Hib meningitis & Hib non-meningitis invasive disease + no biomedical treatment 97% 80–100% Assumption
Non-meningitis invasive Hib disease + hospital treatment 26% 7–44% 9
Non-bacteraemic Hib pneumonia + hospital treatment 3.5% 2.5–4.5% Assumption
Non-bacteraemic Hib pneumonia + outpatient treatment only 7% 2.5–10% Assumption
Non-bacteraemic Hib pneumonia + no biomedical treatment 25% 15–35% 27

DTP, diphtheria-tetanus-pertussis; hep B, hepatitis B; Hib, Haemophilus influenzae type b; SD, standard deviation.