The clinical burden of malaria in Nairobi: a historical review and contemporary audit

Abstract

Background: Widespread urbanization over the next 20 years has the potential to drastically change the risk of malaria within Africa. The burden of the disease, its management, risk factors and appropriateness of targeted intervention across varied urban environments in Africa remain largely undefined. This paper presents a combined historical and contemporary review of the clinical burden of malaria within one of Africa's largest urban settlements, Nairobi, Kenya.

Methods: A review of historical reported malaria case burdens since 1911 within Nairobi was undertaken using archived government and city council reports. Contemporary information on out-patient case burdens due to malaria were assembled from the National Health Management and Information System (HMIS). Finally, an audit of 22 randomly selected health facilities within Nairobi was undertaken covering 12 months 2009-2010. The audit included interviews with health workers, and a checklist of commodities and guidelines necessary to diagnose, treat and record malaria.

Results: From the 1930's through to the mid-1960's malaria incidence declined coincidental with rapid population growth. During this period malaria notification and prevention were a priority for the city council. From 2001-2008 reporting systems for malaria were inadequate to define the extent or distribution of malaria risk within Nairobi. A more detailed facility review suggests, however that malaria remains a common diagnosis (11% of all paediatric diagnoses made) and where laboratories (n = 15) exist slide positivity rates are on average 15%. Information on the quality of diagnosis, slide reading and whether those reported as positive were imported infections was not established. The facilities and health workers included in this study were not universally prepared to treat malaria according to national guidelines or identify foci of risks due to shortages of national first-line drugs, inadequate record keeping and a view among some health workers (17%) that slide negative patients could still have malaria.

Conclusion: Combined with historical evidence there is a strong suggestion that very low risks of locally acquired malaria exist today within Nairobi's city limits and this requires further investigation. To be prepared for effective prevention and case-management of malaria among a diverse, mobile population in Nairobi requires a major paradigm shift and investment in improved quality of malaria diagnosis and case management, health system strengthening and case reporting.

Figure 1

A division map of Nairobi showing the location of public health facilities in Nairobi. The red dot represents health facilities selected for the survey and the pink dots represent other health facilities run by MoMS or the LA in Nairobi. Surveyed facilities are as follows: 1 = Kangemi Health Centre; 2 = Dandora 2 Health Centre; 3 = Pumwani Dispensary; 4 = Lower Kabete; Health Centre; 5 = Kaloleni Sub-Health Centre; 6 = Jericho Health Centre; 7 = Waithaka Health Centre; 8 = Karen Health Centre; 9 = Ngong Road Health Centre; 10 = Langata Health Centre; 11 = Kahawa Health Centre; 12 = Kamiti Health Centre; 13 = Railways Training School Clinic; 14 = Kibera DO Health Centre; 15 = Westlands Health Centre; 16 = Karura Health Centre; 17 = Riruta Health Centre; 18 = Kariobangi Health Centre; 19 = Locomotive Health Centre; 20 = Mji Wa Huruma Dispensary; 21 = Soweto/Kayole Dispensary; 22 = Makadara Health Centre.

Figure 2

Malaria morbidity among residents in Nairobi between 1930 and 1964. The blue line represents malaria cases among Europeans; the red line represents cases among Asians and the green line that among Africans. (Data assembled Annual Reports of the Medical Officer of Health 1930-1964; missing 1940 - 1945).