Trends in outpatient malaria cases, following Mass Long Lasting Insecticidal Nets (LLIN) distribution in epidemic prone and endemic areas of Kenya

Abstract

Background: There were over 6 million case of malaria reported in Kenya in 2015 and it remains a major public health priority despite significant investments in interventions to control and prevent infections in high risk areas.

Objectives: To analyse trends from 2011-2015, and report i) outpatient department (OPD) malaria case prevalence, ii) the proportion of confirmed malaria cases of all OPD cases stratified by age category, and iii) the proportion of the population potentially protected by long-lasting insecticidal nets (LLINs), following mass distribution of LLINs in malaria epidemic prone and endemic areas.

Design: A retrospective study.

Setting: Kenya’s Coast endemic, Lake endemic and Highland epidemic zones.

Subjects: All outpatient malaria cases reported in the District Health Information System.

Results: The proportion of people who received mass LLINs ranged from 80-95% in epidemic prone and endemic areas of Kenya. The coastal endemic zone had the lowest number of reported malaria cases at almost 840,000 in 2011, compared with the lake endemic zone which reported 4.3 million total cases. Confirmed malaria cases of all the OPD morbidity increased by 1%, 20% and 4% in the Highland epidemic prone, the Lake and Coast endemic region in 2011 to 2015, respectively. There was a trend towards fewer cases across all three high risk regions from 2012-2013, but this reversed with increasing cases being reported in 2014-2015.

Conclusion: Despite a high LLIN coverage malaria cases increased over time. There is need for patient-level studies to assess if LLINs are being used appropriately and to look towards other complimentary malaria prevention strategies.