ISDS Annual Conference Proceedings 2019. This is an Open Access article distributed under the terms of the Creative Commons 

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Online Journal of Public Health Informatics * ISSN 1947-2579 * http://ojphi.org * 11(1): e397, 2019 

 

ISDS 2019 Conference Abstracts 

Malaria burden through routing reporting: Relationship 
between incidence estimates 

Simon P. Kigozi1, 2 

1
Disease Control, London School of Hygiene & Tropical Medicine, Kampala, Uganda, 

2
Infectious disease Research Collaboration, Kampala, 

Uganda 

Objective 

To evaluate the relationship between test positivity rate and test-confirmed malaria case rate both in time and space, to 

provide better understanding of the utility and representativeness of HMIS data for changing malaria burden in endemic  

settings. 

Introduction 

Routine surveillance is an important global strategy for malaria control. However, there have been few studies comparing 

routine indicators of burden, including test positivity rate (TPR) and test-confirmed malaria case rates (CMCR), over spatial 

and temporal scales. 

Methods 

We studied the relationship between these indicators in children under 11 years, presenting with suspected malaria at outpatient 

department clinics in three health facilities in locations of varying transmission across Uganda. We evaluated trends in each 

indicator over time (month) and space (by village) and explored the relationship between them using multivariable regression 

models. 

Results 

Overall, 65,710 participants visited the three clinics during the study period. Pairwise relationships between TPR and CMCR 

showed good agreement over time, particularly for TPR’s below 50% and during low transmission seasons, but the 

relationship was complex at the village level. Village mean annual TPR remained  constant while CMCR was drastically 

reduced with increased distance from health facility, highlighting health care access’ importance. The forth quartile of distance 

from the health facility, relative to the first, was associated with reduction in CMCR with IRR of 0.40 (95% CI: 0.23 -0.63; 

p=0.001), 0.55 (0.40-0.75; p<0.001), and 0.25 (0.12-0.51; p<0.001) for Nagongera, Kihihi, and Walukuba respectively. 

Regression analysis results emphasized a non-linear (cubic) relationship between TPR and CMCR, after accounting for 

month, village, season and demographic factors. 

Conclusions 

Altogether, these results suggested a strong non-linear relationship between the two indicators regardless of transmission 

setting. However, the current malaria surveillance system in Uganda may under-represent burden from patients living furthest 

from sentinel health facilities. 

Acknowledgement 

We would like to thank all the: staff at the three health centre IV’s of Nagongera, Walukuba, and Kihihi; the Uganda malaria 

surveillance project data officers at these sites; and, the wider UMSP/IDRC team that have been instrumental to the smooth 

running of this surveillance work over the years. 

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