Spatiotemporal Clustering Analysis of Malaria Infection in Pakistan.

Muhammad Farooq Umer,Wenbiao Hu,Abdul Majeed,Guihua Zhuang,Xin Qi,Shumaila Zofeen

doi:10.3390/ijerph15061202

Abstract

Despite tremendous progress, malaria remains a serious public health problem in Pakistan. Very few studies have been done on spatiotemporal evaluation of malaria infection in Pakistan. The study aimed to detect the spatiotemporal pattern of malaria infection at the district level in Pakistan, and to identify the clusters of high-risk disease areas in the country. Annual data on malaria for two dominant species (Plasmodium falciparum, Plasmodium vivax) and mixed infections from 2011 to 2016 were obtained from the Directorate of Malaria Control Program, Pakistan. Population data were collected from the Pakistan Bureau of Statistics. A geographical information system was used to display the spatial distribution of malaria at the district level throughout Pakistan. Purely spatiotemporal clustering analysis was performed to identify the high-risk areas of malaria infection in Pakistan. A total of 1,593,409 positive cases were included in this study over a period of 6 years (2011–2016). The maximum number of P. vivax cases (474,478) were reported in Khyber Pakhtunkhwa (KPK). The highest burden of P. falciparum (145,445) was in Balochistan, while the highest counts of mixed Plasmodium cases were reported in Sindh (22,421) and Balochistan (22,229), respectively. In Balochistan, incidence of all three types of malaria was very high. Cluster analysis showed that primary clusters of P. vivax malaria were in the same districts in 2014, 2015 and 2016 (total 24 districts, 12 in Federally Administered Tribal Areas (FATA), 9 in KPK, 2 in Punjab and 1 in Balochistan); those of P. falciparum malaria were unchanged in 2012 and 2013 (total 18 districts, all in Balochistan), and mixed infections remained the same in 2014 and 2015 (total 7 districts, 6 in Balochistan and 1 in FATA). This study indicated that the transmission cycles of malaria infection vary in different spatiotemporal settings in Pakistan. Efforts in controlling P. vivax malaria in particular need to be enhanced in high-risk areas. Based on these findings, further research is needed to investigate the impact of risk factors on transmission of malaria in Pakistan.

Highlights

Malaria is a deadly vector-borne infectious disease, rendering around 42% of the world’s population at risk [1]
Our study confirmed the occurrence of three species of malaria (P. vivax, P. falciparum and mixed Plasmodium) in the country, and incidence of P. vivax malaria was significantly higher than for the other two species [39,40]
Spatial distribution of the most significant high-risk clusters of malaria by species exhibited that P. vivax primary clusters comprised districts in FATA and KPK, P. falciparum primary clusters were mainly in Balochistan, while mixed Plasmodium primary clusters included districts in Sindh and Balochistan

Summary

Introduction

Malaria is a deadly vector-borne infectious disease, rendering around 42% of the world’s population at risk [1]. In the year 2016, malaria resulted in 216 million cases and 445,000 deaths worldwide [2]. Malaria in humans is predominantly due to Plasmodium falciparum and Plasmodium vivax, which are transmitted mostly by the same species of the genus Anopheles [2,3]. Res. Public Health 2018, 15, 1202; doi:10.3390/ijerph15061202 www.mdpi.com/journal/ijerph

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