Increasing trends of malaria in a border area of the Greater Mekong Subregion

Jinting Geng,Liwang Cui,Jiaqi Zhang,Zhaoqing Yang,Yaming Cao,Yan Zhao,Myat Phone Kyaw,Cuiying Li,Qinghui Wang,Shiling Xu,Pallavi Malla

doi:10.1186/s12936-019-2924-6

Abstract

BackgroundIntensive malaria transmission along international borders is a significant impediment to malaria elimination in the Greater Mekong Subregion (GMS) of Southeast Asia. Passive case detection (PCD) was used to study the dynamics and trends of malaria transmission at the China–Myanmar border to provide epidemiologic information for improved malaria control.MethodsPCD was conducted in one hospital and 12 clinics near the Laiza town in northeast Myanmar from 2011 to 2016. Clinical malaria was diagnosed by microscopy and demographic information was captured using a structured questionnaire at the time of the patient’s presentation for care.ResultsOver the study period, 6175 (19.7%) malaria cases were confirmed by microscopy from 31,326 suspected cases. The four human malaria parasite species were all identified, with Plasmodium vivax and Plasmodium falciparum accounting for 5607 (90.8%) and 481 (7.8%) of the confirmed cases, respectively. In contrast to the steady decline of malaria in the general GMS, the study site had an upward trend of malaria incidence with vivax malaria outbreaks in 2013 and 2016. Adult males, children under the age of 15, and those with occupations such as farming, being a soldier or student, had significantly higher risks of clinical malaria compared to having fevers from other aetiologies. A self-reported history of clinical malaria was also associated with a higher risk of confirmed malaria.ConclusionsThe China–Myanmar border area has experienced an overall upward trend of malaria incidence in recent years with P. vivax becoming the predominant species. Evidence-based control strategies need to focus on high-risk populations.

Highlights

Intensive malaria transmission along international borders is a significant impediment to malaria elimination in the Greater Mekong Subregion (GMS) of Southeast Asia
Demographics of suspected and confirmed malaria cases During the six-year study period, a total of 31,326 febrile patients suspected of having malaria presented to the Laiza township hospital and nearby clinics in the northeastern Myanmar border
Risk factors for clinical malaria Whereas males experienced a higher odds of vivax malaria [odds ratio (OR) = 1.16], this risk was more pronounced in males for falciparum malaria [OR = 2.20] (Table 3)

Summary

Introduction

Intensive malaria transmission along international borders is a significant impediment to malaria elimination in the Greater Mekong Subregion (GMS) of Southeast Asia. Between 2000 and 2015, malaria incidence declined from an estimated 237 million cases to 211 million cases and mortality decreased by 29% globally These reductions appear to have plateaued, with 2016 and 2017 reporting a slight increase in the number of malaria cases [1]. All reported cases in China were imported from endemic areas outside its borders. In this elimination phase, close surveillance at malaria transmission hotspots along international borders is critical to prevent cross-border re-introduction of the malaria parasites [7]

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Discussion

Conclusion