Slater Hannah C, Griffin Jamie T, Ghani Azra C, Okell Lucy C
Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, W2 1PG, UK.
Malar J. 2016 Jan 6;15:10. doi: 10.1186/s12936-015-1075-7.
Artemisinin and partner drug resistant malaria parasites have emerged in Southeast Asia. If resistance were to emerge in Africa it could have a devastating impact on malaria-related morbidity and mortality. This study estimates the potential impact of artemisinin and partner drug resistance on disease burden in Africa if it were to emerge.
Using data from Asia and Africa, five possible artemisinin and partner drug resistance scenarios are characterized. An individual-based malaria transmission model is used to estimate the impact of each resistance scenario on clinical incidence and parasite prevalence across Africa. Artemisinin resistance is characterized by slow parasite clearance and partner drug resistance is associated with late clinical failure or late parasitological failure.
Scenarios with high levels of recrudescent infections resulted in far greater increases in clinical incidence compared to scenarios with high levels of slow parasite clearance. Across Africa, it is estimated that artemisinin and partner drug resistance at levels similar to those observed in Oddar Meanchey province in Cambodia could result in an additional 78 million cases over a 5 year period, a 7% increase in cases compared to a scenario with no resistance. A scenario with high levels of slow clearance but no recrudescence resulted in an additional 10 million additional cases over the same period.
Artemisinin resistance is potentially a more pressing concern than partner drug resistance due to the lack of viable alternatives. However, it is predicted that a failing partner drug will result in greater increases in malaria cases and morbidity than would be observed from artemisinin resistance only.
东南亚已出现对青蒿素及其联合用药产生耐药性的疟原虫。如果非洲也出现耐药性，可能会对疟疾相关的发病率和死亡率产生毁灭性影响。本研究估计了青蒿素及其联合用药耐药性在非洲出现后对疾病负担的潜在影响。
利用来自亚洲和非洲的数据，描述了五种可能的青蒿素及其联合用药耐药性情况。采用基于个体的疟疾传播模型来估计每种耐药性情况对非洲临床发病率和寄生虫流行率的影响。青蒿素耐药性的特征是寄生虫清除缓慢，联合用药耐药性与临床晚期失败或寄生虫学晚期失败有关。
与寄生虫清除缓慢程度高的情况相比，复发感染水平高的情况导致临床发病率的增加幅度要大得多。据估计，在非洲，青蒿素及其联合用药的耐药性水平若与柬埔寨奥多棉吉省观察到的水平相似，在5年期间可能会额外增加7800万病例，与无耐药性的情况相比，病例数增加7%。在同一时期，寄生虫清除缓慢程度高但无复发的情况会额外增加1000万病例。
由于缺乏可行的替代药物，青蒿素耐药性可能是比联合用药耐药性更紧迫的问题。然而，预计联合用药失效导致的疟疾病例和发病率增加幅度将大于仅由青蒿素耐药性导致的增加幅度。
