Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
Epidemics. 2012 Mar;4(1):1-8. doi: 10.1016/j.epidem.2011.10.003. Epub 2011 Nov 7.
Recent declines in malaria burden in many parts of the world have prompted consideration of how interruption of Plasmodium falciparum transmission could be maintained, if achieved, and notably whether large-scale vector control could be replaced with surveillance. This information is essential for elimination feasibility assessments and planning. The risk of re-establishment of transmission depends mainly on vectorial capacity (receptivity), likely to rebound once vector control is removed, the rate of importation of infections (vulnerability), the capacity to detect and treat infections and the level of immunity in infected individuals. Timely detection and removal of new infections is likely to be critical to prevent re-establishment of transmission. We assess, through mathematical modeling and simulation, which levels of case detection and treatment (case management) are required to prevent re-establishment of transmission of P. falciparum after local interruption of transmission has been achieved, in settings with varying receptivity and vulnerability. We find that, even at rather low levels of receptivity, case management alone cannot reliably prevent re-establishment of P. falciparum malaria transmission in the face of medium to high importation rates. Thus, if vector control is to be discontinued, preventing the importations by controlling transmission in source areas will generally be necessary for preventing reintroduction in such settings, and cannot be substituted by very high levels of case management coverage.
近年来，世界许多地区疟疾负担有所下降，促使人们考虑如果实现了疟原虫传播的中断，如何维持这种状态，特别是大规模的病媒控制是否可以被监测所取代。这些信息对于消除可行性评估和规划至关重要。传播的重新建立风险主要取决于媒介能力（易感性），一旦去除媒介控制，很可能会反弹；感染的输入率（脆弱性）；检测和治疗感染的能力以及受感染者的免疫水平。及时发现和消除新的感染很可能对防止传播的重新建立至关重要。我们通过数学建模和模拟评估了在具有不同易感性和脆弱性的环境中，在实现局部传播中断后，需要达到何种水平的病例检测和治疗（病例管理），才能防止疟原虫传播的重新建立。我们发现，即使在易感性较低的情况下，在中等至高输入率的情况下，仅病例管理本身也不能可靠地防止疟原虫疟疾传播的重新建立。因此，如果要停止病媒控制，在这种情况下，一般需要通过控制源头地区的传播来防止输入，而不能用非常高的病例管理覆盖率来替代。
