Center for Infectious Disease Dynamics & Department of Entomology, Merkle Lab, Penn State University, University Park, PA 16802, USA.
Malar J. 2011 Jul 7;10:183. doi: 10.1186/1475-2875-10-183.
The majority of the mosquito and parasite life-history traits that combine to determine malaria transmission intensity are temperature sensitive. In most cases, the process-based models used to estimate malaria risk and inform control and prevention strategies utilize measures of mean outdoor temperature. Evidence suggests, however, that certain malaria vectors can spend large parts of their adult life resting indoors.
If significant proportions of mosquitoes are resting indoors and indoor conditions differ markedly from ambient conditions, simple use of outdoor temperatures will not provide reliable estimates of malaria transmission intensity. To date, few studies have quantified the differential effects of indoor vs outdoor temperatures explicitly, reflecting a lack of proper understanding of mosquito resting behaviour and associated microclimate.
Published records from 8 village sites in East Africa revealed temperatures to be warmer indoors than outdoors and to generally show less daily variation. Exploring the effects of these temperatures on malaria parasite development rate suggested indoor-resting mosquitoes could transmit malaria between 0.3 and 22.5 days earlier than outdoor-resting mosquitoes. These differences translate to increases in transmission risk ranging from 5 to approaching 3,000%, relative to predictions based on outdoor temperatures. The pattern appears robust for low- and highland areas, with differences increasing with altitude.
Differences in indoor vs outdoor environments lead to large differences in the limits and the intensity of malaria transmission. This finding highlights a need to better understand mosquito resting behaviour and the associated microclimate, and to broaden assessments of transmission ecology and risk to consider the potentially important role of endophily.
大多数决定疟疾传播强度的蚊子和寄生虫生活史特征对温度敏感。在大多数情况下，用于估计疟疾风险并为控制和预防策略提供信息的基于过程的模型都利用了室外平均温度的测量值。然而，有证据表明，某些疟疾媒介可以在很大程度上在室内度过成虫期。
如果大量蚊子在室内休息，并且室内条件与室外条件有明显差异，那么简单地使用室外温度将无法可靠估计疟疾的传播强度。迄今为止，很少有研究明确量化室内与室外温度的差异影响，这反映了对蚊子休息行为及其相关小气候缺乏适当理解。
来自东非 8 个村庄的已发表记录显示，室内温度比室外高，且通常日变化较小。探索这些温度对疟原虫发育率的影响表明，室内休息的蚊子可能比室外休息的蚊子提前 0.3 至 22.5 天传播疟疾。与基于室外温度的预测相比，这些差异导致传播风险增加 5%至近 3000%。对于低地和高地，这种模式似乎都是稳健的，差异随海拔升高而增加。
室内与室外环境的差异导致疟疾传播的极限和强度存在很大差异。这一发现强调了需要更好地理解蚊子的休息行为及其相关的小气候，并扩大对传播生态学和风险的评估，以考虑内栖性的潜在重要作用。
