Revisiting the basic reproductive number for malaria and its implications for malaria control.
Revisiting the basic reproductive number for malaria and its implications for malaria control.
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DOI：
10.1371/journal.pbio.0050042
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发表时间：
2007-03
期刊：
影响因子：
9.8
通讯作者：
Hay SI
中科院分区：
文献类型：
--
作者：
Smith DL;McKenzie FE;Snow RW;Hay SI
疟疾控制成功的前景部分取决于疟疾的基本再生数 R 0 。在这里，我们以一种新颖的方式估计了 121 个非洲人口的 R 0 ，从而将疟疾的 R 0 估计数增加了一个数量级。估计数量从大约 1 到超过 3,000 不等。我们还考虑了数量为 H 的有限人口中的疟疾传播和控制。我们表明，经典公式近似了在一代寄生虫后可将感染追溯到一只蚊子的预期蚊子数量 Z 0(H)，但它们高估了每个感染者的预期感染人数 R 0(H)。异质咬合会增加 R 0 和 Z 0(H)，正如我们所表明的，但我们也表明它有时会降低 R 0(H)；被咬伤最多的人会感染许多媒介并吸收传染性叮咬。大范围的 R 0 估计有力地支持了长期持有的观点，即疟疾控制在其传播谱上提出了不同的挑战。在 R 0 最高的人群中，疟疾控制将需要针对被叮咬最严重的人群采取多种综合方法。因此，疟疾控制战略规划应考虑R 0、传播的空间规模、人口密度和异质性叮咬。每年疟疾导致超过一百万人死亡。控制这种疾病需要了解其传播方式。对于所有传染病，基本再生数 R 0 描述了传播的最重要方面。这是在一次疾病世代后可以将其感染直接追溯到单个宿主的预期宿主数量。对于媒介传播的疾病，例如疟疾，R 0 由经典公式给出。我们对非洲人群中恶性疟原虫疟疾的 R 0 进行了 121 次估计。估计范围从大约 1 到超过 3,000，提供的估计值比之前认为的要高得多。我们还表明，在少数人群中，当计算蚊子之间的感染时，R 0 近似于传播，但高估了人与人之间的传播。先前的研究表明，如果某些人被咬伤的次数多于其他人，传播就会放大。我们证实，这种异质性叮咬会放大蚊子之间的传播计数，但也会抑制人与人之间的传播计数。被蚊子叮咬最多的人既感染大量蚊子，又吸收许多传染性叮咬。这对于控制意味着什么？当 R 0 达到数千时，消除疟疾似乎是不可能的。然而，如果能够针对被咬伤最严重的人类进行传播，那么局部消除仍然是可以实现的。一种新的数学方法应用于 121 名感染疟疾的人群，将基本再生数（传播强度的指标）修正了一个数量级，这对有效控制疟疾产生了严重影响。
The prospects for the success of malaria control depend, in part, on the basic reproductive number for malaria, R 0. Here, we estimate R 0 in a novel way for 121 African populations, and thereby increase the number of R 0 estimates for malaria by an order of magnitude. The estimates range from around one to more than 3,000. We also consider malaria transmission and control in finite human populations, of size H. We show that classic formulas approximate the expected number of mosquitoes that could trace infection back to one mosquito after one parasite generation, Z 0(H), but they overestimate the expected number of infected humans per infected human, R 0(H). Heterogeneous biting increases R 0 and, as we show, Z 0(H), but we also show that it sometimes reduces R 0(H); those who are bitten most both infect many vectors and absorb infectious bites. The large range of R 0 estimates strongly supports the long-held notion that malaria control presents variable challenges across its transmission spectrum. In populations where R 0 is highest, malaria control will require multiple, integrated methods that target those who are bitten most. Therefore, strategic planning for malaria control should consider R 0, the spatial scale of transmission, human population density, and heterogeneous biting. Each year malaria results in more than a million deaths. Controlling this disease involves understanding its transmission. For all infectious disease, the basic reproductive number, R 0, describes the most important aspects of transmission. This is the expected number of hosts that can trace their infection directly back to a single host after one disease generation. For vector-borne diseases, such as malaria, R 0 is given by a classic formula. We made 121 estimates of R 0 for Plasmodium falciparum malaria in African populations. The estimates range from around one to over 3,000, providing much higher estimates than previously thought. We also show that in small human populations, R 0 approximates transmission when counting infections from mosquito to mosquito, but overestimates it from human to human. Previous studies showed that transmission is amplified if some humans are bitten more than others. We confirm that such heterogeneous biting amplifies transmission counting from mosquito to mosquito, but it can also dampen transmission counting from human to human. Humans who are bitten most both infect a large number of mosquitoes and absorb many infectious bites. What does this mean for control? When R 0 is in the thousands, eliminating malaria may seem impossible. If transmission from the humans who are bitten the most can be targeted, however, local elimination can still be within reach. A new mathematical approach applied to 121 human populations infected with malaria revises the basic reproductive number--an indication of the transmission intensity--up by an order of magnitude, with serious implications for effective malaria control.
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DOI：
10.4269/ajtmh.1988.39.135
发表时间：
1988-08-01
影响因子：
3.3
作者：
BURKOT, TR;GRAVES, PM;HEYWOOD, PF
通讯作者：
HEYWOOD, PF
DOI：
10.1016/s0035-9203(53)80005-2
发表时间：
1953-01-01
影响因子：
2.2
作者：
DAVIDSON, G;DRAPER, CC
通讯作者：
DRAPER, CC
影响因子：
2.3
作者：
Dietz, K
通讯作者：
Dietz, K
影响因子：
3.3
作者：
Conteh, L;Sharp, BL;Konar, S
通讯作者：
Konar, S
DOI：
10.1016/0035-9203(86)90199-9
发表时间：
1986-01-01
影响因子：
2.2
作者：
DYE, C;HASIBEDER, G
通讯作者：
HASIBEDER, G