Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
University of Basel, Basel, Switzerland.
PLoS Negl Trop Dis. 2022 Jun 29;16(6):e0010541. doi: 10.1371/journal.pntd.0010541. eCollection 2022 Jun.
In areas with both Plasmodium vivax and Plasmodium falciparum malaria, interventions can reduce the burden of both species but the impact may vary due to their different biology. Knowing the expected relative impact on the two species over time for vector- and drug-based interventions, and the factors affecting this, could help plan and evaluate intervention strategies.
For three interventions (treated bed nets (ITN), mass drug administration (MDA) and indoor residual spraying (IRS)), we identified studies providing information on the proportion of clinical illness and patent infections attributed to P. vivax over time using a literature search. The change in the proportion of malaria attributed to P. vivax up to two years since implementation was estimated using logistic regression accounting for clustering with random effects. Potential factors (intervention type, coverage, relapse pattern, transmission intensity, seasonality, initial proportion of P. vivax and round of intervention) were assessed.
In total there were 55 studies found that led to 72 series of time-points for clinical case data and 69 series for patent infection data. The main reason of study exclusion was insufficient information on interventions. There was considerable variation in the proportion of malaria attributed to P. vivax over time by study and location for all of the interventions. Overall, there was an increase apart from MDA in the short-term. The potential factors could not be ruled in or out. Although not consistently significant, coverage, transmission intensity and relapse pattern are possible factors that explain some of the variation found.
While there are reports of an increase in the proportion of malaria due to P. vivax following interventions in the long-term, there was substantial variation for the shorter time-scales considered in this study (up to 24 months for IRS and ITN, and up to six months for MDA). The large variability points to the need for the monitoring of both species after an intervention. Studies should report intervention timing and characteristics to allow inclusion in systematic reviews.
在同时存在间日疟原虫和恶性疟原虫疟疾的地区，干预措施可以减轻这两种疾病的负担，但由于它们的生物学特性不同，其影响可能有所不同。了解基于媒介和药物的干预措施对这两种疾病的预期相对影响及其影响因素，有助于规划和评估干预策略。
我们通过文献检索，确定了三项干预措施（驱虫蚊帐、大规模药物治疗和室内滞留喷洒）的研究，这些研究提供了有关时间推移时间日疟原虫引起的临床疾病和带虫感染比例的信息。使用逻辑回归，考虑到随机效应的聚类，估算了干预实施后两年内疟疾归因于间日疟原虫的比例变化。评估了潜在因素（干预类型、覆盖率、复发模式、传播强度、季节性、间日疟原虫初始比例和干预轮次）。
共发现 55 项研究，涉及 72 个临床病例数据系列和 69 个带虫感染数据系列。研究排除的主要原因是干预措施的信息不足。所有干预措施中，不同研究和地点间疟疾归因于间日疟原虫的比例随时间变化差异较大。总体而言，除大规模药物治疗外，短期内均有增加。潜在因素无法排除或证实。虽然并非始终具有统计学意义，但覆盖率、传播强度和复发模式可能是解释部分发现的变化的因素。
虽然有报道称干预后间日疟原虫引起的疟疾比例增加，但本研究考虑的较短时间范围内（室内滞留喷洒和驱虫蚊帐最长 24 个月，大规模药物治疗最长 6 个月）存在很大差异。这种巨大的可变性表明，干预后需要对这两种疾病进行监测。研究应报告干预时间和特征，以便纳入系统评价。
