BACKGROUND Adding 8-aminoquinoline to the treatment of falciparum, in addition to vivax malaria, in locations where infections with both species are prevalent could prevent vivax reactivation. The potential risk of haemolysis under a universal radical cure policy using 8-aminoquinoline needs to be weighed against the benefit of preventing repeated vivax episodes. Estimating the frequency of sequential Plasmodium vivax infections following either falciparum or vivax malaria episodes is needed for such an assessment. METHODS Quarterly surveillance data collected during a mass drug administration trial in the Greater Mekong Subregion in 2013-17 was used to estimate the probability of asymptomatic sequential infections by the same and different Plasmodium species. Asymptomatic Plasmodium infections were detected by high-volume ultrasensitive qPCR. Quarterly surveys of asymptomatic Plasmodium prevalence were used to estimate the probability of a P. vivax infection following Plasmodium falciparum and P. vivax infections. RESULTS 16,959 valid sequential paired test results were available for analysis. Of these, 534 (3%) had an initial P. falciparum monoinfection, 1169 (7%) a P. vivax monoinfection, 217 (1%) had mixed (P. falciparum + P. vivax) infections, and 15,039 (89%) had no Plasmodium detected in the initial survey. Participants who had no evidence of a Plasmodium infection had a 4% probability to be found infected with P. vivax during the subsequent survey. Following an asymptomatic P. falciparum monoinfection participants had a 9% probability of having a subsequent P. vivax infection (RR 2.4; 95% CI 1.8 to 3.2). Following an asymptomatic P. vivax monoinfection, the participants had a 45% probability of having a subsequent P. vivax infection. The radical cure of 12 asymptomatic P. falciparum monoinfections would have prevented one subsequent P. vivax infection, whereas treatment of 2 P. vivax monoinfections may suffice to prevent one P. vivax relapse. CONCLUSION Universal radical cure could play a role in the elimination of vivax malaria. The decision whether to implement universal radical cure for P. falciparum as well as for P. vivax depends on the prevalence of P. falciparum and P. vivax infections, the prevalence and severity of G6PD deficiency in the population and the feasibility to administer 8-aminoquinoline regimens safely. Trial registration ClinicalTrials.gov Identifier: NCT01872702, first posted June 7th 2013, https://clinicaltrials.gov/ct2/show/NCT01872702. This study was registered with ClinicalTrials.gov under NCT02802813 on 16th June 2016. https://clinicaltrials.gov/ct2/show/NCT02802813.

中文翻译：

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缅甸、越南、柬埔寨和老挝无症状恶性疟原虫和间日疟原虫感染后继发间日疟原虫感染的可能性。

背景技术除了间日疟之外，在两种疟疾感染流行的地区，在治疗恶性疟和间日疟时添加 8-氨基喹啉可以防止间日疟重新激活。在使用 8-氨基喹啉的通用根治策略下，需要权衡溶血的潜在风险和预防间日疟反复发作的益处。此类评估需要估计恶性疟或间日疟疾发作后连续间日疟原虫感染的频率。方法 使用 2013-17 年大湄公河次区域大规模药物管理试验期间收集的季度监测数据来估计相同和不同疟原虫种类无症状连续感染的概率。通过高容量超灵敏 qPCR 检测无症状疟原虫感染。无症状疟原虫流行率的季度调查用于估计恶性疟原虫和间日疟原虫感染后发生间日疟原虫感染的可能性。结果 16,959 个有效的连续配对测试结果可供分析。其中，534 例 (3%) 最初患有恶性疟原虫单一感染，1169 例 (7%) 患有间日疟原虫单一感染，217 例 (1%) 患有混合感染（恶性疟原虫 + 间日疟原虫），以及 15,039 例 (89%) ）在初步调查中没有检测到疟原虫。在随后的调查中，没有疟原虫感染证据的参与者有 4% 的可能性被发现感染间日疟原虫。在无症状恶性疟原虫单一感染后，参与者有 9% 的概率随后感染间日疟原虫（RR 2.4；95% CI 1.8 至 3.2）。在无症状间日疟原虫单一感染后，参与者有 45% 的可能性随后感染间日疟原虫。根治 12 例无症状恶性疟原虫单一感染可预防随后的 1 例间日疟原虫感染，而治疗 2 例间日疟原虫单一感染可能足以预防 1 例间日疟原虫复发。结论 普遍根治可以在消除间日疟疾方面发挥作用。是否对恶性疟原虫和间日疟原虫实施普遍根治的决定取决于恶性疟原虫和间日疟原虫感染的流行率、人群中 G6PD 缺乏症的流行率和严重程度以及施用 8-安全地使用氨基喹啉治疗方案。试验注册 ClinicalTrials.gov 标识符：NCT01872702，首次发布于 2013 年 6 月 7 日，https://clinicaltrials.gov/ct2/show/NCT01872702。本研究于 2016 年 6 月 16 日在 ClinicalTrials.gov 注册，编号为 NCT02802813。https://clinicaltrials.gov/ct2/show/NCT02802813。