Abstract | BACKGROUND: Border malaria, a shared phenomenon in the Greater Mekong Sub-region of Southeast Asia, is a major obstacle for regional malaria elimination. Along the China-Myanmar border, an additional problem arose as a result of the settlement of internally displaced people ( IDP) in the border region. Since asymptomatic malaria significantly impacts transmission dynamics, assessment of the prevalence, dynamics and risk factors of asymptomatic malaria infections is necessary. METHODS: Cross-sectional surveys were carried out in 3 seasons (March and April, July and November) and 2 sites (villages and IDP camps) in 2015. A total of 1680 finger-prick blood samples were collected and used for parasite detection by microscopy and nested RT-PCR (nRT-PCR). Logistic regression models were used to explore the risk factors associated with asymptomatic malaria at individual and household levels. RESULTS: The prevalence of asymptomatic Plasmodium infections was 23.3% by nRT-PCR, significantly higher than that detected by microscopy (1.5%). The proportions of Plasmodium vivax, Plasmodium falciparum and mixed-species infections were 89.6, 8.1 and 2.3%, respectively. Asymptomatic infections showed obvious seasonality with higher prevalence in the rainy season. Logistic regression analysis identified males and school children (≤ 15 years) as the high-risk populations. Vector-based interventions, including bed net and indoor residual spray, were found to have significant impacts on asymptomatic Plasmodium infections, with non-users of these measures carrying much higher risks of infection. In addition, individuals living in poorly constructed households or farther away from clinics were more prone to asymptomatic infections. CONCLUSIONS: Sub-microscopic Plasmodium infections were highly prevalent in the border human populations from IDP camps and surrounding villages. Both individual- and household-level risk factors were identified, which provides useful information for identifying the high-priority populations to implement targeted malaria control.
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Authors | Yan Zhao, Jie Zeng, Yonghong Zhao, Qingyang Liu, Yang He, Jiaqi Zhang, Zhaoqing Yang, Qi Fan, Qinghui Wang, Liwang Cui, Yaming Cao |
Journal | Malaria journal
(Malar J)
Vol. 17
Issue 1
Pg. 247
(Jul 04 2018)
ISSN: 1475-2875 [Electronic] England |
PMID | 29973194
(Publication Type: Journal Article)
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Topics |
- Adolescent
- Adult
- Asymptomatic Infections
(epidemiology)
- China
(epidemiology)
- Coinfection
(epidemiology, parasitology)
- Cross-Sectional Studies
- Female
- Humans
- Malaria, Falciparum
(epidemiology, parasitology)
- Malaria, Vivax
(epidemiology, parasitology)
- Male
- Myanmar
(epidemiology)
- Plasmodium falciparum
(isolation & purification)
- Plasmodium vivax
(isolation & purification)
- Prevalence
- Risk Factors
- Seasons
- Young Adult
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