Health Forefront Organization, Phnom Penh, Cambodia.
Malaria Elimination Initiative, University of California, San Francisco, CA, USA.
Malar J. 2023 Jun 23;22(1):193. doi: 10.1186/s12936-023-04630-2.
Malaria is a mosquito-borne disease that is one of the most serious public health issues globally and a leading cause of mortality in many developing countries worldwide. Knowing the prevalence of both symptomatic and asymptomatic malaria on a subnational scale allows for the estimation of the burden of parasitaemia present in the transmission system, enabling targeting and tailoring of resources towards greater impact and better use of available capacity. This study aimed to determine the PCR-based point prevalence of malaria infection, by parasite species, among three high-risk populations in Mondulkiri province, Cambodia: forest rangers, forest dwellers, and forest goers.
A cross-sectional survey was performed during the transmission season in November and December 2021. Blood samples collected on filter paper from participants (n = 1301) from all target groups were screened for Plasmodium spp using PCR.
Malaria prevalence among all study participants was 6.7% for any Plasmodium species. Malaria prevalence in the forest ranger group was 8.1%, was 6.8% in forest goers, and 6.4% in forest dwellers; all infections were asymptomatic. Plasmodium vivax was detected in all participant groups, while the few Plasmodium falciparum infections were found in goers and dwellers. 81% of all infections were due to P. vivax, 9% were due to P. falciparum, 3% due to Plasmodium cynomolgi, and the rest (7%) remained undefined. Gender was associated with malaria infection prevalence, with male participants having higher odds of malaria infection than female participants (OR = 1.69, 95% CI 1.08-2.64). Passively collected malaria incidence data from the Cambodian government were also investigated. Health facility-reported malaria cases, based on rapid diagnostic tests, for the period Jan-Dec 2021 were 521 Plasmodium vivax (0.89% prevalence), 34 P. falciparum (0.06%) and four P. falciparum + mixed (0.01%)-a total of 559 cases (0.95%) for all of Mondulkiri.
This reservoir of asymptomatic parasitaemia may be perpetuating low levels of transmission, and thus, new strategies are required to realize the goal of eliminating malaria in Cambodia by 2025.
疟疾是一种由蚊子传播的疾病，是全球最严重的公共卫生问题之一，也是全球许多发展中国家死亡的主要原因。在国家以下各级了解有症状和无症状疟疾的流行情况，可以估算出传播系统中寄生虫血症的负担，从而有针对性地调整资源，以实现更大的影响并更好地利用现有能力。本研究旨在确定柬埔寨蒙多基里省三个高危人群（护林员、森林居民和森林访客）中按寄生虫种属确定的基于聚合酶链反应（PCR）的疟疾感染现患率。
在 2021 年 11 月至 12 月的传播季节进行了横断面调查。从所有目标人群中采集滤纸采集的参与者（n=1301）的血液样本，使用 PCR 检测疟原虫属。
所有研究参与者的疟疾总流行率为 6.7%，任何一种疟原虫均为阳性。护林员组的疟疾流行率为 8.1%，访客为 6.8%，居民为 6.4%；所有感染均为无症状。所有参与者群体中均检测到间日疟原虫，而少数恶性疟原虫感染仅见于访客和居民。所有感染中，81%为间日疟原虫，9%为恶性疟原虫，3%为食蟹猴疟原虫，其余（7%）仍无法确定。性别与疟疾感染流行率有关，男性参与者感染疟疾的几率高于女性参与者（OR=1.69，95%CI 1.08-2.64）。还调查了柬埔寨政府被动收集的疟疾发病数据。2021 年 1 月至 12 月期间，根据快速诊断检测报告的卫生机构疟疾病例为 521 例间日疟原虫（0.89%的流行率）、34 例恶性疟原虫（0.06%）和 4 例恶性疟原虫+混合感染（0.01%）-蒙多基里共有 559 例（0.95%）。
这种无症状寄生虫血症的储存库可能使低水平传播持续存在，因此需要采取新的策略，以实现柬埔寨到 2025 年消除疟疾的目标。
