Division of Health Systems, State Health Resource Centre, Raipur, Chhattisgarh, India.
Health Section, UNICEF, Chhattisgarh Field Office, Raipur, India.
PLoS One. 2023 Jul 19;18(7):e0287667. doi: 10.1371/journal.pone.0287667. eCollection 2023.
A key obstacle in the fight against malaria is afebrile malaria. It remains undiagnosed and, therefore, is invisible to the health system. Apart from being a serious illness, it contributes to increased transmission. Existing studies in India have not adequately reported afebrile malaria and its determinants, including the use of long-lasting insecticide-treated nets (LLINs). This study used six waves of mass screening, which were conducted by the state government in the high-malaria-burden region of Chhattisgarh, a state in India, in 2020, 2021, and 2022. Each round of data collection included more than 15000 individuals. Descriptive statistics were used to analyse key indicators of malaria prevalence and LLIN use. Multivariate analyses were performed to identify the determinants of afebrile malaria and LLIN use. Malaria prevalence in the afebrile population varied from 0.6% to 1.4% across the different waves of mass screening. In comparison, malaria positivity among febrile individuals was greater than 33% in each wave. Afebrile malaria contributed to 19.6% to 47.2% of the overall malaria burden in the region. Indigenous communities (scheduled tribes) were more susceptible to malaria, including afebrile malaria. Individuals using LLINs were less likely to be affected by afebrile malaria. Overall, 77% of the individuals used LLINs in early monsoon season, and in winter the rate was lower at 55%. LLIN use was significantly associated with the number of LLINs the households received from the government. Although fever continues to be a primary symptom of malaria, afebrile malaria remains a significant contributor to the malaria burden in the region. The free distribution of LLINs should be expanded to include high-burden populations. Global policies must include strategies for surveillance and control of afebrile malaria in high-burden areas.
疟疾防治的一个关键障碍是无热疟疾。它未被诊断出来，因此在卫生系统中无法被发现。除了是一种严重疾病外，它还会导致传播增加。印度现有的研究没有充分报告无热疟疾及其决定因素，包括使用长效驱虫蚊帐（LLINs）。本研究使用了六轮大规模筛查，这些筛查是由印度恰蒂斯加尔邦高疟疾负担地区的邦政府在 2020 年、2021 年和 2022 年进行的。每一轮数据收集都包括超过 15000 人。描述性统计用于分析疟疾流行率和 LLIN 使用的关键指标。进行多变量分析以确定无热疟疾和 LLIN 使用的决定因素。在不同的大规模筛查轮次中，无热人群中的疟疾流行率从 0.6%到 1.4%不等。相比之下，每个轮次中发热个体的疟疾阳性率都大于 33%。无热疟疾占该地区总疟疾负担的 19.6%到 47.2%。土著社区（在册部落）更容易感染疟疾，包括无热疟疾。使用 LLINs 的个体患无热疟疾的可能性较小。总体而言，77%的人在早季风季使用 LLINs，而在冬季，这一比例较低，为 55%。LLIN 使用与家庭从政府收到的 LLINs 数量显著相关。尽管发热仍然是疟疾的主要症状，但无热疟疾仍然是该地区疟疾负担的一个重要原因。应扩大免费发放 LLINs 的范围，将高负担人群包括在内。全球政策必须包括在高负担地区监测和控制无热疟疾的策略。
