National Neglected Tropical Disease Control Program, Ministry of Health and Sanitation, Freetown, Sierra Leone.
Parasit Vectors. 2012 Jan 11;5:10. doi: 10.1186/1756-3305-5-10.
National mapping of lymphatic filariasis (LF) was conducted using immunochromatographic tests (ICT) in 2005 to determine endemicity and geographic spread of the disease. A baseline microfilaria survey was then conducted to determine LF prevalence and microfilaria intensity.
In 2005 1,982 persons of 15 years and over from 14 health districts were selected and fingertip blood samples were tested with ICT cards. In 2007-8 blood samples were taken between 10 p.m. and 2 a.m. and examined for microfilaria (mf) from 9,288 persons from 16 sentinel sites representing each district and 2 additional sites for districts with populations over 500,000 (Bo and Kenema).
The overall LF prevalence by ICT cards was 21% (males 28%, females 15%). All districts had a prevalence of Wuchereria bancrofti antigen > 1%. Distribution of LF prevalence showed a strong spatial correlation pattern with high prevalence in a large area in the northeast gradually decreasing to a relatively low prevalence in the southwest coast. High prevalence was found in the northeast, Bombali (52%), Koinadugu (46%), Tonkolili (37%) and Kono (30%). Low prevalence was found in the southwest, Bonthe (3%) and Pujehun (4%). The mf prevalence was higher in the northeast: Bombali, 6.7%, Koinadugu 5.7%, Port Loko 4.4% and Kono 2.4%. Overall there was a significant difference in mf prevalence by gender: males 2.9%, females 1.8% (p = 0.0002) and within districts in Kailahun, Kono, Port Loko, Moyamba and Koinadugu (all p < 0.05). The mf prevalence was higher in people > 20 years (2.5%) than in people ≤ 20 years (1.7%) (p = 0.043). The overall arithmetic mean mf density was 50.30 mf/ml among mf-positive individuals and 1.19 mf/ml in the population examined which varied significantly between districts.
The ICT results showed that LF was endemic nationwide and that preventive chemotherapy (PCT) was justified across the country. Both the ICT and microfilaraemia surveys found that prevalence was greater in males than females. The increase in microfilaraemia prevalence by age was evident when grouped as ≤ 20 versus > 20 years demonstrating early exposure. Baseline LF microfilaria load will be used to monitor PCT program progress.
2005 年，采用免疫层析检测法（ICT）对淋巴丝虫病（LF）进行了全国范围的绘图，以确定该疾病的流行程度和地理分布范围。随后进行了基线微丝蚴调查，以确定 LF 的流行率和微丝蚴密度。
2005 年，从 14 个卫生区中选取了 1982 名 15 岁及以上的人，并使用 ICT 卡对其指尖血样进行了检测。2007-2008 年，从代表每个区的 16 个哨点和人口超过 50 万的 2 个额外区的 9288 人身上采集了夜间 10 点至凌晨 2 点之间的血液样本，并检查了微丝蚴（mf）。
ICT 卡的 LF 总流行率为 21%（男性 28%，女性 15%）。所有地区的班氏丝虫抗原流行率均>1%。LF 流行率的分布呈强空间相关模式，东北部地区的流行率较高，逐渐下降到西南沿海地区的相对较低水平。东北部地区的流行率较高，博城（52%）、科伊纳杜古（46%）、通科利利（37%）和科诺（30%）。西南部地区的流行率较低，邦特（3%）和普杰洪（4%）。东北部的 mf 流行率较高：博城 6.7%，科伊纳杜古 5.7%，洛科港 4.4%，科诺 2.4%。总体而言，性别之间 mf 流行率存在显著差异：男性 2.9%，女性 1.8%（p=0.0002），在凯拉洪、科诺、洛科港、莫扬巴和科伊纳杜古等地区也存在显著差异（均 p<0.05）。20 岁以上人群的 mf 流行率（2.5%）高于 20 岁以下人群（1.7%）（p=0.043）。mf 阳性个体的总算术平均 mf 密度为 50.30 mf/ml，所检查人群的 mf 密度为 1.19 mf/ml，各区之间的 mf 密度存在显著差异。
ICT 结果表明 LF 在全国范围内流行，全国范围内有理由开展预防性化疗（PCT）。ICT 和微丝蚴调查都发现，男性的流行率高于女性。按≤20 岁与>20 岁分组时，微丝蚴流行率随年龄的增加而增加，表明早期暴露。基线 LF 微丝蚴负荷将用于监测 PCT 项目进展。
