Mishima Nobuyuki, Jemu Samuel K, Kuroda Tomoaki, Tabuchi Koichiro, Darcy Andrew W, Shimono Takaki, Lamaningao Pheophet, Miyake Mari, Kanda Seiji, Ng'ambi Susan, Komai Yoshihiro, Maeba Hirofumi, Amano Hiroyuki, Nishiyama Toshimasa
1Department of Hygiene and Public Health, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1010 Japan.
2Center for Travel Medicine, Kansai Medical University Medical Center, Osaka, Japan.
Trop Med Health. 2019 May 2;47:28. doi: 10.1186/s41182-019-0155-8. eCollection 2019.
In Malawi, hematobium schistosomiasis is highly endemic. According to previous studies, countermeasures have been conducted mainly in school-aged children. In this study, we focused on the age groups, which are assumed to be major labor force generation. Hematobium schistosomiasis is supposed to be related to occupational activities in schistosome-endemic countries because of its infectious route. We chronologically followed the transition of schistosome egg-positive prevalence before and after mass drug administration of praziquantel (MDA) by using a urine filtering examination. We also analyzed the effectiveness of urine reagent strips from the cost perspective.
The egg-positive prevalence was 34.3% (95% CI 28.5-40.5) just before MDA in June 2010 and the highest prevalence was in the age of twenties. The egg-positive prevalence reduced to 12.7% (95% CI 9.2-17.3, < 0.01) 8 weeks after the first MDA and the prevalence reduced to 6.9% (95% CI 4.6-10.0, < 0.01) after the second MDA in August 2011. The egg-positive prevalence after MDA in 2013 was reduced from 3.8% (95% CI 2.1-6.9) to 0.9% (95% CI 0.3-3.4) and value was 0.050. Using urine reagent strips after MDA, the positive predictive value decreased, but the negative predictive value remained high. The cost of one urine reagent strip and one tablet of praziquantel were US$0.06 and US$0.125 in 2013 in Malawi. If the egg-positive prevalence is 40%, screening subjects for MDA using urine reagent strips, the cost reduction can be estimated to be about 24%, showing an overall cost reduction.
MDA of praziquantel can assuredly reduce schistosome egg-positive prevalence. The combination of MDA and urine reagent strips could be both a practical and cost-effective countermeasure for hematobium schistosomiasis. It is key to recognize that hematobium schistosomiasis could be considered a disease that is assumed to have some concern with occupational risk at Nkhotakota and Lilongwe in Malawi. From this point of view, it is very important to manage workers' health; the sound labor force generation is vital for economic growth and development in these areas and countries.
在马拉维，埃及血吸虫病流行程度极高。根据以往研究，主要针对学龄儿童采取了应对措施。在本研究中，我们关注的是被认为是主要劳动力群体的年龄组。由于埃及血吸虫病的传播途径，在血吸虫病流行国家，该病被认为与职业活动有关。我们通过尿液过滤检查按时间顺序跟踪了吡喹酮大规模药物治疗（MDA）前后血吸虫卵阳性率的变化。我们还从成本角度分析了尿液试剂条的有效性。
2010年6月MDA前，卵阳性率为34.3%（95%CI 28.5 - 40.5），最高患病率出现在二十多岁的年龄组。首次MDA后8周，卵阳性率降至12.7%（95%CI 9.2 - 17.3，<0.01），2011年8月第二次MDA后患病率降至6.9%（95%CI 4.6 - 10.0，<0.01）。2013年MDA后的卵阳性率从3.8%（95%CI 2.1 - 6.9）降至0.9%（95%CI 0.3 - 3.4），P值为0.050。MDA后使用尿液试剂条，阳性预测值下降，但阴性预测值仍很高。2013年在马拉维，一条尿液试剂条和一片吡喹酮的成本分别为0.06美元和0.125美元。如果卵阳性率为40%，使用尿液试剂条筛查MDA的对象，估计成本可降低约24%，总体成本降低。
吡喹酮MDA肯定能降低血吸虫卵阳性率。MDA与尿液试剂条的联合使用可能是埃及血吸虫病既实用又具成本效益的应对措施。关键在于认识到在马拉维的恩科塔科塔和利隆圭，埃及血吸虫病可被视为一种与职业风险有关的疾病。从这一角度来看，管理工人健康非常重要；健康劳动力群体的形成对这些地区和国家的经济增长与发展至关重要。
