Insufficiency of annual praziquantel treatment to control Schistosoma mansoni infections in adult women: A longitudinal cohort study in rural Tanzania
Insufficiency of annual praziquantel treatment to control Schistosoma mansoni infections in adult women: A longitudinal cohort study in rural Tanzania
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DOI：
10.1371/journal.pntd.0007844
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发表时间：
2019-11-01
影响因子：
3.8
通讯作者：
Downs, Jennifer A.
中科院分区：
文献类型：
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作者：
Mishra, Pallavi;Colombe, Soledad;Downs, Jennifer A.
目前世界卫生组织（WHO）的指南建议在高流行性地区每年使用吡喹酮进行大规模药物管理。然而，对经常接触病毒的妇女治疗后的发病率和再感染率知之甚少。我们试图量化抗肿瘤治疗和事件S的反应。在坦桑尼亚西北部一个流行性疾病流行区的农村妇女队列中，方法和主要发现我们招募了有和没有S。mansoni感染进入一个12个月的纵向队列。每3个月，妇女进行了测试，为虫卵过滤尿，加藤卡茨幻灯片，血清循环阳极抗原（CAA）的显微镜检查，以确定是否感染。根据标准治疗，那些患有寄生虫感染的患者接受吡喹酮40 mg/kg治疗。我们研究了35名妇女谁是S。粪便显微镜检查为mansoni阳性，46名妇女没有感染，至少返回一次随访。在最初感染的妇女中，14名（40%）在随访时呈阳性。4名妇女发生了偶发感染，在最初未感染的妇女中，全年的累积发病率为8.7%，发病率为0.99/100人月。在任何随访中，只有3名妇女的卵子呈阳性。在研究期间，持续性、复发性或偶发性感染的女性明显比未感染或感染清除且未复发的女性年轻（p = 0.032），且生育的子女较少（p = 0.003）。在控制了年龄因素后，子女数量仍然显著减少（p = 0.023）。CAA或粪便虫卵计数、HIV状态或社会经济状况的初始感染强度无差异。虽然两组之间的大多数水接触行为是可比的，但复发性或偶发性感染的女性最近在湖中游泳的可能性更大（p = 0.023）。结论：我们的数据表明，每年吡喹酮治疗降低了寄生虫感染的强度，但不足以在流行社区超过三分之一的妇女提供稳定的寄生虫根除。此外，显微镜检查缺乏足够的灵敏度来评价该人群的治疗疗效。我们的工作表明，进一步调查治疗效果和再感染率是必要的，并建议，需要增加吡喹酮治疗的频率，以提高治愈率在高危population.Author摘要血吸虫病是一种寄生虫感染，通过污染的水，主要影响胃肠道和泌尿生殖道。此前在坦桑尼亚的研究表明，感染了艾滋病病毒的成年妇女感染艾滋病毒的风险也更高。虽然建议生活在暴露于吡喹酮的地区的人每年用吡喹酮治疗一次，但成年妇女治疗后新感染或再感染的比率尚不清楚。我们对一组受感染的女性和一组未感染的对照组进行了为期12个月的随访。他们每3个月进行一次染色体检测，如果感染就用吡喹酮治疗。超过40%的女性在随访期间的某个时候检测出了阳性的病毒感染，其中大多数来自研究开始时感染的那组。这些妇女在一次治疗后可能没有完全清除感染，或者由于免疫系统的变化，她们可能更容易再次感染。建议进行进一步的研究，以调查是否需要更高频率的治疗来控制成年女性的艾滋病毒感染，特别是考虑到减少艾滋病毒感染可能有助于降低与我们相似的人群中的艾滋病毒风险。
Background Current World Health Organization (WHO) guidelines recommend annual mass drug administration using praziquantel in areas with high schistosome endemicity. Yet little is known about incidence and reinfection rates after treatment in women with frequent exposure to schistosomes. We sought to quantify response to anti-schistosome treatment and incident S. mansoni infections in a cohort of rural women living in a schistosome-endemic area of northwest Tanzania. Methods and principal findings We enrolled women with and without S. mansoni infection into a 12-month longitudinal cohort. Every 3 months, women were tested for schistosome infection using microscopic examinations for ova on filtered urine, Kato Katz slides, and serum Circulating Anodic Antigen (CAA). Those with schistosome infection received treatment with praziquantel 40 mg/kg according to the standard of care. We studied 35 women who were S. mansoni positive by stool microscopy and 46 women without schistosome infection who returned for at least one follow-up. Of the women who were initially infected, 14 (40%) were schistosome-positive at a follow-up visit. Four women developed incident infections, for a cumulative incidence of 8.7% and incidence rate of 0.99 per 100 person-months throughout the year among initially uninfected women. Only 3 women were egg-positive at any follow-up. Women with persistent, recurrent, or incident infection during the study period were significantly younger (p = 0.032) and had fewer children than women who remained uninfected or those who cleared the infection and did not experience recurrence (p = 0.003). Having fewer children remained significant after controlling for age (p = 0.023). There was no difference in initial intensity of infection by CAA or stool egg count, HIV status, or socioeconomic status. Although most water contact behaviors were comparable between the two groups, women with recurrent or incident schistosome infections were significantly more likely to have recently swum in the lake (p = 0.023). Conclusions Our data suggests that annual praziquantel treatment reduces intensity of schistosome infections but is insufficient in providing stable parasite eradication in over a third of women in endemic communities. Furthermore, microscopy lacks adequate sensitivity to evaluate efficacy of treatment in this population. Our work demonstrates that further investigation into treatment efficacy and reinfection rates is warranted and suggests that increased frequency of praziquantel treatment is needed to improve cure rates in high-risk populations.Author summary Schistosomiasis is a parasitic infection transmitted through contaminated water that primarily affects the gastrointestinal and urogenital tracts. Previous studies in Tanzania have shown that adult women infected with schistosomes also have a higher risk of contracting HIV. Although it is recommended that people living in areas where they are exposed to schistosomes be treated with praziquantel once a year, the rate of new infections or reinfection after treatment in adult women is not known. We followed a group of schistosome-infected women and an uninfected control group for 12 months. They were tested for schistosomes every 3 months, and treated with praziquantel if they were infected. Over 40% of the women tested positive for schistosome infection at some point during the follow-up period, and the majority of them were from the group that was infected at the beginning of the study. These women may not have fully cleared the infection after one treatment, or they may be more susceptible to reinfection due to variations in their immune systems. Further studies are recommended to investigate whether a higher frequency of treatment is needed to control schistosome infection in adult women, especially given that reducing schistosome infection may help to reduce HIV risk in populations similar to ours.