背景:微量营养素缺乏在印度普遍存在。土壤传播的蠕虫(STH)感染是通过与被人类粪便污染的土壤和水相互作用而获得的,并导致血液流失和微量营养素吸收不良。目前控制性病相关发病率的建议是有针对性的驱虫,然而,在不同的卫生条件下,驱虫对微量营养素状况的有效性知之甚少。印度各州的患病率在1%到40%之间,尽管印度投资于通过促进全社区的卫生设施来消除排便,但露天排便(OD)仍然很高。这种变化为研究驱虫之间的关系提供了机会,微量营养素状况,和OD在规模。
结果:在2016年至2018年的国家综合营养调查中获得了具有印度代表性的横截面数据集(n=105,060名1至19岁的个体)。驱虫药物的消费按年龄和社区OD水平描述。使用Logistic回归模型来检验驱虫,簇OD,以及它们的相互作用,贫血和微量营养素缺乏(铁,锌,维生素A,叶酸,和维生素B12),控制年龄,性别,财富,饮食,和季节性。这些回归模型进一步使我们能够确定最小OD率,之后驱虫变得无效。在敏感性分析中,驱虫和缺陷之间的关联在社区的子样本中进行了测试,这些子样本基于统计三分位数分为3个OD水平:无OD(社区中有0%的家庭使用OD),中度OD(>0%和<30%),或高OD(至少30%)。样本中的平均驱虫覆盖率和OD患病率分别为43.4%[IQR26.0,59.0]和19.1%[IQR0,28.5],分别。控制营养状况的其他决定因素,生活在OD水平较高的社区的青少年驱虫覆盖率较低,贫血患病率较高,锌,维生素A,B12缺陷。与那些没有被驱虫的人相比,驱虫儿童和青少年贫血的几率较低(调整后的优势比0.72,(95%CI[0.67,0.78],p<0.001)和铁缺乏0.78,(95%CI[0.74,0.82],p<0.001)和叶酸0.69(95%CI[0.64,0.74],p<0.001))在无OD社区中。这些保护作用对贫血仍然显着,但对中等或高OD社区的其他微量营养素缺乏症却有所减弱。对社区OD的分析表明阈值范围为30%至60%,在这之上,有针对性的驱虫不再与较低的贫血显著相关,铁,叶酸缺乏。该研究的主要局限性包括遗漏变量偏差的可能性和无法捕获纵向效应。
结论:中等至高的OD率显着改变了印度驱虫与微量营养素状态之间的关联。公共卫生政策可能涉及排序干预,重点是提高已达到OD最低阈值的社区的驱虫覆盖率,并在驱虫天数之前重新触发高OD社区的卫生干预措施,确保两者的高覆盖率。在这个年龄组中,补充微量营养素作为改善营养结果以及驱虫和消除OD的补充策略的有效性需要进一步研究。
BACKGROUND: Micronutrient deficiencies are widespread in India. Soil-transmitted helminth (STH) infections are acquired by interaction with soil and water contaminated by human feces and lead to blood loss and poor micronutrient absorption. The current recommendation for control of STH-related morbidity is targeted deworming, yet little is known about the effectiveness of deworming on micronutrient status in varying sanitation contexts. Ranging between 1% and 40% prevalence across Indian states, open defecation (OD) remains high despite India\'s investments at elimination by promoting community-wide sanitation. This variation provides an opportunity to
study the relationship between deworming, micronutrient status, and OD at-scale.
RESULTS: Cross-sectional datasets that were representative for India were obtained the Comprehensive National Nutrition Survey in 2016 to 2018 (n = 105,060 individuals aged 1 to 19 years). Consumption of deworming medication was described by age and community OD level. Logistic regression models were used to examine the relationship between deworming, cluster OD, and their interactions, with anemia and micronutrient deficiencies (iron, zinc, vitamin A, folate, and vitamin B12), controlling for age, sex, wealth, diet, and seasonality. These regression models further allowed us to identify a minimum OD rate after which deworming becomes ineffective. In sensitivity analyses, the association between deworming and deficiencies were tested in subsamples of communities classified into 3 OD levels based on statistical tertiles: OD free (0% of households in the community practicing OD), moderate OD (>0% and <30%), or high OD (at least 30%). Average deworming coverage and OD prevalence in the sample were 43.4% [IQR 26.0, 59.0] and 19.1% [IQR 0, 28.5], respectively. Controlling for other determinants of nutritional status, adolescents living in communities with higher OD levels had lower coverage of deworming and higher prevalence of anemia, zinc, vitamin A, and B12 deficiencies. Compared to those who were not dewormed, dewormed children and adolescents had lower odds of anemia (adjusted odds ratio 0.72, (95% CI [0.67, 0.78], p < 0.001) and deficiencies of iron 0.78, (95% CI [0.74, 0.82], p < 0.001) and folate 0.69, (95% CI [0.64,0.74], p<0.001)) in OD free communities. These protective effects remained significant for anemia but diminished for other micronutrient deficiencies in communities with moderate or high OD. Analysis of community OD indicated a threshold range of 30% to 60%, above which targeted deworming was no longer significantly associated with lower anemia, iron, and folate deficiency. The primary limitations of the
study included potential for omitted variables bias and inability to capture longitudinal effects.
CONCLUSIONS: Moderate to high rates of OD significantly modify the association between deworming and micronutrient status in India. Public health policy could involve sequencing interventions, with focus on improving deworming coverage in communities that have achieved minimum thresholds of OD and re- triggering sanitation interventions in high OD communities prior to deworming days, ensuring high coverage for both. The efficacy of micronutrient supplementation as a complementary strategy to improve nutritional outcomes alongside deworming and OD elimination in this age group needs further
study.