le Roux David M, Nicol Mark P, Myer Landon, Vanker Aneesa, Stadler Jacob A M, von Delft Eckart, Zar Heather J
Department of Paediatrics and Child Health, Red Cross War Memorial Children's Hospital and Medical Research Council Unit on Child and Adolescent Health, University of Cape Town, Cape Town, South Africa.
Department of Paediatrics, New Somerset Hospital, Cape Town, South Africa.
Clin Infect Dis. 2019 Oct 15;69(9):1588-1596. doi: 10.1093/cid/ciz017.
Childhood lower respiratory tract infections (LRTIs) cause substantial morbidity and under-5 child mortality. The epidemiology of LRTI is changing in low- and middle-income countries with expanding access to conjugate vaccines, yet there are few data on the incidence and risk factors for LRTI in these settings.
A prospective birth cohort enrolled mother-infant pairs in 2 communities near Cape Town, South Africa. Active surveillance for LRTI was performed for the first 2 years of life over 4 respiratory seasons. Comprehensive data collection of risk factors was done through 2 years of life. World Health Organization definitions were used to classify clinical LRTI and chest radiographs.
From March 2012 to February 2017, 1143 children were enrolled and followed until 2 years of age. Thirty-two percent of children were exposed to antenatal maternal smoking; 15% were born at low birth weights. Seven hundred ninety-five LRTI events occurred in 429 children by February 2017; incidence of LRTI was 0.51 and 0.25 episodes per child-year in the first and second years of life, respectively. Human immunodeficiency virus (HIV)-exposed, uninfected infants (vs HIV-unexposed infants) were at increased risk of hospitalized LRTI in the first 6 months of life. In regression models, male sex, low birth weight, and maternal smoking were independent risk factors for both ambulatory and hospitalized LRTI; delayed or incomplete vaccination was associated with hospitalized LRTI.
LRTI incidence was high in the first year of life, with substantial morbidity. Strategies to ameliorate harmful exposures are needed to reduce LRTI burden in vulnerable populations.
儿童下呼吸道感染（LRTIs）会导致严重发病和5岁以下儿童死亡。随着低收入和中等收入国家使用结合疫苗的机会增加，LRTI的流行病学正在发生变化，但这些地区LRTI的发病率和危险因素的数据很少。
一项前瞻性出生队列研究在南非开普敦附近的2个社区招募了母婴对。在4个呼吸道季节对出生后头2年的LRTI进行主动监测。通过2年的时间全面收集危险因素数据。使用世界卫生组织的定义对临床LRTI和胸部X光片进行分类。
从2012年3月至2017年2月，招募了1143名儿童并随访至2岁。32%的儿童暴露于产前母亲吸烟；15%出生时体重低。到2017年2月，429名儿童发生了795次LRTI事件；LRTI的发病率在出生后第一年和第二年分别为每名儿童每年0.51次和0.25次。暴露于人类免疫缺陷病毒（HIV）但未感染的婴儿（与未暴露于HIV的婴儿相比）在出生后头6个月患住院LRTI的风险增加。在回归模型中，男性、低出生体重和母亲吸烟是门诊和住院LRTI的独立危险因素；延迟或未完全接种疫苗与住院LRTI有关。
LRTI在出生后第一年的发病率很高，发病严重。需要采取策略改善有害暴露，以减轻弱势群体的LRTI负担。
