Sinha A, Sazawal S, Kumar R, Sood S, Reddaiah V P, Singh B, Rao M, Naficy A, Clemens J D, Bhan M K
Indian Council for Medical Research, Advanced Centre for Diarrhoeal Disease Research, Division of Paediatric Gastroenterology, New Delhi.
Lancet. 1999 Aug 28;354(9180):734-7. doi: 10.1016/S0140-6736(98)09001-1.
Calculation of the incidence of typhoid fever during preschool years is important to define the optimum age of immunisation and the choice of vaccines for public-health programmes in developing countries. Hospital-based studies have suggested that children younger than 5 years do not need vaccination against typhoid fever, but this view needs to be re-examined in community-based longitudinal studies. We undertook a prospective follow-up study of residents of a low-income urban area of Delhi, India, with active surveillance for case detection.
A baseline census was undertaken in 1995. Between Nov 1, 1995, and Oct 31, 1996, we visited 8172 residents of 1820 households in Kalkaji, Delhi, twice weekly to detect febrile cases. Blood samples were obtained from febrile patients, and those who tested positive for Salmonella typhi were treated with ciprofloxacin.
63 culture-positive typhoid fever cases were detected. Of these, 28 (44%) were in children aged under 5 years. The incidence rate of typhoid per 1000 person-years was 27.3 at age under 5 years, 11.7 at 5-19 years, and 1.1 between 19 and 40 years. The difference in the incidence of typhoid fever between those under 5 years and those aged 5-19 years (15.6 per 1000 person-years [95% CI 4.7-26.5]), and those aged 19-40 years (26.2 [16.0-36.3]) was significant (p<0.001 for both). The difference between the incidence of typhoid at 5-19 years and the incidence at 19-40 years was also significant (10.6 [6.3-14.8], p<0.001). Morbidity in those under 5 and in older people was similar in terms of duration of fever, signs and symptoms, and need for hospital admission.
Our findings challenge the common view that typhoid fever is a disorder of school-age children and of adults. Typhoid is a common and significant cause of morbidity between 1 and 5 years of age. The optimum age of typhoid immunisation and the choice of vaccines needs to be reassessed.
计算学龄前儿童伤寒热发病率对于确定最佳免疫年龄以及为发展中国家公共卫生项目选择疫苗至关重要。基于医院的研究表明，5岁以下儿童无需接种伤寒热疫苗，但这一观点需要在基于社区的纵向研究中重新审视。我们对印度德里一个低收入城市地区的居民进行了一项前瞻性随访研究，并积极监测病例发现情况。
1995年进行了基线普查。在1995年11月1日至1996年10月31日期间，我们每周两次走访德里卡尔卡吉1820户家庭的8172名居民，以发现发热病例。从发热患者身上采集血样，伤寒沙门氏菌检测呈阳性的患者用环丙沙星治疗。
检测到63例培养阳性的伤寒热病例。其中，28例（44%）为5岁以下儿童。5岁以下儿童每1000人年的伤寒发病率为27.3，5至19岁为11.7，19至40岁为1.1。5岁以下儿童与5至19岁儿童（每1000人年15.6 [95%可信区间4.7 - 26.5]）以及19至40岁儿童（26.2 [16.0 - 36.3]）之间的伤寒热发病率差异具有统计学意义（两者p<0.001）。5至19岁儿童与19至40岁儿童的伤寒发病率差异也具有统计学意义（10.6 [6.3 - 14.8]，p<0.001）。5岁以下儿童和老年人在发热持续时间、体征和症状以及住院需求方面的发病率相似。
我们的研究结果挑战了伤寒热是学龄儿童和成年人疾病的普遍观点。伤寒是1至5岁儿童发病的常见且重要原因。需要重新评估伤寒免疫的最佳年龄和疫苗选择。
