Caiyun Chang1,2, Huilai Ma2, Wenjia Liang3, Pei Hu3, Xianghuan Mo4,5, Zhijie An6, Huizhen Zheng3. 1. a Jinan Center for Disease Control and Prevention , Jinan , Shandong , China. 2. b Chinese Field Epidemiology Training Program (CFETP), Chinese Center for Disease Control and Prevention , Beijing , China. 3. c Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , Guangdong , China. 4. d Dongguan Center for Disease Control and Prevention , Dongguan , Guangdong , China. 5. e Guangdong Field Epidemiology Training Program (GDFETP), Guangdong Provincial Center for Disease Control and Prevention , Guangzhou , Guangdong , China. 6. f National Center of Immunization Program, Chinese Center for Disease Control and Prevention , Beijing , China.
Abstract
BACKGROUND: An active response to a rubella outbreak may interrupt disease transmission, and outbreak response immunization (ORI) can increase immunity among persons who might otherwise not be protected. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China. We conducted an investigation to assess impact of a policy of exclusion of cases from school and of ORI. METHODS: Active surveillance was used to find cases of rubella. Investigators interviewed teachers and reviewed the absentee records to determine implementation details of school exclusion. ORI was recommended on 2 occasions during the outbreak, one small-scale and one large-scale. Laboratory confirmation tests included serum IgM and IgG measurements to distinguish between acute infection and immunity. A serological survey in 4 classes was used to determine immunity status and identify symptomatic and asymptomatic cases. RESULTS: From February 17 to May 23, 2014, 162 rubella cases (24 laboratory-confirmed and 138 epidemiologically linked) were detected among 1,621 students. Cases ultimately occurred in 27 classes (72.97%) across 37 classes. In 11 classes in which exclusion from school was delayed by 1 or more days, the secondary attack rate was 12.30%, compared with 2.35% in 15 classes with immediate exclusion. ORI increased vaccine coverage from 25.83 % to 86.92%, and the final case of the epidemic was reported one month later. A serological survey of 91 students in 4 classes identified 15 cases, 6 of which were asymptomatic. CONCLUSIONS: The outbreak happened in school with low rubella-containing vaccination coverage. Exclusion from school upon rash/fever onset was associated with lowering the secondary attack rate, but school exclusion alone was not able to stop this outbreak - a large ORI was needed. Assuring complete vaccination upon entry to school is likely to be necessary to ensure coverage is above the herd immunity threshold and prevent outbreaks from happening.
BACKGROUND: An active response to a rubella outbreak may interrupt disease transmission, and outbreak response immunization (ORI) can increase immunity among persons who might otherwise not be protected. On March 17, 2014, a rubella outbreak was reported in a middle school in Guangzhou city, China. We conducted an investigation to assess impact of a policy of exclusion of cases from school and of ORI. METHODS: Active surveillance was used to find cases of rubella. Investigators interviewed teachers and reviewed the absentee records to determine implementation details of school exclusion. ORI was recommended on 2 occasions during the outbreak, one small-scale and one large-scale. Laboratory confirmation tests included serum IgM and IgG measurements to distinguish between acute infection and immunity. A serological survey in 4 classes was used to determine immunity status and identify symptomatic and asymptomatic cases. RESULTS: From February 17 to May 23, 2014, 162 rubella cases (24 laboratory-confirmed and 138 epidemiologically linked) were detected among 1,621 students. Cases ultimately occurred in 27 classes (72.97%) across 37 classes. In 11 classes in which exclusion from school was delayed by 1 or more days, the secondary attack rate was 12.30%, compared with 2.35% in 15 classes with immediate exclusion. ORI increased vaccine coverage from 25.83 % to 86.92%, and the final case of the epidemic was reported one month later. A serological survey of 91 students in 4 classes identified 15 cases, 6 of which were asymptomatic. CONCLUSIONS: The outbreak happened in school with low rubella-containing vaccination coverage. Exclusion from school upon rash/fever onset was associated with lowering the secondary attack rate, but school exclusion alone was not able to stop this outbreak - a large ORI was needed. Assuring complete vaccination upon entry to school is likely to be necessary to ensure coverage is above the herd immunity threshold and prevent outbreaks from happening.
Authors: Qiru Su; Zhilan Feng; Lixin Hao; Chao Ma; José E Hagan; Gavin B Grant; Ning Wen; Chunxiang Fan; Hong Yang; Lance E Rodewald; Huaqing Wang; John W Glasser Journal: Lancet Infect Dis Date: 2021-01-27 Impact factor: 71.421
Authors: Reem A Al Dossary; Sarah Althuwaiqeb; Khaled R Alkharsah; Nahid H O Wanni; Basavaraja C Hunasemaranda; Obeid E Obeid; Zaheenul Islam Siddiqui; Ayman A El-Badry; Nourah Hasan Al Qahtani Journal: Int J Gen Med Date: 2022-04-02