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Investigation of a Measles Outbreak in China to Identify Gaps in Vaccination Coverage, Routes of Transmission, and Interventions.

Zheng X, Zhang N, Zhang X, Hao L, Su Q, Wang H, Meng K, Zhang B, Liu J, Wang H, Luo H, Li L, Li H, Ma C - PLoS ONE (2015)

Bottom Line: The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures.This outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases.The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated.

View Article: PubMed Central - PubMed

Affiliation: National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China; Chinese Field Epidemiology Training Program, Chinese Center for Disease Control and Prevention, Beijing, China; Taizhou Prefecture Center for Disease Control and Prevention, Taizhou Prefecture, Zhejiang Province, China.

ABSTRACT

Background: A measles outbreak occurred in a western county of China in 2013, the year after China's historic nadir of measles. We conducted a field investigation to identify gaps in measles vaccination coverage and immunization program weaknesses, and to provide recommendations for measles outbreak response and immunization program improvement.

Methods: We analyzed surveillance data from 2008 to 2013 to describe the measles epidemiology of the county. Measles-containing vaccine coverage was estimated using two methods: previously-reported administrative coverage and an estimation of coverage by clinic-kept vaccination records (n = 542). We conducted a rapid field coverage assessment in a migrant population village to evaluate coverage after emergency vaccination. We conducted a review of hospital records of measles cases to address the role hospital transmission played during the early stage of this outbreak.

Results: There were 153 cases in the outbreak, primarily among children too young to vaccinate, unvaccinated children less than 3 years old, and adults. Measles-containing vaccine coverage by the field assessment showed that 20% of children aged 8-17 months had zero doses, and 9% of ≥2 years old children had fewer than two doses. The vaccination statuses of all adult cases were either zero doses or unknown. At least 61% of cases had been hospitalized. The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures.

Conclusions: This outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases. The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated. Hospitals were sites of transmission in the early stage of the outbreak. A strict hospital isolation policy could decrease spread of measles. Emergency vaccination was associated with stopping measles transmission in low coverage areas.

No MeSH data available.


Related in: MedlinePlus

Hospital exposure histories prior to rash onset for 13 cases.
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pone.0133983.g003: Hospital exposure histories prior to rash onset for 13 cases.

Mentions: The field review showed that among the 94 cases hospitalized (61% of the total), 52 had been hospitalized after the onset of measles, and 42 had been hospital-exposed during their measles incubation period. There were 25 cases whose illness onset dates were before April; 13 of these 25 cases (52%) had been hospital-exposed during their incubation period; 10 of the 13 cases (77%) were less than one year old (Fig 3). All of the 13 cases had been hospital-exposed before or after 4 days of their rash onset. The sources of infections could not be identified. Age stratified data showed that 35% of cases (54/153) had been hospital-exposed during their incubation period and 44% of cases (20/45) were between 8 months and 2 years old.


Investigation of a Measles Outbreak in China to Identify Gaps in Vaccination Coverage, Routes of Transmission, and Interventions.

Zheng X, Zhang N, Zhang X, Hao L, Su Q, Wang H, Meng K, Zhang B, Liu J, Wang H, Luo H, Li L, Li H, Ma C - PLoS ONE (2015)

Hospital exposure histories prior to rash onset for 13 cases.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4514761&req=5

pone.0133983.g003: Hospital exposure histories prior to rash onset for 13 cases.
Mentions: The field review showed that among the 94 cases hospitalized (61% of the total), 52 had been hospitalized after the onset of measles, and 42 had been hospital-exposed during their measles incubation period. There were 25 cases whose illness onset dates were before April; 13 of these 25 cases (52%) had been hospital-exposed during their incubation period; 10 of the 13 cases (77%) were less than one year old (Fig 3). All of the 13 cases had been hospital-exposed before or after 4 days of their rash onset. The sources of infections could not be identified. Age stratified data showed that 35% of cases (54/153) had been hospital-exposed during their incubation period and 44% of cases (20/45) were between 8 months and 2 years old.

Bottom Line: The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures.This outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases.The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated.

View Article: PubMed Central - PubMed

Affiliation: National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China; Chinese Field Epidemiology Training Program, Chinese Center for Disease Control and Prevention, Beijing, China; Taizhou Prefecture Center for Disease Control and Prevention, Taizhou Prefecture, Zhejiang Province, China.

ABSTRACT

Background: A measles outbreak occurred in a western county of China in 2013, the year after China's historic nadir of measles. We conducted a field investigation to identify gaps in measles vaccination coverage and immunization program weaknesses, and to provide recommendations for measles outbreak response and immunization program improvement.

Methods: We analyzed surveillance data from 2008 to 2013 to describe the measles epidemiology of the county. Measles-containing vaccine coverage was estimated using two methods: previously-reported administrative coverage and an estimation of coverage by clinic-kept vaccination records (n = 542). We conducted a rapid field coverage assessment in a migrant population village to evaluate coverage after emergency vaccination. We conducted a review of hospital records of measles cases to address the role hospital transmission played during the early stage of this outbreak.

Results: There were 153 cases in the outbreak, primarily among children too young to vaccinate, unvaccinated children less than 3 years old, and adults. Measles-containing vaccine coverage by the field assessment showed that 20% of children aged 8-17 months had zero doses, and 9% of ≥2 years old children had fewer than two doses. The vaccination statuses of all adult cases were either zero doses or unknown. At least 61% of cases had been hospitalized. The proportion of cases who had been hospital-exposed 7 to 21 days prior to rash onset decreased from 52% to 22% after hospitals strengthen their isolation measures.

Conclusions: This outbreak was a result of measles vaccination coverage gaps among young children and adults, and insufficient hospital isolation of cases. The lower coverage seen in the field estimation compared with reported coverage showed that reported coverage could have been overestimated. Hospitals were sites of transmission in the early stage of the outbreak. A strict hospital isolation policy could decrease spread of measles. Emergency vaccination was associated with stopping measles transmission in low coverage areas.

No MeSH data available.


Related in: MedlinePlus