Risk factors for measles infection in 0-7 month old children in China after the 2010 nationwide measles campaign: A multi-site case-control study, 2012-2013

A study on relationship between the incidence of measles and nosocomial exposure at measles epidemic season in Chongqing

After measles vaccine supplementary immunization, the epidemiological characteristics of measles have changed in Chongqing, China. In addition, according to data from the National Measles Surveillance Information System, the proportion of measles cases with a history of hospital visit 7 to 21 days prior to onset of measles increased year by year to 32.1% in 2016. Further studies are necessary to eliminate the influence of nosocomial exposure on measles. We performed a case-control study in seven districts of Chongqing from June to August 2016 to identify risk factors for measles virus infection and susceptibility. Laboratory-confirmed measles who younger than 5 years old were matched with one control by age and residence. We interviewed case patients and controls regarding potential risk factors for measles virus infection and susceptibility. Unadjusted and adjusted matched odds ratios and 95% confidence intervals (CIs) were calculated using non-conditional logistic regression. After a cross-sectional analysis of the behavioral characteristics of visiting hospitals in the case and control groups, it was found that there was a difference between the two groups in the choice of hospitals visited for the first time (χ2 = 35.500, P = .000), and that nosocomial transmission risk tended to develop in outpatient services of respiratory medicine. After analysis using one-way ANOVA, the relationship between hospital visits prior to onset and the incidence risk of measles was that visiting hospitals five times within 1 to 3 weeks prior to onset affected the incidence (OR = 44.866, 95%CI = 5.938-338.981). The relationship between the number of types of hospitals visited prior to onset and the risk of nosocomial exposure to measles showed that visiting any community hospital, children's hospital, or general hospital had no risk, but visiting two or more of these hospitals affected the incidence (OR = 6.928, 95%CI = 3.849-13.754). Based on further analysis, the relationship between the number of hospital visits after onset and the risk of nosocomial exposure to measles was that the chances of visiting hospitals increased after onset. Risks of nosocomial exposure to measles and infections are high in pediatric hospitals. Nosocomial exposure risk factors should be considered when controlling measles.

Impact of the coronavirus disease 2019 epidemic and a free influenza vaccine strategy on the willingness of residents to receive influenza vaccines in Shanghai, China

The influenza vaccine is not included in China's national immunization program. Here, we assessed influenza vaccine coverage among Shanghai residents and estimated the impacts of the coronavirus disease 2019 (COVID-19) epidemic and a hypothetical free vaccine strategy on the willingness of participants to receive influenza vaccines. The coverage of influenza vaccines among Shanghai residents from 2015 to 2019 was 1.4% (range: 1%-2.4%). A total of 792 adult participants (aged 19-59 years) along with 821 children and 445 older individuals were included in the analysis. The willingness of participants to receive influenza vaccines reached 68.4% following the COVID-19 epidemic. Furthermore, if the vaccine was made available at no cost, 85.9% of participants were willing to be vaccinated. Our data indicated that influenza vaccine coverage is extremely low in Shanghai but that more than two-thirds of participants were willing to receive influenza vaccines following the COVID-19 epidemic. Making influenza vaccines available for free could further increase coverage.

Risk factors for measles virus infection and susceptibility in persons aged 15 years and older in China: A multi-site case-control study, 2012–2013

INTRODUCTION

Endemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated >100 million children in 2010. An increasing proportion of infections now occur among adults and there is concern that persistent susceptibility in adults is an obstacle to measles elimination in China. We performed a case-control study in six Chinese provinces between January 2012 to June 2013 to identify risk factors for measles virus infection and susceptibility among adults.

METHODS

Persons ≥15 years old with laboratory-confirmed measles were age and neighborhood matched with three controls. Controls had blood specimens collected to determine their measles IgG serostatus. We interviewed case-patients and controls about potential risk factors for measles virus infection and susceptibility. Unadjusted and adjusted matched odds ratios and 95% confidence intervals (CIs) were calculated via conditional logistic regression. We calculated attributable fractions for infection for risk factors that could be interpreted as causal.

RESULTS

899 cases and 2498 controls were enrolled. Among controls, 165 (6.6%) were seronegative for measles IgG indicating persistent susceptibility to infection. In multivariable analysis, hospital visit and travel outside the prefecture in the prior 1-3 weeks were significant risk factors for measles virus infection. Occupation and reluctance to accept measles vaccination were significant risk factors for measles susceptibility. The calculated attributable fraction of measles cases from hospital visitation was 28.6% (95% CI: 20.6-38.8%).

CONCLUSIONS

Exposure to a healthcare facility was the largest risk factor for measles virus infection in adults in China. Improved adherence to hospital infection control practices could reduce risk of ongoing measles virus transmission and increase the likelihood of achieving and sustaining measles elimination in China. The use of control groups stratified by serological status identified distinct risk factors for measles virus infection and susceptibility among adults.

Notifiable Respiratory Infectious Diseases in China: A Spatial-Temporal Epidemiology Analysis

Nowadays, tuberculosis, scarlet fever, measles, influenza, and mumps are five major notifiable respiratory infectious diseases (RIDs) in China. The objective of this study was to describe, visualize, and compare the spatial-temporal distributions of these five RIDs from 2006 to 2016. In addition to descriptive epidemiology analysis, seasonality and spatial autocorrelation analysis were also applied to explore the epidemiologic trends and spatial changing patterns of the five RIDs, respectively. The results indicated that the incidence of tuberculosis, measles, and mumps presented a downtrend trend, while those of scarlet fever and influenza was in a strong uptrend across the research period. The incidences of the five diseases all peaked in spring. There were significant spatial disparities in the distribution of tuberculosis, scarlet fever, and measles cases, with the hotspots mainly located in the western plateau region, northern plain region, and southern mountainous region. To conclude, notable epidemiological differences were observed across regions, indicating that some provincial units should pay more attention to prevent and control respiratory infectious diseases.

Epidemiological changes in measles infections in southern China between 2009 and 2016: a retrospective database analysis

Background

The incidence rate of measles in China reached a nadir in 2012 after 2 supplementary immunization activities (SIAs) were undertaken in 2009 and 2010. However, the disease began re-emerging in 2013, with a high prevalence rate observed in 2013–2014 in the southern province of Guangdong. In this study, we assessed the changes that occurred in measles epidemiology during 2009–2016, particularly between 2009 and 2011 (when the influence of the SIAs were in full effect) and between 2012 and 2016 (when this influence subsided).

Methods

Data from 22,362 patients with measles diagnosed between 2009 and 2016, and whose diagnoses were confirmed clinically and/or with laboratory testing, were extracted from the National Infectious Disease Monitoring Information System. Descriptive analyses were performed, and changes in epidemiological characteristics between 2009 and 2011 and 2012–2016 were compared.

Results

There was a substantial surge in 0–8-month-old patients after 2012; the incidence rate increased from 4.0 per 100,000 population in 2011 (10.3% of the total) to 280 per 100,000 population in 2013 (32.8% of the total). Patients aged 0–6 years represented 73.4% of the total increase between 2011 and 2013. Compared with 2009–2011, adults aged ≥25 years accounted for a higher proportion of patients in 2013 and after (p < 0.01), and were highest in 2016 (31% of the patient total).

Conclusion

Despite the remarkable results achieved by SIAs in terms of providing herd immunity, the 2013 resurgence of measles revealed insufficient immunization coverage among children. Therefore routine immunization programs should be strengthened, and supplementary vaccinations targeting adults should also be contemplated.

Global trends in measles publications

INTRODUCTION

Beginning with the 1960s, this review analyzes trends in publications on measles indexed by the National Library of Medicine from January 1960 to mid-2018. It notes both the growth in numbers of published papers, and the increasing number and proportion of publications, in the current century, of articles on such items as costing, measles elimination, and determinants of coverage.

METHODS

A two-person team extracted from the National Library of Medicine (NLM) homepage all citations on measles beginning in 1960 and continuing through mid-2018. These were then classified both by overall number and by subject matter, with tabular summaries of both by decade and by subject matter. The tabular presentation forms the basis for a discussion of the ten most frequently cited subjects, and publication trends, with a special emphasis on the current century.

RESULTS

As in the past, the most often currently published items have been on coverage and its determinants, measles elimination, outbreak reports, SSPE, and SIAs. The putative relationship between vaccination and autism saw a spurt of articles in the 1990s, rapidly declining after the IOM report rejecting the causative hypothesis.

CONCLUSION

There is a discussion on the sequencing of polio and measles eradication, the former unlikely before 2022, and an examination of likely research priorities as the world moves from measles control to measles eradication. There is a key role for social science in combatting vaccination reticence. The role of technical innovations, such as micropatch vaccination, is discussed.

Measles in Zhejiang, China, 2004-2017: Population Density and Proportion of Floating Populations Effects on Measles Epidemic

The target of eliminating measles has not been achieved, and measles has resurged in Zhejiang, China, since 2013. In this study, we hypothesized that population density and the proportion of the floating population were the potential causes of measles persistence in Zhejiang. Measles cases in Zhejiang from 2004 through 2017 were analyzed using data from the National Notifiable Diseases Reporting System (NNDRS). Reported measles incidence and annual incidence by age were described. Spearman correlation coefficients were used to assess correlations between measles incidence and population density and the proportion of floating population. A total of 48,648 measles cases were reported during the 14-year period. Two large measles epidemics occurred in 2005 (14,317 cases, incidence of 29.38/100,000) and 2008 (12,782 cases, incidence of 25.26/100,000). A higher proportion of cases occurred in young adults aged 20 to 34 years and infants under 1 year of age. A positive correlation was observed between measles incidence and either population density or proportion of inter-provincial floating populations. In general, Zhejiang suffers from a high incidence of measles partly because of its high population density and the low vaccination rates among inter-provincial floating populations. To meet the target of measles elimination, convincing susceptible young adults and migrant children to get vaccinated remains a critical issue.

Early Waning of Maternal Measles Antibodies in Infants in Zhejiang Province, China: A Comparison of Two Cross-Sectional Serosurveys

In China, children aged <8 months, who were expected to be protected by maternal antibodies before receiving the first dose of measles vaccine, were the age group with the greatest risk of infection in recent years. In this study, we evaluated whether infants yet to be age-eligible for measles vaccine had a sufficient seropositive level of maternal measles antibodies in 2009 and 2013. Blood samples were collected from infants aged <8 months through population-based serological surveys conducted in Zhejiang, China. Serum levels of immunoglobulin G measles antibodies were quantified using enzyme-linked immunosorbent assay. In 2013, the mean geometric mean titres (GMTs) of infants aged 4 to 8 months were below the seropositivity threshold (<200 mIU/mL), decreasing from 118.6 mIU/mL (95% confidence interval [CI] 83.0, 169.3 mIU/mL) at 4 months to 28.6 mIU/mL (95% CI 15.6, 52.3 mIU/mL) at 7 months. Antibody levels were significantly lower in 2013 than in 2009 starting from 5 months of age. In conclusion, infants aged 4 to 8 months are susceptible to measles due to low levels of maternal measles antibodies. It is thus suggested to provide infants with a supplementary dose on top of the routine schedule, and/or launch catch-up vaccination campaigns among young women.

Characteristics of measles epidemics in China (1951-2004) and implications for elimination: A case study of three key locations

Measles is a highly infectious, severe viral disease. The disease is targeted for global eradication; however, this result has proven challenging. In China, where countrywide vaccination coverage for the last decade has been above 95% (the threshold for measles elimination), measles continues to cause large epidemics. To diagnose factors contributing to the persistency of measles, here we develop a model-inference system to infer measles transmission dynamics in China. The model-inference system uses demographic and vaccination data for each year as model inputs to directly account for changing population dynamics (including births, deaths, migrations, and vaccination). In addition, it simultaneously estimates unobserved model variables and parameters based on incidence data. When fitted to yearly incidence data for the entire population, it is able to accurately estimate independent, out-of-sample age-specific incidence. Using this validated model-inference system, we are thus able to estimate epidemiological and demographical characteristics key to measles transmission during 1951-2004 for three key locations in China, including its capital Beijing. These characteristics include age-specific population susceptibility and incidence rates, the basic reproductive number (R0), reporting rate, population mixing intensity, and amplitude of seasonality. Key differences among the three sites reveal population and epidemiological characteristics crucial for understanding the current persistence of measles epidemics in China. We also discuss the implications our findings have for future elimination strategies.

Clinical profile of measles in children with special reference to infants

This study was conducted to analyse the clinical characteristics of measles in infants and to compare them with those in older children. Clinical and sociodemographic details of all hospitalised children with suspected measles were recorded and confirmed cases were analysed further. Twenty-four infants and 34 children aged >1 year were included. Most infants were boys and 15 (62.5%) of them were aged <9 months. Early onset of rash (within three days of fever in 62.5% of cases) occurred in infants. The complications of measles in infants included bronchopneumonia (n = 17, 71%), acute diarrhoea (n = 8, 33%), meningitis (n = 1, 4%) and staphylococcal sepsis (n = 2, 8%). The number of infants with complications was significantly high (88% and 65%; P = 0.05). Measles in infants can have atypical presentations, a greater risk for complications and may occur before they are due to receive the conventional first dose of measles vaccine.

Measles Outbreak in Pediatric Hematology and Oncology Patients in Shanghai, 2015

Background:

Despite substantial progress toward measles control are making in China, measles outbreaks in immunocompromised population still pose a challenge to interrupt endemic transmission. This study aimed to investigate the features of measles in pediatric hematology and oncology patients and explore the reasons behind the outbreak.

Methods:

We collected demographic, epidemiological, and clinical data of immunocompromised measles children. All suspected measles cases were laboratory-confirmed based on the presence of measles IgM and/or identification of measles RNA. The clinical data were statistically analyzed by t-test for continuous variables and Fisher's exact test for categorical variables.

Results:

From March 9 to July 25 in 2015, a total of 23 children with malignancies and post hematopoietic stem cell transplantation (post-HSCT) were notified to develop measles in Shanghai. Of these 23 patients with the median age of 5.5 years (range: 11 months–14 years), 20 (87.0%) had received 1–3 doses of measles vaccine previously; all patients had fever with the median fever duration of 8 days; 21 (91.3%) had cough; 18 (78.3%) had rash; 13 (56.5%) had Koplik's spot; 13 (56.5%) had complications including pneumonia and acute liver failure; and five (21.7%) vaccinated patients died from severe pneumonia or acute liver failure. Except the first patient, all patients had hospital visits within 7–21 days before measles onset and 20 patients were likely to be exposed to each other.

Conclusions:

The outcome of measles outbreak in previously vaccinated oncology and post-HSCT pediatric patients during chemotherapy and immunosuppressant medication was severe. Complete loss of protective immunity induced by measles vaccine during chemotherapy was the potential reason. Improved infection control practice was critical for the prevention of measles in malignancy patients and transplant recipients.

Risk factors for measles among infants in Tianjin, China

OBJECTIVES

Infants aged <8 months are ineligible for measles vaccination in China but represent a disproportionate number of cases. We examined the risk factors for measles among infants in Tianjin, China.

STUDY DESIGN

Case-control study.

METHODS

Cases were enrolled from a surveillance system, and IgG-negative controls were sampled from registries at immunization clinics. A logistic regression model assessed for risk factors.

RESULTS

Among 82 cases and 485 controls, exposure to a municipal hospital (OR [odds ratio]: 5.21; 95% confidence interval [CI]: 1.19-22.82) or a specialty hospital (OR: 13.22; 95% CI: 6.13-28.51) was associated with the disease, whereas visiting a township or district hospitals was not associated with increased odds of measles.

CONCLUSIONS

Hospitals were an important focal point of measles transmission for infants. Hospitals, particularly higher-level municipal and specialty hospitals, should enforce infection control programs to separate infants with highly communicable diseases to prevent transmission.

Risk factors for measles in children aged 8 months-14 years in China after nationwide measles campaign: A multi-site case-control study, 2012-2013

INTRODUCTION

Endemic measles persists in China, despite >95% reported coverage of two measles-containing vaccine doses and nationwide campaign that vaccinated more than 100 million children in 2010. In 2011, almost half of the 9943 measles cases in China occurred in children eligible for measles vaccination. We conducted a case-control study during 2012-2013 to identify risk factors for measles infection in children aged 8 months-14 years.

METHODS

Children with laboratory-confirmed measles were age- and neighborhood-matched with three controls. We interviewed parents of case and control infants on potential risk factors for measles. We calculated adjusted matched odds ratios and 95% confidence intervals of risk factors. We calculated attributable fractions for risk factors that could be interpreted as causal and vaccine efficacy (VE) for the measles containing vaccine (MCV) used in the Chinese immunization program.

RESULTS

In all, 969 case-patients and 2845 controls were enrolled. In multivariable analysis, lack of measles vaccination both overall (mOR 22.7 [16.6, 31.1] and when stratified by region (east region, mOR 74.2 [27.3, 202]; central/western regions mOR 17.4 [12.5, 24.3]), hospital exposure (mOR 63.0, 95% CI [32.8, 121]), and migration among counties (overall mOR 3.0 [2.3, 3.9]) were significant risk factors. The calculated VE was 91.9-96.1% for a single dose of MCV and 96.6-99.5% for 2 doses.

CONCLUSIONS

Lack of vaccination was the leading risk factor for measles infection, especially in children born since the 2010 supplementary immunization activity. Reducing missed vaccination opportunities, improving immunization access for migrant children, and strengthening school/kindergarten vaccine checks are needed to strengthen the routine immunization program and maintain progress toward measles elimination in China.