Mumps Epidemiology and Mumps Virus Genotypes Circulating in Mainland China during 2013-2015

Abstract

With the implementation of mumps virus (MuV) vaccination in the expanded program on immunization (EPI) in mainland China since 2008, the incidence of mumps has decreased, and the natural epidemic pattern of mumps has slightly changed during 2013–2015. The two epidemic peaks (April-July and November-December) became less obvious than those observed from 2004 to 2012. Children and adolescents younger than 15, particularly in the five-to-nine-year-old age group, remain the target group and should be the focus of high-quality immunization activities in mainland China. However, it was also found that the incidence and reported cases of mumps decreased in each age group during 2013–2015, particularly in the five-to-nine-year-old and ten-to-fourteen-year-old age groups. The proportion of mumps cases among adults in some provinces also increased. Unlike the changes in the epidemiological characteristics of mumps affected by vaccination, the data of MuV virology surveillance indicated that most of the MuV transmission chains have not yet been effectively interrupted, and MuV remains a natural epidemic pattern in mainland China. In the MuV virology surveillance, 194 MuV strains during 2013–2015 were isolated from 10 of 31 provinces in mainland China. Based on the phylogenetic analysis of the small hydrophobic (SH) gene, both genotype (99.0%) and (1.0%) were identified, and genotype was still the predominant genotype continuously circulating in mainland China. Representative genotype and strains isolated in China from 1995 to 2012 were selected for further analysis. The results indicated that there were multiple transmission chains within genotype , with no obvious geographical or time differences. The high genetic diversity of genotype F strains could be a result of the continuous transmission and evolution of the MuV in mainland China. Genotype was also detected in four provinces in mainland China. Because of the limited epidemiological data, it was uncertain whether the genotype MuV strains found in 2011 and 2013 were imported from other countries. Therefore, combined high-quality epidemiological and virological surveillance is necessary for mumps control; it can also be used to observe the changes in epidemiological characteristics and viral transmission of mumps over time after mumps-containing vaccine (MuCV) implementation and to provide a comprehensive epidemiological and genetic baseline for mumps elimination in mainland China.

Infectious diseases in children and adolescents in China: analysis of national surveillance data from 2008 to 2017

“…Both hepatitis A and B vaccines were included in the national immunisation programme (in 2008 and 2001, respectively) and a vaccine against hepatitis E virus is now licensed in China 29. The implementation of mumps into the expanded programme for immunisation in mainland China in 2008 would have contributed to its decreasing incidence,30 but in the past two years its incidence has increased so that it is now the most common infection in children and adolescents aged 10-22 years. The reasons for this rebound remain unclear but raise questions around vaccine coverage, notwithstanding that other vaccine preventable diseases such as measles, rubella, pertussis, diphtheria, poliomyelitis, and neonatal tetanus have shown continuing declines.…”

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

“…There was an epidemic during 2011-2012, even after a mumps-containing vaccine (MuCV) was formally introduced into the national immunization program in China in 2008. Cui et al [14] reported it might result from the accumulation of many mumps-susceptible individuals and low mumps vaccination coverage. After that, the incidence of mumps significantly decreased.…”

“…For influenza and mumps, the results of global spatial autocorrelation were not significant in some years, indicating influenza and mumps was prevalent in all the provincial units. However, from a regional perspective, the high-risk areas of influenza and mumps noticeably moved southward from 2006 to 2016 due to the spread of vaccines in western China [14]. Now, the southern mountainous region in China has become the severely afflicted area, which has a subtropical and humid climate and is characterized by high temperatures, precipitation, and humidity.…”

Assessing the Changes of Mumps Characteristics with Different Vaccination Strategies Using Surveillance Data: Importance to Introduce the 2-Dose Schedule in Quzhou of China

“…Since the prevaccination era, a 99% decrease in mumps cases has been observed in the United States [1]. In 2015, amongst the 194 World Health Organization (WHO) countries, 121 (62%) had incorporated MuV into their national immunization program, the majority of which used the MMR vaccine [11]. From 2005 to 2016, the prevention and control of mumps has gone through three periods in Quzhou.…”