Measles surveillance in Taiwan, 2012–2014: Changing epidemiology, immune response, and circulating genotypes

Abstract

In Taiwan, although the coverage rate of two doses of measles-containing vaccine has been maintained at over 95% since 2001, measles outbreaks occurred in 2002, 2009, and 2011. The present study reports that 43 cases were confirmed by laboratory testing in Taiwan in 2012-2014 and that adults have emerged as one of groups susceptible to measles virus (MV) infection, who may have discrepant humoral immune reactions--indicated by the level of IgM and IgG antibodies compared to a naïve, susceptible measles case. Thirty-seven of 43 cases confirmed by RT-PCR were further characterized by genotyping. In Taiwan, genotype H1 was the major strain in circulation prior to 2010, while D9 was the most frequently detected MV genotype between 2010 and 2011. The genotyping data collected between 2012 and 2014 revealed that H1 rebounded in 2012 after an absence in 2011 and was imported from China and Vietnam. In 2014, genotype B3 first appeared in Taiwan following import from the Philippines and became the most frequently detected strain. Genotype D8, linked to importation from various countries, including India, Indonesia, Thailand, and Vietnam, showed sequence divergence. D9 was imported from Malaysia in 2014. The MV genotypes detected in Taiwan reflected the genotypes of circulating endemic measles strains in neighboring countries. A significant rise in the number of measles cases and in measles with genotypes imported from surrounding countries indicated that measles resurged in Asia in 2014.

Approaching measles elimination in Switzerland: changing epidemiology 2007–2018

“…This difference in the impact of vaccination by age explains the increase in the median age of cases. The age continues to rise as vaccination coverage grows, as observed recently in Switzerland and also elsewhere in Europe [12,13], North America [14], Japan [15], Taiwan [16] and China [11,17]. Contrary to recent observations in Beijing, where increasing vaccination coverage coincided with a rising proportion of cases among infants below 1 year of age, this proportion remained low in Switzerland during both the epidemic and the post-epidemic period [11].…”

“…The average annual incidence rate of measles fell from 133 cases per million inhabitants during the epidemic period (range 11-291) to 9 cases per million inhabitants (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) during the post-epidemic period. This constitutes a decline in the incidence of measles of 94% between these two periods.…”

Occurrence of measles genotype D8 during a 2014 outbreak in Banjarmasin, South Kalimantan, Indonesia

“…1 Recently, MV-D8 was reported in two Taiwanese travelers visiting Indonesia. 5 According to a WHO report 6 and personal communication with an Indonesian Ministry of Health representative and PT Bio Farma, MV-D8 was detected co-circulating with genotypes D9 and B3 in 2013 and 2014 in Sumatera and Jakarta, Indonesia. It is possible that MV-D8 has been circulating within Indonesia in areas of low vaccination coverage, but the origin of the strain is difficult to specify.…”

The phylodynamic of H1a genotype measles virus in Jiangsu province, China, 2005-2017

“…Based on the sequence analysis of H and N genes, not only genotype of measles virus was identified [16][17][18], but also the source of wild types measles viruses associated with outbreaks was inferred [9,[19][20][21]. For example, the new genotype of measles emerged in a given region was associated with the imported virus by travelers between various countries [22,23].…”