Measles death in Washington state is first in US since 2003
Measles was confirmed as the culprit in a Washington state woman's death this spring, the Washington State Department of Health (WSDH) said on Jul 2, the first US measles death in 12 years.
"The woman was most likely exposed to measles at a local medical facility during a recent outbreak in Clallam County. She was there at the same time as a person who later developed a rash and was contagious for measles," the agency said in a news release.
"The cause of death was pneumonia due to measles," the WSDH said.
The woman, from Clallam County, had several other medical conditions and was taking immune-suppressing medication, which would make her especially vulnerable to measles. The agency gave no other details about the woman, including her age.
Her diagnosis brings the state's measles case count to 11 for the year, the WSDH said, adding that the most recent active case was reported in late April. As of Jun 26, 178 people in 24 states have contracted the disease, according to the Centers for Disease Control and Prevention. Two thirds of those are attributed to a Disneyland-linked outbreak that began in December.
Jul 2 WSDH news release
Careful planning needed for global polio vaccine switch in 2016
The planned global switch from trivalent (three-strain) to bivalent (two-strain) oral polio vaccines (OPVs) next April will take careful planning to minimize the risk of new outbreaks of vaccine-derived polio virus (VDPV) infections, says a report in the Jul 3 Morbidity and Mortality Weekly Report (MMWR).
OPVs contain live attenuated polio viruses, which can mutate in the human intestine, notes the report, written by experts with the Global Polio Eradication Initiative. In rare cases in populations with low vaccine coverage, these VDPVs can lead to polio disease.
No cases of wild poliovirus type 2 (WPV2) have been reported since 1999, and no WPV3 cases have been identified since November 2012, notes the report. With WPV2 eliminated, plans call for removing that strain from OPVs next year to eliminate the risk of outbreaks of circulating type 2 VDPVs (cVDPV2s).
Among 686 polio cases caused by cVDPVs that have been detected since 2006, type 2 viruses accounted for more than 97%, the report says. It explains that OPV serotype 2 "will be withdrawn from all immunization activities and programs through a global, synchronized replacement" of all trivalent OPV (tOPV) with bivalent OPV (bOPV) containing only types 1 and 3 polioviruses.
"Careful synchronization of the switch from tOPV to bOPV within and across OPV-using countries will be critical to minimize the risk for new cVDPV2 outbreaks," the article states. "If, for example, a country continues to use tOPV after its neighbors have switched to bOPV, that country could export type 2 VDPVs to populations that are becoming increasingly susceptible to infection. The more tightly the switch to bOPV is synchronized, the lower the risk for new cVDPV2 outbreaks following it."
The report also explains that trivalent inactivated polio vaccine (IPV) is currently being introduced in all countries, with the aim of reducing the risk of cVDPV2 outbreaks and facilitating responses to any that do occur. As of Jun 24, 90 of 194 World Health Organization (WHO) member countries were using IPV, and 102 others had set dates for introducing it.
To further boost the response to any type 2 polio outbreaks, a global stockpile of monovalent OPV2 is being assembled, the report notes. It also says that a WHO action plan calls for the destruction or containment of WPV2 and cVDPV2 strains held in research or manufacturing facilities by the end of this year.
Jul 3 MMWR article
Report: New norovirus strain predominated in Japan in March
Not only did a novel GII.17 norovirus variant emerge in China and Japan last winter, but by March it had become the dominant strain in Japan, researchers reported last week in Eurosurveillance.
Japanese investigators noted that, among 2,133 norovirus isolates from patients with diarrhea from October 2014 through March 2015, 373 were genotype GII.4, 146 were GII.3, and 100 were a novel GII.17 called GII.P17-GII.17. Incidence of the new strain in 2015, however, rose sharply, from 11 cases in January to 55 in February and 31 in March, making it the most prevalent strain in that month. The novel GII.17 strain caused only 3 cases of diarrheal illness the previous winter.
The team conducted phylogenetic analyses on the isolates, which showed that GII.P17-GII.17 has a different evolutionary history than previously identified GII.17 strains.
A commentary by an international group of experts that accompanied the report gave an overview of the new strain. The authors concluded that it remained to be seen whether the novel strain will predominate in other parts of the world besides East Asia.
"Nevertheless," the authors wrote, "the public health community and surveillance systems need to be prepared in case of a potential increase of norovirus activity in the next seasons caused by this novel GII.P17-GII.17 norovirus."
Jul 2 Eurosurveill report
Jul 2 Eurosurveill commentary