CDC/ACIP [to 27 Oct 2018 ]
MMWR News Synopsis for October 26, 2018
Influenza A(H3N2) Variant Virus Outbreak at Three Fairs — Maryland, 2017
People at high risk for serious influenza complications should avoid pigs and swine barns because of the risk of contracting a variant type of influenza that circulates in pigs. In 2017, an outbreak of variant influenza – human infection with influenza viruses that normally circulate in swine – was detected in Maryland. Influenza A(H3N2) variant virus infection was identified in 40 patients with exposure to swine at one of three Maryland agricultural fairs. More than one-third (35%) of patients reported only indirect contact with swine. Sixty percent of patients were children younger than 5 years. Three-fourths of these patients were at high risk for serious influenza complications (age <5 or ≥65 years, or a chronic medical condition). This outbreak highlights the risk, particularly among children, for contracting variant influenza virus at agricultural fairs, and underscores the need for increased public awareness that people in high-risk groups should avoid pigs and swine barns.
Update: Influenza Activity — United States and Worldwide, May 20–October 13, 2018
CDC recommends yearly influenza vaccination for everyone 6 months of age and older without contraindications. CDC recommends getting vaccinated by the end of October; however, vaccination should continue throughout the influenza season as long as influenza viruses are circulating. While annual influenza vaccination is the best way to prevent influenza and its potentially serious complications, prescription influenza antiviral medications can be used to treat influenza illness. Early treatment is recommended for patients with influenza illness who are very sick or who are sick and at high risk for influenza complications. Antiviral medications can shorten the duration and severity of illness and help prevent more severe illness; they work best when started within 48 hours of symptom onset. This article summarizes influenza activity in the U.S. and globally from May 20 through October 13, 2018. While influenza A (H1N1)pdm09, influenza A (H3N2) and influenza B viruses were identified, influenza A(H1N1) predominated in the U.S. and globally in most regions. Summertime influenza activity in the United States has been low and influenza activity in the Southern Hemisphere during their influenza season has been relatively low and fairly mild. Antigenic testing of available influenza A and B viruses has not detected significant antigenic drift in circulating viruses. It is difficult to predict which influenza virus will predominate or how severe influenza disease activity will be during the 2018-2019 influenza season.
Measles Outbreak in a Highly Vaccinated Population — Israel, July–August 2017
In outbreak settings, health care providers should maintain a high index of suspicion for measles, regardless of vaccination status, and conduct a thorough epidemiologic and laboratory investigation of suspected measles cases. During the summer of 2017, nine measles cases occurred among vaccinated Israeli soldiers. The primary case had recently traveled to Europe. All other cases were his direct contacts. All patients had mild illness; no tertiary cases occurred. Unlike most previous outbreaks in Israel, which occurred in unvaccinated or partially vaccinated populations, this outbreak occurred in a population with high two-dose measles vaccination coverage. Because of the mild symptoms, without active surveillance the possibility of measles would likely not have been considered and circulation of the virus might have continued. The fact that most contacts were fully vaccinated probably contributed to rapid containment.
Update on Vaccine-Derived Polioviruses — Worldwide, January 2017–June 2018
Vaccine-derived polioviruses will continue to cause rare outbreaks and infect individuals with immunodeficiency until all use of oral poliovirus vaccine can cease after wild poliovirus transmission is eradicated. All countries must maintain high population immunity to polio through vaccination. Vaccine-derived polioviruses (VDPVs) are strains genetically divergent from the oral poliovirus vaccine (OPV) that fall into three categories: 1) circulating VDPVs (cVDPVs) from outbreaks, 2) immunodeficiency-associated VDPVs (iVDPVs) from patients with primary immunodeficiencies, and 3) ambiguous VDPVs (aVDPVs) that cannot be more definitively identified. During January 2017–June 2018, new cVDPV outbreaks were identified in the Democratic Republic of the Congo, Kenya, Nigeria, Papua New Guinea, Somalia, and Syria. Six newly identified persons in four countries were found to excrete iVDPVs.