Weekly Digest: California Governor signs bill ending vaccine exemptions, Ebola returns to Liberia

“Antibiotics are truly amazing […] but they’re also different from other drugs: If I were to take a statin, that doesn’t diminish the effectiveness of the statin for any of you.” CDDEP Director Ramanan Laxminarayan spoke at the Aspen Ideas Festival Spotlight Health panel session last week entitled “The Looming Antibiotic Crisis.” The panel also included National Institute of Allergies and Infectious Disease (NIAID) Director Anthony Fauci and former FDA Commissioner Margaret Hamburg, who spoke about U.S. policies and research to limit the spread of resistance. A short clip of Laxminarayan, focusing on antibiotic resistance as a societal problem, is available online, as is video of the full panel session. [Aspen Ideas Festival, YouTube]

California Governor Jerry Brown signed state Senate Bill 277 into law this week, eliminating vaccine exemptions for personal beliefs and religious reasons. Under the new law, all children attending public and private schools must be current on required vaccinations, with exemptions allowed only for medical reasons. The law, which was proposed by state legislators following a measles outbreak that began at Disneyland in December 2014, will take effect on July 1, 2016. [San Jose Mercury News]

Patients in nursing homes that are on the high end of the antibiotic use curve have an increased risk of getting an antibiotic-resistant infection—even if they haven’t taken antibiotics themselves, according to a study published in JAMA Internal Medicine. The study arrayed 607 nursing homes in Canada by their level of antibiotic use, which covered a wide range. The risk of antibiotic-related adverse events—including infection with Clostridium difficile and antibiotic-resistant bacteria—increased for all residents as overall antibiotic use by the nursing home increased. [JAMA Internal Medicine]

Ebola has returned to Liberia. A teenager who had been treated for symptoms of malaria died of the disease and two others were infected with the virus. Efforts to curb the spread of Ebola in Guinea and Sierra Leone have stalled in the last month, with a combined total of at least 20 new cases each of the past five weeks. Finding a treatment for the virus has also proved difficult: Trials for TKM-Ebola, a drug that had showed some positive results in monkeys, were stopped two weeks ago for lack of efficacy.  [CIDRAP, WHO, Science]

Current levels of antibiotic use in China’s food animals are largely unknown but likely to be high, according to an editorial in Antimicrobial Resistance and Infection Control by Peter Collignon and Andreas Voss. China consumes more meat than any other country and use of antibiotics for growth promotion is thought to be commensurately high. No available methodology is appropriate to estimate how high, however, including methods appropriate for the United States, and no way to verify how much and of what types is being used. The authors contend that obtaining such data, from both human and agricultural sectors across the world, is a critical step towards assessing and addressing the global problem of antibiotic resistance. [Antimicrobial Resistance and Infection Control]

Cuba has been declared by the World Health Organization to be the first country to end mother-to-child transmission of HIV and syphilis. They accomplished the feat by increasing access to antiretroviral drugs, HIV testing and prenatal care and by treating mothers testing positive for HIV. Cuba was the first country to request the certification, and since then more than twenty other countries have applied for it, according to a spokeswoman for the Pan American Health Organization.  [The New York Times, WHO]

Last year’s flu vaccine conferred only 19 percent protection against the virus, and now researchers know some of the reasons why. Their conclusions, published in Cell Reports, center around the viral protein hemagglutinin. When exposed to a strain of the virus—such as in a flu vaccine—the human immune system creates antibodies that attach to hemagglutinin and inactivate the virus, but mutations in the virus’ genome can create new forms of hemagglutinin and render the pre-made antibodies ineffective. Suspecting that this was why the 2014-15 vaccine was less effective than expected, they found that such mutations had occurred in one of the strains used in the vaccine. One of the isolated mutations, named F159S, had a particularly strong effect, and has been added to the mix of strains in next year’s vaccine. [Science, Cell Reports]

Multi-drug resistant tuberculosis (MDRTB) may be harder to spread within households than non-drug resistant TB, according to a study published in PLOS Medicine. The three-year prospective cohort study examined household contacts of drug-sensitive and drug-resistant RB patients in two Peruvian cities. They found the risk of MDRTB transmission was about half the risk of transmitting a sensitive strain [PLOS Medicine]

Extreme weather events—including unusually high heat and precipitation—are associated with increased risk of Salmonella infections. A study by researchers at the University of Maryland examined the effects of long-term increases in extreme temperature and precipitation between 2002 and 2012 on Salmonella rates. They found that the increased risk was even more pronounced in coastal areas, and noted that the types of weather events they studied are likely to occur more frequently in the future as a result of climate change. [Environment International]