Weekly Digest: Zika infections in pregnant U.S. women; Flu vaccine 59 percent effective

The International Congress of Infectious Diseases will take place March 2-5, 2016 in Hyderabad, India. CDDEP Director Ramanan Laxminarayan serves as the Chair of the National Organizing Committee and CDDEP is co-hosting the event. Laxminarayan will also chair “Antibiotic Resistance: National Actions Contribute to a Global Solution,” a symposium focused on the Global Antibiotic Resistance Partnership, and deliver a plenary address entitled “Malaria: Past, Present, and Future.” CDDEP Senior Research Analyst Suraj Pant will present a poster on CDDEP’s Drug Resistance Index, a tool that measures the effectiveness of available antibiotics in a given setting, such as a country or hospital. [International Society for Infectious Diseases, CDDEP Drug Resistance Index]

Innovative and cooperative financing mechanisms can help address global health concerns, which are often “commons problems,” writes CDDEP Director Ramanan Laxminarayan in the Oxford Review of Economic Policy. In these trans-boundary commons problems, the actions of one country can have significant implications for countries surrounding it—for instance, if one country under-reports a disease outbreak to protect tourism, other countries may bear an added risk. Laxminarayan writes that such problems require innovative solutions, like large-scale efforts that incentivize countries to report disease outbreaks. They also require coordinated financing mechanisms that go beyond bilateral assistance, such as a subsidy that lowers the cost of quality drugs for all countries in a region, to ensure impacts that don’t disproportionately affect single countries. [Oxford Review of Economic Policy]

A common diagnostic tool for soil-transmitted helminth (STH) infections may not adequately assess STH prevalence in certain areas. Researchers, led by former CDDEP researcher Alice Easton, assessed cryopreserved stool samples from individuals in western Kenya with qPCR for a variety of STH infections and compared the test results with the point-of-contact diagnostic, called the 2-stool 2-slide Kato-Katz (KK) method. For several organisms, the KK method’s sensitivity, which measures the likelihood that a test will come out positive if the infection is present, was significantly lower than the qPCR. For other organisms, qPCR detected organisms that the KK method missed, and for a final group of STH infections, qPCR returned a positive test where the KK method cannot detect the organism at all. [Parasites & Vectors]

The U.S. Centers for Disease Control and Prevention estimated this season’s flu vaccine efficacy at 59 percent.  CDC announced the early vaccine effectiveness (VE) estimate, which measures the degree to which the vaccine lowered the risk of an individual requiring treatment for flu during a given season. The number was significantly higher than last year’s VE, which was estimated at 19 percent. [CIDRAP, CDC]

Human papillomavirus infection rates among girls age 14-19 in the United States have declined 64 percent following the introduction of Gardasil, the HPV vaccine. The vaccine has been recommended for teenage girls since 2006, and is now recommended for both boys and girls aged 13-17—though currently only about 40 percent of eligible girls and 20 percent of boys are vaccinated. According to research in Pediatrics, for sexually active girls and women aged 14-24 years, HPV prevalence among those vaccinated was 2 percent, versus 17 percent among the unvaccinated. [Pediatrics, The Incidental Economist]

At least two U.S. women have chosen to have abortions after a Zika diagnosis. Two other pregnant American women with the virus suffered miscarriages, and of three infected women who gave birth, two had healthy children and one had a child with serious birth defects. Based on examining a stillborn baby with Zika in Brazil and other evidence, epidemiologists concluded that microcephaly may not be the only severe abnormality caused by the virus. According to Albert Ko of Yale University, leader of the investigative team, “the virus may cause severe damage to fetuses leading to stillbirths and may be associated with effects other than those seen in the central nervous system.” [Washington Post, The Guardian]

ZMapp, an experimental drug for Ebola, performed well in the first rigorous efficacy trial. The drug trial was too small to draw firm conclusions because the Ebola outbreak ended before sufficient patients could be enrolled. Of the 72 Ebola patients enrolled in Guinea, Liberia and Sierra Leone, 36 patients received optimal standard treatment (mainly supportive care) and 36 received ZMapp in addition. In the standard treatment group, 37 percent of patients died within 28 days, compared with 22 percent in the ZMapp group. The small company that developed the drug, Mapp Biopharmaceutical, has stated its intent to seek FDA approval.  [The New York Times]

Social norm feedback, an antibiotic stewardship intervention that informs high-prescribing clinicians of their prescription rate in comparison to their peers, may lower antibiotic prescribing rates. UK researchers randomly assigned 1581 general practitioner practices in the National Health Service in the highest 20 percent of antibiotic prescribers to two groups: 1) an intervention group that received letters from England’s Chief Medical Officer informing the practice that they prescribed antibiotics at a higher rate than 80 percent of practices in their local area, and 2) a control group that received no letter. Six months after the letters were sent, practices in the intervention group dispensed 127 items per 1000 people while practices in the control group dispensed 131 per 1000 people. Over the six months, the difference represented over 73,000 fewer prescriptions in the intervention group. [The Lancet]

The world’s first dengue vaccine will be administered to schoolchildren in the Philippines starting in April. The vaccine, Dengvaxia, was created by Sanofi Pasteur and has been approved for use in Mexico, Brazil and El Salvador in addition to the Philippines. It is approved to prevent all four types of dengue for people aged 9-45 living in endemic areas. In experimental trials, the vaccine reduced the likelihood of contracting dengue by two-thirds. Sanofi Pasteur expects to eventually manufacture 100 million doses of the vaccine per year to meet worldwide demand. [The Wall Street Journal]

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