Yellow Fever Alert Issued to Countries with Year-Round or Seasonal Dengue
David Bruce Conn, M.S., Ph.D.
Berry College OneHealth Ctr; Harvard Univ. Museum Comp Zoology; Senior Scientific Advisor U.S. State Dept.
Since I posted my brief on the emerging Yellow Fever (YF) situation in China by way of Angola one week ago, some significant new developments have occurred: 1) The number of human cases of YF imported to China from Angola by unvaccinated viremic travelers has now increased from 4 to 6, with addition of a new location in the Fujian Province of east China, reported on 24 March 2016; 2) a fatal case of YF occurred on 20 March 2016 in the northwestern Africa country of Mauritania in a patient who flew there from Angola days before; 3) the urban YF outbreak in Luanda, Angola is continuing, despite strong efforts of the Angola government, WHO, and others to combat the spread.
In response to this situation, and the potential for much wider spread into countries that have not yet experienced YF, but which have the characteristics for developing and sustaining major outbreaks, the International Society for Infectious Diseases, through its ProMED-mail program, has taken the rare step of issuing a major Yellow Fever Alert, targeted only to countries that typically have year-round or seasonal dengue. These countries are highly vulnerable to a potential YF outbreak due to the fact that dengue and YF are transmitted by the same mosquitoes in areas with dense human populations. Although a YF vaccine is available and effective, there is a global shortage presently, and distribution of available stocks takes time and resources that may be inadequate. Strategic countermeasures through enhanced surveillance, isolation of infected travelers from potential mosquito vectors, more comprehensive and aggressive vector control, and proactive training for vaccine deployment are warranted and recommended. A major outbreak of YF in areas not previously exposed, including India and other Asian and African countries, could be catastrophic.
Professor, Department Chair & Director of the Center for Vector Biology at Rutgers University
8yDoes anyone know which mosquito species are vectoring this epidemic? I recently read Brown et al 2014 Evolution 68(2): 514–525 and they argue that Aedes aegypti formosus, the feral dark form of Ae. aegypti was becoming urbanized in several African cities. These atypical vectors might select for atypical YF viral strains with atypical patterns of spread. Therefore assuming that current vectors of dengue will be good vectors of these strains might not be warranted, although as a safety precaution is definitely not misguided. I would like to know if infected mosquitoes have been identified. Thank you.
Health equity advocate and continuous learner
8yThank you David for this update, as these outbreaks do not always make it to mainstream travel health sites in a timely way; also another reason we advocate for humanitarian aid workers to be pre vaccinated prior travel!
Multidisciplinary Biomedical Scientist/Volunteer
8yThank you for your post David. It is very important to note that the world cannot afford another outbreak at the moment. I believe that further aggressive health promotion campaign in both Asian and African regions that are affected could make a very strong impact. People respond more to issues that are known to threaten their existence.
Walking cheerfully over the Earth around Kent County, Maryland
8yThank you for posting.