When infections go viral Zika Virus

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1 When infections go viral Zika Virus John Fangman, MD Associate Professor of Medicine (Infectious Diseases) Senior Medical Director of Ambulatory, Medical College Physicians Medical College of Wisconsin Overview The basics of Zika Virus How we came to care about Zika Tracking the virus Developing a plan to combat Zika Future Challenges Zika Virus: Basics Single stranded RNA virus. Genus Flavivirus, family flaviviridae. Closely related to dengue, yellow fever, Japanese encephalitis, and West Nile viruses. Primarily transmitted through the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). Aedes aegypti Aedes albopictus 1

2 Zika Virus: Symptoms Incubation period for Zika is 3 14 days Many infections asymptomatic Most common symptoms Abrupt onset of fever Red, bumpy rash on trunk Joint pain Conjunctivitis (pink eye) Other symptoms include muscle pain and headache Zika stays in the blood from a few days to 1 week Virus remains in semen and urine longer than in blood Zika Virus: Background Zika Virus: Outcomes Clinical illness is usually mild Symptoms last several days to a week Severe disease requiring hospitalization is uncommon Fatalities are rare Research suggests that Guillain Barré Syndrome (GBS) is strongly associated with Zika; however only a small proportion of people with recent Zika infection get GBS 2

3 Zika Virus: Pregnancy Zika infection in pregnancy can lead to severe brain defects Microcephaly: birth defect in which a baby s head is smaller than expected when compared to babies of the same sex and age. Also linked to other problems pregnancies and in fetuses and infants infected with Zika before birth. Miscarriage, stillbirth, absent or poorly developed brain structures, eye defects, hearing deficits, limb abnormalities, and impaired growth Zika Virus: Tracking an Outbreak NY Times Feb 6, 2016 Zika Virus: The Challenge 3

4 Zika Virus: The Mosquito Aedes sp. mosquitos are found worldwide Daytime biters Closely linked to population centers Require warm environments to survive year round Transmit a variety of infections including Dengue Fever, Yellow Fever and Chickungunya Don t travel more than 6 blocks in their lifespan To date, no Aedes sp. Mosquitos have been discovered in Wisconsin Zika Virus: Current State of the Epidemic Infection in Brazil have peaked though cases spreading throughout Central and South America, the Caribbean and Mexico As of October 5, 2016, CDC reports 3818 total case of Zika in US including: 3712 travel associated infection 30 sexually transmitted cases 837 pregnant women 13 cases of GBS 105 locally acquired mosquito associated cases In Wisconsin, 780 people have been tested and 48 were positive Zika Virus: Diagnosis Important to keep an open mind to all potential causes of fever and rash in returning travelers and in areas where Zika may become established in mosquitos Zika can be diagnosed both by direct measurement of viral material in blood or body fluids or by measuring the body s response to the infection (antibodies) Diagnostic tests can be both falsely positive and negative, especially when tested person has previous infection or vaccination to virus related to Zika 4

5 Zika Virus: Prevention Zika Virus: Vaccine Development There vaccines for yellow fever and Japanese encephalitis virus and animal studies have shown adequate immune response to both traditional killed virus and DNA vaccines Development of vaccine for Zika complicated by high rates of asymptomatic infections, rapid spread in affected communities, and fact that those most likely to benefit (pregnant women) are people most difficult to study Trials of candidate vaccines launched last month Novel approaches to spread of Zika include use of genetically modified Aedes sp. mosquitos Zika Virus: Future Challenges Recent events have highlighted that interconnected nature of the world and the risks that sub standard health care and public health infrastructure contribute to the emergence of novel infections locally The global community is learning from SARS, MERS, Ebola and Zika and the time from identification to coordinated response is improving Emergence of global pandemics appears to be occurring more frequently and it is in all our interests to prepare an effective, coordinated response regardless of where they first arises Bill Gates N Engl J Med 372:15 April 9,

6 Additional Zika Resources virus event/zika virus 6