“A sudden, sharp increase in babies with ‘no foreheads and very strange heads’ was baffling doctors in Brazil. That set off a search for answers that led to a little-known pathogen, the ZIKA virus.” — NY Times, February 6. 2016.
The Zika virus, ZIKV, belongs to a group of viruses related to Yellow Fever, Dengue and West Nile Fever. In 1947, it was first identified in the rhesus monkey in the tropical Zika Forest of Uganda and a year later it was detected in mosquitos. The virus spreads to humans predominantly by the bites of the Aedes mosquitos. In 1952, it was identified for the first time in humans living in Uganda and Tanzania.
Prior to 2007, there were only fourteen human cases of ZIKV disease worldwide. In 2007, the ZIKV spread from Africa and Asia to the small, Pacific Island of Yap, population of 11,250. It was the first major ZIKV outbreak and infected 185 inhabitants. However, the virus in 2013-2014 also caused outbreaks in four other groups of Pacific Islands.
But the Zika outbreak that shook up the health world happened in 2015, in Recife, Brazil. Health workers in that country’s northeast city noticed an unusual upshot in the incidence of microcephaly (see below) in newborn infants. As one health worker described it, newborn infants appeared with virtually “no foreheads and very strange heads.” Below are some key facts or takeaways about the ZIKA virus.
KEY FACTS
- Zika virus disease (ZIKV) is transmitted to humans by the bites of mosquitos, Aedes mosquitos. They circulate in Africa, the Americas, Asia and the Pacific.
- The virus can spread from mother to child during pregnancy and childbirth. It can also be sexually transmitted from one partner to another.
- People with the Zika virus disease can have symptoms that include mild fever, skin rash, conjunctivitis, muscle and joint pain, malaise or headache. These symptoms normally last for 2-7 days.
- Eight out of ten people infected with the ZIKV have no symptoms.
- Although travel history, symptoms and findings are helpful, laboratory testing is necessary to confirm the diagnosis of the Zika virus.
- There is no specific treatment or vaccine currently available.
- The ZIKV is most dangerous during the first trimester of the developing fetus.
- The virus can cause birth defects such as microcephaly (the circumference of an infant’s head is smaller than normal because the brain has not developed).
- The virus has been detected in pregnant women’s amniotic fluid and fetal brain tissue whose fetuses have been diagnosed with microcephaly.
- The virus has been associated with Guillain-Barre syndrome, a rare disorder of the nervous system in which your body’s immune system attacks your own nerves. In rare instances, it can lead to paralysis of your body.
- The best form of prevention is protection against mosquito bites and to avoid areas where the Aedes mosquitos -ZIKV- are most prevalent.
Public health is population health and on February 1, 2016 WHO declared a Public Health Emergency of International Concern because of the recent spread and association of ZIKV with “clusters of microcephaly and other neurological disorders.”
Prior to 2007, as noted, there were only fourteen human cases of ZIKV disease worldwide. Today, there are many thousands confirmed cases of Zika virus disease. “As of May11, 2016 58 (fifty eight) countries and territories report continuing mosquito-borne transmission of the virus to people.
U.S. Senator Dick Durbin of Illinois on April 29, 2016 said, “More than 1,000 Americans in 42 states have contracted the virus, including more than 90 pregnant women.” Presently, there are no incidences of the virus being transmitted by the bites of Aedes mosquitos in the U.S.
However, Mayor League Baseball cancelled a two game series scheduled to be played in Puerto Rico on May 30-31, 2016 because of the players concern of contracting the mosquito-borne viral disease Zika which has been
linked to birth defects.
It’s imperative to understand the key issues with ZIKV and to keep Zika in mind if we’re travelling. ZIKV is an ongoing story and facts and figures will change. We need to do our best not to be an unfortunate chapter in this story.
References
- WHO, World Heath Organization; Situation Report; Zika Virus, Microcephaly and Guillain-Barre syndrome; 12 May 2016
- CDC, Centers for Disease Control and Prevention; All Countries and Territories with Active Zika Virus Transmission; 12 May 2016
- Zika Virus Infects Cortical Neural Progenitors; Cell Stem Cell; Volume 18, issue 6; 5 May 2016
- Senator Dick Durbin, Senator of Illinois; Zika Appropriation Prooosal; April 29, 2016