Florida Department of Health, Brevard County Zika Virus Update
By William “Barry” Inman, BA/BS, CIC // May 5, 2016
personally protect against bites and drain, dump and cover mosquito breeding grounds
Editor’s Note: We are delighted to welcome Barry Inman, epidemiologist for the Florida Department of Health here in Brevard County, to provide an update on the Zika virus.
The federal Centers for Disease Control and Prevention recently confirmed that there is no longer any doubt that the mosquito-borne virus causes babies to be born with abnormally small heads and other severe brain defects.
With reports now indicating that the Zika virus may soon be endemic in southern U.S. states by this summer, the American College of Obstetrics and Gynecology (ACOG) and public health officials have been vocal advocates for Congress to increase funding to U.S. public health departments to develop and prepare for aggressive preventive programs and more effective treatment of the viral infection.
Congressional negotiators are moving closer to an agreement to provide at least $1.1 billion in emergency financing to combat the rapidly spreading mosquito-borne virus.
— Dr. Jim Palermo, Editor-in-Chief
BREVARD COUNTY • VIERA, FLORIDA — Currently 426 cases of Zika virus have been reported in the United States with no transmission occurring from mosquitoes here in the states.
Florida leads the nation with 115 reported cases, which comprise 27 percent of the cases in the United States. The vast majority of cases reported in Florida are from Dade County, with Brevard County reporting two cases.
Zika Virus History
Zika virus was first discovered in 1947 while physicians were conducting a study on yellow fever in the Zika forest of Uganda, thus the name “Zika.” A flavivirus similar to Dengue, Chikungunya and Yellow fever viruses, Zika infection in humans was first recognized in Nigeria in 1953 after confirmation in three ill patients.
The virus remained rather obscure for nearly 70 years until, in just 1 year, the virus was found in Brazil and the Pacific islands and subsequently spread to the Americas.
Serosurveys found the virus had more wide-spread distribution among humans than previously thought, including many parts of Souteast Asia and Africa.
However, no outbreaks occurred until 2007 when the Yap Island in the Pacific reported an estimated 5,000 infections among the total population of 6,700.
Later in 2013 and 2014, an outbreak occurred in French Polynesia that involved over 32,000 persons and complications of Guillain-Barre′ syndrome were noted. The other outbreaks occurred in other parts of the Pacific region.
Zika virus was first identified in the Americas in March 2015, with 33 countries and territories reporting cases by March 2016. At that time investigators noted an increase in infants born with microcephaly in the same areas as Zika virus was reported.
As found in the early studies of Zika, the virus is transmitted primarily by mosquitoes. Initially the Aedes africanus, Aedes luteocephalus, Aedes furceifer, and Aedes taylor were found to be like enzootic vectors in African and Asia.
However, in urban areas the two main vectors are Aedes aegypti and to a lesser extent A. albopictus.
The Aedes aegypti is the primary vector because it feeds primarily on humans, often bites multiple humans in a single blood meal and many humans are not aware they have been bitten. Aedes aegypti live closely with humans and bite during the day.
Both the Aedes aegypti and A. albopictus are found in Florida and throughout the southeastern United States.
Sexual Transmission Of Zika
Zika has been found in the semen of infected men, but it is not certain how long it stays there and over what period of time a man can transmit the virus through sex.
Sexual transmission has been documented in 14 cases, with transmission occurring more likely from male to female and now one case from male to male. Most cases occurred while the male had symptoms of Zika during sexual contact.
The CDC has issued new guidelines for prevention of sexual transmission of Zika virus, and advises men who’ve returned from a Zika-affected area that they should consider abstaining from sex or using condoms for an unspecified period of time.
The CDC has also provided a comprehensive Q&A on Zika and sexual transmission on their website.
Blood transmission has yet to be reported but is likely to occur given that other flaviviruses have been reported through blood transfusion.
Testing for Zika virus can be complex. The mainstays for diagnosis are the RT-PCR and IgM antibodies.
Detection of viral nucleic acid in serum by RT-PCR is most successful within 1 week after onset of illness, therefore PCR is most applicable in those with acute symptoms.
IgM antibodies may be more useful after one week of symptoms or for pregnant females who reside or have traveled to areas of local transmission and have no symptoms.
Characteristics Of Zika Infection
The Zika virus incubation period is 2-14 days after exposure to mosquitoes. Usually only 20-30 percent of patients may exhibit symptoms such as fever, arthralgia, conjunctivitis and maculopapular rash.
Other symptoms such as malaise, headache, retro-orbital pain and vomiting may also manifest with Zika.
Symptoms usually last seven to 10 days, and few persons are hospitalized with Zika infections.
There is no treatment for Zika virus except supportive therapies, and no vaccine is currently available.
Complications of Zika Infection
There is substantial evidence that Zika virus can be transmitted from mother to the fetus during pregnancy. Viral RNA has been identified in the brain tissue and placentas of children born with microcephaly to mothers also testing positive for Zika virus.
Last month, the Center for Disease Control and Prevention (CDC) reported that the evidence now indicates causality between Zika and microcephaly, a devastating birth defect that results in the underdevelopment of the head and brain.
However, the CDC said this information does not change their existing clinical guidelines on the prevention and treatment of potential Zika virus infection, and that the focus remains on protecting pregnant women and their partners from transmission of the Zika virus.
Other complications such as Guillain-Barre′ syndrome, a rare disorder in which your body’s immune system attacks your nerves, have been reported. The Zika virus with certain Phenotypes may have neurotropism and therefore patients may develop neurological syndromes.
The absolute degree of risk to infants diagnosed with Zika for developing microcephaly or to adults diagnosed with Zika virus for developing Guillain-Barre syndrome is unknown at this time.
Vigilance Is Imperative
The take home message is to control your exposure to mosquitoes. With the coming months of summer, mosquito populations will increase. Mosquitos not only transmit Zika but can also transmit Dengue, Chikungunya and West Nile Virus.
Pregnant women or those who may become pregnant should not travel to areas with local transmission of Zika, such as the Caribbean and Central and South America. Those who travel to these areas should abstain from sexual contact or be sure to use a condom for up to eight weeks.
Locally, make sure your home or business does not have areas of standing water, such as bird baths, gutters, buckets, tires, rot holes in trees, etc., and of course wear insect repellants such as DEET when outside for extended periods. It is safe for pregnant women to use DEET repellants.
The bottom line is: DRAIN-DUMP AND COVER!!
ABOUT THE AUTHOR
William “Barry” Inman, BA/BS, CIC has 40 years of experience as an epidemiologist, is Certified as an Infection Control Preventionist by the CBIC and received his BA and BS of the University of Florida in 1974. He is employed by the Brevard County Health Department in Merritt Island, Florida. He is responsible for control of communicable diseases by surveillance and investigation methods in the Brevard County area-Space Coast. He works directly with the Infection Control personnel in hospitals, long term care, acute long term care, NASA, etc. with assistance in identifying diseases which are communicable.