Zika Returned to the USA in 2019

International travelers continued to return to the USA infected with the Zika virus during 2019
(Zika News)

As 2019 comes to a close, it appears the number of travel-related Zika cases reported in the USA has diminished.

Furthermore, the good news from the Centers for Disease Control and Prevention (CDC) is that there have not been any local transmissions of the Zika virus in the continental United States, as of December 5, 2019.

The leading states in the USA reporting travel-related Zika cases are California (39) and Florida (36).

As of December 1, 2019, data from the California Department of Health indicate the majority of its Zika cases in 2019 were reported in San Diego (7), Los Angeles (6), and Orange (5) counties. 

These travel-related Zika cases originated in various states of Mexico. The Mexican states reporting the most locally-acquired Zika cases as of mid-December 2019 are Jalisco (48), Morelos (28), and Sinaloa (27).

Conversely, the Florida Department of Health’s Arbovirus Surveillance Report published on December 21, 2019, indicates Floridians returned from these Carribean countries infected with the Zika virus: Haiti (11) and Cuba (6).

And, the Florida counties reporting Zika cases during 2019 were: Broward (5), Collier (3), Duval, Hillsborough (2), Indian River, Lee, Miami-Dade (17), Orange (4), Palm Beach, and Sarasota.

Unfortunately, Florida’s Health Department says it ‘is monitoring a total of 23 pregnant women infected with Zika during 2019.’

Throughout the Americas, the Pan American Health Organization (PAHO) reported 31,921 Zika virus cases in the Americas during 2019, with Brazil (27,052) and Peru (2,267) reporting the most cases, as of Week #53.

And, the US Territory of Puerto Rico has reported 57 locally-acquired Zika cases in 2019.

Outbreaks of Zika virus disease have been recorded in the Americas since March 2015, when Brazil reported a large outbreak.

Later, in October 2015, Brazil reported an association between Zika virus infection and microcephaly. 

To date, a total of 86 countries and territories have reported evidence of mosquito-transmitted Zika infection, says the World Health Organization (WHO).

Signs and symptoms

The majority of people infected with the Zika virus do not develop symptoms. Symptoms are generally mild including fever, rash, conjunctivitis, muscle and joint pain, malaise, and headache, and usually last for 2–7 days.

Complications of Zika virus disease

Zika virus infection during pregnancy is a cause of congenital abnormalities in the developing fetus and newborn. Zika infection in pregnancy also results in pregnancy complications such as fetal loss, stillbirth, and preterm birth.

Microcephaly is caused by underlying abnormal brain development or loss of brain tissue. Child outcomes vary according to the extent of brain damage.

Congenital Zika syndrome includes other malformations including limb contractures, high muscle tone, eye abnormalities, and hearing loss. 

Zika virus infection is also a trigger of Guillain-Barré syndrome, neuropathy, and myelitis, particularly in adults and older children.


Zika virus is primarily transmitted by the bite of an infected mosquito from the Aedes genus, mainly Aedes aegypti, in tropical and subtropical regions. Aedes mosquitoes usually bite during the day, peaking during early morning and late afternoon/evening.

Zika virus is also transmitted from mother to fetus during pregnancy, through sexual contact, transfusion of blood and blood products, and organ transplantation.


Infection with the Zika virus may be suspected based on symptoms of persons living in or visiting areas with Zika virus transmission and/or Aedes mosquito vectors. A diagnosis of Zika virus infection can only be confirmed by laboratory tests of blood or other body fluids, such as urine or semen.


There is no treatment available for the Zika virus infection or its associated diseases.


No vaccine is yet available for the prevention or treatment of Zika virus infection. The development of a Zika vaccine remains an active area of research.

Sexual transmission

Zika virus can be transmitted through sexual intercourse. This is of concern due to an association between Zika virus infection and adverse pregnancy and fetal outcomes.

For regions with no active transmission of Zika virus, WHO recommends practicing safe sex or abstinence for a period of six months for men and two months for women who are returning from areas of active Zika virus transmission to prevent infection of their sex partners.

Sexual partners of pregnant women, living in or returning from areas where local transmission of Zika virus occurs, should practice safer sex or abstain from sexual activity throughout pregnancy.

The decision to travel to a country with a history of Zika circulation should be based on a personal risk assessment, done in conjunction with the traveler’s healthcare provider, that account for individual risk factors for severe outcomes from the possibility of a Zika infection, concludes the WHO.

Zika Virus News published by Zika News