From Joseph M. Kontra, M.D., LGH Division Chief, Infectious Diseases, and Philip Bayliss, M.D., Family & Maternity Perinatology
|Dr. Joseph Kontra and Philip Bayliss urge women who are pregnant or planning to become pregnant to avoid travel to regions affected by the Zika virus.
What is the Zika virus?
Zika virus is a mosquito-borne flavivirus that has recently caused a major epidemic in Central and South America, as well as the Caribbean. The virus spread from its African origins to Micronesia in 2007, and subsequently across a string of southern Pacific islands to Chile’s Easter Island in 2014. In May 2015, locally acquired cases were first identified in Brazil, the site of the upcoming Olympics. Zika virus has spread rapidly across the Americas in the last eight months, aided by the weather and the presence of the appropriate mosquito vectors.
What are the symptoms?
Zika virus causes a generally self-limited acute illness characterized by fever, rash, headache, myalgias and conjunctivitis. The onset occurs two to 12 days after the bite of an infected Aedes genus mosquito, and symptoms usually last less than a week. Zika virus infection is generally mild and rarely requires hospitalization. In fact, only about 20 percent of patients who are bitten and infected actually develop clinical disease. So why is this self-limited, often subclinical disease anything more than an ID board question?
Why is Zika virus so dangerous for pregnant women?
Zika virus infection during pregnancy appears to be associated with the devastating outcome of microcephaly, with miscarriage, fetal demise and neonatal deaths also reported. In fact, from May 2015 to January, the Health Ministry of Brazil reported a 20-fold increase (over 3,500 cases) of microcephalic births in mothers infected with Zika virus. Congenital macular atrophy may also be a post-infectious sequelae of Zika virus, as might the significant rise in reported cases of Guillain-Barre syndrome in endemic regions. The full spectrum and exact incidence and prevalence of outcomes related to Zika infection are as yet undefined, but infection with this virus clearly is a cause of serious concern in returning pregnant travelers. Infection during any trimester is considered high-risk.
What precautions should pregnant women take?
Patients who are pregnant or plan to become pregnant should avoid travel to infected countries, which include the Caribbean, Central and South America. If a pregnant patient must travel to an area where Zika transmission is ongoing, strict precautions should be followed to avoid a mosquito bite. These include wearing long-sleeved shirts and pants, using permethrin-treated clothing and gear, using U.S EPA registered insect repellants and sleeping in screened-in or air-conditioned rooms.
Who should be tested for Zika virus?
If a pregnant woman is suspected of infection, diagnostic testing should be considered. There is no commercially available test for Zika virus, and the LGH lab does not perform this testing. Zika virus diagnostic testing, which is carried out only through the CDC Arboviral Diagnostic Lab in Colorado, consists of RT-PCR and serologic methods. Zika virus testing is indicated for women with a travel history to an endemic region who have within two weeks manifested two or more of the symptoms listed above. If testing is indicated, evaluation for CMV, Dengue and Chikungunya virus also should be included. A woman with a travel history to a Zika endemic zone but with no symptoms and a fetal ultrasound negative for microcephaly or intracranial calcifications is at low risk. Testing can be deferred according to current guidelines, unless there are abnormal fetal ultrasound findings.
How do I order a test for Zika virus?
To order a Zika virus test through EPIC, order an “Unidentified Lab Test,” and type in “Zika virus testing.” A gold top tube is the appropriate choice for this test. The specimen will need to be routed through the PA State Department of Health. Information regarding the patient’s travel history, symptoms and date of onset will be requested from the Send Out Lab, so save yourself a phone call and include this information in the text fields of your EPIC order. The turn-around time for the test is at this point unknown. All suspected Zika virus cases should be reported to the PA DOH at 1-877-PA-HEALTH.
What other precautions are necessary for pregnant patients?
Serial ultrasonography to monitor fetal growth and anatomy is indicated for all pregnant women with a history of travel to an area of Zika transmission. In a patient without symptoms, if microcephaly or intracranial calcifications are identified, laboratory testing for Zika virus infection is indicated. The role of prenatal Zika-RT-PCR testing of amniotic fluid remains unclear but should be considered. For live births with clinical evidence of maternal or fetal Zika virus infection, umbilical and placental histopathology with frozen tissue for Zika virus RNA testing and cord serum for Zika and Dengue antibodies should be considered.
Is there a treatment for Zika virus?
There is no specific treatment or vaccine for Zika virus. Management is supportive. But keep in mind that Dengue (as well as Chikungunya virus, among other pathogens) can be acquired in the same endemic regions and cause similar symptoms. Specifically, until Dengue can be ruled out via appropriate serology and PCR testing, aspirin and NSAIDs should be avoided in patients with suspected Zika virus infection, in order to minimize the risk of hemorrhage. In addition, as we approach summer in the Northern Hemisphere, possibly infected persons should avoid mosquito contact so as not to infect local susceptible mosquito populations.
Zika virus needs to be discussed with all pregnant women returning from the Caribbean, Mexico, Central and South America, Indonesia or the south Pacific islands. It is also crucial that women who are pregnant or plan to become pregnant in the next two months avoid travel to these endemic regions.
Please feel free to contact Dr. Kontra or anyone in the LGH Infectious Diseases Division or Infection Control Department with any questions.
For more information, visit the CDC and UpToDate.
Dr. Kontra will speak about the Zika virus during Family Medicine Grand Rounds, 7 to 8 a.m. Tuesday, Feb. 16, in Stager Conference Center. We’ll also be broadcasting live to the WBH conference room for those who cannot attend the session at Stager conference room.
Read “Zika and pregnancy: 4 tips women should follow,” a recent blog post by Serena S. Wu, M.D., of Maternal Fetal Medicine.
Travel questions for Ebola: Following the World Health Organization’s December declaration that Guinea is Ebola-free, the CDC and PA Department of Health revised their Ebola screening recommendations. LG Health/Penn Medicine providers may follow the new recommendations and stop asking travel questions specific to Ebola. However, a travel history should be routinely assessed in all patients.