Zika Virus Information for Oregon Health Care Providers

On this page:

• Disease reporting
• Laboratory testing
• Prevention guidance for specific groups
• For prenatal providers
• For pediatric providers

Disease reporting

Zika infection is reportable in Oregon. Healthcare providers are required to report suspect, presumptive, and confirmed  Zika virus infections to local health department in the patient's county ofo residence within one day (call the "CD Nurse" Communicable Disease number).   

• Community disease reporting numbers by county (English) (pdf)
  
• Números de las Autoridades Locales de Salud Pública en Oregon (pdf)
  

Laboratory testing

As of January 1, 2019 the Oregon State Public Health Laboratory does not perform Zika testing.

Many commercial laboratories offer Zika testing options. Zika IgM testing is no longer recommended because IgM antibodies can cross-react with other flaviviruses like dengue and can persist for months following infection, so they may not be indicative of a recent infection. Providers should refer to their clinical laboratory for guidance on specimen collection and transport when sending Zika testing to commercial laboratories.

Zika testing is recommended for:

• Individuals, including pregnant women, who have at least one symptom of Zika (fever, rash, joint pain, or conjunctivitis) and possible Zika virus exposure defined as
  
• recent travel to an area with risk of Zika or
• unprotected sexual contact with someone who recently traveled to an area with risk of Zika.
• Pregnant women, without symptoms of Zika, who have possible Zika virus exposure and
• have concerning ultrasound findings or who deliver an infant with concerning findings related to congenital Zika syndrome or
• have ongoing possible Zika virus exposure (at least monthly travel to a Zika-affected area, or unprotected sex with a partner who frequently travels to a Zika-affected area).
• Infants whose mothers have possible Zika virus exposure and
• are born with birth defects consistent with congenital Zika syndrome or
• have maternal laboratory evidence of possible Zika virus infection during pregnancy.

NOTE: Zika virus testing is no longer routinely recommended for asymptomatic pregnant women with recent possible Zika virus exposure, but without ongoing exposure.

Testing asymptomatic individuals when there is a smaller number of new cases occurring could increase the likelihood of false-positive test results. Testing is not routinely recommended for asymptomatic pregnant women with some, but not ongoing, exposure; however, testing may be considered based on patient preferences and clinical judgement. Healthcare providers should discuss with their patients the limitations of testing and provide prevention guidance, including avoiding unprotected sex for the duration of the pregnancy.

• Algorithm: Whom to test for Zika virus in Oregon
  

For more detailed information, please see the CDC Testing Guidance and the Oregon Zika Investigative Guidelines (pdf). 

CDC recommends that dengue and chikungunya testing should also be done for those who meet Zika testing criteria as a suspect case. Dengue and chikungunya serologies are not currently available at OSPHL and can be done through commercial labs. Please see CDC laboratory guidance.

CDC resources

• For symptomatic pregnant women with exposure to Zika
  
• For asymptomatic pregnant women with ongoing exposure to Zika
  
• For asymptomatic pregnant women without ongoing exposure to Zika

Limitations of Testing

Zika IgM antibodies can persist for months to years following infection and detection may not be indicative of a recent infection. Plaque reduction neutralization testing (PRNT) is needed to confirm Zika virus infection after a positive IgM test; however, PRNT results do not always yield a specific flavivirus result.

Read more about understanding Zika virus test results.

Prevention guidance

Guidance for pregnant women

• CDC recommends that pregnant women do not travel to any area with Zika virus transmission.
• If travel to a region with Zika virus risk is unavoidable, they should avoid mosquito bites and unprotected sexual contact with others in the affected area.
• Pregnant women should also avoid unprotected sex for the duration of the pregnancy with partners who have recently visited a Zika-affected area.
• Read more here: CDC guidance for pregnant women

Guidance for couples considering pregnancy and women who could become pregnant

• CDC recommends precautions for women and their partners thinking about pregnancy. Couples should consider avoiding nonessential travel to areas with Zika. CDC suggests the timeframes outlined below for couples to wait before trying to get pregnant.

Read more here: CDC guidance for women trying to become pregnant

Guidance for travelers

• Travelers to Zika-affected areas should actively avoid mosquito bites and unprotected sexual contact with others in the affected area. These precautions are recommended for all people who travel to Zika-affected areas.

Returning travelers

• Returning travelers should avoid mosquito bites for three weeks after their last exposure. The goal is to minimize risk of introduction of the virus into local mosquito populations.
• Travelers who have pregnant partners should avoid sex or use a condom or other barrier methods during any sexual activity (vaginal, anal, oral, and sharing of sex toys) for the rest of the pregnancy.
• For more details, see Protect yourself during sex on CDC's Zika website.
• Read more here: CDC guidance to protect yourself and others

For prenatal providers

CDC guidance for clinical management of pregnant women with possible Zika virus exposure can be found here.

For pregnant women with possible Zika virus exposure who were not tested or who were tested more than 12 weeks from their symptom onset or last exposure, placenta testing at the time of birth should be considered if ultrasound findings show evidence of congenital Zika syndrome (for example, microcephaly). Placenta testing can help to confirm maternal Zika infection. Testing is done at CDC and requires pre-approval for submission and testing.

For more detailed information, please see the CDC Testing Guidance and the Oregon Zika Investigative Guidelines (pdf).

See also CDC's Update: Interim Guidance for Prevention of Sexual Transmission of Zika Virus - United States, August 2018.

For pediatric providers

Zika virus can cause serious birth defects in infants whose mothers had Zika infection during pregnancy. A distinct pattern of birth defects has been recognized as congenital Zika syndrome and includes:

• Microcephaly
• Intracranial calcifications
• Damage to the back of the eye
• Congenital contractures
• Hypertonia

It is possible that an infant born to a mother with possible Zika virus exposure may have congenital Zika infection. New findings suggest that infants with congenital Zika infection may appear healthy at birth but could have underlying brain abnormalities or other Zika-related health issues.

The links below provide additional information on the clinical evaluation and management of infants born to mothers with possible Zika virus exposure.

• CDC guidance for follow-up of infants with potential Zika infection
• CDC guidance tool for clinical management and evaluation of infant

If you suspect an infant or fetus might have clinical findings compatible with congenital Zika infection, determine whether the mother has possible exposure to Zika. If so, along with PCR and IgM testing at a private laboratory, placenta testing at CDC may be recommended. Contact the local health department in the mother’s county of residence to discuss recommendations for placenta testing.

Oregon resources for early intervention and family support services

• Care Coordination (CaCoon)
• Babies First
• Family to Family
• Early Intervention/Early Childhood Special Education

For more information, please visit CDC's Zika webpage for health care providers or call your local health department (pdf) (call the "CD Nurse" Communicable Disease number). Clinicians needing communications materials to assist with raising awareness about Zika among their patients, prevention, or counseling for patients with positive test results can visit CDC’s Zika Communication Toolkits and click on the "Healthcare Providers and Management" tab. Alternate language formats available here.