EDs Need to Prepare for More Zika Virus Evaluation

October 3rd, 2016

IRVINE, CA – With the Olympic Games ongoing in Zika virus hotspot Brazil and travel advisories recently issued for a small section of Miami, emergency departments are likely to evaluate patients concerned about the illness, especially pregnant women, even if the diagnosis ends up being something else.

An article published in the Emergency Medicine Clinics of North America publication reviewed what emergency physicians need to know about Zika, its diagnosis, and treatment.

“Associations between Zika virus with congenital anomalies and Guillain Barre syndrome (GBS) underscore the importance of understanding strategies for management and control of the virus,” write the authors, led by University of California, Irvine researchers. “There is significant concern for risk to pregnant women/women of reproductive age and the risks associated with the spreading disease and with travel to endemic areas. Preparations for the 2016 Olympic Games in Brazil cast an increased sense of urgency on the need for improved assessment/identification, management, and containment of Zika virus.”

Study authors add, “Given the potential for increased numbers of infected individuals, it is essential that emergency providers equip themselves with the knowledge and background necessary to effectively assess, manage, and counsel patients.”

Key points of the article include:

• Zika virus is a mosquito-borne arbovirus.
• Most individuals infected with Zika virus have minimal or no symptoms.
• If present, typical symptoms include rash, conjunctivitis, and fever.
• Pregnant women infected with Zika, particularly during the first trimester, appear to be at increased risk of having infants with congenital abnormalities such as microcephaly.
• There is currently no vaccine or treatment for Zika virus. Prevention through minimizing mosquito bites is the best means of decreasing risk of infection.

The review notes that the virus has an incubation period of three to 12 days, usually followed by a subclinical or mild illness. The usually mild symptoms, if present, typically last for two to seven days, according to the article, and could include fever, conjunctivitis, arthralgia/myalgia, diffuse rash, headache, retro-orbital pain, peripheral edema, and/or gastrointestinal upset.

While severe acute infections with Zika virus are rare, research has detected an association, and likely a causal relationship, with the serious sequelae of Guillain–Barre syndrome (GBS). In addition, subsequent studies established a possible link between Zika virus infection and congenital complications, including microcephaly in infants.

Differential diagnoses for Zika include dengue fever, chikungunya virus, initial human immunodeficiency virus (HIV) seroconversion, measles, scarlet fever, rickettsial infection, leptospirosis, parvovirus, enterovirus, rubella, and secondary syphilis.

“Given the nonspecific nature of the signs/symptoms and the broad differential diagnosis, clinical presentation alone is insufficient to make the diagnosis without confirmatory laboratory testing,” according to the report, which recommends RT-PCR testing of blood and saliva. That can be accomplished only with assistance from public health authorities, however, and is not yet available at individual hospitals. As a result, according to review authors, results generally are not accessible in a timely fashion and false-positive results are common.

The article advises that initial evaluation involve a thorough travel history and that a history of sexual contact with at-risk travelers be obtained. Because Zika is a nationally reportable condition, it adds, public health officials must be informed if a case is suspected.