Zika considerations

Unless one has been living under a rock recently, he or she knows about the Zika virus and its trek across the globe. But with headlines full of “breaking news” just about every day and frightening new findings about transmission and connections to neurological conditions, there’s a danger of what is known about Zika being drowned out by sensationalism and rumors run amok.

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Keeping in mind that what we actually know about Zika is dwarfed by what we do not yet know, and that new findings, connections, and recommendations are just about as dynamic as the epidemic of Zika information (and sometimes misinformation) flying around, it’s critical to closely follow official, reputable sources for information and to establish diagnostic and treatment guidelines. To separate the wheat from the chaff, referring to reputable and informed sources is vital. So, here’s what the Centers for Disease Control (CDC) has to say about the virus.

Just the facts

Zika virus is a single-stranded RNA virus of the Flaviviridae family, genus Flavivirus. Zika virus RNA has been identified in asymptomatic blood donors during an ongoing outbreak. During the first week after onset of symptoms, Zika virus disease can often be diagnosed by performing reverse transcriptase-polymerase chain reaction (RT-PCR) on serum. Virus-specific IgM and neutralizing antibodies typically develop toward the end of the first week of illness; cross-reaction with related flaviviruses (e.g., dengue and yellow fever viruses) is common and may be difficult to discern. Plaque-reduction neutralization testing can be performed to measure virus-specific neutralizing antibodies and discriminate between cross-reacting antibodies in primary flavivirus infections.

Laboratory evidence of maternal Zika virus infection can include Zika virus RNA detected by RT-PCR in any clinical specimen; or positive Zika virus IgM with confirmatory neutralizing antibody titers that are ≥4-fold higher than dengue virus neutralizing antibody titers in serum by PRNT. Testing would be considered inconclusive if Zika virus neutralizing antibody titers are < 4-fold higher than dengue virus neutralizing antibody titers.

The virus is transmitted to humans primarily through the bite of an infected Aedes species mosquito, which typically breed in domestic water-holding containers; they are aggressive daytime biters and feed both indoors and outdoors near dwellings. Zika virus can be transmitted from a pregnant mother to her fetus during pregnancy or around the time of birth, although it’s not yet known how often Zika perinatal transmission occurs.

The incubation period for Zika virus disease is not known, but is likely to be a few days to a week. Of those infected, only about 20% develop symptoms. Clinical findings are acute onset of fever with maculopapular rash, arthralgia, or conjunctivitis. Other commonly reported symptoms include myalgia and headache. Clinical illness is usually mild with symptoms lasting for several days to a week.

Severe disease requiring hospitalization is uncommon and case fatality is low. The Brazil Ministry of Health is also investigating the possible association between Zika virus and a reported increase in the number of babies born with microcephaly; there have also been cases of Guillain-Barre syndrome reported in patients following suspected Zika virus infection.

NEXT: Practical considerations for derms

Practical considerations for derms

From a practical standpoint, how should the typical dermatologist fit consideration of Zika into the day-to-day operations of his or her practice? It’s possible that potential patients may present to their dermatologist prior to other healthcare providers for treatment of a maculopapular rash.

Ted Rosen, M.D.Ted Rosen, M.D., professor of dermatology at Baylor College of Medicine and chief of dermatology at the Houston VA Medical Center, advises physicians to be aware of Zika’s general common symptoms (nonspecific maculopapular eruption in the setting of a flu-like illness (fever, headache, myalgia, arthralgia and conjunctivitis) when presented with a patient who has recently been in an area known to be high incidence of the disease.

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“The CDC publishes an updated list of countries in the Western Hemisphere where this disorder is currently occurring. Brazil is the hardest hit, and many other countries in Central and South America have been, also,” Dr. Rosen says.

As an arboviral disease, Zika virus is a nationally notifiable condition, the CDC emphasizes, encouraging healthcare providers to report suspected cases to their state or local health departments to facilitate diagnosis and mitigate the risk of local transmission.

If a patient fitting the travel (or other) demographic presents with suspicious symptoms to a dermatologist, Dr. Rosen suggests the physician take a systematic approach. First, he says, “Establish diagnosis. Call local city or county health department and inquire as to how to get blood tests to CDC to verify or refute diagnosis. Only four state labs currently do the test. This is a tricky test and might need to be repeated.”

And while Dr. Rosen notes that dermatologists are rarely comfortable in giving detailed instructions about sexual habits, it’s still important to address that possible mechanism of transmission. “If the patient is known or suspected of being infected with Zika,” Dr. Rosen says, “the physician should advise the patient to abstain from sex or to use condoms regularly and properly to avoid transmitting. And if the patient’s sexual partner has known or suspected Zika, the physician should advise abstaining from sex or to use condoms regularly and properly to avoid possibly contracting the virus.”

NEXT: Considering the recent connections to sexual transmission

Considering the recent connections to sexual transmission and/or neurological implications (possible connection to Guillain-Barre syndrome), is there a place for dermatologists to proactively address the subject in an “at-risk” patient populations? With all the developments, such “at-risk” patients could now possibly include all sexually active patients, those of child-bearing potential, and/or any who may be traveling to at-risk areas or in close proximity with those who have traveled to such areas, not to mention immune-compromised patient population in general. 

“There is so much in the news about this infection,” Dr. Rosen says, “that I think people are already taking proactive protective steps. The single biggest thing a dermatologist can do is to encourage common sense protective maneuvers against mosquito bites. Long sleeves and pant legs, sleeping in air conditioning and with netting surrounding bed, insect repellent on clothes or skin (as appropriate based on manufacturer’s directions).”

Dr. Rosen suggests that dermatologists presented with possible Zika patients consider making a referral to infectious disease specialist “if symptoms are extreme and patient has visited an implicated country or region. Keep in mind that many cases are asymptomatic. They carry virus, may be contagious, but they (and we) don’t know it. Also, Zika acts much like Dengue or Chikungunya virus infections,” he continues.

All things being equal, he advises a simple, solid course of action. “If diagnosis is uncertain,” he says, “referral is in order.”

In what could become a publicity-induced Zika mania, where increasing numbers of the general population could theoretically be at risk, the typical dermatologist may very well see patients reporting Zika-like symptoms. When that happens, up-to-date understanding of Zika facts puts the physician in the best position to continue providing expert care, reassuring patient anxieties and managing potential infections optimally.