Although the prevalence of Zika has declined, it remains an important concern for women of reproductive age; thus, physicians should discuss infection prevention strategies with patients who are considering traveling to Zika-endemic areas, according to a paper published in Annals of Internal Medicine.
“Since its peak in 2016, the prevalence of Zika virus has decreased; at the same time, travel to Zika-affected countries has rebounded,” Daniel S. Graciaa, MD, MPH, from Emory University School of Medicine, and colleagues wrote. “Many gaps remain in our knowledge about key features of this viral infection, making it difficult to counsel patients who are contemplating travel to Zika-affected countries and to determine appropriate testing strategies on their return.”
In its guidance, the CDC removed routine Zika testing of asymptomatic pregnant women because of the lower prevalence of the disease and the likelihood of false-positive results; however, some experts argue that this may lead to decreased access to testing, they noted.
Graciaa and colleagues emphasize the importance of the CDC’s recommendation that pregnant women not travel to Zika risk areas. They also advised that after travel or symptomatic infection, women take precautions against conception until 2 months and men take precautions until 6 months after returning from the risk area.
However, about 30 million Americans, including pregnant women and individuals planning to conceive, are traveling to Zika-affected areas, whether they are unaware of the risks or are disregarding public health recommendations, according to Graciaa and colleagues.
Up to 80% of Zika infections may be asymptomatic which greatly complicates the issue, they wrote. Asymptomatic infections are most likely underrepresented, but can still result in harmful complications, such as adverse fetal outcomes, they wrote.
“The high prevalence of asymptomatic infections has contributed to uncertainties about the epidemiology and transmissibility of Zika virus, confounding prediction of outbreaks,” they wrote. “Despite decreasing overall incidence, the risk for localized outbreaks will likely persist for the immediate future.”
Estimating the risk of Zika infection in returning travelers with no symptoms is highly difficult, according to Graciaa and colleagues. Therefore, available diagnostic tests are inadequate for decision-making needs and health care providers may use and interpret such tests inappropriately, they added.
“Until the risk for Zika can be further mitigated by vaccination or improved vector control, enhanced surveillance and diagnostic test validation must underpin the tools used in shared decision making with travelers to Zika-affected areas while incidence is decreasing yet unpredictable,” Graciaa and colleagues concluded. “A vector-borne infection that is also sexually transmitted and teratogenic is unprecedented. During an era of increasing travel and migration, novel approaches will be needed to address the unique threats posed by Zika virus.” – by Alaina Tedesco
Graciaa reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.