Zika Linked with Cardiovascular Complications

Last year, both national and international health organizations officially recognized the link between infection with the Zika virus, and the development of several neurological complications in developing fetuses as well as in adults.

The results of a new study have shown that nine individuals in Venezuela who presented with Zika-like symptoms also suffered heart complications soon thereafter. This came as no surprise to the study authors as they noted that other mosquito-borne infections, such as severe forms of malaria, are known to cause cardiovascular complications.

Researchers presented these findings at the American Heart Association meeting in Portland, Oregon, according to a press release. Of the nine patients, eight “developed dangerous heart rhythm disorders, and two-thirds (6) had evidence of heart failure, a condition in which the heart isn’t pumping enough blood to meet the body’s needs.” These patients did not have any history of cardiac disease, and so it was concluded that the irregularities were due to infection with the Zika virus.

Through testing, the researchers concluded that the patients had developed myocarditis, which affects the heart’s muscle as well as electrical system, leading to slowed heartbeats. Although symptoms have since subsided in some of the patients, none have fully recovered.

“While we anticipated we would see cardiovascular effects from Zika, we were surprised at the severity of the findings,” commented Karina Gonzalez Carta, MD, cardiologist and research fellow at the Mayo Clinic and lead author of the study. She also noted that currently, there is no way of determine the incidence of heart complications associated with Zika virus infection. For that reason, she recommends conducting electrocardiograms (ECG) on all patients infected with the Zika virus. If an irregular heartbeat is detected, follow-up testing is advised.

In another study on the effects of the Zika virus, researchers presented findings on the detection of the virus in various tissues in seven rhesus macaque monkeys. According to a press release on the study, the Zika virus was identified in the nervous system, reproductive and urinary tracts, lymph nodes, muscles and joints.

Daniel Streblow, PhD, associate professor of Molecular Microbiology and Immunology at the Gene Therapy Institute at Oregon Health & Science University, said that these findings will contribute to the development of therapies and vaccines that would be effective in humans. “What is different about this research is that we also were able to look at specific points in time to see where the virus grew in the tissues, not just the blood, so we can identify and target the reservoirs where the virus hides.”

The Zika virus is currently circulating in many regions in South America, Mexico, Puerto Rico, and two US states: Florida and Texas. On Friday, the Centers for Disease Control and Prevention issued Zika-related travel notices for Angola, Guinea-Bissau, Maldives, and Solomon Islands. According to the Level 2 notice, travelers are to “practice enhanced precautions.”

With more harmful effects of the Zika virus being revealed, infection prevention is of the utmost importance, but the current forms of prevention do not guarantee an individual will not be infected. In an exclusive interview with Contagion^® Annelies Wilder-Smith, MD, PhD, discussed the effectiveness of personal protection as a means of protecting oneself from the Zika virus. She said, “Of course you can reduce landing and biting rates with personal protection, like spraying [mosquito repellant] and [wearing] long-sleeves, etc. But we have not seen any data that good personal protection, indeed, also translates to less disease.”

Perhaps developing vaccines to protect against the mosquito-borne virus is the only means of truly preventing infection.