This Week in Zika: U.S. Had 'Reactive Response' to Zika Outbreak

— Also, Zika cases in Florida likely originated in Caribbean

MedpageToday

WASHINGTON -- Symptomatic of their recent responses to infectious disease outbreaks, federal agencies acted with "a reactive" approach yielding mixed success handling the Zika outbreak. So said a report released earlier this week by the Government Accountability Office (GAO) Tuesday to coincide with a House subcommittee hearing.

"Emerging infectious diseases have continued to garner global attention," according to a memorandum for the panel. "In each of the aforementioned cases, the GAO found that HHS was reactive in its response to outbreak prevention, preparedness, detection, and response."

"Once again, GAO has shown that we were not fully prepared at the outset of the outbreak," Chairman Tim Murphy (R-Pa.) said during the hearing of the Oversight and Investigations subcommittee of the House Energy and Commerce Committee.

Zika Came from the Caribbean to South Florida

Cases of the virus in southern Florida were most likely linked to transmission from the Caribbean. Researchers writing in Nature sequenced Zika virus genomes from infected patients and mosquitoes. They found that at least four, but potentially as many as 40 introductions of Zika to the Miami area in spring 2016. By sequencing these genomes and comparing them to genomes sequenced from other countries and regions of the Americas, the authors found that most of these introductions were linked to travel to the Caribbean. They attempted to corroborate this evidence using data on travel patterns to Florida from certain countries -- but they were unable to tell if travel from airlines or cruise ships played the biggest role. They concluded that because Florida is unlikely to sustain long-term local Zika transmission, the activity level in other countries will likely play a role in any future outbreaks.

Zika May Have Been in Brazil In 2014

The virus may have been circulating in northeast Brazil as early as late 2013 or early 2014 -- at least a year before it was detected in Brazil. Researchers writing in another study in Nature sequenced 54 complete or partial Zika virus genomes from Brazil found that Zika was likely present in February 2014 and that northeast Brazil played a major role in the spread of the virus through the Americas. The authors noted that this is consistent with the fact that northeast Brazil has both the highest portion of notified Zika cases and confirmed microcephaly cases of any of the five regions in Brazil.

New Directions in Zika Sample Analysis

Researchers writing in Nature Protocols described a method used for genome-sequencing where the Zika virus genome could be sequenced directly from clinical samples, without having to wait for isolation or culture. The authors said the method is suitable for sequencing either DNA or RNA outbreak samples. They argued it could also be used as an inexpensive, convenient method to be used in the lab or it could be used in the field. Researchers said that this method was successfully used by groups studying how Zika evolved and spread across the Americas.