As travel-related Zika cases in the continental United States and local cases in three territories climbed higher, the Centers for Disease Control and Prevention (CDC) today announced it will host a Zika summit Apr 1 to help states and cities craft their plans to prevent and fight the mosquito-borne disease.
Also, the World Health Organization (WHO) said in its outbreak update today that Laos is the latest country to report local Zika virus transmission and that Argentina is investigating a likely case of sexual transmission of the virus.
In the ongoing gush of Zika developments, several newly published studies shed more light on the virus and its complications and there were more headlines coming out of Zika-hit countries.
CDC summit details; Frieden to Puerto Rico
The CDC said in its summit statement that the upcoming event is targeted to state and local health officials and will cover the latest scientific evidence on the threat Zika poses to pregnant women and their babies and on mosquito-control strategies. The meeting, to take place at CDC's Atlanta headquarters, will also cover best communication practices and steps to identify and address preparedness gaps.
Yesterday the CDC said 153 travel-linked Zika infections have been reported in the continental United States, up from 107 reported a week ago. US territories affected by Zika, which include Puerto Rico, American Samoa, and the US Virgin Islands, have reported 107 local cases, all but 5 of them from Puerto Rico.
CDC Director Tom Frieden, MD, MPH, will travel to Puerto Rico Mar 7 to assess the agency's response in the territory, the CDC said in a separate statement today. Federal officials have warned that the island could see hundreds of thousands of cases this year, based on patterns seen with dengue and chikungunya—two other diseases spread by the same mosquito that carries Zika virus. The outbreak in Puerto Rico comes amid a financial crisis on the island.
WHO updates global situation, preps for meeting
The WHO noted possible sexual transmission developments in its weekly situation update today. If sexual transmission, which seems to be occurring more often than originally thought, is confirmed in the Argentinian case, the country would be the fourth to report it, alongside the United States, France, and Italy.
The WHO included the new Laos local transmission in its update and said that, of 55 countries reporting Zika virus transmission since 2007, 41 have reported local spread in 2015 and 2016.
Also discussed by the WHO was preliminary information on Cabo Verde's Zika outbreak, which began last October and appears to be tapering off. Evidence suggests that transmission in the nation, which lies off the northwest coast of Africa, is linked to the African strain of the virus, and so far no neurological complications have been reported.
The WHO is set to begin a 3-day Zika countermeasure research and development meeting on Mar 7 to settle on which vaccines, drugs, diagnostic tests, and mosquito-control tools seem most promising.
Stakeholders meeting in Geneva will cover the latest scientific findings about the disease and its complications and take stock on which countermeasures are on the horizon, with an eye toward hammering out a development roadmap, as they did during the Ebola outbreak. According to the agenda, the group will grapple with difficult topics such as animal models for studying drugs and vaccines and regulatory issues.
The WHO said it will hold a media briefing the last day of the conference to share the group's main findings.
Vaccine development may speed up
An official from Sanofi, one of several companies working on a Zika virus vaccine, signaled yesterday that the company is speeding up development plans, according to a Reuters report yesterday.
The company now has an 80-person team in place to start preclinical animal studies this spring, with human studies projected for next year contingent on regulatory approvals.
In early February Sanofi said it already has approval for vaccines targeting other flaviviruses and hopes to leverage that work toward the development of a vaccine against Zika virus.
Outbreak region highlights
- Colombian researchers have confirmed congenital brain defects in three infants , one with microcephaly, and all have tested positive for Zika virus, Nature News reported today, citing a scientist from the Colombian Collaborative Network on Zika. Colombia's outbreak began after Brazil's, and experts have said a wave of microcephaly cases in the second hardest-hit country would help prove a link between the two conditions. The country reported its first probable microcephaly case on Feb 24, which involved a deformed aborted fetus at 28 weeks gestation.
- Anonymous public health sources in Cuba say the country has recorded 21 Zika virus cases, though the government has denied any, except for one in a doctor who got sick after arriving from Venezuela, according to a report from Cubanet translated and posted by FluTrackers, an infectious disease news message board. An anonymous senior official from the country's military, which has been deployed to help with response activities, said Cuba has already had 20 cases.
Research developments: semen, myelitis, Aedes susceptibility, birth timing
- Zika virus excreted in semen can result in high viral loads that can lead to sexual transmission, according to a brief case report on a 32-year-old French man who got sick in January after returning from Brazil and French Guiana. Semen viral load was 100,000 times higher than that of blood or urine more than 2 weeks after symptom onset, according to the report published yesterday in The Lancet Infectious Diseases.
- The finding of acute myelitis along with Zika virus in the cerebrospinal fluid of a 15-year-old girl from Guadeloupe adds to growing suspicions that the virus may have neurotropic effects, researchers reported yesterday in a brief report in The Lancet.
- Experimental infection of Aedes aegypti and Aedes albopictus mosquitoes from the Caribbean and the Americas with the currently circulating Asian genotype of Zika virus found that they are susceptible to infection but aren't very efficient vectors, which may suggest a greater role for naive population immunity and high densities of human-biting mosquitoes for fueling outbreaks in the Americas, according to a report published yesterday in PLoS Neglected Tropical Diseases.
- Based on the timing of babies born to mothers in Brazil's Bahia state who were infected with Zika virus early in their pregnancies, CDC researchers calculated that microcephaly cases are likely to present 5 to 10 months after transmission begins in a given area. In their report in Emerging Infectious Diseases yesterday, they say the spreadsheet tool they developed could be used to help countries plan for deliveries of infants born to women infected in different trimesters.
Mar 4 CDC Zika summit statement
Mar 4 CDC statement on Frieden Puerto Rico trip
Mar 4 WHO Zika situation report
Mar 3 Reuters story
Feb 2 CIDRAP News story "Companies announce new Zika vaccine initiatives"
Feb 25 CIDRAP News story "Case hints at other severe birth defects tied to Zika"