With all the media coverage of Zika virus has been getting, it may seem the threat of global infection is inevitable. In our last article on this health event, WorldAware Health Intelligence summarized the specifics of the virus concerns and transmission.
Since then, there have been several important updates regarding modes of transmission, new locations at risk, the links between the virus and conditions such as microcephaly and Guillain-Barr syndrome, and the international response to counter this new threat.
Daily new developments often leave the public confused and anxious. Even worse, this flood of information can result in complacency, as affected individuals are struck by disease fatigue.
Nevertheless, those managing operations in any area where Zika is circulating need to be aware of the potential risks involved so they can meet duty-of-care obligations, protect friends and family, and weigh the economic risk.
Zika Virus Latest Updates from Health Authorities
On Jan. 22, the World Health Organization (WHO) declared the linkage between Zika virus and serious complications microcephaly and Guillain-Barr a Public Health Emergency of International Concern (PHEIC). This declaration was made due to the following:
- The seemingly rapid spread of the virus through the Americas
- Its potential link to serious birth defects and neurological disease
- The lack of capacity of some countries to combat this disease without international assistance.
- Emergency release of funding for vaccine development
- Improved ability to accurately test for the disease
- Monies to combat mosquito control
- Research and data collection to further our understanding of the virus and its association with rare neurological conditions.
Moreover, the PHEIC allows for:
ZIka Virus Affected Countries
To date, more than 50 cases of imported Zika virus have also been noted in the US. The current list of countries noted to have some degree of local transmission during the past year include:
- Africa Cape Verde, Gabon
- Asia Indonesia, Malaysia, Philippines, Thailand
- Caribbean Barbados, Curacao, Dominican Republic, Guadeloupe, Haiti, Jamaica, Martinique, Puerto Rico, St. Martin, US Virgin Islands
- Central America Costa Rica, El Salvador, Honduras, Guatemala, Nicaragua, Panama
- South America Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Suriname, Venezuela
- North America Mexico
- South Pacific American Samoa, Fiji, New Caledonia, Samoa, Solomon Islands, Tonga, Vanuatu
Many national public health authorities have issued travel advisories for this list of countries that will expand, as surveillance for the disease improves and the warm weather travel season nears. As spring approaches and Aedes mosquitoes are more active, the risk for imported cases leading to locally acquired disease in other temperate areas in the Northern Hemisphere will also increase.
Medical Research Advances
Recent developments have also included notable scientific research into Zika virus. Several pharmaceutical companies have started research and development on a vaccine against Zika virus, as the PHEIC allows fast-tracking development to combat a potential international crisis. The following information has also been reported by health officials:
- Zika virus has been found in the brain tissue and placenta of infants who were stillborn and suffered microcephaly.
- Zika virus is now known to be able to be transmitted sexually in at least some cases.
- Zika virus has been found in urine and saliva, but its transmissibility through these fluids is unknown.
- Zika virus may reside in the blood of infected individuals longer than their symptoms last for at least seven to 10 days following infection. Many officials are now requiring that people who have traveled to high-risk areas defer blood donations for one month or longer upon return.
The international response to Zika, and particularly to the WHO declaration of a PHEIC, has been mixed. Many areas at risk of having sustained local transmission have stepped up surveillance efforts. Testing has increased, both on mosquito larvae and for at-risk patients such as women who are pregnant and symptomatic. Surveillance for birth defects and neurologic disease has also increased.
Some international airports, especially in Asia, officials have enacted Zika screening, though it remains unclear what this entails other than a thermal scan upon entry from risk areas and a questionnaire, as definitive testing for the virus is complicated. Additionally, there are only a small number of laboratories in Asia able to accurately diagnose this virus.
It is doubtful that the cost of blood-testing the highest-risk travelers would outweigh any preventive measures that could be undertaken for vector control, particularly since only one in five infected patients is symptomatic. Furthermore, it remains unknown how widely the disease is already circulating unrecognized in Asia, since so few laboratories are equipped to test for the disease.
Focus for the Future
As warmer weather approaches in the Northern Hemisphere, many countries where Aedes mosquitoes breed are increasingly concerned about the possibility of local transmission. Those countries that have attempted to manage circulating dengue or chikungunya know well the challenge and expense of controlling vector-borne diseases.
The US has begun intensive vector control in its most at-risk states, with a USD 1.8 billion federal government request for funding to combat the disease. The US state of Florida declared a state of emergency in multiple counties that have reported imported Zika cases. Puerto Rico and other areas in Latin America have similarly declared states of emergency. These declarations drive the release of funds for vector control and eradication, education of residents to reduce breeding grounds, and improved medical surveillance.
Concerns for Special Populations
As educational campaigns step up with the increasing threat of Zika virus, certain populations may have a greater risk of contracting the disease or need additional guidance.
Female Patients and Duty-of-Care
- Women who are pregnant, unsure if they are pregnant, or planning pregnancy should NOT travel to an area where there is local and sustained transmission of the disease.
- Women who have traveled to these areas and have recently found out they were pregnant, or who traveled prior to the advisories, should inform their obstetrician.
- International health authorities, as well as organizations catering to obstetricians, have provided guidance for testing all pregnant women.
- Women should consider delaying efforts at becoming pregnant for up to two years if residing in a high-risk area. Those having transited a high-risk area should consult their healthcare provider for advice on the length of time to wait.
- Women traveling to Asia or Africa, where surveillance for Zika is not yet as prominent as in the Americas but have potential for harboring the disease, and should discuss their plans with a travel health professional before becoming pregnant or traveling while they are pregnant.
- General mosquito avoidance against bites are important for all other women.
- Corporations, educational institutions, and any others responsible for sending people on travel should educate their travelers on the risks and the preventive measures associated with Zika virus in order to meet duty-of-care obligations.
Male Patients and Duty of Care
- Since the announcement of Zikas transmission sexually, it is now recommended that men traveling to areas with local disease and who have a pregnant sex partner either use condoms for sexual activity or abstain from sex for the duration of pregnancy. Zika virus has been shown to reside in semen for two to 10 weeks after active infection
- Men without pregnant partners who have traveled to Zika-affected areas may consider abstaining from sex or using condoms.
- Information regarding Zika, its risks, prevention, and potential for complications should be fully articulated in an effort to meet duty-of-care obligations for those sending travelers on business or study.
Zika Virus and the Olympics
The International Olympic Committee (IOC) and other organizers of the 2016 Summer Olympics in Rio de Janeiro, Brazil scheduled to begin in August have asserted that the risk to athletes and spectators will be minimal. Precautions have and will continue, including the following:
- Continued spraying with insecticides
- Education for athletes, participants, and spectators regarding Zika virus prevention
- Enhanced surveillance for the vector at venue sites
- Accommodations with protective screens and accelerated measures to thwart vectors
- Assertion that August in Rio de Janeiro is cooler and drier, therefore rendering this time of year the lowest for mosquito activity, thereby reducing the threat of infection transmission
Not all are convinced, however, and some athletes have reconsidered having their families join them at the Games. Additionally, Kenya announced that unless there are concrete signs that the Zika situation is improving in the area, its athletes will not participate in the Olympics this year.
Zika Virus Prevention
Until a vaccine is developed and marketed to the general public, the only preventions against Zika virus are as follows:
- Strict mosquito bite prevention in at risk areas (which are updated frequently)
- Applying a repellant frequently in mosquito laden areas
- Wearing light colored, light-weight, long-sleeved shirts and long pants, socks, shoes, and a head covering treated with insect repellant
- Ensuring indoors environments are secure against mosquito entry
- Using condoms for sexual activity when a partner has visited a Zika virus outbreak area in the previous month
There is currently no cure or specific treatment for Zika virus. The only treatment options for Zika virus remain rest, fluids, and comfort measures to relieve symptoms. Available treatment for neurologic complications and birth complications that may be related to Zika virus are dependent upon the health capacity of a particular region.
International health authorities and other stakeholders are working diligently to find answers to many questions about Zika virus. As more information comes to light, improved prevention, protection, and mitigation measures will become available to fight this disease. Until a vaccine or definitive treatment becomes available, the WHO and other notable health authorities have continued to stress the following:
- Mosquito bite prevention
- Mosquito-breeding ground elimination
- Avoidance of travel to countries with current local Zika virus activity for pregnant individuals
- Use of protection by men with sexual partners who have recently traveled to Zika outbreak areas
- Check with a personal healthcare provider and information regarding possible risk by those who are symptomatic following possible exposure
- Reporting to their obstetricians for guidance and follow up testing by pregnant women
The WorldAware Health Intelligence Department will continue to monitor this dynamic situation very closely and provide the latest zika virus updates as new information becomes available