Monthly Archives: March 2016

Zika risk at high elevations
What is the risk of getting Zika at high elevations?
The mosquitoes that spread Zika usually do not live at elevations above 6,500 feet (2,000 meters). Travelers who plan to be only in areas above this elevation are at a very low risk of getting Zika from a mosquito. Travelers are still at risk of sexual transmission of Zika from a male partner who has been in areas with local transmission.

What if I am flying into an airport at a low elevation in an area with Zika but then immediately driving to a high elevation?
You would still be at risk of getting Zika from a mosquito bite while you were at the low elevation. You should strictly follow steps to prevent mosquito bites while in these areas.

I am going to an area that looks like it is in the high-elevation zone, but your map is not detailed enough for me to see for certain. Is this destination in the risk area?
Talk to your doctor about your risk of Zika in the area where you are traveling. Travelers to destinations that cross or are near an elevation border may consider the destination as an area of lower elevation and follow recommendations for travel to areas with Zika.

What source of elevation data did you use to create the maps? Where can I look up elevation data for my destination?
Most of our maps were made based on the Global Multi-resolution Terrain Elevation Data 2010 (GMTED 2010), and for small countries we used the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) elevation dataset. The US government does not maintain or endorse a specific elevation lookup service, but various resources can be found on the internet.

What data sources did you use to show that mosquitoes do not usually live above 6,500 feet?
Aedes species mosquitoes, the mosquitoes that carry Zika, live in areas with certain ecological conditions (temperature, rainfall patterns, local plant growth, and human population density). CDC used elevation data to predict areas where the Aedes mosquitoes are unlikely to live. Our findings show that Aedes mosquitoes are not usually found above 6,500 feet (2,000 meters).

What do you recommend for pregnant women who decide to travel to high elevations in an area with Zika?
The risk of getting Zika from a mosquito at elevations above 6,500 feet (2,000 meters) is minimal. However, traveling through an area of low elevation or stopping, even briefly, in a low elevation area on the way to higher elevation increases the risk of getting Zika from a mosquito, and pregnant woman should strictly follow steps to prevent mosquito bites while in these areas. Pregnant women traveling to these areas should use condoms or not have sex with men who may have traveled to lower elevations in an area with Zika. Pregnant women should also be alert to changes in their travel plans that may take them to elevations below 6,500 feet.

Besides Zika, is it safe for pregnant women to travel to high elevations?
The low oxygen levels found at high elevations can cause problems for travelers who are going to elevations above 8,000 feet (2,400 meters). The best way to prevent altitude illness is to ascend slowly and take time to get used to the lower oxygen levels. Pregnant women should avoid strenuous activities at high elevations, and some doctors recommend that pregnant women not spend the night at altitudes above 12,000 feet (3,650 meters). Pregnant women should also consider whether they will have access to medical care at a high-elevation destination.


A multidisciplinary group of experts convened by the Pan American Health Organization / World Health Organization (PAHO / WHO) is in El Salvador this week to exchange experiences and support national efforts to respond to the Zika virus outbreak in the country.

The experience of Brazil in the management of microcephaly and Guillain-Barre Syndrome is being shared during this mission, along with discussions on surveillance protocols and the preparation of health services for surveillance and patient care, particularly for those with severe neurological manifestations related to Zika.

Since Brazil reported the first cases of local transmission of Zika in May 2015, the virus has spread to 31 countries and territories in the Americas, a situation that is compounded by possible association of Zika with microcephaly and Guillain-Barre syndrome. Brazil, Colombia, El Salvador, Surinam and Venezuela have all documented increases in cases of the syndrome.

El Salvador has reported more than 9,000 cases of Zika virus infection so far, and 138 cases of possibly associated Guillain-Barre syndrome. Of these cases, 70 percent have already been released and 228 pregnant women are being tracked. Among those women, 35 have given birth to children without microcephaly and the rest are being followed, country authorities said.

PAHO has developed a strategy to help countries mitigate the impact of Zika virus, through strengthening their capabilities to detect the introduction and spread of the virus, reducing mosquito populations, ensuring the necessary health services, and communicating effectively with the public about risks and prevention measures.


International experts, convened by WHO, have agreed on top priorities to advance R&D for Zika medical products.

The following tools were prioritized as the most viable options to help fight the spread of Zika virus in the immediate future:

Multiplex tests for ‘flaviviruses’ (viruses related to Zika, such as dengue, chikungunya), in addition to more traditional tests; protective vaccines based on killed virus (or other non-live) preparations for women of childbearing age; and innovative vector control tools that reduce the mosquito population.  “Zika virus induces a mild and mostly harmless infection in the majority of patients,” indicated Dr Marie-Paule Kieny, Assistant Director-General in charge of R&D at WHO. “For that reason medicines to treat it seem less of a priority at this stage. The most pressing need is the development of diagnostic and preventive tools to address the current R&D gap and protect pregnant women and their babies.”

As of 2 March, 67 companies and research institutions were already working on a number of products (31 on diagnostics, 18 on vaccines, 8 on therapeutics, 10 on vector control), which are at various stages of early development. No vaccine or therapeutic has yet been tested on humans.


Experts agreed that the development of a vaccine is a major priority to respond to epidemics in the future. Vaccination of pregnant women and women of childbearing age is the main target, and pragmatic strategies will be needed to fast-track the development of a safe and effective product.

Work is underway for the development of an emergency vaccine target product profile. The target product profile will serve as a guide to consult and build consensus on regulatory requirements for Zika vaccine evaluation and registration. A draft target profile will be submitted to a public consultation in the coming weeks, with a view to having a final profile in May.


Over 30 companies are working on or have developed potential diagnostic tests. There is general support for the development of a target product profile for a multiplex test that can diagnose dengue, chikungunya and Zika viruses. A first draft is ready and this too will undergo public consultation before finalization in mid-April.

WHO continues to encourage manufacturers to apply to the WHO Emergency Use, Assessment and Listing procedure for a quality and performance evaluation of their products.

Emergency use assessment and listing procedure for Zika virus disease
Vector control

Vector control experts have clearly stated that as traditional interventions – such as insecticide spraying – have not had significant impact on dengue transmission the same might apply to Zika. They also cautioned that extreme rigour needs to be applied in evaluating novel tools, such as Wolbachia, recombinant and irradiated mosquitoes. An emergency meeting of the WHO Vector Control Advisory Group next week will fine-tune evaluation methods and a target product profile for innovative techniques


The U.S. Department of Health and Human Services announced that it is arranging and funding shipments of blood products from the continental United States to Puerto Rico. The mainland blood is being provided to ensure an adequate supply of safe blood for island residents as the Commonwealth of Puerto Rico experiences active mosquito-borne Zika transmission.

The risk of Zika virus transmission through blood products is considered likely based on the most current scientific evidence and what is currently being reported about transfusion-associated infection occurring outside of the United States. Blood products shipped to Puerto Rico will be collected from areas in the continental United States without active transmission of Zika virus so that blood products used in Puerto Rico can meet all of the same high safety standards as those used elsewhere in the United States.

The shipments are being provided to Puerto Rico through the American Red Cross, the Blood Centers of America, and America’s Blood Centers. Existing blood collection centers in Puerto Rico will then supply that imported blood to transfusion providers.

“Availability of safe blood products for the residents of Puerto Rico is a major priority for HHS,” said Karen B. DeSalvo, M.D., M.P.H., M.Sc., HHS acting assistant secretary for health. “We are arranging the importation of blood products from areas unaffected by local Zika transmission to ensure the safety of Puerto Rico’s blood supply."

The U.S. Food and Drug Administration (FDA) recommends that whole blood and blood components for transfusion be obtained from areas of the United States without active transmission of Zika virus until a blood donor screening test or pathogen reduction technology (where applicable) for Zika virus becomes available.


Since this emergency committee on Zika virus first met on 1 February, substantial new clinical and epidemiological research has strengthened the association between Zika infection and the occurrence of fetal malformations and neurological disorders.

In addition, the geographical distribution of the disease is wider. The risk group is broader. And the modes of transmission now include sexual intercourse as well as mosquito bites.

Local transmission has now been reported in 31 countries and territories in Latin America and the Caribbean.

In this region, cases of dengue, which is carried by the same mosquito species as Zika, typically increase during the rainy season, which lasts from January to May. We can expect to see more cases and further geographical spread.

Imported cases of Zika have been reported from every region in the world.

Concerning the link with fetal malformations, the virus has been detected in amniotic fluid. Evidence shows it can cross the placental barrier and infect the fetus. We can now conclude that Zika virus is neurotropic, preferentially affecting tissues in the brain and brain stem of the developing fetus.

Zika has been detected in the blood, brain tissue, and cerebrospinal fluid of foetuses following miscarriage, stillbirth, or termination of pregnancy.

Microcephaly is now only one of several documented birth abnormalities associated with Zika infection during pregnancy. Grave outcomes include fetal death, placental insufficiency, fetal growth retardation, and injury to the central nervous system.

To date, microcephaly has been documented in only two countries: French Polynesia and Brazil. However, intense surveillance for fetal abnormalities is currently under way in countries, like Colombia, where the outbreaks started later than in Brazil.

Nine countries are now reporting an increased incidence of Guillain-Barré syndrome or laboratory confirmation of a Zika virus infection among GBS cases. A retrospective case-control study of GBS associated with Zika in French Polynesia recorded no deaths, but the disease progressed rapidly and a large percentage of patients required admission to an intensive care unit for as long as 51 days.

Growing evidence of a link with GBS expands the group at risk of complications well beyond women of child-bearing age. GBS has been detected in children and adolescents but is more common in older adults and slightly more common in men. The anticipated need for expanded intensive care adds a further burden on health systems.

Reports and investigations from several countries strongly suggest that sexual transmission of the virus is more common than previously assumed.

All of this news is alarming.

Women who are pregnant in affected countries or travel to these countries are understandably deeply worried.

I convened this second meeting of the Emergency Committee to gather expert advice on the strength and significance of these new research results. We also asked the experts whether the findings warrant changes in WHO recommendations to countries.

The Committee underscored the increasing strength of evidence showing a likely association between Zika infection and fetal malformations and neurological disorders.

At the same time, the experts pinpointed the types of studies needed to establish a causal relationship, but stressed their view that strong public health actions should not wait for definitive scientific proof.


Study results from Zika virus infected immune deficient mice treated with BioCryst's BCX4430 will be presented at a World Health Organization (WHO) conference. The primary goal of the study was to assess the effect of BCX4430 treatment on survival through Day 28 in immune-deficient mice infected with the Zika virus. BCX4430 was administered by intramuscular (I.M.) injection twice a day beginning prior to virus challenge and continuing for eight days. In the standard dose BCX4430 group, 7 of 8 mice survived through Day 28. In the low dose BCX4430 group (n=8), and in control groups administered vehicle placebo (n=8) or ribavirin at two dose levels (n=16), no animals survived to Day 28.
This study was conducted at Utah State University, under the ongoing Animal Models of Infectious Disease Program at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. BCX4430 is a broad spectrum antiviral that is being tested in a Phase 1 clinical safety and pharmacology study in healthy subjects. BCX4430 has demonstrated survival benefits in nonclinical studies against a variety of serious pathogens, including Ebola, Marburg, and Yellow Fever viruses. Since September 2013, NIAID has supported BioCryst in developing BCX4430 as a therapeutic for Ebola and Marburg viruses under Contract No. HHSN272201300017C.
BCX4430 is an RNA dependent-RNA polymerase inhibitor that has demonstrated broad-spectrum activity in vitro against more than 20 RNA viruses in nine different families, including filoviruses, togaviruses, bunyaviruses, arenaviruses, paramyxoviruses, coronaviruses and flaviviruses. BioCryst is developing BCX4430 in collaboration with NIAID and the Biomedical Advanced Research and Development Authority (BARDA), following the Animal Rule regulatory pathway.
BioCryst Pharmaceuticals designs, optimizes and develops novel small molecule drugs that block key enzymes involved in rare diseases. BioCryst's ongoing development programs include oral plasma kallikrein inhibitors for hereditary angioedema, avoralstat, BCX7353 and other second generation compounds, and BCX4430, a broad spectrum viral RNA polymerase inhibitor. For more information, please visit the Company's website at


Light at the End of the Tunnel

Thomas Masterson, MD, Editor,

When the Zika epidemic was young, there was controversy.  The world did not associate Zika with microcephaly, and was reluctant to rush to judgement.  Fingers were pointed in many directions.  Two recent reports have changed the landscape of doubt and uncertainty.  The first is a work at Johns Hopkins and Florida State

demonstrating that the Zika Virus specifically targets Human Cortical Stem Cells.  The second is a study of pregnant Brazilian women with rashes in Brazil.  In rash study, when the rash came from Zika, 29% of the pregnancies had serious issues and when rash didn't come from Zika, there were no issues in this report.

Controversy and conspiracy is always more interesting than reasoned logic, but the time has come to step away from the noise and embrace what researchers are discovering. is dropping it's list of controversial microcephaly theories links.


Brasilia, Brazil
Brasilia, Brazil

The FDA has new guidelines for blood donation. No donation for six months after that trip to Zika endemic areas -- see list at the end of the article.  Donors should be considered ineligible if they were diagnosed with Zika virus infection, were in an area with active Zika virus transmission, or had sex with a male with either of those risk factors, within the past six months. Donors of umbilical cord blood, placenta, or other gestational tissues should be considered ineligible if they have had any of the above risk factors at any point during their pregnancy.
A deferral period of six months was chosen because of the limited data available on the length of time the virus can persist in all tissues. Zika virus has been detected in tissues and body fluids after the virus is no longer detectable in the blood stream, and has been detected in semen possibly up to 10 weeks after the onset of symptoms. Given the uncertainty, six months was determined to provide the appropriate level of caution.

CDC Travel Advisory on Zika Virus. Level 2 Countries:
Pacific Islands: American Samoa, Marshall Islands, Samoa, Tonga
Caribbean: Aruba, Barbados, Bonaire, Curaçao, The Dominican Republic, Guadeloupe, Haiti, Jamaica, Martinique,The Commonwealth of Puerto Rico, a U.S. territory, Saint Martin, Trinidad and Tobago, U.S. Virgin Islands
North America: Mexico
South America: Bolivia, Brazil,Colombia, Ecuador, French Guiana, Guyana, Paraguay, Suriname, Venezuela
Central America: Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama
Africa: Cape de Verde

Thomas Masterson, MD, Editor,