Why the Zika virus is causing alarm
- Global health officials are racing to better understand the Zika virus
behind a major outbreak that began in Brazil last year and has spread to
many countries in the Americas.
The following are some questions and answers about the virus and current
How do people become infected?
Zika is transmitted to people through the bite of infected female
mosquitoes, primarily the Aedes aegypti mosquito, the same type that
spreads dengue, chikungunya and yellow fever. The Pan American Health
Organization (PAHO) said Aedes mosquitoes are found in all countries in
the Americas except Canada and continental Chile, and the virus will
likely reach all countries and territories of the region where Aedes
mosquitoes are found.
How do you treat Zika?
There is no treatment or vaccine for Zika infection. Companies and
scientists are racing to develop a safe and effective vaccine for Zika,
but the World Health Organization (WHO) had said it would take at least
18 months to start large-scale clinical trials of potential preventative
How dangerous is it?
The U.S. Centers for Disease Control and Prevention concluded that
infection with the Zika virus in pregnant women is a cause of the birth
defect microcephaly and other severe brain abnormalities in babies. The
CDC said now that the causal relationship has been established, several
important questions must still be answered with studies that could take
According to the World Health Organization, there is strong scientific
consensus that Zika can cause the birth defect microcephaly in babies, a
condition defined by unusually small heads that can result in
developmental problems. In addition, the agency said it could cause
Guillain-Barre syndrome, a rare neurological disorder that can result in
paralysis. Conclusive proof of the damage caused by Zika may take months
Brazil has confirmed 1,113 cases of microcephaly, and considers most of
them to be related to Zika infections in the mothers. Brazil is
investigating an additional 3,836 suspected cases of microcephaly.
Colombia has confirmed two cases of microcephaly linked to Zika.
Current research in Brazil indicates the greatest microcephaly risk is
associated with infection during the first trimester of pregnancy, but
health officials have warned an impact could be seen in later weeks.
Recent studies have shown evidence of Zika in amniotic fluid, placenta
and fetal brain tissue.
What are the symptoms of Zika infection?
People infected with Zika may have a mild fever, skin rash,
conjunctivitis, muscle and joint pain and fatigue that can last for two
to seven days. But as many as 80 percent of people infected never
develop symptoms. The symptoms are similar to those of dengue or
chikungunya, which are transmitted by the same type of mosquito.
How can Zika be contained?
Efforts to control the spread of the virus focus on eliminating mosquito
breeding sites and taking precautions against mosquito bites such as
using insect repellent and mosquito nets. U.S. and international health
officials have advised pregnant women to avoid travel to Latin American
and Caribbean countries where they may be exposed to Zika. Cases of
sexual transmission have also been reported, prompting health officials
to advise use of condoms, or abstaining from sex, to prevent infection
How widespread is the outbreak?
Active Zika outbreaks have been reported in at least 43 countries or
territories, most of them in the Americas, according to the U.S. Centers
for Disease Control and Prevention (CDC). Brazil has been the country
most affected. (1.usa.gov/1ovAJyh)
Africa (1): Cape Verde
Americas (35): Aruba, Barbados, Belize, Bolivia, Bonaire, Brazil,
Colombia, Costa Rica, Cuba, Curaçao, Dominica, Dominican Republic,
Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana,
Haiti, Honduras, Jamaica, Martinique, Mexico, Nicaragua, Panama,
Paraguay, Puerto Rico, Saint Lucia, Saint Martin, Saint Vincent and the
Grenadines, St. Maarten, Suriname, Trinidad and Tobago, U.S. Virgin
Islands and Venezuela
Oceania/Pacific Islands (7): American Samoa, Fiji, Kosrae, Federated
States of Micronesia, Marshall Islands, New Caledonia, Samoa, and Tonga.
What is the history of the Zika virus?
The Zika virus is found in tropical locales with large mosquito
populations. Outbreaks of Zika have been recorded in Africa, the
Americas, Southern Asia and the Western Pacific. The virus was first
identified in Uganda in 1947 in rhesus monkeys and was first identified
in people in 1952 in Uganda and Tanzania, according to the WHO.
Can Zika be transmitted through sexual contact?
The World Health Organization (WHO) said sexual transmission is
"relatively common" and has advised pregnant women not to travel to
areas with ongoing outbreaks of Zika virus.
The U.S. CDC is investigating about a dozen cases of possible sexual
transmission. All cases involve possible transmission of the virus from
men to their sex partners. The WHO has also identified Zika cases in
Argentina, Chile, France, Italy and New Zealand as likely caused by
British health officials reported Zika was found in a man's semen two
months after he was infected, suggesting the virus may linger in semen
long after infection symptoms fade.
The PAHO said Zika can be transmitted through blood, but this is an
infrequent transmission mechanism. There is no evidence Zika can be
transmitted to babies through breast milk.
What other complications are associated with Zika?
Zika has also been associated with other neurological disordes,
including serious brain and spinal cord infections. The long-term health
consequences of Zika infection are unclear. Other uncertainties surround
the incubation period of the virus and how Zika interacts with other
viruses that are transmitted by mosquitoes, such as dengue.
(Compiled by the Americas Desk)
Source: Why the Zika virus is causing alarm | Reuters -