According to World Health Organization
Key facts
Zika virus disease is caused by a virus transmitted
by Aedes mosquitoes.
People with Zika virus disease usually have
symptoms that can include mild fever, skin rashes,
conjunctivitis, muscle and joint pain, malaise or
headache. These symptoms normally last for 2-7
days.
There is no specific treatment or vaccine currently
available.
The best form of prevention is protection against
mosquito bites.
The virus is known to circulate in Africa, the
Americas, Asia and the Pacific.
Introduction
Zika virus is an emerging mosquito-borne virus that
was first identified in Uganda in 1947 in rhesus
monkeys through a monitoring network of sylvatic
yellow fever. It was subsequently identified in humans
in 1952 in Uganda and the United Republic of Tanzania.
Outbreaks of Zika virus disease have been recorded in
Africa, the Americas, Asia and the Pacific.
Genre: Flavivirus
Vector: Aedes mosquitoes (which usually bite during
the morning and late afternoon/evening hours)
Reservoir: Unknown
Signs and Symptoms
The incubation period (the time from exposure to
symptoms) of Zika virus disease is not clear, but is
likely to be a few days. The symptoms are similar to
other arbovirus infections such as dengue, and include
fever, skin rashes, conjunctivitis, muscle and joint pain,
malaise, and headache. These symptoms are usually
mild and last for 2-7 days.
Potential complications of Zika virus disease
During large outbreaks in French Polynesia and Brazil
in 2013 and 2015 respectively, national health
authorities reported potential neurological and auto-
immune complications of Zika virus disease. Recently
in Brazil, local health authorities have observed an
increase in Guillain-Barré syndrome which coincided
with Zika virus infections in the general public, as well
as an increase in babies born with microcephaly in
northeast Brazil. Agencies investigating the Zika
outbreaks are finding an increasing body of evidence
about the link between Zika virus and microcephaly.
However, more investigation is needed to better
understand the relationship between microcephaly in
babies and the Zika virus. Other potential causes are
also being investigated.
Transmission
Zika virus is transmitted to people through the bite of an
infected mosquito from the Aedes genus, mainly Aedes
aegypti in tropical regions. This is the same mosquito
that transmits dengue, chikungunya and yellow fever.
Zika virus disease outbreaks were reported for the first
time from the Pacific in 2007 and 2013 (Yap and French
Polynesia, respectively), and in 2015 from the Americas
(Brazil and Colombia) and Africa (Cape Verde). In
addition, more than 13 countries in the Americas have
reported sporadic Zika virus infections indicating rapid
geographic expansion of Zika virus.
Diagnosis
Infection with Zika virus may be suspected based on
symptoms and recent history (e.g. residence or travel to
an area where Zika virus is known to be present). Zika
virus diagnosis can only be confirmed by laboratory
testing for the presence of Zika virus RNA in the blood
or other body fluids, such as urine or saliva.
Prevention
Mosquitoes and their breeding sites pose a significant
risk factor for Zika virus infection. Prevention and
control relies on reducing mosquitoes through source
reduction (removal and modification of breeding sites)
and reducing contact between mosquitoes and people.
This can be done by using insect repellent; wearing
clothes (preferably light-coloured) that cover as much
of the body as possible; using physical barriers such as
screens, closed doors and windows; and sleeping under
mosquito nets. It is also important to empty, clean or
cover containers that can hold water such as buckets,
flower pots or tyres, so that places where mosquitoes
can breed are removed.
Special attention and help should be given to those who
may not be able to protect themselves adequately, such
as young children, the sick or elderly.
During outbreaks, health authorities may advise that
spraying of insecticides be carried out. Insecticides
recommended by the WHO Pesticide Evaluation Scheme
may also be used as larvicides to treat relatively large
water containers.
Travellers should take the basic precautions described
above to protect themselves from mosquito bites.
Treatment
Zika virus disease is usually relatively mild and
requires no specific treatment. People sick with Zika
virus should get plenty of rest, drink enough fluids, and
treat pain and fever with common medicines. If
symptoms worsen, they should seek medical care and
advice. There is currently no vaccine available.
WHO response
WHO is supporting countries to control Zika virus
disease through:
Define and prioritize research into Zika virus disease
by convening experts and partners.
Enhance surveillance of Zika virus and potential
complications.
Strengthen capacity in risk communication to help
countries meet their commitments under the
International Health Regulations.
Provide training on clinical management, diagnosis
and vector control including through a number of
WHO Collaborating Centres.
Strengthen the capacity of laboratories to detect the
virus.
Support health authorities to implement vector
control strategies aimed at reducing Aedes mosquito
populations such as providing larvicide to treat
standing water sites that cannot be treated in other
ways, such as cleaning, emptying, and covering
them.
Prepare recommendations for clinical care and
follow-up of people with Zika virus, in collaboration
with experts and other health agencies.
Key facts
Zika virus disease is caused by a virus transmitted
by Aedes mosquitoes.
People with Zika virus disease usually have
symptoms that can include mild fever, skin rashes,
conjunctivitis, muscle and joint pain, malaise or
headache. These symptoms normally last for 2-7
days.
There is no specific treatment or vaccine currently
available.
The best form of prevention is protection against
mosquito bites.
The virus is known to circulate in Africa, the
Americas, Asia and the Pacific.
Introduction
Zika virus is an emerging mosquito-borne virus that
was first identified in Uganda in 1947 in rhesus
monkeys through a monitoring network of sylvatic
yellow fever. It was subsequently identified in humans
in 1952 in Uganda and the United Republic of Tanzania.
Outbreaks of Zika virus disease have been recorded in
Africa, the Americas, Asia and the Pacific.
Genre: Flavivirus
Vector: Aedes mosquitoes (which usually bite during
the morning and late afternoon/evening hours)
Reservoir: Unknown
Signs and Symptoms
The incubation period (the time from exposure to
symptoms) of Zika virus disease is not clear, but is
likely to be a few days. The symptoms are similar to
other arbovirus infections such as dengue, and include
fever, skin rashes, conjunctivitis, muscle and joint pain,
malaise, and headache. These symptoms are usually
mild and last for 2-7 days.
Potential complications of Zika virus disease
During large outbreaks in French Polynesia and Brazil
in 2013 and 2015 respectively, national health
authorities reported potential neurological and auto-
immune complications of Zika virus disease. Recently
in Brazil, local health authorities have observed an
increase in Guillain-Barré syndrome which coincided
with Zika virus infections in the general public, as well
as an increase in babies born with microcephaly in
northeast Brazil. Agencies investigating the Zika
outbreaks are finding an increasing body of evidence
about the link between Zika virus and microcephaly.
However, more investigation is needed to better
understand the relationship between microcephaly in
babies and the Zika virus. Other potential causes are
also being investigated.
Transmission
Zika virus is transmitted to people through the bite of an
infected mosquito from the Aedes genus, mainly Aedes
aegypti in tropical regions. This is the same mosquito
that transmits dengue, chikungunya and yellow fever.
Zika virus disease outbreaks were reported for the first
time from the Pacific in 2007 and 2013 (Yap and French
Polynesia, respectively), and in 2015 from the Americas
(Brazil and Colombia) and Africa (Cape Verde). In
addition, more than 13 countries in the Americas have
reported sporadic Zika virus infections indicating rapid
geographic expansion of Zika virus.
Diagnosis
Infection with Zika virus may be suspected based on
symptoms and recent history (e.g. residence or travel to
an area where Zika virus is known to be present). Zika
virus diagnosis can only be confirmed by laboratory
testing for the presence of Zika virus RNA in the blood
or other body fluids, such as urine or saliva.
Prevention
Mosquitoes and their breeding sites pose a significant
risk factor for Zika virus infection. Prevention and
control relies on reducing mosquitoes through source
reduction (removal and modification of breeding sites)
and reducing contact between mosquitoes and people.
This can be done by using insect repellent; wearing
clothes (preferably light-coloured) that cover as much
of the body as possible; using physical barriers such as
screens, closed doors and windows; and sleeping under
mosquito nets. It is also important to empty, clean or
cover containers that can hold water such as buckets,
flower pots or tyres, so that places where mosquitoes
can breed are removed.
Special attention and help should be given to those who
may not be able to protect themselves adequately, such
as young children, the sick or elderly.
During outbreaks, health authorities may advise that
spraying of insecticides be carried out. Insecticides
recommended by the WHO Pesticide Evaluation Scheme
may also be used as larvicides to treat relatively large
water containers.
Travellers should take the basic precautions described
above to protect themselves from mosquito bites.
Treatment
Zika virus disease is usually relatively mild and
requires no specific treatment. People sick with Zika
virus should get plenty of rest, drink enough fluids, and
treat pain and fever with common medicines. If
symptoms worsen, they should seek medical care and
advice. There is currently no vaccine available.
WHO response
WHO is supporting countries to control Zika virus
disease through:
Define and prioritize research into Zika virus disease
by convening experts and partners.
Enhance surveillance of Zika virus and potential
complications.
Strengthen capacity in risk communication to help
countries meet their commitments under the
International Health Regulations.
Provide training on clinical management, diagnosis
and vector control including through a number of
WHO Collaborating Centres.
Strengthen the capacity of laboratories to detect the
virus.
Support health authorities to implement vector
control strategies aimed at reducing Aedes mosquito
populations such as providing larvicide to treat
standing water sites that cannot be treated in other
ways, such as cleaning, emptying, and covering
them.
Prepare recommendations for clinical care and
follow-up of people with Zika virus, in collaboration
with experts and other health agencies.
