All you need to know about the new "Zika" virus disease

          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

   (*vector in biological term is the organism or let's say the thing that infects people the with the virus or carries the virus around)

          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. However, sexual transmission of Zika virus has been

described in 2 cases, and the presence of the Zika virus in semen in 1

additional case.

    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 (Cabo 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 regularly; wearing clothes

(preferably light-coloured) that cover as much of the body as possible;

using physical barriers such as window screens, closed doors and

windows; and if needed, additional personal protection, such as sleeping

under mosquito nets during the day. It is extremely important to empty,

clean or cover containers regularly that can store water, such as buckets,

drums, pots etc. Other mosquito breeding sites should be cleaned or

removed including flower pots, used tyres and roof gutters. Communities

must support the efforts of the local government to reduce the density of

mosquitoes in their locality.

    Repellents should contain DEET (N, N-diethyl-3-methylbenzamide),

IR3535 (3-[N-acetyl-N-butyl]-aminopropionic acid ethyl ester) or icaridin

(1-piperidinecarboxylic acid, 2-(2-hydroxyethyl)-1-methylpropylester).

Product label instructions should be strictly followed. 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 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 still 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.

 Source :    World Health Organization