Zika virus : epidemiology, symptoms, diagnosis, treatment and prevention

What is Zika Virus ?

Zika virus falls under member of Flavivirus.  The vector for Zika vius is Aedes mosquito. Zika virus is an emerging mosquito-borne virus that was first isolated in Zika forest of Uganda in 1947. Since then, it has been observed mainly in Africa, with small and sporadic outbreaks in Asia.

Fig. Zika virus is transmitted by daytime mosquitoes
under the genus Aedes.
Credit: Photo from Wikipedia

Where has Zika virus been found?

·  Prior to 2015, Zika virus outbreaks have occurred in areas of Africa, Southeast Asia, and the Pacific Islands.

·   In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus infections in Brazil.

·   Currently, outbreaks are occurring in many countries.

·         Zika virus will continue to spread and it will be difficult to determine how the virus will spread over time.

Fig. Zika virus affected countries

Zika in the United States and its territories:

·      No locally transmitted Zika cases have been reported in the continental United States, but cases have been reported in returning travelers.

·        Locally transmitted Zika virus has been reported in the Commonwealth of Puerto Rico.

·  With the recent outbreaks, the number of Zika cases among travelers visiting or returning to the United States will likely increase.

·         These imported cases could result in local spread of the virus in some areas of the United States.

Symptoms:

·         About 1 in 5 people infected with Zika virus become ill (i.e., develop Zika).

·     The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis (red eyes). Other common symptoms include muscle pain and headache. The incubation period (the time from exposure to symptoms) for Zika virus disease is not known, but is likely to be a few days to a week.

·         The illness is usually mild with symptoms lasting for several days to a week.

·         Zika virus usually remains in the blood of an infected person for a few days but it can be found longer in some people.

·         Severe disease requiring hospitalization is uncommon.

·         Deaths are rare.

Diagnosis:

·         The symptoms of Zika are similar to those of dengue and chikungunya, diseases spread through the same mosquitoes that transmit Zika.

·     See your healthcare provider if you develop the symptoms described above and have visited an area where Zika is found.

·         If you have recently traveled, tell your healthcare provider when and where you traveled.

·         Your healthcare provider may order blood tests to look for Zika or other similar viruses like dengue or chikungunya.

Treatment:

·         No vaccine or medications are available to prevent or treat Zika infections.

·         Treat the symptoms:

o    Get plenty of rest

o    Drink fluids to prevent dehydration

o    Take medicines, such as acetaminophen or paracetamol, to relieve fever and pain

o    Do not take aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and naproxen. Aspirin and NSAIDs should be avoided until dengue can be ruled out to reduce the risk of hemorrhage (bleeding). If you are taking medicine for another medical condition, talk to your healthcare provider before taking additional medication.

·         If you have Zika, avoid mosquito bites for the first week of your illness.

o    During the first week of infection, Zika virus can be found in the blood and passed from an infected person to another mosquito through mosquito bites.

o    An infected mosquito can then spread the virus to other people.

Frequently Asked Questions (FAQs) for Zika Virus:

How is Zika virus (Zika) transmitted?

Zika is primarily transmitted through the bite of infected Aedes mosquitoes. It can also be transmitted from a pregnant mother to her baby during pregnancy or around the time of birth. We do not know how often Zika is transmitted from mother to baby during pregnancy or around the time of birth. 

Who is at risk of being infected?

Anyone who is living in or traveling to an area where Zika virus is found who has not already been infected with Zika virus is at risk for infection, including pregnant women. 

What are the symptoms of Zika virus infection (Zika)?

About one in five people infected with Zika will get sick. For people who get sick, the illness is usually mild. For this reason, many people might not realize they have been infected.

The most common symptoms of Zika virus disease are fever, rash, joint pain, or conjunctivitis (red eyes). Symptoms typically begin 2 to 7 days after being bitten by an infected mosquito. 

I am pregnant. How will Zika virus affect me or my unborn baby?

CDC has issued a travel alert (Level 2-Practice Enhanced Precautions) for people traveling to regions and certain countries where Zika virus transmission is ongoing: Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Suriname, and Venezuela.

This alert follows reports in Brazil of microcephaly and other poor pregnancy outcomes in babies of mothers who were infected with Zika virus while pregnant. However, additional studies are needed to further characterize this relationship. More studies are planned to learn more about the risks of Zika virus infection during pregnancy.

Until more is known, and out of an abundance of caution, CDC recommends special precautions for pregnant women and women trying to become pregnant:

·   Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing. Pregnant women who do travel to one of these areas should talk to their doctor or other healthcare provider first and strictly follow steps to avoid mosquito bites during the trip.

·         Women trying to become pregnant should consult with their healthcare provider before traveling to these areas and strictly follow steps to prevent mosquito bites during the trip. 

Is there a vaccine to prevent or medicine to treat Zika?

No. There is no vaccine to prevent infection or medicine to treat Zika. 

Is it safe to use an insect repellent if I am pregnant or nursing?

Yes! Using an insect repellent is safe and effective. Pregnant women and women who are breastfeeding can and should choose an EPA-registered insect repellents and use it according to the product label. 

If a woman who is not pregnant is bitten by a mosquito and infected with Zika virus, will her future pregnancies be at risk?

We do not know the risk to the baby if a woman is infected with Zika virus while she is pregnant.  However, Zika virus infection does not pose a risk of birth defects for future pregnancies.  Zika virus usually remains in the blood of an infected person for only a few days to a week.  The virus will not cause infections in a baby that is conceived after the virus is cleared from the blood. 

What should I do if I have Zika?

Treat the symptoms:

·         Get plenty of rest

·         Drink fluids to prevent dehydration

·         Take medicines such as acetaminophen or paracetamol to reduce fever and pain

·         Do not take aspirin or other non-steroidal anti-inflammatory drugs

(For more information: Please visit http://www.cdc.gov/zika/index.html )

References:    1.  http://www.cdc.gov

 2. www.paho.org