Zika virus disease : what you should know
Zika virus disease is a mosquito-borne disease caused by zika virus, On 1st February 2016 the World Health Organization has declared the Zika virus (ZIKV) outbreak to be a public health emergency of international concern (PHEIC). Until 2007, there were only isolated cases in Africa and Southeast Asia.
The pathogen Zika virus disease is caused by the Zika virus (ZIKV) : it belongs to the virus family Flaviviridae, which includes the viruses that cause dengue fever, yellow fever, tick-borne encephalitis (TBE), Japanese encephalitis, and West Nile fever.
Zika virus transmission
Zika virus is spread to people mainly through the bite of an infected mosquito
Zika virus is transmitted through Aedes aegypti / albopictus mosquitoes.
These mosquitoes are mainly active during the day and early evening hours, but they can also bite at night. Aedes mosquitoes are quite aggressive and prefer to bite humans. They are mainly found in cities.
Sexual zika virus transmission have been reported
There have been several documented cases of sexual transmission (man to woman, woman to man, man to man, even after the acute phase of the disease)
Reservoir for zika virus
Reservoir for zika virus are :
- and mosquitoes.
Incubation period is not exactly known : probably 3-14 days.
Many people infected with Zika virus don’t have any symptoms : One out of five infected people get sick.
People infected can have some common symptoms such as fever with a rash, joint pain, red eyes (Conjunctivitis), muscle pain, headache, for several days to a week.
Several countries that have experienced zika outbreaks recently have reported increases in people who have Guillain-Barré syndrome (GBS).
From what we know about similar infections, once a person has been infected with Zika virus, he or she is likely to be protected from a future Zika infection.
Zika virus during pregnancy causes severe birth defects, including microcephaly and severe fetal brain abnormalities.
Possible exposures include :
- travel to an area where there is epidemic or endemic zika virus transmission,
- sex with a partner who has traveled to or lived in an area with epidemic or endemic zika virus transmission
Zika virus has been detected in whole blood (also serum and plasma), urine, cerebrospinal fluid, amniotic fluid, semen and saliva. There is accumulating evidence that zika virus is present in urine and semen for longer periods than in whole blood or saliva.
Zika virus usually remains in the blood of an infected person for about a week.
Diagnosis of zika is based on a person’s recent travel history, symptoms, and test results.
A blood or urine test can confirm a Zika infection.
- CDC website : testing for zika virus
- World health organisation : Laboratory testing for Zika virus infection
- Recommendations of the Expert Committee of Travel Medicine (ECTM) of Switzerland
There is no vaccine or medicine for zika virus infection.
Therefore, preventive personal measures are recommended to avoid mosquito bites during the daytime.
Prevention : to protect yourself from zika
Travelers can protect themselves by preventing mosquito bites:
- cover exposed skin by wearing long-sleeved shirts and long pants,
- use EPA-registered insect repellents ( always use as directed) containing
- oil of lemon eucalyptus (OLE, also called para-menthane-diol [PMD]),
- or IR3535.
- Pregnant and breastfeeding women can use all EPA-registered insect repellents, including DEET, according to the product label.
- use permethrin-treated clothing and gear (such as boots, pants, socks, and tents),
- stay in places with air conditioning and window and door screens to keep mosquitoes outside,
- sleep under a mosquito bed net if air conditioned or screened rooms are not available or if sleeping outdoors.
Zika can be sexually transmitted, therefore, if you have sex (vaginal, anal, or oral) while traveling, you should use condoms.
When large numbers of mosquitoes are found, airplanes can be used to treat very large areas with insecticides
These countries are currently experiencing outbreaks of zika, and travel notices have been posted to alert travelers, particularly pregnant women, of the risk.
These countries are considered epidemic because
the mosquito that carries zika virus is present,
zika has not been reported there in the past,
and very little, if any, of the population is likely to be immune.
When zika is first introduced into a country, it generally spreads quickly through the population. Over time, as the outbreaks decrease, these countries will change from the “epidemic” to the “endemic” classification, and travel notices will be removed.
These countries have reported cases of zika in the past and may occasionally report new cases.
A large number of local residents are likely to be immune, so occasional cases may occur but generally not in numbers large enough to be considered an outbreak.
Because the risk to travelers is likely much lower in these countries than in epidemic countries, travel notices will not be posted unless the number of cases rises to the level of an outbreak.
You can also read the following posts :
- European Centre for Disease Prevention and Control website : current zika transmission
- Prevention of sexual transmission of zika virus : interim guidance update
- European centre for disease prevention and control : zika virus disease, factsheet for health professionals
- WHO, World health organisation : situation report zika virus microcephaly, Guillain-Barré syndrome, 8 september 2016
- Swiss Tropical and Public Health
- INVS, France : zika