ZIKA – The mosquito, the disease, the way to protect yourself

Written the 12.02.2016
anti mosquito
In less than a year, the Aedes mosquito, e.g Aedes aegypti, has spread the ZIKA virus to more than 25 countries. No vaccine is yet available but the World Health Organization (WHO) is publishing new information every day about the disease, trying to answer to every question from the concerned population.
The Merck IR3535® team wrote this article to advise you about the most important ZIKA news: interesting facts about the mosquito carrying the Zika virus, the infection and how to protect yourself and your loved ones from the mosquito. 

Who is Aedes?

The Aedes aegypti mosquito is the main vector that is transmitting the Zika virus. In the past this species lived in a forest but over the decades it has adapted to rural, suburban human environments.

The virus is only passed by the female mosquito. The mosquito gets the virus while blood feeding on a person that is already infected. After a period between eight and twelve days the virus can be transmitted to other humans by bites.

As the flight range of female Aedes studies show, they spend their lifetime around the habitat where they emerge and do not go any further than 400 metres. This fact shows that it is people, rather than mosquitoes, who spread the virus.

Zika & Your family

People with the Zika virus disease show symptoms that include mild fever, skin rashes, conjunctivitis, muscle and joint pain, malaise or headache. These symptoms last between 2 and 7 days. For most people, Zika will feel like a bad and exhausting week, with lot of rest, drinking water, treating the pain and recovering with common medicines. But for some others, Zika means more…


pregnant woman
The connection between Microcephaly in newborns and the ZIKA virus still has not been fully studied. The number of babies born with microcephaly are occurring at the same time as ZIKA virus has appeared. Scientists intensively research in order to have evidence how the virus causes the increased incidence of microcephaly in newborns.

What is microcephaly?
Microcephaly is a condition where a baby is born with a small head (<33cm) or with a head which stops growing after birth.
Moreover, the condition is combined with poor brain growth which can lead to developmental disabilities. Usually, it is a very rare condition. Indeed, only one baby in several thousand is born with the abnormality.
Today there is no specific treatment for microcephaly. Early intervention with stimulation and play programmes may show positive impacts on development.
The current situation is that 4000 confirmed cases of microcephaly have already been reported.

What did scientists find so far?
Microcephaly is not the only condition that we can see occurring recently. Scientists also found retina and hearing damage in newborns in addition to many other symptoms, which they named “Fetus Syndrome related to Zika Virus”. At this time, the studies so far cannot clearly prove the connection between the disabilities, diseases or other damages to the Zika infection. 


If you are pregnant or wish to have a baby, 4 Latin American countries are recommended to avoid visiting during pregnancy in order to avoid any risk for the baby: Colombia, El Salvador, Ecuador and Jamaica2
Scientists found that the major neurological damages in babies happen during the 1st quarter of pregnancy but could also occur until the end of the 2nd quarter showing milder disabilities. Therefore it is important to safeguard from mosquito bites during at least the first 6 months of pregnancy.

Zika – A virus moving fast

As mentioned, the virus is passed by the female mosquito but recently Zika has been found in human semen and one researcher found a case where Zika had been transmitted between two persons during sexual contact. Moreover, even if it doesn’t mean that the transmission can happen that way, the virus also has been found in saliva and urine. Seeing all those evolve in such a short notice, scientists do believe that the Zika Virus is a rare and evolving virus. Indeed, no other virus has been transmitted by three ways: host, semen and saliva.

In conclusion, given the right proportions and its consequences, this virus is already being compared to HIV in the early 80's where there was no information about it.

Protect yourself and your loved ones

The World Health Organization gives recommendations to both patients already infected and healthy people.
Infected patients are recommended to:
  • Stay under a bed net or stay in a place with intact window/door screens, 
  • Protect themselves with “IR3535® or Icaridin” from further bites.
The recommendations for nursing staff and population living in same areas as the mosquito are:
  • Rest under a mosquito net treated with or without insecticide,
  • Wear clothes that cover the extremities, 
  • Stay in places with air conditioning,
  • Eliminate potential mosquito breeding sites – that include containers that can hold amounts of water,
  • Apply repellents to exposed skin and clothes containing insect repellents like IR3535®, DEET or Icaridin.
IR3535® has been shown to be effective against various Aedes species (e. g. Aedes aegypti and Aedes albopictus), which are, amongst others, the main vectors for the Zika virus, Dengue virus, Yellow Fever virus, West Nile virus and Chikingunya virus. 
Various efficacy tests with Culex species that may also transmit West Nile virus have been performed.
Tests have been conducted either with IR3535® in cage tests and/or field trials.
Depending on the setup of the tests and the composition of the formulations, protection times have been derived up to 12 hours. 
Merck has proven by multiple efficacy studies that IR3535® based formulations can aid the population from any generation, from baby to elderly, against the above-mentioned vector-borne diseases. 

1 http://www.who.int/features/qa/zika-pregnancy/en/

2  http://www.bbc.com/news/world-latin-america-35388842

3 http://www.who.int/mediacentre/factsheets/zika/en/

4 http://www.who.int/features/qa/zika-pregnancy/en/

5 http://www.who.int/emergencies/zika-virus/situation-report/en/

6 http://www.europe1.fr/sante/le-virus-zika-detecte-dans-lurine-et-la-salive-2663673