FAQ 1 Tiger Mosquitoes and Diseases

Frequently Asked Questions: Tiger Mosquitoes

 

 

Frequently Asked Questions: Chikungunya and Dengue

 

Why do mosquitoes bite?

 

   Mosquitoes require blood to develop their fertilized eggs. The female mosquitoes produce the eggs; therefore, they seek out other life forms, for example humans, to bite and ingest their essential blood meal. Male mosquitoes do not lay the eggs and as a result they also do not bite. They mainly feed on nectar from plants.

What is particularly special about tiger mosquitoes?

 

   First and foremost, the tiger mosquitoes are capable of transmitting serious diseases such as Chikungunya and Dengue fever.  They obtain these viruses from one bite of an infected human.  The virus then begins to proliferate inside the mosquito and after roughly ten days the mosquito can transmit the disease to other humans with only one bite.

   In addition to these hazardous threats, the tiger mosquitoes distinguish themselves from other mosquitoes by being day feeders.  They are abnormally aggressive and persistent.  Tiger mosquitoes mainly do not fly in large swarms so do not base the success of the catch results on a large bulk of normal mosquitoes being caught but rather on the actual number of tiger mosquitoes that are caught.

What are tiger mosquitoes attracted to?

 

   Every tiger mosquito responds differently to the various signals that are emitted by their prey. Tiger mosquitoes react to a combination of particular visual signals, air plumes, and specific scents of the human skin. The Biogents® Mosquitaire™ trap is highly effective because it is specifically developed for tiger mosquitoes. It is a patented combination of visual signals, artificially generated air plumes, and a patented 3 component scent that mimics human skin and further enhances the efficiency of the trap.

How do I recognize a tiger mosquito?

 

   Tiger mosquitoes are not bigger than normal mosquitoes.  In fact, they are often somewhat smaller. Their entire body is accentuated with white-silvery markings.  Tiger mosquitoes are primarily recognized by their white-silvery stripes that begin between their eyes and continue down the middle of their back. Their hind legs also consist of the same color scheme so that they look like black and white ringed segments.

Where are tiger mosquitoes found? 


   Tiger mosquitoes are originally from Southeast Asia; however, over the last 25 years they have dispersed to many different regions around the world.  Now you can find tiger mosquitoes in parts of Africa and the Americas. They are also prevalent in Europe where Italy is predominantly affected by them. There are very few regions in Italy where the tiger mosquitoes have not yet made themselves at home.

What do tiger mosquitoes have to do with diseases such as Chikungunya and Dengue fever? 

 

   Tiger mosquitoes can carry and transmit Chikungunya and Dengue fever. Because they are day active and often bite several people in a short period of time, they can be very dangerous vectors of disease.

Which regions have already had Chikungunya and Dengue fever epidemics? 

 

   In the tropical and sub-tropical bands of the earth (Southeast Asia, Indian Subcontinent, Africa, Latin America, etc.) there are Chikungunya and Dengue fever epidemics every year with millions of people infected.  Dengue epidemics result in thousands of fatalities annually and among them are notably small children.  In 2007, Europe had its first outbreak of Chikungunya in Italy with over 200 people infected.

How high is the risk for an outbreak in Europe?  

 

   The risk is indeed not exactly predictable, but with the distribution of the tiger mosquitoes throughout Europe and large parts of southern Europe having the necessary, adequate warm climates, it is only a matter of time before the viruses find their way through Europe. Every year hundreds of thousands of people travel to regions at risk and return back to their countries. In the last couple of years, hundreds of these travelers brought back Chikungunya or Dengue infections with them. It is now only a matter of time until the tiger mosquito will bite an infected person and be able to transmit it to other individuals. Above all, Chikungunya will be transmitted especially well by tiger mosquitoes. 

Has Europe already been affected by such an epidemic?  

 

   Yes, in 2007 Europe had its first outbreak of Chikungunya fever in Ravenna, Italy where more than 200 people were infected. In this case, the disease was introduced by a man who was infected while traveling in India when he returned back to Italy.

What are the symptoms and implications of Chikungunya fever?  

 

   Chikungunya fever was first described in East Africa in the 1950’s. Today, the distribution area of the disease reaches from eastern and southern Africa over the Indian subcontinent and to Southeast Asia. Currently, the tiger mosquitoes and their close relatives, the Yellow fever mosquitoes, which are not yet found in Europe, are the only definite carriers of this virus that have been observed. Chikungunya is a word from the Tanzanian language that means “that which bends up” or “that which contorts”. The infected person normally has a rapidly increasing high fever. Severe joint and muscle pains cause extreme sensibility to where the individual can barely hold an erect position. The fever usually lasts only a couple of days. Normally, the illness simply runs its course and the symptoms begin to subside after approximately one to two weeks, unless complications occur. Consistent complications and deaths are rare. There is no vaccination currently available. After overcoming the disease, the individual is immune against Chikungunya for life. 

What are the symptoms and implications of Dengue fever?  

 

   Dengue fever (also known as Break Bone Fever) is transmitted by the Asian tiger mosquito and the Yellow fever mosquito. Regions of the greatest risk are northern Australia, southeast Asia, India, parts of Africa and parts of the Americas. In 90% of the cases of infection, flu-like symptoms will be observed. In the other 10% of the cases, a sudden high fever of up to 41° C is accompanied by a headache, limb, joint, and muscle pain and occasionally a skin rash. After approximately five days another fever attack usually follows and then the recovery phase begins which can drag on for several weeks. The most severe form of Dengue fever is the so-called Dengue Hemorrhagic Fever (DHF) and it is associated with internal bleeding. 

   Each year more than 10 million people will become infected with the Dengue virus, and a hundred thousand people will develop the severe form, DHF. In most countries roughly 5% of people suffering from DHF die. Where there are good medical services this percentage drops to less than 1%. Most of the fatalities occur among children and young adults.

   Currently there is no vaccination against Dengue fever. There are four closely related types of the Dengue virus, and a sufferer of one type of Dengue virus is not necessarily protected against the others. On the contrary, the risk of contracting the severe form of Dengue fever, DHF, increases with the second infection of a different virus type.

 

How are Chikungunya and Dengue fever transmitted from tiger mosquitoes? 

 

   The Chikungunya or Dengue virus will be transmitted to a tiger mosquito when that mosquito bites a person that is infected with that virus. The virus begins to proliferate in the mosquito. After roughly 10 days, the virus can be transmitted to a person that is bit by the infected mosquito. If the mosquito is killed within this time period then the disease cannot be passed on. 

Can I vaccinate myself against Chikungunya or Dengue fever? 

 

   No, there are still no vaccinations against Chikungunya or Dengue fever despite much research from health authorities and pharmaceutical companies.