Vector-Borne Diseases

With the onset of summer, the days are finally longer and warmer. However, with rising temperatures, the number of biting insects around us also increases. Many of you have spent a sleepless night trying to find the source of the buzzing (bug wings) in the bedroom or, even worse, the itching and swelling after a bite. But a much bigger problem you may not be aware of is the potential for disease to spread.

Vector-Borne Diseases

A vector is defined as a living organism that can transmit pathogens from one infected person to another. A vector-borne disease is one transmitted by the bite of an infected arthropod species, such as mosquitoes, ticks, or flies. Mosquitoes are among the biggest vectors of disease worldwide, with over a billion cases reported each year and over a million people dying as a result. Mosquitoes can transmit malaria, chikungunya, dengue, yellow fever, West Nile virus, Zika and many other infectious viruses.

Increased risk of vector-borne diseases

Both climate change and globalization have led to the spread of vector-borne diseases beyond the tropics. Vector-borne diseases are increasingly found in temperate regions. Every year there are new reports from countries about new cases of invasive insects and diseases. As the prevalence of these diseases increases, so does consumer awareness about adopting preventive measures.

Since the late 1990s, the European Center for Disease Control has been warning of a massive spread of invasive mosquito species in Europe, including: Anopheles sp. (carrier of the malarial pathogen), Culex sp. (West Nile virus carrier) or Aedes sp. (carrier of zika, dengue and chikungunya viruses).

Some of the dominant species of Anopheles vectors in Europe are Anopheles atroparvus and Anopheles sergentii, which are carriers of the malarial pathogen. An increasing number of imported cases of malaria have occurred in recent years due to international travel and immigrants from countries where malaria is endemic. Of the 8,400 cases of malaria, 99% were due to infected travelers returning home, but sporadic cases of local infection are also on the rise.

Spread of disease

Culex pipiens, the common mosquito, is found worldwide and can transmit West Nile virus. Between 2017 and 2018, the number of reported cases with this virus in Europe increased to over 1,500. That number increased sevenfold from year to year and also exceeded the total number of cases in the previous seven years combined.

Mosquitoes of the Aedes aegypti species, which transmit dengue, have already established themselves in Madeira and the coastal areas of the Black Sea since 2005. Between 2012 and 2013, in Madeira alone, more than 2,000 cases of infection with the dengue virus were reported.

The Aedes albopictus, commonly known as the Asian tiger mosquito, carries Zika, dengue and chikungunya viruses. This is the most relevant example of vector propagation caused by human activity. They were introduced to Europe via Albania in 1979 and since then over 25 European countries have reported their presence for the first time.

Given this growing threat from invasive mosquito species, it’s important to remember how to protect yourself and your family from mosquito-borne illnesses.

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