Disease vectors beyond their normal habitat

Climate change, the development of international trade and international travel have led to the fact that insects, carriers of infectious disease, began to rapidly spread beyond their normal habitat, adapt to different seasons, to migrate.

In 1999, the West Nile virus, originated in Uganda and spread by mosquitoes, killed 7 people in New York. In 2014, another virus, carried by mosquitoes – chikungunya afflicted 12 Florida residents.

According to Kim Knowlton, a senior scientist and deputy director of the Natural Resources Defense Council, A longer warm-weather season and changing rainfall patterns are allowing the insects that can transmit disease to humans to thrive for longer periods each year—and to simultaneously move into broader areas. Nowadays, more people are suffering from viral infections such as dengue fever, Zika, Chikungunya, Yellow fever, West Nile fever. Many of them do not yet have specific antiviral agents or vaccines.

For many years, mosquitoes Aedes – the carriers of the above-mentioned infections – existed exclusively in the tropical and subtropical zones, but have already spread to some European countries and the United States. The lack of natural predators and the availability of food prompts mosquitoes to live next to humans.

The spread of this type of mosquitoes is a major public health problem. They are hard to root out – their larvae are able to survive for months, even under conditions of insufficient moisture and temperature.

For example, Zika virus received great attention from the media due to its association with neurological disorders, such as the Guinean-Barré syndrome (GBS), and the development of microcephaly in fetuses.

This virus is difficult to diagnose; there is no vaccine. Originally it was discovered in 1947 in the Zika forest of Uganda. Given the growing presence of the main vector of the given disease – Aedes albopictus – in temperate zones, including Europe and America, its spread is a matter of a serious concern.

The first recorded outbreak of Zika was reported in 2007 in Micronesia, then it has spread to French Polynesia and Brazil, where in 2015 it has infected 1.3 million people.

70+sites around the world have confirmed cases of Zika virus. By March 2017 it was reported that 2,130 Europeans were infected with travel-associated Zika.

As of August 1, 2018, 34 cases of Zika infection have been recorded in the United States – travelers who have returned from the affected areas. 74 cases have been recorded for this period in the United States.

Hence, mosquitoes are able to adapt and spread beyond their normal habitat, since global warming creates favorable conditions for them. But there is also good news: people already have considerable experience in the study of effective methods and means of combating mosquitoes. So, in order to avoid a catastrophe in the long run, it is necessary to apply the acquired knowledge practically: to create effective anti-mosquito solutions.