Over the last decade, diseases such as Ebola, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) have caused health scares across the world.
The one thing that these diseases have in common is that they always originate in animals before transferring across to humans. Like the mosquito, ticks are known for transferring diseases from animals to humans and with more and more tick-borne diseases emerging, the possibility of a global outbreak is becoming all the more probable.
The tick problem
As a species, ticks are extremely understudied and the list of microbes found in these small arachnids grow larger every year as new tick species are discovered.
They can carry a wide array of pathogens including bacteria, viruses and protozoa. This makes them a huge threat to humans because once a tick feeds, the pathogen can enter the human’s bloodstream along with the tick’s saliva.
The changing world
Global warming is encouraging the spread of ticks. As temperatures get warmer, some ticks are expanding their ranges into places where cool winters previously limited their dispersal.
Transport links between borders present even further opportunities for ticks to spread to new habitats.
Lyme disease is the most common tick-related disease and its discovery in 1975 has led to more research into diseases spread by ticks.
In the media, Lyme disease often overshadows other equally dangerous diseases such as tick-borne rickettsiosis (TBR) and babesiosis. These diseases have the same symptoms as Lyme disease with joint and muscle pain, rashes and fatigue.
A disease known as severe fever with thrombocytopenia syndrome (SFTS), which has affected people in Japan, is known to be carried by two tick species. These species of tick can currently be found in the US, UK and Australia, meaning that this disease could potentially spread in these areas.
It is crucial that more in depth research takes place before ticks begin to pose as a serious threat to humans.