Nature’s biggest killer: The Mosquito
Tonight’s barbeque just got a lot more dangerous.
When we typically think of mosquitoes, the first thing that comes to mind might be the irritating buzzing sound they make or the annoying bites they leave.
But maybe we should be more concerned about the deadly infections some mosquitos carry!
Mosquitos are estimated to kill almost one million people a year. This is significantly higher than snakes, which are responsible for the death of around 100 000 people, or crocodiles, who kill around 1000 people per year.
Mosquitos find us by detecting carbon dioxide on our skin, as well as by our smell and temperature. Only female mosquitos actually bite humans and suck blood. They do this through their specialised mouth, called a ‘proboscis.’ Specifically, two tubes enter the skin. One tube sucks up blood to use to support their eggs. The other tube secretes saliva, an enzyme to stop blood clotting. This tube can also potentially transfer pathogens to humans.
There are over three thousand types of mosquitos, however only a few hundred types actually carry diseases that harm us. But these types of mosquitoes are dangerous. They are responsible for a number of serious and potentially deadly diseases including Malaria, Zika virus, Yellow fever, Elephantiasis, Dengue fever and Ross River virus.
Malaria is the most deadly of the mosquito borne diseases. It causes upwards of four hundred thousand deaths a year. Most of the casualties are children under five years of age. Malaria is most commonly caused by the Anopheles mosquito. It is a tropical disease and disproportionately harms people in developing countries, particularly Africa. The malaria parasite enters the blood when the female mosquito bites human skin. It travels to the liver and begins to reproduce. Over the coming days and weeks, it re-enters the bloodstream and further multiplies in the red blood cells. This causes symptoms like cycles of high temperatures and chills, headaches, backaches, and sweating between periods of tiredness.
We do have a range of preventative medication and treatment to combat malaria. However, drug resistance is a growing concern. Also, because the malaria parasite is complex, we don’t currently have a highly effective and available vaccine for malaria.
Overall, it is a very unpleasant and life threating illness that is best to be avoided.
Malaria and Australia
Australia has a long history with malaria. In Northern Australia, many early settlers died from malaria. The disease has also taken the lives of many Australian troops in warfare. However, in 1981, Australia became ‘malaria free.’ The Australian Government achieved this status through Public Health strategies. One strategy they used was to reduce the number of mosquitoes carrying the disease by draining the stagnant water where mosquitoes breed. This was done by developing effective water drainage systems in towns. Also, public awareness of malaria was increased. Specifically, both the importance of taking preventative medication when visiting countries where malaria is endemic, and the need to use insect repellent and nets when sleeping were stressed.
There are still a few hundred cases of malaria each year in Australia. It is important that these are met with early diagnosis and immediate treatment. This process includes a period of isolation to prevent the spread of malaria is needed.
Malaria and Climate Change
Concerningly, our changing climate is predicted to increase the global threat of mosquito borne diseases. This is because the warmer weather patterns and changes in rainfall associated with global warming, is expected to increase the world’s mosquito populations, and introduce mosquitoes into new areas.
This could threaten our status as a ‘malaria free’ country. Scientists are already predicting that the mosquito borne diseases, Dengue fever and the Ross River virus, will affect new areas of Australia.
Given the potential for mosquito borne diseases to increase in the future, our summer barbecues will only become more dangerous!
Although not an immediate threat in Australia, we need to keep in mind that mosquitoes can be deadly. Remember to take the proper preventative medications when travelling and use mosquito nets and repellent!