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.

A mosquito. Photo from Sinu Kumar via Flickr

 

The Mosquito 

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

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.

 

Map of areas of world where malaria is present. Image from GIS UWE via Flickr

 

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.

 

What now? 

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!

 

http://https://www.nationalgeographic.com/animals/invertebrates/group/mosquitoes/

https://www.mja.com.au/journal/1996/164/6/malaria-transmission-and-climate-change-australia

http:/https://www.afro.who.int/health-topics/malaria

http:/https://www1.racgp.org.au/newsgp/clinical/managing-malaria-in-australia

http:/https://www.sahealth.sa.gov.au/wps/wcm/connect/public+content/sa+health+internet/protecting+public+health/alerts/health+alerts/increase+in+imported+malaria+cases


12 Responses to “Nature’s biggest killer: The Mosquito”

  1. Lucy Baker says:

    100%! very scary stuff

  2. Lucy Baker says:

    yes that is another angle too! found it very interesting but didn’t fit as well in my narrative for the blog sadly :(.

  3. Lucy Baker says:

    thanks very much. those are some good points

  4. Lucy Baker says:

    thank you! hope you found it interesting

  5. Lucy Baker says:

    thank you very much! Yes, sadly wish there was a more optimistic conclusion!

  6. Lucy Baker says:

    yeah that is a really good point! It is extremely important to stress the issues coming with climate change

  7. Hanwen Hou says:

    Interesting topic! Mosquito is responsible for the transmission for a lot of diseases, it is important for people to be aware of that and prevent mosquito bite as much as possible. Besides, mosquito bite is really itchy!

  8. Devanshi says:

    Great post! I think the link between climate change and increased spread of vector borne infections cannot be emphasised enough. Unfortunately many people are still quite apathetic about climate change, so I think it’s great to spread more knowledge about how climate change will directly impact humans in the hope that it will influence more people to take action.

  9. Matilda Doran says:

    Loved the link you made between mosquitoes and climate change…. the outcome not so much. Thanks Luc, really informative 🙂

  10. Mei says:

    By the way, it is very nice to see some further links at the end of the article!

  11. Mei says:

    Detailed insect pic warning! lol. Well done!
    This article is very close to our daily life, which is very engaging and interesting! The article is also very comprehensive! I like the flow you went through and the connection between mosquitos and Malaria.
    Some points can possibly improved. Firstly, clarify which mosquito species the first picture is on the figure caption. Secondly, explain a bit why you chose Malaria specifically over other diseases. Thirdly, explain more about the second graph as I was lost untill I googled the terms on the map. Lastly, probably mention something about other environmental issues that can help mosquitos reproduce. For example, as you mentioned, juvenile mosquitos live in stagnant water. I assume there are issues with waste water management as well.

  12. Yilin Zhao says:

    Very interesting blog! I have seen the news that the objectives selected by mosquitoes are not directly related to blood type, gender, etc. In most cases, mosquitoes are indiscriminately attacked, as long as they detect people, they will attack. However, they may prefer people with odour and higher temperatures, such as those who love sports, easy to sweat, have large lung capacity, and heavy breathing, and pregnant women and some women in the period.