Matt Stone discovers what makes a tiny mosquito one of the world’s most efficient killers.
By Matt Stone
I’M PRETTY sure we’ve all been there. Snuggled under the doona at night, semi asleep, with only the head out, when you are awakened by that most annoying, high-pitched whine – a mosquito. Involuntarily you slap at the noise, give yourself a ringing in the ear, and miss the mosquito. Under the covers goes your head in the hope that, if sharing your bed with a partner, the mosquito may decide they look a better option. All’s fair in love and war.
Liane tells me I’m paranoid about mosquitoes, but I have to admit they’re pretty amazing little critters. My (admitted) paranoia relates to getting malaria while on a volunteer assignment in Madang, PNG. While we always take our “doxy”, we checked and the World Health site indicated Madang was malaria free – so we didn’t bother to medicate.
I’M PRETTY sure we’ve all been there. Snuggled under the doona at night, semi asleep, with only the head out, when you are awakened by that most annoying, high-pitched whine – a mosquito. Involuntarily you slap at the noise, give yourself a ringing in the ear, and miss the mosquito. Under the covers goes your head in the hope that, if sharing your bed with a partner, the mosquito may decide they look a better option. All’s fair in love and war.
Liane tells me I’m paranoid about mosquitoes, but I have to admit they’re pretty amazing little critters. My (admitted) paranoia relates to getting malaria while on a volunteer assignment in Madang, PNG. While we always take our “doxy”, we checked and the World Health site indicated Madang was malaria free – so we didn’t bother to medicate.
A couple of days before we returned to Australia one of our students invited us to spend the night on an island off the mainland to check out their new B&B. It was still under construction, and they very kindly made a lovely black plastic igloo over a long-drop toilet for our convenience – seat on top of a tea chest and all!
Not until my apparel was around my ankles did I sense it was also a home for dozens of hungry mozzies, looking for food (my blood). We arrived home in Australia and 12-14 days later I broke out in sweats and chills - I had malaria.
So back to the culprit: a female (yes, they are the only ones who seek our blood) mosquito of the Anopheles species are the sole spreaders of all human types of malaria. We generally accuse them of biting, but in fact they “drill and suck” using one proboscis with five separate needles (stylets), each with a separate role. The whole bundle is held inside a flexible outer sheath, which retracts during a “bite” – we’ll use “bite” as the description for convenience. The key parts of that single proboscis are the outer sheath which guides the needles but does not enter the skin, the tube the mosquito uses to suck blood, the needle that delivers saliva (anticoagulants + anaesthetic), a pair of sharp blades that pierce the skin and the pair of serrated “micro‑saws” that cut through tissue and anchor the whole shebang.
Even more incredible is that when obtaining a “blood meal”, they secrete from the tail a type of very dilute urine, a process where the mosquito excretes excess water and salts during feeding so it can fit more blood into that little body.
Back to malaria – if a mosquito carries malaria, when it delivers the saliva it also delivers sporozoites (a tiny parasite) which enter the blood stream. They immediately head to the liver and multiply massively, then return to the blood stream and attack the red blood cells.
Once the sporozoites are inside, the cell bursts, releasing haemoglobins into the blood. That’s where the fever and chills start. The spleen then valiantly tries to clean the debris from the blood but cannot remove it quicker than the marrow can replace the burst blood cells, causing severe anaemia.
If untreated, the cycle repeats itself about once a month ad infinitum or, tragically, until death.
Sadly, malaria is prevalent throughout Africa, Asia and the Pacific, where the slight yellow in the whites of the eyes of the locals indicates malaria sufferers. There is treatment – one course of pills to kill the sporozoites in the blood, then another course to kill them in the liver. Because of how good our medical system is I received both treatments (free), while those in developing countries can only afford the first treatment, if at all – hence repeat doses of malaria. Even with the first treatment, you would be incapacitated for three to four days, with an enormous impact on the workforce’s continuity.
As mentioned, untreated you will die. The impact of malaria is well documented in The Mosquito. A Human History of Our Deadliest Predator by Timothy C. Weingard, an absolute tome of 450 pages of small print. The title says it all. Over the centuries the malaria-carrying mosquito has killed tens of thousands of invading armies, particularly across Europe, as we know it now.
It's fair to say the mosquito never actually defeated invading armies through the ages: however, it did weaken them significantly enough to prevent success. One example is the all-conquering Hannibal and his Carthaginian parade of 70,000 troops, 12,000 horses and 37 war elephants crossing the Alps heading for the Rome of Romulus and Remus. They had already been ravaged by malaria in their travels through Italy, and in the end were unsuccessful in taking Rome. Hannibal’s journeys and ultimate defeat is a good read, so I will let you follow up, if interested.
Australia has Anopheles mosquitoes, but malaria is no longer endemic in Australia and we were declared malaria‑free in 1981. However, the vectors still exist in the tropical north.
Unfortunately, we do have the Anopheles mosquito’s “nasty cousin”, the Aedes mosquito, which is widespread throughout Australia and can transmit a catalogue of mosquito-borne diseases such as yellow fever, dengue, west Nile, zika and various strains of encephalitis, depending on where you live.
Finishing on a happy note, there are many natural and pharmaceutical unguents that will protect you, as will long trousers and sleeved shirts, preferably of a light colour.
Take it from me, if you travel to malaria-declared areas, dose up on doxy!
Not until my apparel was around my ankles did I sense it was also a home for dozens of hungry mozzies, looking for food (my blood). We arrived home in Australia and 12-14 days later I broke out in sweats and chills - I had malaria.
So back to the culprit: a female (yes, they are the only ones who seek our blood) mosquito of the Anopheles species are the sole spreaders of all human types of malaria. We generally accuse them of biting, but in fact they “drill and suck” using one proboscis with five separate needles (stylets), each with a separate role. The whole bundle is held inside a flexible outer sheath, which retracts during a “bite” – we’ll use “bite” as the description for convenience. The key parts of that single proboscis are the outer sheath which guides the needles but does not enter the skin, the tube the mosquito uses to suck blood, the needle that delivers saliva (anticoagulants + anaesthetic), a pair of sharp blades that pierce the skin and the pair of serrated “micro‑saws” that cut through tissue and anchor the whole shebang.
Even more incredible is that when obtaining a “blood meal”, they secrete from the tail a type of very dilute urine, a process where the mosquito excretes excess water and salts during feeding so it can fit more blood into that little body.
Back to malaria – if a mosquito carries malaria, when it delivers the saliva it also delivers sporozoites (a tiny parasite) which enter the blood stream. They immediately head to the liver and multiply massively, then return to the blood stream and attack the red blood cells.
Once the sporozoites are inside, the cell bursts, releasing haemoglobins into the blood. That’s where the fever and chills start. The spleen then valiantly tries to clean the debris from the blood but cannot remove it quicker than the marrow can replace the burst blood cells, causing severe anaemia.
If untreated, the cycle repeats itself about once a month ad infinitum or, tragically, until death.
Sadly, malaria is prevalent throughout Africa, Asia and the Pacific, where the slight yellow in the whites of the eyes of the locals indicates malaria sufferers. There is treatment – one course of pills to kill the sporozoites in the blood, then another course to kill them in the liver. Because of how good our medical system is I received both treatments (free), while those in developing countries can only afford the first treatment, if at all – hence repeat doses of malaria. Even with the first treatment, you would be incapacitated for three to four days, with an enormous impact on the workforce’s continuity.
As mentioned, untreated you will die. The impact of malaria is well documented in The Mosquito. A Human History of Our Deadliest Predator by Timothy C. Weingard, an absolute tome of 450 pages of small print. The title says it all. Over the centuries the malaria-carrying mosquito has killed tens of thousands of invading armies, particularly across Europe, as we know it now.
It's fair to say the mosquito never actually defeated invading armies through the ages: however, it did weaken them significantly enough to prevent success. One example is the all-conquering Hannibal and his Carthaginian parade of 70,000 troops, 12,000 horses and 37 war elephants crossing the Alps heading for the Rome of Romulus and Remus. They had already been ravaged by malaria in their travels through Italy, and in the end were unsuccessful in taking Rome. Hannibal’s journeys and ultimate defeat is a good read, so I will let you follow up, if interested.
Australia has Anopheles mosquitoes, but malaria is no longer endemic in Australia and we were declared malaria‑free in 1981. However, the vectors still exist in the tropical north.
Unfortunately, we do have the Anopheles mosquito’s “nasty cousin”, the Aedes mosquito, which is widespread throughout Australia and can transmit a catalogue of mosquito-borne diseases such as yellow fever, dengue, west Nile, zika and various strains of encephalitis, depending on where you live.
Finishing on a happy note, there are many natural and pharmaceutical unguents that will protect you, as will long trousers and sleeved shirts, preferably of a light colour.
Take it from me, if you travel to malaria-declared areas, dose up on doxy!