Scientists have discovered yet another reason to despise mosquitoes, after it emerged that the insects are potential carriers of a mysterious and “poorly understood” new disease.
First described by experts in 1990 and identified in 2008 as an “emergent global threat for humans”, very little research has been done into the dangers posed by the bacteria Rickettsia felis.
It causes symptoms similar to many bacterial infections, and recent research found it was often found in cases where doctors registered an illness as “fever of unknown origin”.
This was particularly the case in malaria-endemic areas – and sure enough, a study in which mosquitoes were fed on Rickettsia felis-infected mice found that the insects were able to transmit the disease.
Also known as cat-flea typhus, the disease made headlines in Australia in 2009 when the mysterious case of an infected nine-year-old girl sparked what was described as “a lengthy investigation similar to those featured in the hit TV series House”.
Philippe Parola, one of the new study’s co-authors, told QZ.com that so little is known about infections of Rickettsia felis in part because it can only be identified by a laboratory diagnosis.
10 Deadliest Animals In The World
10 Deadliest Animals In The World
1/10 10: Poison Dart Frog
They might look cute, but the backs of the Amazonian poison dart frog ooze a slimy neurotoxin to keep predators away. Each frog produces enough of the toxin to kill 10 humans.
2/10 9: Polar Bear
The strength of a polar bear is enough to decapitate a human being with a single swipe of the paw.
3/10 8: African Elephant
The brute force of an elephant is unrivalled by any land mammal. Weighing in around 16,000lb on average, they are responsible for around 500 human deaths each year.
4/10 7: Cape Buffalo
Cape Buffalos charge head-on with their razor-sharp horns when confronted with a predator - all 1,500lb of them. And the problem is, they tend to do so as a herd.
5/10 6: Crocodile
The stealth and combined strength of a crocodile allows it to lie in the water undetected, before it strikes, drags its pray underwater, barrel rolls and dismembers it.
6/10 5: African Lion
These big cats are ruthlessly agile, armed with razor-sharp teeth and talons and near-perfect hunters.
7/10 4: Great White Shark
These kings of the sea have 3,000 teeth with which to tear their pray to shreds. On average, are 15ft long and 5,000lb, and can detect a drop of blood in 25 gallons of water.
8/10 3: Australian Box Jellyfish
Each tentacle has 5,000 stinging cells and enough toxin to kill 60 humans. Each jellyfish has 60 tentacles each at 15 ft long. That's a lot of killing power for an animal the size of a salad bowl.
9/10 2: Asian Cobra
It might not be the most poisonous snake, but thanks to its unique spit and strike attack technique, the Asian Cobra is responsible for more human deaths than any other snake on the planet.
10/10 1: Mosquito
Tiny but deadly, mosquitoes carry and transfer malaria causing parasites to humans. As a result, they cause on average 2million human deaths a year, making the insect one of the world's deadliest creatures. Aside from human beings, of course.
The symptoms of the disease are ill-defined and easily confused with other diseases, he said – meaning the disease is almost certainly under-diagnosed in humans.
Even when it was thought that Rickettsia felis was only transmitted by fleas and ticks, the disease was considered by the Centres for Disease Control and Prevention as “representing a high potential risk for public health”.
Speaking about Rickettsia felis in 2010, the CDC’s Dr Chris Paddock said: “What’s interesting about this particular Rickettsial disease is that it’s been described on nearly every continent around the world, except for Antarctica.
“There have been no known deaths attributable to Rickettsia felis infection. Nonetheless, because it’s so broadly distributed, we think that it’s probably a very important Rickettsial disease.”
The new research by Professor Parola et al appeared in this week's Proceedings of the National Academy of Sciences.Reuse content