Smart parasites? It sounds ominous, but new research into malaria parasites is giving scientists a better understanding of disease transmission. It seems that the malaria parasite is able to increase its own transmission rate by ‘relapsing’ during the times that the host animal is bitten by the insects that are capable of spreading it.
Researchers worked with domestic canaries infected with Plasmodium relictum, which is the most common parasite involved in cases of bird malaria in Eastern songbirds. They found that when the canaries were bitten by uninfected mosquitoes, parasite numbers in their blood increased, which in turn resulted in higher infection rates of the mosquitoes.
Pretty efficient. So how can understanding parasite evolution help us? Ultimately, understanding the factors that lead to these ‘relapses’ could help researchers develop better ways to control the disease. While it’s not yet known whether this type of transmission is present in humans, there are many other human pathogens that can also relapse after dormant periods (such as HIV, Herpes Simplex, and Mycobacterium tuburculosis), so it’s possible that this research could help scientists understand potential triggers for relapse in these diseases, as well. Read more about it here:
Now that summer’s here, have you noticed that the mosquitoes are out in full force? Did you know that mosquitoes cause more human suffering and disease than any other organism on the planet? Over 750,000 people a year die from mosquito-borne illnesses, and it’s not just humans that are affected! Mosquitoes spread dog heartworms, Eastern equine encephalitis, and many other diseases that affect our pets and local wildlife. But there might soon be a solution!
Researchers have figured out a way to genetically engineer mosquitoes that could dramatically reduce or eliminate some mosquito-borne illnesses. In these mosquitoes, when sperm is produced, the X chromosome that the male would normally pass on to its female young is destroyed, so 95% of the time they only have male offspring. Why does this matter? Well, male mosquitoes don’t bite- the females do. Females spread disease, and one female can lay up to 3,000 eggs over the course of her lifetime.
Hopefully, this type of pest control could eliminate many mosquito-borne illnesses. But could this type of gender control work in other species? Could this research have applications in the understanding and management of X-linked diseases? What do you think?
In an interesting example of animal research in action, it was found that mosquitos carrying Wolbachia bacteria cannot transmit dengue. So, mosquitos engineered to carry this bacteria- as well as transmit it to their offspring- were painstakingly hand-transported to an island off the coast of Vietnam (where dengue is a serious problem) in an attempt to replace the indigenous mosquito population. Read more in a post earlier this month: http://fbresearch.org/dengue-mosquitos-infected-with-bacteria/
People on the island are welcoming their new ‘pests’- they take care to allow these mosquitos to live, understanding that an increase in the Wolbachia mosquito population is critical! Researchers estimate that people on the island will be protected from dengue when the Wolbachia mosquito population reaches 80%- and in recent news- it’s up to about 65% and climbing!
Amazing! While researchers are still working on vaccines and treatments for dengue (of which there currently are none), this creative approach to the problem is a great example of animal research at work. In an attempt to save human populations, while introducing a bacteria that won’t do any damage to the ecosystem, this is a great example of ingenuity in research. Keep it up, guys!