I sat by as Nike and Moji discussed how they protect their infants from being bitten by mosquitoes at night. It was the first time they discussed the topic but their actions were similar: whenever they find that a mosquito has entered their insecticide-treated nets, they lose their sleep. They would sit up and stay awake till they kill the mosquito. Perhaps the actions were similar for other mothers in Nigeria, the country with the world’s highest number of malaria cases (and deaths).
Mosquitoes are infamously called the world’s deadliest animal because of the number of deaths they cause. They spread diseases like malaria, dengue fever, Zika fever, yellow fever, West Nile fever, Chikungunya fever, among others. While they do not cause the diseases by themselves, they carry pathogens (the disease-causing organisms, especially viruses) around and pass these into humans and animals when they bite us to suck our blood.
They Looked for Yellow Fever Virus
During the 2018 Yellow Fever outbreak in Nigeria, scientists at the African Centre of Excellence for Genomics of Infectious Diseases (ACEGID), Redeemer’s University and their partners collected mosquitoes from 9 states across Nigeria. They captured 1,300 mosquitoes and analysed them to know the viruses they carried.
They used an advanced technique called metagenomic sequencing (a technique through which all the genetic materials in a sample are analysed and identified) to analyse the samples. This was the first time that metagenomics was used in Nigeria to study pathogens spread by mosquitoes.
“Mosquitoes carry other viruses that we know little or nothing about. Since we had access to an approach that can give us a more complete view of viruses that are spread by mosquitoes, we decided to look beyond now and into the future,” said Dr. Judith Oguzie, Doctoral Research Fellow at ACEGID and the lead author of their publication.
It was a case of throwing a net inside the river instead of catching fish with a hook. With metagenomics, researchers can unveil the bacteria, viruses and other parasites as well as in the samples. Their report focussed on the viruses present in the mosquitoes.
But Found Other Viruses
Dr Oguzie’s team did not identify the yellow fever virus in any of the samples. However, they found 7 types of viruses (insect-specific viruses). Thankfully, none of the viruses has been identified to cause diseases in humans. These viruses (classified as insect-specific viruses) live in mosquitoes but they do not survive in human bodies or cells.
They have not been studied closely and they are “relatives” of pathogenic viruses (that cause diseases). However, they interfere with the spread of viruses that cause diseases in humans. Little is known about these insect-specific viruses that they identified.
“We know that these mosquitoes carry a lot of viruses and they will continue to feed on humans for blood. Of course, their intention is not to infect us. But at what point would any of these viruses that we know little about become problems to humans?” concluded Dr Oguzie.
The researchers hope to investigate the identified viruses, to understand their potential to cause diseases and their ability to promote or inhibit the transmission of other disease-causing viruses. Public health workers will use such knowledge to better understand the country’s disease risks and plan how to control mosquitoes. With that, mothers like Nike and Moji can sleep peacefully with their babies.