Samples taken from what scientists have deemed a backyard ‘mosquito toilet’ revealed the first-known evidence of a virus that has never been seen in the Americas before.
Researchers at Rutgers University in New Jersey 3D printed a device to collect waste from mosquitoes – much like human waste is collected from wastewater to monitor the community spread of viruses such as Covid.
Dana Price, lead author of the study and an associate professor at the Center for Vector Biology, said: ‘What we did, colloquially, was build a mosquito toilet.’
The small traces of mosquito waste collected by the device, from a single backyard collection site in New Jersey, ‘revealed a hidden world,’ researchers wrote.
By analyzing and sequencing the materials, the team recovered a complete West Nile virus genome, found the first known evidence of a Hedwig-like virus in the Americas and detected several other viruses that may be new to researchers.
Hedwig-like virus is a little-studied virus related to the Hedwig virus, which has been detected in birds and mosquitoes.
Researchers believe these viruses may circulate in nature through mosquito transmission, but their natural hosts and transmission patterns are not yet fully understood. There is currently no evidence that Hedwig-like viruses cause illness in humans.
Meanwhile, West Nile virus is a mosquito-borne virus that can infect humans, birds, horses, and other animals. Most people who become infected do not develop symptoms, but about one in five experience a mild illness that can include fever, headache, body aches, fatigue, and nausea.
Typically, mosquito surveillance involves labor-intensive work of collecting large number of the insects, sorting them by species, combining them into pools and grinding them up for laboratory testing. Pictured above are Asian Tiger mosquitoes in a petri dish at the Zagreb-based teaching institute for public health in Zagreb, Croatia
In rare cases, the virus can cause severe neurological disease, such as meningitis or encephalitis, particularly in older adults and people with weakened immune systems.
The virus is most commonly spread through the bite of an infected mosquito and is typically most active during the warmer months of the year.
The samples collected for the study, published in the journal Microbiology Spectrum, also identified parasites and were able to confirm which types of mosquitoes carried which virus.
Typically, mosquito surveillance involves the labor-intensive work of collecting a large number of the insects, sorting them by species, combining them into pools and grinding them up for laboratory testing.
And if there is an outbreak of a mosquito-borne illness, this process can delay information needed to contain and stop the spread of life-threatening diseases.
Additionally, current methods also only test for specific mosquito-borne illnesses, such as malaria, Dengue fever or West Nile virus, so scientists must know what they are looking for.
However, Price said this new method of collection could become a lower-effort, powerful surveillance tool, allowing researchers to more broadly search for pathogens and threats scientists may not know exist yet.
For the research, the team collected waste from two groups of 50 wild Culex mosquitoes from a yard in New Brunswick, New Jersey in 2021 and 2022.
The team then sequenced the material. The complete genome of West Nile virus was found in the 2022 sample.
‘What came out was an entire viral genome,’ Price said. ‘Rather than just positive or negative, we have genetic data.’
Dana Price, lead author of the study and an associate professor at the Center for Vector Biology, is shown above setting up a mosquito-waste collection trap in the field as researchers work to adapt the approach for real-world surveillance
This type of detail could help scientists track how variants of the virus emerge, spread and mutate.
Much less is known about the Hedwig-like virus. The team wrote they aren’t sure if the virus infects birds, facilitates the spread of mosquito-borne illnesses or what kind of threat it poses.
However, Price said the team’s findings don’t establish the virus as a threat to Americans.
Now, the scientists are working with the New Jersey Department of Environmental Protection’s Division of Fish and Wildlife to screen organ and tissue samples from deceased birds for the virus.
Additionally, the mosquito waste samples also contained materials that the researchers said were very different from currently known mosquito-borne viruses and they classified them as potentially new viruses.
Further research needs to be done in order to determine what exactly those viruses are and if they pose a threat to humans or animals.
‘The more data we generate, the more we start to wonder if everything is everywhere,’ Price said. ‘Although we don’t yet know how much of everything is everywhere, it may be a lot more than we realize.’
