NEWS - Parasitic nematodes that infect more than a billion people worldwide carry viruses that could solve the puzzle of why they cause serious disease. Brugia malayi (BMRV1) which causes lymphatic filariasis and Onchocerca volvulus (OVRV1) which causes onchocerciasis come a long way in carrying viruses.
The researchers used cutting-edge bioinformatics data mining techniques to identify 91 RNA viruses in 28 species of parasitic nematodes that account for 70% of infections in humans and animals. Often asymptomatic or not serious, some can cause severe, life-changing disease.
Nematode worms are extremely abundant on Earth with some species infecting humans, animals and plants and in some cases causing specific diseases. The researchers’ next question was whether viruses in nematodes could cause chronic conditions?
“Could the diseases caused by these parasites be caused by viruses rather than directly by the nematodes? That’s an exciting discovery and changes our understanding of the millions of infections caused by parasitic nematodes,” said Mark Taylor from the Liverpool School of Tropical Medicine.
“Finding RNA viruses in any organism is significant, because these are well-known disease agents. When the worms live in our bodies and spread throughout our blood and tissues, they trigger an immune response,” Taylor said.
Hookworms and whipworms can cause severe stomach problems and diarrhoea, stunted growth and anaemia. Infections with B. malayi and O. volvulus can cause devastating conditions such as lymphoedema or elephantiasis and onchocerciasis or river blindness, which causes blindness and skin disease.
The researchers said viruses may play a role in some Onchocerciasis-Associated Epilepsy (OAE) conditions in children and adolescents in Sub-Saharan Africa that are linked to onchocerciasis, but it is not known why they cause neurological symptoms such as uncontrolled repetitive head bobbing, growth retardation, delayed puberty and mental health problems.
One of the viruses in the parasite identified in the study is a rhabdovirus that causes rabies. If this virus infects or damages the nerves or brain tissue in humans, it could explain the symptoms of OAE. The diversity of viruses in parasitic nematodes, their biology and potential to cause disease in humans and animals require further study.
“As a child, I saw a lot of people infected with these diseases and I had dengue three times. That got me interested in tropical diseases,” says Shannon Quek of Liverpool School of Tropical Medicine, who is originally from Indonesia, a country burdened by parasitic nematodes.
Quek initially used the same data mining methods to screen for viruses in mosquitoes that transmit disease, before deciding to investigate nematodes. Much of the research has been on the mosquito microbiome and the bacteria that live in it.
“These interactions between organisms in the same host made me wonder, what else could be in parasitic nematodes?” says Quek.
“Diseases caused by parasitic nematodes are long-term, lifelong diseases that affect people. They have a significant impact on people’s quality of life, their economic outcomes and their mental health,” says Quek.
Original research
Quek, S., Hadermann, A., Wu, Y. et al. (2024). Diverse RNA viruses of parasitic nematodes can elicit antibody responses in vertebrate hosts. Nature Microbiology, DOI:10.1038/s41564-024-01796-6
The researchers used cutting-edge bioinformatics data mining techniques to identify 91 RNA viruses in 28 species of parasitic nematodes that account for 70% of infections in humans and animals. Often asymptomatic or not serious, some can cause severe, life-changing disease.
Nematode worms are extremely abundant on Earth with some species infecting humans, animals and plants and in some cases causing specific diseases. The researchers’ next question was whether viruses in nematodes could cause chronic conditions?
“Could the diseases caused by these parasites be caused by viruses rather than directly by the nematodes? That’s an exciting discovery and changes our understanding of the millions of infections caused by parasitic nematodes,” said Mark Taylor from the Liverpool School of Tropical Medicine.
“Finding RNA viruses in any organism is significant, because these are well-known disease agents. When the worms live in our bodies and spread throughout our blood and tissues, they trigger an immune response,” Taylor said.
Hookworms and whipworms can cause severe stomach problems and diarrhoea, stunted growth and anaemia. Infections with B. malayi and O. volvulus can cause devastating conditions such as lymphoedema or elephantiasis and onchocerciasis or river blindness, which causes blindness and skin disease.
The researchers said viruses may play a role in some Onchocerciasis-Associated Epilepsy (OAE) conditions in children and adolescents in Sub-Saharan Africa that are linked to onchocerciasis, but it is not known why they cause neurological symptoms such as uncontrolled repetitive head bobbing, growth retardation, delayed puberty and mental health problems.
One of the viruses in the parasite identified in the study is a rhabdovirus that causes rabies. If this virus infects or damages the nerves or brain tissue in humans, it could explain the symptoms of OAE. The diversity of viruses in parasitic nematodes, their biology and potential to cause disease in humans and animals require further study.
“As a child, I saw a lot of people infected with these diseases and I had dengue three times. That got me interested in tropical diseases,” says Shannon Quek of Liverpool School of Tropical Medicine, who is originally from Indonesia, a country burdened by parasitic nematodes.
Quek initially used the same data mining methods to screen for viruses in mosquitoes that transmit disease, before deciding to investigate nematodes. Much of the research has been on the mosquito microbiome and the bacteria that live in it.
“These interactions between organisms in the same host made me wonder, what else could be in parasitic nematodes?” says Quek.
“Diseases caused by parasitic nematodes are long-term, lifelong diseases that affect people. They have a significant impact on people’s quality of life, their economic outcomes and their mental health,” says Quek.
Original research
Quek, S., Hadermann, A., Wu, Y. et al. (2024). Diverse RNA viruses of parasitic nematodes can elicit antibody responses in vertebrate hosts. Nature Microbiology, DOI:10.1038/s41564-024-01796-6