New research has solved the mystery surrounding the eight-decade spread of Buruli ulcer, a chronic infection of the skin and bones, causing permanent disfigurement and long-term disability.
It was not clear exactly how the infection spreads, and in the new research, the results showed that mosquitoes become infected by biting an opossum (also called a marsupial mouse or sac mouse, an animal characterized by the presence of a sac or pouch attached to the outer layer of the abdomen), which carries the bacteria. The mosquitoes then transmit the infection to humans through their bites.
What is Buruli ulcer?
Buruli ulcer, also known as Bairnsdale ulcer or Searles' ulcer, is a skin infection caused by the bacterium Mycobacterium ulcerans.
It begins as a small mosquito bite, and over several months, slowly develops into an ulcer, with widespread destruction of the underlying tissue.
Although the infection is often painless at first, it can become very serious. If left untreated, the ulcer can continue to expand. Hence it gets the name "meat-eater".
Fortunately, Buruli ulcer is treatable. A specific course of antibiotics for six to eight weeks is an effective treatment, and is sometimes supported by surgery to remove infected tissue.
Where can I catch the infection?
The World Health Organization considers Buruli ulcer a neglected tropical skin disease. Cases have been reported in 33 countries, most of them in West and Central Africa.
However, since the early 2000s, Buruli ulcer has also been increasingly recorded in the coast of the Australian state of Victoria, including the surrounding suburbs of Melbourne and Geelong.
Scientists have long known that native Australian opossums were partly responsible for spreading the disease, and suspected mosquitoes also played a role in the increase in cases. This new research confirms this.
According to the paper published in the journal Nature Microbiology, the researchers conducted large-scale surveys across an area of 350 square kilometers in Victoria.
They collected mosquitoes and analyzed the samples to determine whether they carried the pathogen, and their relationship to infected opossums and infected people.
Molecular testing of mosquito samples showed that of the two most abundant mosquito species, only Aedes notoscriptus (a species widespread in Australia) was positive for Mycobacterium ulcerans.
The team then used genomic testing to show that the bacteria found on these mosquitoes matched bacteria found in the feces of opossums and humans with Buruli ulcer.
They also analyzed mosquito samples containing blood to show that Aedes notoscriptus was feeding on both opossums and humans.
In order to tie everything together, geospatial analysis revealed that areas where human Buruli ulcer cases occur overlap with areas where mosquitoes and opossums harboring M. ulcerans are active.
The researchers pointed out the importance of their findings in helping to take simple steps to avoid infection, such as applying insect repellent and removing stagnant water in the home in which mosquitoes breed.
A major breakthrough a deaf boy hears for the first time after pioneering gene therapy!
An 11-year-old boy was able to hear sounds in his surroundings, for the first time in his life, after receiving advanced gene therapy.
Children's Hospital of Philadelphia (CHOP), which performed the first treatment of its kind in the United States, said this achievement represents hope for patients around the world who suffer from hearing loss caused by genetic mutations.
Aisam Dam was born “profoundly deaf” due to an extremely rare defect in a single gene.
“While the gene therapy we performed in our patient was aimed at correcting a defect in one very rare gene, the studies may open the door to the future use of some other genes that treat the disease,” said surgeon John Germiller, director of clinical research in the Department of Otolaryngology at CHOP. "More than 150 genes cause hearing loss in children."
Dame's defective gene prevents the production of autoferlin, a protein necessary for "hair cells" in the inner ear to be able to convert sound vibrations into chemical signals that are sent to the brain.
Autoferlin gene defects are extremely rare, accounting for 1 to 8% of hearing loss cases present at birth.
On October 4, 2023, the patient underwent surgery that involved partially lifting the eardrum and then injecting a harmless virus, which had been modified to carry working copies of the autoferlin gene, into the inner fluid of the cochlea.
As a result, the hair cells began to produce the missing protein and function properly.
The hospital statement stated that after about four months of receiving treatment in one ear, Dam's hearing improved to the point that he only suffers from mild to moderate hearing loss, and he "literally hears sound for the first time in his life."
The New York Times reported that despite his ability to hear, Dam, who was born in Morocco and later moved to Spain, may never learn to speak, as the brain's window for acquiring speech closes around the age of five.
The US Food and Drug Administration, which gave the green light to the study, wanted to start research on older children first, for safety reasons.
The trial, sponsored by Akouos, Inc., a wholly-owned subsidiary of Eli Lilly and Company, is one of several underway or about to begin in the United States, Europe and China, where a small number of other children have already been cured.