Scientists have discovered a new bacteria that they hope will lead to better ways to prevent, detect and treat noma, a fatal and disfiguring childhood disease that sounds like something out of a medieval plague diary.
Noma, which is fatal in 90% of cases without treatment, starts as a simple gum sore before deciding that’s not nearly dramatic enough and moving on to destroy the tissues of the mouth and face. It mainly affects young, poor and malnourished children, earning the charming nickname “the face of poverty”. Survivors are left with lifelong scarring and disfigurement. Data is patchy, but experts estimate tens of thousands of cases occur each year, mostly in the Sahel region of Africa, though it also pops up elsewhere.
The disease can be treated with broad-spectrum antibiotics, which suggests a bacterial cause, but the precise culprit has remained frustratingly elusive - until now. A team led by the Liverpool School of Tropical Medicine analysed bacterial communities in mouth samples from 19 children in Nigeria.
Modern genetic analysis revealed a microbial community in disarray: lower levels of healthy bacteria and higher levels of certain other strains. Deeper digging uncovered a previously unknown species of Treponema bacteria in most of the noma patient samples. When PhD student Angus O’Ferrall presented the finding, senior author Prof Adam Roberts said he was “astonished”. Which, fair.
The scientists then reanalysed older samples from other noma patients and found the same bacteria - currently called Treponema A - present in those too. “We don’t know causality,” Roberts stressed. “We don’t know if it can colonise a noma wound because of the architecture and the environment, or if it causes the noma wound.” So it might be the cause, or it might just be a squatter. The team is now running a larger study across multiple countries to find out.
Once noma reaches its necrotising stage, patients have two options: get antibiotics quickly and survive with massive disfigurement and lifelong stigma, or die. “We want to stop it reaching that point,” Roberts said. A future test for gingivitis that detects Treponema A could save kids from either fate, he hopes. Currently, diagnosis relies on symptoms like “a foul smell or holes in the skin”. If Treponema A is always or 99% associated with noma at the gingivitis stage, prophylactic antibiotics could stop it in its tracks.
Current treatment uses broad-spectrum antibiotics, which risks increasing antimicrobial resistance. A targeted treatment aimed at Treponema A could reduce that threat. And the drop in healthy bacteria seen in noma patients opens the door for a probiotic preventive intervention.
The study, published in PLOS Neglected Tropical Diseases, also involved researchers from the University of Liverpool, Médecins Sans Frontières, and the Noma Children’s Hospital in Sokoto, Nigeria. Dr Michael Head of the University of Southampton called the findings a “useful first step” to understanding a “currently mysterious condition”, noting that a different version of this bacteria causes syphilis, which also causes mouth ulcers. Prof Philippe Guérin of the University of Oxford agreed it’s “a valuable starting point” that should stimulate interest from researchers and funders - because nothing says “fund me” like a bacteria that eats faces.