(CN) — This year four men in Winnipeg were diagnosed with trench fever, a disease hardly seen since the end of World War II, according to new research from Canadian infectious disease experts.
Trench fever, caused by Bartonella quintana bacteria, is transmitted by body lice feces, usually in crowded or unhygienic conditions. The paper, published Monday in the Canadian Medical Association Journal, warns that people experiencing homelessness may be at particular risk for catching the potentially fatal disease.
“This is a disease of immense poverty, this is a disease that is associated with World War I and the trenches, it’s associated with refugee camps surrounding genocide in East Africa. This is a terrible disease,” said study co-author Carl Boodman, an infectious disease physician at the University of Manitoba in Winnipeg, in a recorded podcast interview for the journal. “And it’s one that really does reflect the very poor conditions that our underhoused population experiences.”
In the interview, Boodman described one case of trench fever in detail: a 47-year-old man, who was living with HIV and was frequently homeless, arrived to a Winnipeg hospital with shortness of breath, rapid breathing and hypoxemia.
He was unwell for 24 hours before acutely deteriorating “within minutes,” according to Boodman.
“I spoke to people who lived with him at the supportive housing unit, and they mentioned that he was quote-unquote ‘the life of the party’ at dinner the day before,” Boodman explained. “All of his friends and his roommates mentioned that he was actually apparently close to his baseline, and then things changed acutely prior to presentation.”
The man was immediately intubated, and his heart was threatening to fail. Doctors performed a valvular replacement surgery and prescribed antibiotics, “and he did very well on this regimen,” Boodman noted.
Though trench fever rarely kills, recovering patients might suffer neurological complications, heart conditions or chronic muscle ache. Modern infections, if left untreated, are known to develop into life-threatening endocarditis: inflammation of the heart’s inner lining and usually its valves, as in this patient’s case.
The doctor described three more cases of endocarditis caused by the same bacterium responsible for trench fever. All were men between 25 and 50 who had stayed in shelters.
“To hammer home how surprising this was: there’ve only been three or four cases of this disease reported in Canada since the mid-90s, and then in approximately four months, only in one city — in Winnipeg — we diagnosed just as many cases,” Boodman added.
The infectious disease owes its name to its widespread propagation among European soldiers during World War I. Historians estimate that nearly half a million were affected in the British, French and Belgian armies alone between 1915 and 1918.
Trench fever was scarcely reported in the decades following World War II until the 1990s, when “urban trench fever” was found among homeless populations in the U.S. and Europe, as well as refugee camps across the world.
Homeless people often must shelter in overcrowded or unhygienic conditions. People living with HIV — and homelessness is a risk factor for the virus — are highly susceptible to getting infected with trench fever.
“Ultimately, you cannot get Bartonella quintana, as far as we know, without body lice,” Boodman said in the interview. “So either evidence of body lice on exam — either body lice seen in the clothing and the seams of patients who are underhoused, or seeing scabs and lesions and old scars of body lice — are quite helpful in making this diagnosis, or at least increasing your pretest probability, your ‘Spidey-sense’ so to speak, that this diagnosis may be there.”
Small outbreaks have been reported in Colorado this year, as well as in Seattle in 2018 and San Francisco in 2007.
“Our public health message is that this disease is present in Canada and that people and physicians aren’t always aware,” Boodman said in a statement. “It’s associated with homelessness and homeless shelters, and physicians should consider B. quintana infection in people who are unwell and have a history of body lice infestation.”
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