Surely you can’t connect Tolkien with microbiology!? Read on to find out more…
Back in 1916 there was no treatment for trench fever. Tolkien convalesced for a month in hospital in Birmingham before serving on the home front for the rest of the war. His infection relapsed many times and he was never fit for front line service again.
What is trench fever?
Trench fever is the old fashioned (World War I) name for a bacterial infection caused by Bartonella quintana. The bacterium is transmitted by the bite of an infected body louse (Pediculus humanus corporis). The bacterium multiplies in the intestine of the louse throughout its life time, about 5 weeks, and is transmitted via infected louse faeces which would then invariably contaminate a scratched louse bite or other wound and enter the person’s blood stream.
The incubation period of trench fever following contamination of a bite/wound is about 7 days (range 5-20 days) and once infected bacteria circulate in the person’s blood stream ready to infect further lice when they bite, and so the cycle continues.
More than a million soldiers in The Great War had trench fever; it was so bad that the War Office set up a Trench Fever Investigation Commission to try and find first the cause and then a cure. They did discover the cause but failed to find a cure.
Nowadays, trench fever is primarily seen in situations where sanitation has broken down such as in conflicts, refugees and other humanitarian crises.
How does trench fever present?
Trench fever usually presents with a fever associated with a headache, malaise, lower leg pain and dizziness. The fever often relapses every 5 days (hence the name B. quintana – from the Latin “quinque” meaning five). Splenomegaly, a macular rash and conjunctivitis can also occur.
Untreated trench fever often follows a relapsing course with further episodes occurring every few months or years.
With infection in the bloodstream, endocarditis can occur but is uncommon; it is a cause of culture negative infective endocarditis.
How is trench fever diagnosed?
In the past we used to do serological tests looking for antibody against B. quintana. These tests are no longer available in the UK as there are problems with cross-reactivity and false positive results. The sensitivity was about 53-65% and the specificity was 91-93%; that meant a false negative rate of 35% and a false positive rate of 7%... so not a great test.
Bartonella spp. will occasionally grow in blood culture systems, but can take 21-45 days. Prolonged incubation is essential and it is crucial that the lab is told that Bartonella spp. infection is part of the differential diagnosis so they can prolong the incubation period. UK laboratories tend not to extend incubation beyond 14 days due to lack of capacity therefore it is extremely unlikely we would ever grow B. quintana unless we “really try” to.
Nowadays PCR is the only real option for trying to diagnose trench fever (or in fact any Bartonella spp. infection). PCR can be performed on blood samples as well as tissue samples (e.g. heart valves). The main draw back to PCR is that it requires the bacterium to be circulating in the blood stream and so between relapses the test can be negative. The sensitivity of PCR on blood is about the same as serology, about 58%, and so false negatives still occur. However, PCR has a better specificity of 100% so no false positives. PCR on heart valves is much better though with a sensitivity of 95% and a specificity of 100%.
NB If you struggle with the concept of false positives and true negatives there is a new section in the book which explains all that predictive values gobbledygook!! Thanks for all those of you who have purchased a copy; the ECIC has been paid her sweet allocation from the proceeds!
How is trench fever treated?
The normal treatment of trench fever is 2 weeks of IV Gentamicin PLUS PO Doxycycline, followed by a further 2 weeks of PO Doxycycline. Antibiotic treatment is only about 80% effective and relapses requiring repeated treatment (with same as above) do occur.
For endocarditis, treatment duration depends on whether the infected heart valve can be removed. If the valve is removed PO Doxycycline should be continued for 6 weeks; if surgery is impossible then the duration of PO Doxycycline is 3 months.
Careful attention should be made to killing off lice as part of the patient’s treatment as well.
There are no specific infection control measures as there is no direct person-to-person spread of infection. HOWEVER, a history of trench fever is an absolute contraindication to donating blood for transfusion as the bacterium can be spread via contaminated blood.
So was the film Tolkien any good? Well I think it should be said that the film is “based” on Tolkien’s life and is not completely accurate; but then the Peter Jackson films of The Lord of the Rings also had many inaccuracies and were only “based” on the Tolkien book and don’t get me started on The Hobbit which in some respects only really appeared to share the name! However it is an entertaining story of a period of time in which there was a lot of social change which still resonates today. If you are a fan of history and period dramas then it’s worth watching, but remember, I’m biased by being a bit of a Tolkien groupie!
Editorial note: as a non-Tolkien fan, the costumes were good and it felt “wholesome” but the film was a bit incoherent in places and lacked a strong storyline… however it did come with popcorn, and who can argue with that!