A case of prolonged fatigue following an acute rickettsial infection
+ Author Affiliations
Sir,
We note the recent publication by Unsworth et al.1
where a survey of individuals with chronic illness showed evidence of
exposure to rickettsiae. Here, we report a case of
prolonged fatigue following a serologically proven
acute rickettsial illness in an otherwise well young man from Sydney,
Australia.
A 33-year-old man, who lived in urban Sydney,
presented with an acute febrile illness associated with rash. Symptoms
began
to develop 5 days prior to presentation. These were
fevers, fatigue, decreased appetite, stiff joints and intermittent
non-colicky
right upper abdominal pain. The day of presentation,
he developed a widespread rash.
The only medication was paracetamol for the
acute symptoms. There was no significant past medical or psychiatric
history.
He lived in an urban area and worked as an accountant.
On weekends, he was a ‘surf life saver’ on a beach near bushland in
the northern suburbs of Sydney. This required a high
level of physical fitness and activity. Three weeks prior to his
presentation,
he had travelled to Tasmania where he camped in
bushland.
He appeared unwell was febrile (>38°C) and
tachycardic. There was an erythematous macular and papular rash. The
lesions were
approximately 5 mm in diameter. The rash was
distributed over the trunk and limbs, including the palms and soles (see
Figures 1 and 2). No tick or eschar was detected. There was no lymphadenopathy. There was some mild abdominal tenderness in the right upper
quadrant.
Figure 1.
Rash on the palm of the hand.
Figure 2.
Rash on the trunk.
The lymphocyte count was 0.9 × 109/l
(1.5–4.0). The neutrophil count was normal. C-reactive protein was 98
(mg/l) (<3). The erythrocyte sedimentation rate was
normal. Urea, creatinine and electrolyte parameters
showed no significant abnormalities. The liver function tests were
initially
normal. The alanine amino-transferase subsequently
increased to 160 U/l (5–40). The chest X-ray was clear. Urine microscopy
and culture was negative. Blood cultures were
negative.
A presumptive diagnosis of a rickettsial illness was made and this was confirmed on acute and convalescent serological testing
(see Table 1). Rickettsial PCR testing on acute and convalescent specimens of blood was negative.
View this table:
Table 1
Rickettsial microimmuno-fluorescence serology results
Doxycycline therapy was commenced and continued for 14 days. The majority of symptoms resolved over the next 72 h.
Fatigue was the most significant ongoing
symptom. He described this as a lack of stamina or energy. This was
associated with
poor concentration, discomfort in the knees, muscular
aches, frontal headache, reduced appetite, unrefreshing sleep and
increased
sleep duration. He denied substance abuse, depression
or anxiety. He described feeling significant frustration at his
decreased
level of activity.
Investigations for other underlying medical causes of fatigue were negative and additional courses of doxycycline (up to 4
weeks) had no discernable effect.
He did not return to work for 7 weeks after the acute illness. The fatigue and other symptoms gradually resolved over ∼2 years.
The main differential diagnoses of the acute rickettsial illness were the two tick-borne spotted fevers known to exist in
Australia. Queensland tick typhus is caused by Rickettsia australis and Flinders Island Spotted Fever is caused by Rickettsia honei. Rickettsia australis infection has been contracted in the northern suburbs of Sydney where this man was a ‘surf life-saver’ and R. honei infection has occurred where he was camping in Tasmania.2,,3 However, due to the cross reactivity of human antibodies to rickettsial antigens it was not possible to confirm the identity
of the causative organism.
The lack of response of the chronic symptoms to repeated courses of anti-microbial therapy is consistent with a post-infectious
phenomenon rather than a chronic infection.
Unsworth et al.1
document exposure to rickettsia in a cohort suffering from chronic
symptoms. This is a novel case of prolonged fatigue occurring
after an acute rickettsial infection.
