QJM Advance Access originally published online on May 12, 2008
QJM 2008 101(7):591-593; doi:10.1093/qjmed/hcn064
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A case of prolonged fatigue following an acute rickettsial infection
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.
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The lymphocyte count was 0.9 x 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.
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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.
Department of Microbiology
Royal North Shore Hospital
St Leonards
New South Wales
Australia
mawatts{at}nsccahs.health.nsw.gov.au
References
1. Unsworth N, Graves S, Nguyen C, Kemp G, Graham J, Stenos J. Markers of exposure to spotted fever rickettsiae in patients with chronic illness, including fatigue, in two Australian populations. Q J Med (2008) 101:269–74.[Web of Science]
2. Baird RW, Stenos J, Stewart R, Hudson B, Lloyd M, Aiuto S, et al. Genetic variation in Australian spotted fever group rickettsiae. J Clin Microbiol (1996) 34:1526–30.[Abstract]
3. Unsworth NB, Stenos J, McGregor AR, Dyer JR, Graves SR. Not only ‘Flinders Island’ spotted fever. Pathology (2005) 37:242–5.[CrossRef][Web of Science][Medline]
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