Incidence of chronic Q fever and chronic fatigue syndrome: A 6 year follow‐up of a large Q fever outbreak

Abstract

Acute Q fever is a generally self-limiting infection caused by the intracellular gramnegative bacterium Coxiella burnetii. For yet unknown reasons, a subset of patients develops chronic infection. Furthermore, chronic fatigue syndrome (CFS) as post-acute Q fever sequelae has been described. We here investigated the rates of chronic Q fever and incidences of CFS 6 years after one of the largest European Q fever outbreaks that occurred in Jena, Germany in 2005 with 331 reported cases, who lived in proximity of a grazing flock of sheep. A total of 80 patients and their 52 non-diseased household members from the former outbreak, were enrolled 6 years after the outbreak. Blood samples were collected and tested for chronic Q fever which was determined by seroprevalence using referenced immunofluorescence assays. Also, the presence of CFS was assessed using the Short Form Symptom Inventory developed by the Centers (United States) for Disease Control and Prevention (SF CDC-SI). In 80 out of 132 (60.6%) study participants, previous Q fever infection was confirmed serologically, while no previous infection was detected in the 52 household members. None of the participants fulfilled the serological criteria of chronic Q fever. The evaluation of the CDC-SI did not show any differences between the two groups. Also, there was no difference between both groups regarding fulfillment of CFS-defining criteria (n = 3 (3.8%; sero-positive) versus n = 2 (3.8%; sero-negative), p = 0.655). Our 6-year followup study of a large Q fever outbreak did not find evidence of chronic Q fever or post Q fever CFS. There was no asymptomatic sero-positivity in household members of Q fever patients.

Unexplained post-acute infection syndromes

“…Moreover, in yet another Q fever outbreak involving a UK cohort of slaughterhouse workers, ME/CFS criteria were fulfilled by 28% of participants 5-14 years after Q fever but by none of the matched controls 77 . In contrast, a recent study from Germany found a significantly higher frequency of unrefreshing sleep, but not of other typical post-acute features, in cases relative to seronegative household contacts 6 years after Q fever, on the basis of assessments by the Short Form Symptom Inventory questionnaire 78 . This result suggests that assessment methods and the choice of appropriate questionnaire might play an important role in ascertaining infection-associated chronic disability.…”

“…Prospective cohort van Loenhout 183 , Wildman 74 , Ayres 75 , Ankert 78 , Hickie 31 , Hatchette 184 Case-control Ayres 73 , Marmion 77 , van Woerden 76 Cross-sectional Bronner 79 Case report Leung-Shea 185…”

Identifying disrupted biological factors and patient-tailored interventions for chronic fatigue in adolescents and young adults with Q-Fever Fatigue Syndrome, Chronic Fatigue Syndrome and Juvenile Idiopathic Arthritis (QFS-study): study protocol for a randomized controlled trial with single-subject experimental case series design

“…Most of those affected with acute Q-fever, recover from fatigue within 6 to 12 months (4). Approximately 20% does not recover within this timeframe, leading to Q-fever Fatigue Syndrome (QFS) diagnosis (4,7). QFS has been associated with immune deregulation (8) and possibly mitochondrial dysfunction (9), however the aetiology and pathophysiology of QFS is still largely unknown (8,9).…”

Identifying disrupted biological factors and patient-tailored interventions for chronic fatigue in adolescents and young adults with Q-Fever Fatigue Syndrome, Chronic Fatigue Syndrome and Juvenile Idiopathic Arthritis (QFS-study): study protocol for a randomized controlled trial with single-subject experimental case series design

“…Most of those affected with acute Q-fever recover from fatigue within 6 to 12 months [4]. Approximately 20% does not recover within this timeframe, leading to Q-fever fatigue syndrome (QFS) diagnosis [4,7]. QFS has been associated with immune deregulation [8] and possibly mitochondrial dysfunction [9]; however, the etiology and pathophysiology of QFS is still largely unknown [8,9].…”

“…The term QFS is derived from chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), because of its similar expression. Like with CFS/ ME, individuals with QFS have, in addition to severe fatigue, a complex set of symptoms including, e.g., headache, muscle and/or joint strains, sore throat, and painful lymph nodes [6,7,10]. Post exertional malaise, unrefreshing sleep, memory or concentration difficulties, and issues regarding mental well-being, are also common [6,7,10].…”