Familial Q fever clustering with variable manifestations imitating infectious and autoimmune disease

Pediatric Q Fever

Purpose of Review

The non-specific presentation of acute Q fever makes it difficult to diagnose in children, but untreated Q fever can result in chronic infections that have severe complications.

Recent Findings

Pediatric Q fever cases continue to be infrequently reported in the literature, and primarily document cases of persistent infections with Coxiella burnetii. Standardized treatment protocols for chronic Q fever in children still do not exist. Doxycycline and hydroxychloroquine are the treatment combination most utilized by healthcare providers to treat Q fever endocarditis or osteomyelitis in children, but a variety of other antibiotic combinations have been reported with varying results. The use of adjunctive therapies, such as such as interferon gamma, has produced mixed outcomes.

Summary

The true impact of Coxiella burnetii on the health of children remains unknown; long-term longitudinal follow-up of children with acute or chronic Q fever has not been reported. Both the acute and chronic forms of Q fever are underreported and underdiagnosed. Healthcare providers should consider Q fever in pediatric patients with culture-negative endocarditis or osteomyelitis.

Autoimmunity and B-cell dyscrasia in acute and chronic Q fever: A review of the literature

Q fever infection can lead to chronic Q fever, a potentially lethal disease occurring in 1-5% of patients infected with Coxiella burnetii, characterized by the persistence of this intracellular bacterium. It usually presents as endocarditis, infected vascular aneurysms, or infected vascular prostheses. This systematic review of the literature discusses the various autoimmune syndromes and B-cell dyscrasias in acute and chronic Q fever patients, that may interfere with or impede recognition and diagnosis of Q fever. Reportedly, high concentrations of anti-cardiolipin antibodies may be found in acute Q fever patients, while specifically cardiac muscle antibodies have been reported during chronic Q fever. Systemic lupus erythematosus and antiphospholipid syndrome are the most frequently reported autoimmune syndromes, followed by neuromuscular disorders and vasculitis. B-cell dyscrasia, mostly cryoglobulinaemia, is predominantly described in chronic Q fever patients with endocarditis. We conclude that immunological (epi)phenomena are not rare during Q fever and may obscure the infectious etiology of the disease.

Molecular screening of Ctenocephalides felis fleas collected from stray cats in the Jerusalem District, Israel, for Bartonella spp., Rickettsia spp. and Coxiella burnetii

Four hundred and sixty seven Ctenocephalides felis fleas removed from 185 feral cats living in residential areas of Jerusalem, Israel, were screened for bacterial infections of public health importance. The fleas were screened for bartonellae, rickettsiae and Coxiella burnetii by PCR and sequencing. Bartonella DNA was detected in 156 individual fleas collected from 91 of the 185 (49.2%) cats. DNA of Bartonella clarridgeiae, Bartonella henselae and Bartonella koehlerae was detected in 112/467 (24%), 29/467 (6.2%) and 15/467 (3.2%), respectively, indicating a significantly different distribution (P<0.00001) of these Bartonella spp. among the fleas. However, no differences were observed between female and male fleas in their Bartonella-infection status (P>0.05). Ninety one individual cats carried fleas infected with 1 to 3 Bartonella species. No differences were found between fleas collected from male and female, pregnant and non-pregnant or young, juvenile and adult cats. Interestingly, a significant association was observed between the clinical status of the cat hosts (apparently healthy versus sick) and the carriage of Bartonella-positive fleas. One of the 467 (0.2%) fleas was positive for Rickettsia felis DNA and no other Rickettsia spp. or C. burnetii DNA were detected. Our findings indicate a relatively high prevalence of Bartonella spp. known to be human pathogens, and low prevalence of R. felis in fleas from the Jerusalem district cats, highlighting the abundance and importance of bartonellae for public health in this urban region.