Estimation of acute and chronic Q fever incidence in children during a three-year outbreak in the Netherlands and a comparison with international literature

Genotyping and phylogenetic analysis of Coxiella burnetii in domestic ruminant and clinical samples in Iran: insights into Q fever epidemiology

Coxiella burnetii, a zoonotic pathogen, is the causative agent of Q fever, an endemic disease in Iran. However, there is currently a lack of available data on the genotypes of C. burnetii in the country. Here, we typed 26 C. burnetii isolates detected in milk, abortion, cotylodon, and cardiac valve samples from various geographical areas and hosts (7 cattle, 8 goats, 10 sheep, and 1 human) using Multilocus Variable Number Tandem Repeat Analysis (MLVA/VNTR) with five loci:ms24, ms27, ms28, ms33, and ms34. As IS1111 was observed to be spontaneously inserted in locus ms23 across all of our examined C. burnetii samples, five loci were employed for MLVA/VNTR genotyping. Among the 26 C. burnetii strains, 22 distinct genotypes (A-V) were identified in the discriminative loci. In silico analysis categorized Iranian C. burnetii strains into five genomic groups along with seven singletons, representing 11 exiting clonal complexes worldwide. Clusters 10 and 11 exclusively consisted of Iranian samples. These findings revealed high genotyping diversity among C. burnetii isolates in Iran. The genotypes circulating in Iran differed significantly from those found in other regions worldwide. To gain a comprehensive understanding of Q fever epidemiology in Iran, it is crucial to conduct large-scale studies that assess the distribution of C. burnetii genotypes across different geographical areas, hosts, and sources.

The First Confirmed Pediatric Chronic Osteomyelitis due to Coxiella Burnetii in Oman

We describe here the first confirmed case in Oman of chronic osteomyelitis due to Coxiella burnetii, in a previously healthy four-year-old Omani girl. After laboratory confirmation of C. burnetii infection using molecular and qualitative and quantitative serological assays, the case was successfully managed with a combination of oral ciprofloxacin and cotrimoxazole and thereafter followed up for a long period without remission.

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.

Chronic Q Fever Infections in Israeli Children: A 25-year Nationwide Study

BACKGROUND

Q fever is a zoonosis caused by the bacterium Coxiella burnetii (C. burnetii) with a worldwide distribution. Our aim was to assess the epidemiology, clinical manifestations and treatment regimens of chronic Q fever infections in Israeli children during the past 25 years.

METHODS

Cases were collected from the national Q fever reference laboratory database. Demographic, epidemiologic and clinical data were reviewed using a structured questionnaire sent to the referring physician. Cases were defined according to the new Dutch Consensus Guidelines.

RESULTS

A total of 16 children originating from all regions of the country were found positive for chronic Q fever infections. The most common infection site was bone or joint (8/16, 50%), all in previously healthy children. Endovascular infections were found in 5 children (31%), all with an antecedent cardiac graft insertion. According to the new Consensus Guidelines, 9 children (56%) had a proven infection, 3 (19%) a probable infection and 4 (25%) a possible chronic Q fever infection. Almost all cases were treated with a long-term antibiotic regimen, often necessitating a change in medication because of persistent or rising titers.

CONCLUSIONS

Although pediatric chronic Q fever infections are rare, incidence has been rising. The most common infection site was bone or joint. A high index of suspicion is necessary, even in cases of previously healthy children without a possible exposure history. Use of the relatively new diagnostic tools in combination with serologic methods is helpful in diagnosing proven cases. There is no consensus as to the selection or duration of antibiotic treatment.

Livestock-associated risk factors for pneumonia in an area of intensive animal farming in the Netherlands

Previous research conducted in 2009 found a significant positive association between pneumonia in humans and living close to goat and poultry farms. However, as this result might have been affected by a large goat-related Q fever epidemic, the aim of the current study was to re-evaluate this association, now that the Q-fever epidemic had ended. In 2014/15, 2,494 adults (aged 20–72 years) living in a livestock-dense area in the Netherlands participated in a medical examination and completed a questionnaire on respiratory health, lifestyle and other items. We retrieved additional information for 2,426/2,494 (97%) participants from electronic medical records (EMR) from general practitioners. The outcome was self-reported, physician-diagnosed pneumonia or pneumonia recorded in the EMR in the previous three years. Livestock license data was used to determine exposure to livestock. We quantified associations between livestock exposures and pneumonia using odds ratios adjusted for participant characteristics and comorbidities (aOR). The three-year cumulative frequency of pneumonia was 186/2,426 (7.7%). Residents within 2,000m of a farm with at least 50 goats had an increased risk of pneumonia, which increased the closer they lived to the farm (2,000m aOR 1.9, 95% CI 1.4–2.6; 500m aOR 4.4, 95% CI 2.0–9.8). We found no significant associations between exposure to other farm animals and pneumonia. However, when conducting sensitivity analyses using pneumonia outcome based on EMR only, we found a weak but statistically significant association with presence of a poultry farm within 1,000m (aOR: 1.7, 95% CI 1.1–2.7). Living close to goat and poultry farms still constitute risk factors for pneumonia. Individuals with pneumonia were not more often seropositive for Coxiella burnetii, indicating that results are not explained by Q fever. We strongly recommend identification of pneumonia causes by the use of molecular diagnostics and investigating the role of non-infectious agents such as particulate matter or endotoxins.

From Q Fever to Coxiella burnetii Infection: a Paradigm Change

Coxiella burnetii is the agent of Q fever, or "query fever," a zoonosis first described in Australia in 1937. Since this first description, knowledge about this pathogen and its associated infections has increased dramatically. We review here all the progress made over the last 20 years on this topic. C. burnetii is classically a strict intracellular, Gram-negative bacterium. However, a major step in the characterization of this pathogen was achieved by the establishment of its axenic culture. C. burnetii infects a wide range of animals, from arthropods to humans. The genetic determinants of virulence are now better known, thanks to the achievement of determining the genome sequences of several strains of this species and comparative genomic analyses. Q fever can be found worldwide, but the epidemiological features of this disease vary according to the geographic area considered, including situations where it is endemic or hyperendemic, and the occurrence of large epidemic outbreaks. In recent years, a major breakthrough in the understanding of the natural history of human infection with C. burnetii was the breaking of the old dichotomy between "acute" and "chronic" Q fever. The clinical presentation of C. burnetii infection depends on both the virulence of the infecting C. burnetii strain and specific risks factors in the infected patient. Moreover, no persistent infection can exist without a focus of infection. This paradigm change should allow better diagnosis and management of primary infection and long-term complications in patients with C. burnetii infection.