Clinical presentation of acute Q fever in Spain: seasonal and geographical differences

Epidemiology of Q Fever in Southeast Europe for a 20-Year Period (2002-2021)

This study aimed to assess epidemiological trends of Q fever in six countries of Southeast Europe by analysing surveillance data for 2002-2021 period. In this descriptive analysis, we collected and analysed data on confirmed human Q fever cases, obtained from the national Public Health Institutes of Bosnia and Herzegovina, Croatia, Greece, Montenegro, North Macedonia and Serbia. Overall, 2714 Q fever cases were registered during the 20-year period. The crude average annual notification rate was 0.82 (± 2.06) (95% CI: 0.47-1.16) per 100,000 inhabitants, ranged from 0.06 (± 0.04) (95% CI: 0.04-0.08) /100,000 in Greece to 2.78 (± 4.80) (95% CI: 0.53-5.02) /100,000 in the Republic of Srpska (entity of Bosnia and Herzegovina). Significant declining trends of Q fever age standardized rates were registered in Croatia, the Federation of Bosnia and Herzegovina, North Macedonia and Serbia, with an average annual change of -30.15%; -17.13%; -28.33% and - 24.77%, respectively. An unequal spatial distribution was observed. The highest average age-specific notification rate was reported in the 20-59 age group (0.84 (± 0.40) (95% CI: 0.65-1.02) /100,000). Most cases (53.69%) were reported during the spring. Q fever remains a significant public health threat in this part of Europe. The findings of this study revealed the endemic maintenance of this disease in the including countries, with large regional and subnational disparities in notification rates. A downward trend was found in Q fever notification rates across the study countries with the average notification rate higher than in the EU/EEA, during the same period.

Bivalvular Endocarditis Due to Polymicrobial Coinfection with Enterococcus faecalis and Coxiella burnetii: A Case Report and Review of the Literature

Polymicrobial endocarditis is uncommon, and polymicrobial endocarditis in combination with Coxiella burnetii is very rare. We herein describe an extremely rare case of polymicrobial bivalvular endocarditis due to coinfection with Enterococcus faecalis and Coxiella burnetii in a 62-year-old male patient, and extensively review the relevant medical literature. To the best of our knowledge, only three similar cases have been previously reported. Q fever is a worldwide endemic bacterial zoonosis, but it and its most common chronic complication, endocarditis, are still underestimated and underdiagnosed worldwide. This situation reflects the paucity of reported cases of polymicrobial endocarditis in combination with Coxiella burnetii. Clinical presentation of Q fever endocarditis is highly nonspecific, and diagnosis may be delayed or missed, leading to severe and potentially fatal disease. Our case and the previously reported similar cases emphasize the need for further evaluation of infective endocarditis due to Coxiella burnetii, in all cases of culture-negative endocarditis, and in prolonged oligo-symptomatic inflammatory syndrome, particularly in the presence of valvular heart disease. This approach should be applied even when typical pathogens are isolated, especially in endemic areas of Q fever, and with atypical presentation.

Epidemiology of Q fever in humans in four selected regions, Spain, 2016 to 2022

BackgroundQ fever is a bacterial zoonosis caused by Coxiella burnetii. Spain has the highest number of notified human cases in Europe. Small ruminants are a key reservoir for the pathogen, transmission from animals to humans is usually airborne.AimWe aimed at exploring temporal and spatial epidemiological patterns of sporadic and outbreak cases of Q fever in four Spanish regions with the highest number of notified cases.MethodsWe extracted data on Q fever cases in the Canary Islands, Basque Country, La Rioja and Navarre between 2016 and 2022 from the Spanish National Epidemiological Surveillance Network. We calculated standardised incidence ratios (SIR), spatial relative risks (sRR) and posterior probabilities (PP) utilising Besag-York-Mollié models.ResultsThere were 1,059 notifications, with a predominance of males aged 30-60 years. In Basque Country, La Rioja and Navarre area, 11 outbreaks were reported, while no in the Canary Islands. A seasonal increase in incidence rates was observed between March and June. In the Canary Islands, elevated sRR was seen in La Palma, Gran Canaria, Lanzarote and Fuerteventura. In Basque Country, La Rioja and Navarre area, the highest sRR was identified in the south of Biscay province.ConclusionGoats were the main source for humans in outbreaks reported in the literature. Seasonal increase may be related to the parturition season of small ruminants and specific environmental conditions. Local variations in sRR within these regions likely result from diverse environmental factors. Future One Health-oriented studies are essential to deepen our understanding of Q fever epidemiology.

Exposure to Coxiella burnetii in Wild Lagomorphs in Spanish Mediterranean Ecosystems

Coxiella burnetii is an important zoonotic pathogen of worldwide distribution that can infect a wide range of wild and domestic species. The European wild rabbit (Oryctolagus cuniculus) can play a role as a reservoir for this bacterium in certain epidemiological scenarios, but, to date, a very limited numbers of large-scale serosurveys have been conducted for this species worldwide. Although exposure in hare species has also been described, C. burnetii in Iberian hare (Lepus granatensis) has never been assessed. Here, we aimed to determine the seroprevalence and risk factors associated with C. burnetii exposure in wild lagomorphs in the Mediterranean ecosystems of southern Spain. Between the 2018/2019 and 2021/2022 hunting seasons, blood samples from 638 wild lagomorphs, including 471 wild rabbits and 167 Iberian hares, were collected from 112 hunting grounds distributed across all eight provinces of Andalusia (southern Spain). The overall apparent individual seroprevalence was 8.9% (57/638; 95% CI: 6.8-11.4). Antibodies against C. burnetii were found in 11.3% (53/471; 95% CI: 8.4-14.1) of the wild rabbits and 2.4% (4/167; 95% CI: 0.1-4.7) of the Iberian hares. Seropositive animals were detected for 16 (14.3%; 95% CI: 7.8-20.8) of the 112 hunting grounds tested and in all the hunting seasons sampled. A generalized estimating equations model showed that the geographical area (western Andalusia) and presence of sheep were risk factors potentially associated with C. burnetii exposure in wild lagomorphs. A statistically significant spatial cluster (p < 0.001) was identified in the south-west of Andalusia. Our results provide evidence of moderate, endemic and heterogeneous circulation of C. burnetii in wild lagomorph populations in Spanish Mediterranean ecosystems. Risk-based strategies for integrative surveillance programs should be implemented in these species to reduce the risk of transmission of the bacterium to sympatric species, including humans.

Seroprevalence of Q Fever and Risk Factors Affecting Transmission of Coxiella burnetii in Industrial Slaughterhouse; A Survey from Northeastern Iran

Background: Q fever is a generally neglected infection caused by Coxiella burnetii. Slaughterhouse workers exposed to livestock are among occupationally at-risk people. Objectives: This study was conducted to investigate the seroprevalence of anti-Coxiella burnetii (Q fever) IgG antibody among industrial slaughterhouse workers and factors affecting the risk of infection. Methods: In this cross-sectional study serum samples were taken from 91 individuals working at the central industrial abattoir in Mashhad, Iran using a convenient sampling method. Sera were kept at -80°C until assayed for specific anti-Coxiella burnetii IgG antibodies (phase 1) using the commercial ELISA kit. The participants filled out a checklist addressing potential risk factors of acquiring the infection. SPSS 11.5 was used for data analysis considering a significance level of P < 0.05. Results: The participants’ mean age was 38.7 ± 8 years. Fifty-six percent of the studied individuals (51 out of 91) were found positive for anti-Coxiella burnetii antibodies. The most prevalent cases were sheep (29, 57%) and cow (18, 35%) butchers. The odds of Q fever infection increased among those with a history of accidental hand cuts of more than five times during the previous years (OR = 2.56, CI95% = 1.02 - 6.33, P-value = 0.04) and those dealing with sheep as the primary livestock (OR = 2.9, CI95% = 1.09 - 7.66, P = 0.02). Conclusions: The high seropositivity rate of anti-Coxiella burnetii IgG reflects high exposure rate of workers to this potentially serious pathogen in slaughtherhouses; therefore, careful education, follow-up, and revision of decontamination policies and improved occupational care and environmental hygiene should be strictly implemented in slaughterhouses to reduce the risk.

Urban landscape and infection risk in free-roaming cats

Despite public concern on the role of free‐roaming cats as reservoirs of zoonotic agents, little is known about the influence of urban and peri‐urban landscapes on the exposure risk. We evaluated the seroprevalence of three zoonotic agents (Chlamydia felis, Coxiella burnetii and Toxoplasma gondii) in domestic cats (Felis catus). Two hundred and ninety‐one free‐roaming cats were trapped in Murcia municipality (Southeast Spain), and their sera were tested for specific antibodies against T. gondii using a modified agglutination test (MAT), and for C. felis, C. burnetii and feline immunodeficiency virus (FIV) antibodies with ELISA technique. Pathogen seroprevalence at 95% CI was calculated for each sex and age category (up to and over 12 months) and compared with a chi‐squared test. The role of human population density and urban landscape characteristics on the risk of pathogen exposure in the cat population was explored using generalized linear models. Seropositivity against a single pathogen was found in 60% of the cats, while 19% was seropositive for two or three pathogens. Seroprevalence of C. felis was 8% (CI_95%: 5–11), 37% (CI_95%: 31–42) for C. burnetii and 42% (CI_95%: 36–47) for T. gondii. In addition to these three pathogens, FIV seropositivity was low (1%, CI_95%: −0.1 to 2) and adult cats were more likely to be seropositive to C. burnetii than young individuals (OR: 2.3, CI_95%: 1.2–4.2). No sex or age class differences in seroprevalence were observed for the rest of the pathogens. Seropositivity was correlated with water surface areas for C. felis, and not with crop areas. Coxiella burnetii seropositivity was correlated with the percentage of urban areas (continuous with only buildings and discontinuous, that include buildings, parks, and pedestrian and urban green areas), human population size and peri‐urban areas with shrubs, and not correlated with other agricultural landscapes (orchards and crop areas). However, the seroprevalence of T. gondii was only associated with agricultural landscapes such as orchards. The detection of hotspot areas of high pathogen exposure risk is the basis for municipal services to implement surveillance and risk factor control campaigns in specific‐risk areas, including (a) efficient health management of urban cat colonies by geographical location, population census and health status monitoring of the components of each cat colony, (b) improvement of hygiene and sanitary conditions at the feeding points of the cat colony and (c) free‐roaming cat trapping for health monitoring and, in the long term, to know the evolution of the health status of their populations.

Epidemiological, clinical and laboratory characteristics of acute Q fever in an endemic area in Israel, 2006-2016

Our purpose was to describe the clinical, epidemiological and laboratory characteristics of patients hospitalised with acute Q fever in an endemic area of Israel. We conducted a historical cohort study of all patients hospitalised with a definite diagnosis of acute Q fever, and compared them to patients suspected to have acute Q fever, but diagnosis was ruled out. A total of 38 patients had a definitive diagnosis, 47% occurred during the autumn and winter seasons, only 18% lived in rural regions. Leucopaenia and thrombocytopaenia were uncommon (16% and 18%, respectively), but mild hepatitis was common (mean aspartate aminotransferase 76 U/l, mean alanine aminotransferase 81 U/l). We compared them with 74 patients in which acute Q fever was ruled out, and found that these parameters were not significantly different. Patients with acute Q fever had a shorter hospitalisation and they were treated more often with doxycycline than those without acute Q fever (6.4 vs. 14 days, P = 0.007, 71% vs. 38%, P = 0.001, respectively). In conclusion, acute Q fever can manifest as an unspecified febrile illness, with no seasonality. We suggest that in endemic areas, Q fever should be considered in the differential diagnosis in any febrile patient with risk factors for a persistent infection.

Diagnostic usefulness of molecular detection of Coxiella burnetii from blood of patients with suspected acute Q fever

Diagnosis of Q fever is difficult due to the lack of distinct clinical features that distinguish it from other febrile diseases. Serologic testing is the gold standard method for diagnosing Q fever, but antibody formation may not be detectable for 2 to 3 weeks from symptom onset, limiting early diagnosis. We thus evaluated the diagnostic utility of polymerase chain reaction (PCR) to detect Coxellia burnetii DNA in serum from patients with suspected acute Q fever.All adult patients with suspected acute Q fever were prospectively enrolled at a tertiary-care hospital from January 2016 through July 2018. Acute Q fever was diagnosed using clinical and laboratory criteria: fever with at least one other symptoms (myalgia, headache, pneumonia, or hepatitis) and single phase II immunoglobulin G (IgG) antibody titers ≥1:200 or immunoglobulin M (IgM) antibody titer ≥1:50 (probable), or a fourfold increase or seroconversion in phase II IgG antibody titers as measured by indirect immunofluorescence assays between paired samples (confirmed). We performed PCR targeting the transposase gene insertion element IS1111a of C. burnetii.Of the 35 patients with suspected acute Q fever, 16 (46%) were diagnosed with acute Q fever including 8 probable and 8 confirmed cases; the remaining 19 (54%) were diagnosed with other febrile diseases. The proportion of males diagnosed with Q fever was higher than those diagnosed with other febrile diseases (88% vs 44%, P = .03), but there were no other significant differences in clinical characteristics between the 2 groups. The Q fever PCR sensitivity was 81% (95% confidence interval [CI], 54-96), specificity was 90% (95% CI, 67-99), positive predictive value was 87% (95% CI, 63-96), and negative predictive value was 85% (95% CI, 67-94).Q fever PCR testing using blood from patients with suspected acute Q fever seems to be a rapid and useful test for early diagnosis of Q fever.

Q fever in Spain: Description of a new series, and systematic review

BACKGROUND

Forms of presentation of Q fever vary widely across Spain, with differences between the north and south. In the absence of reported case series from Galicia (north-west Spain), this study sought to describe a Q-fever case series in this region for the first time, and conduct a systematic review to analyse all available data on the disease in Spain.

METHODS

Patients with positive serum antibodies to Coxiella burnetii from a single institution over a 5-year period (January 2011-December 2015) were included. Patients with phase II titres above 1/128 (or documented seroconversion) and compatible clinical criterial were considered as having Q fever. Patients with clinical suspicion of chronic Q-fever and IgG antibodies to phase I-antigen of over 1/1024, or persistently high levels six months after treatment were considered to be cases of probable chronic Q-fever. Systematic review: We conducted a search of the Pubmed/Medline database using the terms: Q Fever OR Coxiella burnetii AND Spain. Our search yielded a total of 318 studies: 244 were excluded because they failed to match the main criteria, and 41 were discarded due to methodological problems, incomplete information or duplication. Finally, 33 studies were included.

RESULTS

A total of 155 patients, all of them from Galicia, with positive serological determination were located during the study period; 116 (75%) were deemed to be serologically positive patients without Q fever and the remaining 39 (25%) were diagnosed with Q fever. A potential exposure risk was found in 2 patients (5%). The most frequent form of presentation was pneumonia (87%), followed by isolated fever (5%), diarrhoea (5%) and endocarditis (3%). The main symptoms were headache (100%), cough (77%) and fever (69%). A trend to a paucisymptomatic illness was observed in women. Hospital admission was required in 37 cases, and 6 patients died while in hospital. Only 2 patients developed chronic Q-fever. Systematic review: Most cases were sporadic, mainly presented during the winter and spring, as pneumonia in 37%, hepatitis in 31% and isolated fever in 29.6% of patients. In the north of Spain, 71% of patients had pneumonia, 13.2% isolated fever and 13% hepatitis. In the central and southern areas, isolated fever was the most frequent form of presentation (40%), followed by hepatitis (38.4%) and pneumonia (17.6%). Only 31.7% of patients reported risk factors, and an urban-environment was the most frequent place of origin. Overall mortality was 0.9%, and the percentage of patients with chronic forms of Q-fever was 2%.

CONCLUSIONS

This is the first study to report on a Q-fever case series in Galicia. It shows that in this region, the disease affects the elderly population -even in the absence of risk factors- and is linked to a higher mortality than reported by previous studies. While pneumonia is the most frequent form of presentation in the north of the country, isolated fever and hepatitis tend to be more frequent in the central and southern areas. In Spain, 32% of Q-fever cases do not report contact with traditional risk factors, and around 58% live in urban areas.

Legionnaire's Disease and its Mimics: A Clinical Perspective

Whenever the cardinal manifestations of a disorder occur in similar disorders, there is potential for a disease mimic. Legionnaire's disease has protean manifestations and has the potential to mimic or be mimicked by other community acquired pneumonias (CAPs). In CAPs caused by other than Legionella species, the more characteristic features in common with legionnaire's disease the more difficult the diagnostic conundrum. In hospitalized adults with CAP, legionnaire's disease may mimic influenza or other viral pneumonias. Of the bacterial causes of CAP, psittacosis and Q fever, but not tularemia, are frequent mimics of legionnaire's disease.

Acute Q fever in febrile patients in northwestern of Iran

BACKGROUND

Q fever is an endemic disease in different parts of Iran. This study aimed to investigate the prevalence of acute Q fever disease among at-risk individuals in northwestern Iran.

METHODOLOGY

An etiological study was carried out in 2013 in Tabriz County. A total of 116 individuals who were in contact with livestock and had a nonspecific febrile illness were enrolled in the study. IgG phase II antibodies against Coxiella burnetii were detected using ELISA.

PRINCIPAL FINDINGS

The prevalence of acute Q fever was 13.8% (95% confidence interval [CI]: 8.0, 21.0%). Headache (87.5%) and fatigue and weakness (81.3%) were the dominant clinical characteristics among patients whit acute Q fever. Acute lower respiratory tract infection and chills were poorly associated with acute Q fever. Furthermore, 32% (95% CI: 24, 41%) of participants had a history of previous exposure to Q fever agent (past infection). Consumption of unpasteurized dairy products was a weak risk factor for previous exposure to C. burnetii.

CONCLUSION

This study identified patients with acute Q fever in northwestern of Iran. The evidence from this study and previous studies conducted in different regions of Iran support this fact that Q fever is one of the important endemic zoonotic diseases in Iran and needs due attention by clinical physicians and health care system.

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.

Wide exposure to Coxiella burnetii in ruminant and feline species living in a natural environment: zoonoses in a human-livestock-wildlife interface

Assessment of the role of wild and domestic hosts as potential reservoirs of misdiagnosed zoonoses, such as Q fever by Coxiella burnetii, is an important public health issue today both for wildlife conservation and management of disease in human-livestock-wildlife interface. This study used ELISA, an indirect antibody, to research (2003-2013) C. burnetii infection in seven free-living wild and domestic ruminant species and in European wildcats (Felis silvestris). The animals studied were 0 European wildcats, 21 Spanish ibex (Capra pyrenaica), 314 red deer (Cervus elaphus), 556 fallow deer (Dama dama), 211 European mouflon (Ovis aries musimon), eight roe deer (Capreolus capreolus), 407 bovines (Bos taurus) and 3739 sheep (Ovis aries). All the animals shared the same habitat in the Serranía de Cuenca Natural Park (Castile-La Mancha, Spain). The study area is an example of human-domestic-wildlife interface where people and domestic animals live in close proximity to wildlife. Observed C. burnetii seropositive frequencies were: 33·3% European wildcats, 23·8% Spanish ibex, 22·5% domestic sheep 1·5% red deer, 1·4% European mouflon, 0·24% cattle, 0·18% fallow deer and 0% roe deer. The study found a wide C. burnetii prevalence of previous and present exposure in wild and domestic ruminant hosts in the Serranía de Cuenca Natural Park and reports the first evidence of C. burnetii exposure in free-living European wildcats.

Genotypes of Coxiella burnetii in wildlife: disentangling the molecular epidemiology of a multi-host pathogen

Evidences point to a relevant role of wildlife in the ecology of Coxiella burnetii worldwide. The lack of information on C. burnetii genotypes in wildlife prevents tracing-back clinical animal and human Q fever cases with potential wildlife origin. To compare C. burnetii genotypes circulating in wildlife, livestock and humans, 107 samples from red deer, European wild rabbit, racoon, small mammals, goat and sheep were genotyped by polymerase chain reaction and reverse line blot hybridization. Genomic groups I, II, VI and VII were found in wildlife and groups I, II, III and IV in domestic ruminants. Livestock genotypes clustered mainly with genotypes reported previously in livestock. Genotyping confirmed previous findings that suggest that C. burnetii may display host specificity since most genotypes of sympatric deer and rabbits clustered in separate groups. Wildlife genotypes clustered with genotypes from ticks and from acute hepatitis human Q fever cases, suggesting that particular C. burnetii genotypes circulating in a wildlife-tick cycle may occasionally jump into humans through tick bites or exposure to wildlife. This finding could be behind the reported geographic variation in the clinical presentation of acute Q fever in humans in Spain: atypical pneumonia in the north and hepatitis in the south.