Most common clinical presentation of Q fever in a province in the north of Spain

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.

[Acute Q Fever: 35 cases in Castilla-La Mancha]

We report 35 sporadic cases of acute Q fever diagnosed in the area of Castilla-La Mancha (Spain). Diagnosis was based on a fourfold or greater rise in specific antibody titer. The mean age of the patients was 33 years and the male/female ratio was 2.5. Seventeen patients had hepatitis, 9 had pneumonia, 8 had isolated fever and 1 had myocarditis. An underlying disease was more frequent among patients with pneumonia.

[Outbreak of Q fever and seroprevalence in a rural population from Soria Province]

BACKGROUND

The aim of this study was to describe an outbreak of acute fever in a rural town from Soria (Spain) in the spring of 1998 and to know the prevalence of IgG antibodies to Coxiella burnetii in this population.

METHODS

1. Outbreak of Q fever: epidemiological, clinical and analytical data were obtained by standardised questionnaire and the clinical records from all clinical cases. These cases were confirmed by complement fixation test.2. Seroprevalence: 253 sera were chosen by not probabilistic sampling of convenience of sera samples collected between 1 September 1996 and 28 February 1999. Were regarded as positive anti-phase II C. burnetii IgG titles by indirect inmunoflourescence assay equal or higher to 1/80.

RESULTS

1. A total of 14 cases of Q fever with a mean age of 21.5 +/-3.1 years were confirmed. 64% presented pneumonia and in 36% the symptoms were nonspecific. No patient had direct contact with animals but near to the town there were 4 flocks with 2,614 sheeps overall. 2. The seroprevalence was 60% (95% confidence interval: 54-66). The seroprevalence was not increased with the outbreak (p > 0.05).

CONCLUSION

The high prevalence of antibodies to C. burnetii in this population shows that this area is hyperendemic for such infection, but generally is asymptomatic or clinical signs are extremely mild because no cases of Q fever had been reported in the years before. Probably indirect exposure to flocks of sheep was the source of infection and transmission mechanism airborne.