No 22 - 2011

Travel-associated Q-fever

Q-fever (query fever) is a zoonosis caused by infection with the Coxiella burnetii bacterium, which can assume a highly environment-resistant spore-like form, EPI-NEWS 46/06 (pdf).

This bacterium is particularly common in cattle, sheep and goats, but it is also found in other mammals such as cats and small rodents. Infected animals are frequently asymptomatic, but may shed bacteria in vast numbers in the placenta and to a lesser extent in breast milk. The infection may trigger miscarriage in animals.

In 2010-2011 three cases of acute Q-fever have been diagnosed in persons who had visited the Canary Islands. Two of the persons in question had visited a goat farm at their vacation site. As none of the affected persons are employed in agriculture in Denmark, infection at the vacation site is considered probable.

Patient number 1

A 66-year-old previously healthy male who had travelled to Fuerteventura as a tourist for a week in January 2010. He had visited a goat farm where he ingested a locally produced goat cheese. He presented with fever and fatigue by late April.

The patient was admitted in mid May with elevated CRP and liver enzymes. By early June, positive antibody titres for C. burnetii were detected. The patient was then in good state of health, afebrile and his echocardiography was normal.

The patient was followed for three months as an outpatient during which period Coxiella titres decreased rapidly. Follow-up was then concluded. Specific antibiotic treatment was not given.

Patient number 2

A 74-year-old male who was receiving hydrea treatment for essential thrombocytosis. The patient had spent a week as a tourist on Fuerteventura in February 2011. He had visited a goat farm where he had ingested a locally produced goat cheese.

By mid March he presented with subacute symptoms including fever, fatigue, reduced appetite, jaundice, abdominal pain, dyspepsia, nausea and diarrhoea. The patient was admitted by late March. Moderately increased liver counts were observed along with mild leucocytosis and a two-digit CRP increase. A liver biopsy showed acute and chronic inflammation.

Image diagnostics and endoscopy yielded no pathological findings.

The patient's hepatitis serology was negative and no autoantibodies were detected. Positive C. burnetti serology was detected by mid April and the patient was started on doxycycline, 200 mg per day for three weeks.

Patient number 3

A 67-year-old previously healthy male, who had travelled to Gran Canaria as a tourist for a week in January 2011. There was no obvious exposure at the vacation site.

By mid March, the patient presented with acute fever and chills accompanied by headache, general malaise and a mild dry cough. The patient was admitted three days after symptom onset. During the admission, slightly increasing liver counts and an elevated CRP were observed. ECG, chest x-ray, echocardiography and CT were all normal.

The patient ran a high fever and became increasingly drowsy until initiation of doxycykline treatment by late March. By the beginning of April, serology was available and findings were consistent with acute Q-fever infection. The patient subsequently recovered with no signs of endocarditis.

Occurrence in the Canary Islands

In 2003 the seroprevalence of C. burnetii antibodies among the local population of the Canary Islands was found to be 22 %. Among goats, sheep and cattle, the seroprevalence was 60 %, 32 % and 12 %, respectively.

In consequence, the Canary Islands should be considered a highly endemic area for Q-fever.

Occurrence in the rest of Europe

High Q-fever occurrence has been reported in several European countries, including Southern France, Southern Italy, Northern Ireland and Northern Spain. Since 2007, Holland has seen Q-fever outbreaks in areas with intensive goat farming, EPI-NEWS 11/10.

Occurrence in Denmark

C. burnetii was practically unacknowledged in Denmark prior to 2005 when new diagnostic methods showed that it is endemic in cattle.

Q-fever is not notifiable and the diagnosis can only be made at the SSI. In 2010 a total of 26 persons had serological findings consistent with acute or previous infection.

A report from 2006/7 concluded that the over-whelming majority of cases were associated with occupational exposure to cattle in Denmark, EPI-NEWS 3/09 (pdf).

Mode of transmission

The disease is present all over the world, particularly in agricultural areas. Farmers with infected animals and veterinarians, slaughterhouse workers and laboratory staff have an elevated infection risk.

In addition to direct contact with infected animals and their afterbirth, airborne infection via aerosols or dust from contaminated areas is an important mode of transmission.

Fields and meadows may become contaminated in connection with animal partitions and from there the bacterium can spread with the wind. C. burnetii may survive for months to years outside a host.
Especially in dry areas, such as the Mediterranean, outbreaks have been observed in the local population in periods with many animal partitions and strong winds.

There is no evidence of human-to-human transmission.

Clinical picture

Q-fever infection can be asymptomatic and frequently presents as a self-limiting febrile illness. The incubation period varies, but it is normally 2-3 weeks.

Acute Q-fever presents as sudden-onset of fever, headache and muscle pain with varying degrees of pneumonia and/or hepatitis. Patients with cardiac valve anomalies, arterial aneurysms, cancer or immunosuppression and pregnant women are particularly predisposed to chronic Q-fever. Pregnant women infected with C. burnetii probably have an increased risk of abortion and premature birth.

Diagnosis and treatment

C. burnetii infection is diagnosed by serology and/or by PCR, EPI-NEWS 46/06 (pdf).

The first choice treatment for acute Q-fever in non-pregnant adults is doxycycline 100 mg x 2 for a period of 2-3 weeks, EPI-NEWS 46/06 (pdf).

Commentary

Q-fever should be considered as a differential diagnosis in case of influenza-like symptoms, pneumonia, hepatitis or endocarditis in persons returning from even rather short visits to highly endemic areas. In Europe, no Q-fever vaccine is available.

The Danish National Board of Health recommends that pregnant women and persons with a weakened immune system and/or chronic heart disorders, particularly cardiac valve conditions, avoid sheep, cattle and goat farms with abortion problems where an infectious cause is suspected.

(J.N. Rasmussen, K. Mølbak, T.G. Krause, Dept. of Epidemiology, M. Frølund, DBMP, SSI, E. Petersen, S. Villumsen, O.D. Larsen, Department of Infectious Diseases, Aarhus, Hvidovre and Odense University Hosp.)

Outbreak of E. coli VTEC O104 in Germany

On 30 May the German authorities had knowledge of 373 cases of haemolytic uraemic syndrome (HUS) and 796 cases of bloody diarrhoea with onset in May 2011. This unusual outbreak is caused by infection with the verocytotoxin-producing (VTEC) E. coli O104:H4

The precise source of infection is currently unknown, but is assumed to be raw vegetables distributed in Northern Germany. There is no evidence to suggest food-borne infection in Denmark.

Danish physicians should ensure immediate testing for VTEC bacteria of any patient presenting with bloody diarrhoea of symptoms or renal failure in the form of HUS. This is done by submitting a stool sample to a clinical microbiology department offering PCR or methods for detecting verocytotoxin.

The recommendation also covers close contacts with relevant symptoms, who have had contact to possibly infected persons. Any information on travels to Germany and/or relevant exposure to foodstuffs should be stated when submitting the sample.

Individually notifiable diseases and selected laboratory diagnosed infections (pdf)

1 June 2011