20 May 2009

Q fever in humans: Netherlands

Between 1 January and 11 May 2009, 345 human cases (including 13 probable cases) of Q fever have been reported in the Netherlands [1]. Most cases in 2009 have been reported from Noord-Brabant, a province with a high density of goat farms.

Q fever is an emerging infectious disease in the Netherlands, with previous epidemics occurring during 2007 (168 cases) and 2008 (1,000 cases) [2,3]. The peak incidence of cases in previous years occurred during the months of December to May [3]. 

Mandatory vaccination of goats and sheep has been in force since April 2009 with the aim of reducing the number of infections in animals by the lambing season of 2010 [1].

Q fever

Q fever is a bacterial infection caused by the organism Coxiella burnetii. It occurs throughout the world but is an emerging infectious disease in the Netherlands and other parts of Europe [1-3]. It is uncommon in the United Kingdom [4].

Q fever is a zoonosis, or infection of animals. The usual source of infection for humans is domesticated mammals (e.g. goats, sheep and cattle) that acquire the bacteria from ticks. Animals can remain asymptomatic once infected. Q fever in humans usually occurs with inhalation of aerosolised bacteria after contact with placental products, blood, urine or faeces from an infected animal, after inhalation of the organism from dust, straw or dried faeces, or less commonly, through ingestion of infected milk [5,6]. As the organism forms spores, it can survive in the environment for months [6].

Q fever can be asymptomatic or present as a self-limited febrile illness with headache, fatigue and myalgias occurring 2 to 3 weeks or longer after exposure. More severe illness includes pneumonia, hepatitis and rarely, aseptic meningitis and encephalitis. Endocarditis can also occur, usually in individuals with pre-existing heart valve disease [7]. Pregnant women who contract the infection have an increased risk of miscarriage, neonatal death or delivering low birth weight babies [6,8].

Antibiotics and supportive care and management of symptoms are the standard treatment.

Advice for travellers

Those who come into contact with ruminants (goats, sheep, cattle) as part of their work are at increased risk of exposure to C. burnetii (e.g. farmers, shearers, abattoir workers, butchers).  Travellers to endemic areas who visit farms or rural areas can be at risk.

Travellers to endemic areas can reduce their risk of infection by the following measures:

• Avoid contact with ruminants particularly during lambing or calving.  This is particularly important for pregnant women.
• If contact cannot be avoided, practise good hand hygiene and cover open wounds
• If undertaking high risk activity, e.g. working with infected animals, use additional protective equipment such as a face mask and take specialist advice
• Avoid consumption of un-pasteurised dairy products in areas of risk.   
• Take insect bite avoidance measures. Check body for ticks and remove if found.

There is no vaccine available in the UK or the Netherlands [3] to protect humans against Q fever. Vaccine may be available in parts of the world where the disease is considered an occupational risk (e.g. Australia) [9].

References

1. B Schimmer, P Vellema, P M Schneeberger et al. Sustained intensive transmission of Q fever in the south of the Netherlands, 2009. Eurosurveillance.Volume 14, Issue 19. 14 May 2000. [Accessed 19 May 2009]. Available at http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=

19210

2. Schimmer B, Morroy G, Dijkstra F et al. Large ongoing Q fever outbreak in the south of the Netherlands, 2008. Euro Surveill. 2008;13(31):pii=18939. [Accessed 19 May]. Available from: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=

18939

3. C.E. Delsing, B.J. Kullberg. Q fever in the Netherlands: a concise overview and implications of the largest ongoing outbreak. The Netherlands Journal of Medicine. October 2008; 66(9):365-67

4. Health Protection Agency. Q fever. [Accessed 19 May 2009]. Available at http://www.hpa.org.uk/webw/HPAweb&Page&HPAwebAutoList

Name/Page/1191942172161?p=1191942172161

5. Cowan GO. Rickettsial Infections.  In Cook GC, Zumla A Eds. Manson’s Tropical Diseases. Twenty-first edn. 2003. London Elsevier Science.

6. Parker N, Barralet JH, Bell AM. Q fever. Lancet 2006;367:679-688

7. Fenollar F, Fournier P, Carrieri MP et al. Risk factors and prevention of Q fever endocarditis. Clin Infect Dis 2001;33:312-16

8. Carpopino X, Raoult D, Pretelle F et al. Managing Q fever during pregnancy: the benefits of long-term cotrimoxazole therapy. Clin Infect Dis 2007;45:548-55

9. Australian Government. Department of Health and Ageing. Q fever. [Accessed 19 May 2009]. Available at http://www.immunise.health.gov.au/internet/immunise/

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