No 19 - 2012

Fox tapeworm in Denmark: New status

The fox tapeworm, Echinococcus multilocularis, was recently detected by the National Veterinary Institute, Technical University of Denmark, in a fox from the southern part of Jutland. The parasite was initially detected in three foxes in the Copenhagen area twelve years ago, EPI-NEWS 5/00, but has not since been monitored continuously. In recent years, an increased incidence of E. multilocularis has been observed among foxes in several parts of Europe, e.g. in Germany and Sweden. On the basis of the most recent finding, it cannot be excluded that the parasite has gained a permanent foothold in Denmark, even though the incidence presumably is low.

The parasite has carnivores, including dogs, raccoon dogs and foxes as definitive hosts, while mice and other small rodents serve as intermediate hosts. Monitoring of the occurrence among wild carnivores in Denmark was initiated in 2011, financed by the Danish Veterinary and Food Administration. So far, more than 350 foxes and raccoon dogs have been tested and only one was positive.

E. multilocularis may cause alveolar echinococcosis in humans. The incidence of human cases is correlated with the prevalence in wild foxes and with the density of fox populations. Particularly dog owners, farmers, hunters and others spending time in woods and farmland have an increased risk of infection.

Infection occurs via contact with faeces from infected animals. Thus good hygiene is important particularly when handling animals, during gardening and ingestion of vegetables, fruit or berries which may have been in contact with animal faeces.

The incubation period is long, in the majority of cases from 5 to 15 years, and therefore clinical infection is more frequent among the elderly, even though cases have been described in children as young as seven years of age. At present, no autochthonous cases have been detected in Denmark. However, one person has died due to this tapeworm, EPI-NEWS 18/04. Echinococcosis in humans is caused by either E. multilocularis or E. granulosus, both of which may cause cyst formation, primarily in the liver. In alveolar echinococcosis cysts measuring up to 15-20 cm in diameter are seen. Growth is proliferative and includes formation of metastases during the late stages of infection. Lethality is high if the infection is not diagnosed and treated in time. In approx. one third of cases metastases are found in one or more extrahepatic organs at the time of the initial diagnosis. The initial phase of the infection is asymptomatic. During the progressive phase patients present with fatigue, abdominal pain, hepatomegaly and in some cases jaundice, fever and anaemia.

Early diagnosis of subclinical cases is a fundamental for efficient management. The clinical diagnosis of alveolar echinococcosis is based on a combination of

1. history and clinical findings,
2. imaging diagnostics (ultrasound, computer tomography (CT)), magnetic resonance imaging (MRI), 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET)
3. serology, and if the above do not produce a conclusive diagnosis:
4. histopathology and PCR analysis of cyst material.  Liver biopsy, however, entails a risk of causing metastases and should be avoided if poss.

A positive antibody response does not necessarily mean that the patient will develop clinical echinococcosis.  In the majority of cases, imaging techniques will indicate which of the two echinococcosis species that can be suspected. As E. granulosus is not found in Denmark, information about travel activity is also relevant. Antibodies directed against these parasites will only cross-react to a limited degree, and it is recommended to test for both species in case of inconclusive image diagnosis or clinical suspicion. Based on the new finding of E. multilocularis in Denmark, suspicion of alveolar echinococcosis may be relevant even in cases with no history of foreign travel.

(H.L. Enemark, DTU VET, H.V. Nielsen, Dept. of Microbiology and Diagnostics)

Ornithosis 2011

In 2010 a total of seven persons were notified with ornithosis which is caused by the zoonotic bacterium Chlamydophila psittaci. This number is in line with that observed in previous years. Among the cases, seven were females and four males, and the median age was 61 years (range 53-75 years). For clinical particulars and routes of infection, see EPI-NEWS 5/08 and 19-20/10. Six had been infected in Denmark, three in connection with privately kept birds, one in connection with other contact to birds and in two cases the route and mode of infection were uncertain. One had presumably been infected during a tourist travel to a European country. The mode of infection for this case was uncertain.

All seven patients were admitted to hospital with pneumonia; for one case CNS affection was noted, one received artificial respiratory support and one died. All seven cases were diagnosed by PCR in secretions from the lower airways. Findings of C. psittaci by PCR testing is considered a certain diagnosis.  

(C. Kjelsø, Dept. of Inf. Disease Epidemiology, S. Uldum, DBMP)

National Board of Health Guideline: Infectious diseases in children and adolescents

General practitioners play an important role in connection with infectious diseases in children and when there is a need for a doctor's note due to absence from work, etc.

Conjunctivitis, for instance, is a condition which frequently gives cause for discussions among parents and pedagogues, which may be because some GP are unaware of the new provisions. The National Board of Health would therefore once again like to draw attention to the new version of "Infectious diseases in children and adolescents. Guideline on prevention in day-care institutions, schools etc." which was made public in January 2011.

The guideline is the fifth version of the previous publication in the field and has been thoroughly revised. The present version includes new chapters on the fundamental provisions in the field concerning who does what and on prevention of spreading of infection. Furthermore, sections on HIV infection, tuberculosis and MRSA were added. The provisions detailing when a child may return to his or her day-care institution have been slightly revised, and the new provisions are outlined clearly in pages 8 and 9. Other substantial changes:

- for conjunctivitis it is only the more severe forms which require antibiotic treatment, and in such cases the child should only return to his or her day-care institution after a minimum of two days of treatment. If children with the milder forms of conjunctivitis are treated, this may cause problems in relation to attendance at institutions and interpretation of the provisions.

- previously a provision on whooping cough stipulated that children below one year of age who had not had whooping cough or previously received two whooping cough vaccinations should be sent home in case of whooping cough at their institution. This provision is no longer in force.

Revised guidelines, see www.sst.dk.

(Danish National Board of Health)

9 May 2012