No 6 - 2016

Rabies prophylaxis

In Denmark, being bitten by a bat is normally the only indication for prophylactic treatment against rabies. If, after being bitten by other animals, there is reason to suspect that the animal has rabies, the animal should be examined by a veterinary. The veterinary will destroy the animal, if necessary, and will arrange further investigation.

In other parts of the world, rabies is more widespread. Transmission occurs through the penetrating bite of an animal infected with rabies or, on rare occasions, through direct contact between infected saliva and mucous membranes or wounds.

The recommendations for post-exposure prophylaxis are available in EPI-NEWS 37/10 where pre- as well as post-exposure prophylaxis is described.

Post-exposure prophylaxis

In 2015, a total of 188 persons were given prophylactic treatment against rabies after being bitten by animals suspected of having the condition, Table 1. Only 2 of these persons had received pre-exposure vaccination.

Bat bites in Denmark were the reason why 16 persons received prophylactic treatment, including 1 child. For one person, the treatment was discontinued because the bat tested negative to rabies virus.

A total of 172 Danes were possibly exposed to rabies abroad: 111 in Asia (including 65 in Thailand, 15 in Indonesia and 12 in India), 24 in Turkey, 12 in Europe, 11 in Africa, 9 in South & Central America, 3 in MENA (the Middle East and North Africa) and 1 in Greenland. For one person, the country was not stated.

A total of 97 persons who had possibly been exposed to rabies abroad were treated with rabies immunoglobulin (RIG); for 66 persons treatment was not initiated until they had returned to Denmark, 30 of these had not seen a doctor abroad. Table 2 shows how many persons received RIG and the first vaccine, respectively, in Denmark and abroad.



Among the 65 persons who were possibly exposed to rabies in Thailand, 29 had been bitten by dogs, 28 by monkeys and 8 by cats.
Of the 65 persons, 58 initiated treatment in Thailand, whereas 7 persons only initiated treatment after returning to Denmark. Of the 58 who initiated treatment in Thailand, only 20 received both vaccination and RIG.

Among the 24 persons who were exposed to rabies in Turkey, 22 were also vaccinated in Turkey. Only 1 concurrently received RIG.

Dispensing of post-exposure prophylaxis

Prophylactic treatment after possible exposure is discussed with the Department of Infectious Disease Epidemiology, Statens Serum Institut, also outside normal working hours. If post-exposure prophylaxis is indicated, Statens Serum Institut may provide human rabies immunoglobulin (RIG) and vaccines urgently to GPs at the expense of the Region.

Outside normal working hours, RIG and vaccines can only be supplied urgently for hospitals, which themselves cover the costs, including transportation costs. RIG and vaccines for post-exposure treatment cannot be provided for vaccination clinics and the like.

Commentary

In case of bat bites in Denmark, the bat should be caught, if possible, and submitted for rabies testing at the National Veterinary Institute, Technical University of Denmark by agreement with the Regional Food Inspectorate. It is important to follow the occurrence of rabies in Danish bats.

The prevalence of rabies among bats in Denmark remains unknown as only a limited number of bats are tested. If a bat tests negative, the vaccination series is terminated.

Possible exposure to rabies abroad is the primary cause of post-exposure prophylaxis; this applied to 172 (91%) of all treated persons in 2015. In 2015, 2 of the exposed persons had received pre-exposure rabies vaccination and therefore only needed 2 post-exposure vaccinations.

When giving advice prior to foreign travel, it is important to mention the risk of rabies associated with contact to animals. Travellers should be advised to limit contact to animals and to see a physician without delay in case of a bite.

Recommendation of pre-exposure vaccination against rabies may be considered even in connection with short journeys to rabies-endemic countries. Such vaccination is particularly relevant if the nature of the journey will make it difficult to obtain medical treatment within few days. It is also important to inform travellers that in many parts of the world, RIG treatment is unavailable.

Patients who have received pre-exposure vaccination and who get bitten by an animal do not need RIG as they have already produced antibodies, but they should be given two vaccinations; one on Day 0 and the other on Day 3, EPI-NEWS 37/10.
(A.H. Christiansen, S. Cowan, Department of Infectious Disease Epidemiology)

Rabies in animals

Rabies is caused by lyssavirus. Two types exist: classic rabies virus and European Bat Lyssavirus (EBLV), also known as bat rabies. Classic rabies is endemic to most of Eastern Europe, whereas it has been eradicated in Western Europe. Nevertheless, illegal import of pets from Third-World countries to Europe continues to pose a problem; and cases of rabies are now and then reported in dogs and cats imported from North Africa to Southern Europe.

In 2015, a total of 16 animals from Denmark were tested for classic rabies and/or bat rabies, all of which tested negative, Table 3.



Classic rabies has not been observed in Denmark since 1982, while bat rabies, which is considered endemic, was detected for the first time in 1985. The latest case of bat rabies was detected in a bat in 2009.

Classic rabies virus is endemic to Greenland, where Arctic foxes frequently transmit the infection to other mammals. In 2015, classic rabies virus was detected in 2 polar foxes, Table 3.
(T. B. Rasmussen, Technical University of Denmark, Lindholm)

Link to previous issues of EPI-NEWS

10 February 2016