Rabies postexposure prophylaxis, Marseille, France, 1994-2005

Emerging Infectious Diseases, Sept, 2008 by Philippe Gautret, Georges Soula, Hamadou Adamou, Marie-Jose Soavi, Jean Delmont, Yolande Rotivel, Philippe Parola, Philippe Brouqui

The administration of human rabies postexposure prophylaxis near Marseille (southern France) has changed since the eradication of terrestrial mammal rabies in 2001. Most injuries were associated with indigenous dogs; rabies vaccine was overprescribed. We suggest that the World Health Organization guidelines be adapted for countries free of terrestrial mammal rabies.

**********

The last case of human rabies acquired in France was reported in 1924, and rabies was officially declared eliminated in terrestrial mammals in 2001 (1). However, confirmed rabid dogs from North Africa have been imported into France (2,3), and indigenous bats have been regularly found to be infected by rabies-related viruses (4). Marseille is the main international seaport in southern France; it handles heavy daily maritime traffic from North Africa, where numerous human cases are reported in relation with rabid dog bites. Management of patients exposed to these potentially rabid animals poses specific problems, and the decision to prescribe rabies vaccine and/or rabies immunoglobulin depends on the origin of the animal, as it does in the United Kingdom (5).

The Study

From 1994 through 2005, epidemiologic data on animal-related injuries and associated postexposure prophylaxis (PEP) treatment were prospectively collected for Marseille Rabies Treatment Centre patients. Only patients who had been injured in France were selected; rabies PEP for travelers who were injured abroad is detailed elsewhere (6). Of the 4,965 eligible patients, 4,367 were outpatients or inpatients (192-488/year), and from 2001 through 2005, a total of 598 were managed by teleconsultation only because their exposure risk was considered to be zero.

The number of inpatients and outpatients decreased markedly from 1999 to 2001 (Figure 1), which is consistent with the general decrease in the number of PEP treatments in France after the elimination of terrestrial mammal rabies (7). Furthermore, prescreening of persons by telephone also contributed to this decrease. The increase observed during 2004-2005 is likely an effect of the international alert in relation to the cases of rabid dogs imported from Morocco; these cases were intensively reported by the French media. The proportion of animal-related injuries tended to increase in late spring/early summer (Figure 2), probably as a result of increased outdoor activities in southern France, which makes contact with animals more likely.

The overall annual incidence of injured patients seeking care for rabies PEP was 16/100,000, which is consistent with incidence recently reported in United States (8, 9) (where rabies is enzootic in bats and raccoons) but far less than that reported in recently available studies from the canine rabies-endemic countries of Turkey (467/100,000) (10) and India (1,700/100,000) (11). The overall mean annual incidence in our study was 20/100,000 before 2001 and 11/100,000 after 2001.

Dogs accounted for 81.2% of all injuries. By contrast, a recent study on pet demographics in France indicated that dog and cat populations are nearly similar at 8.51 million and 9.94 million, respectively (12). This finding suggests that dogs, more often than cats, are responsible for severe injuries that lead persons to seek care for rabies PEP. The mean annual incidence of animal-related injuries was lower in rural than in urban communities (online Technical Appendix, available from www.cdc.gov/EID/ content/14/9/1452-Techapp.pdf). Because an estimation of the dog population in France indicated that 41% live in urban areas (12), our results suggest that a high human population density increases the probability of human--dog interactions and risk for injuries.

[FIGURE 1 OMITTED]

[FIGURE 2 OMITTED]

Among patients seeking care for rabies PEP, most were male (male:female ratio 1.49) and mean age was 31.5 (median 29, range 0-96) years. Patients <15 years of age represented 26% of the cohort. The likelihood for animal-related injuries among male patients was also dependant on the animal species involved; dogs, bats, and monkeys accounted for most injuries (online Technical Appendix). In contrast, female patients were more likely to be injured by cats, a finding consistent with previous reports (13).

The mean time between injury and consultation was 2.6 days (range 0-365 days) and did not statistically vary by sex or age group. Time was longer in patients who were injured by bats (p<[10.sup.-6], online Technical Appendix), probably because most bat bites are nonpainful and considered benign by patients who ignore the risk for rabies after bat contact.

Most injured persons experienced severe contact with animals (95.1%), categorized by the World Health Organization (WHO) as category III (14). Most injuries were on the limbs (online Technical Appendix).

Animals were available for observation by a veterinarian in 1,441 cases (33%). Rabies testing of animal is not available in southern France, and animals from this region should be sent to the Rabies Laboratory at the Pasteur Institute in Paris, which was done for 89 cases, of which 20 cases were related to a confirmed rabid source from Africa or the Middle East (Table 1).