ABSTRACT
Abstract Contagious Ecthyma (CE) is a severe exanthematous dermatitis caused by the Orf virus (ORFV) that mainly affects domestic small ruminants such as sheep and goats. It is a worldwide-distributed occupational zoonosis, particularly infecting those in close contact with animals or animal products such as shepherds, farmers and veterinarians, among others. In the present work, we report the first human CE case confirmed in Argentina. A phylogenetic analysis based on four gene sequences of the isolated strain responsible for the disease showed that this isolate grouped with other ORFV sequences that caused reported CE cases in sheep from the same Argentine province. We also sequenced a sample from a Chilean human case reported in 2017, whose phylogenetic analysis showed that it groups together with other Argentine isolates from locations close to the border with Chile. Keywords: Contagious Ecthyma; Dermatitis; Human Orf; Zoonosis; Molecular characterization.
Resumen El ectima contagioso (EC) es una dermatitis exantemática grave causada por el virus Orf (ORFV), que afecta mayormente a pequeños rumiantes domésticos, como ovinos y caprinos. Es una zoonosis ocupacional con distribución mundial, infecta a humanos en estrecho contacto con animales o sus productos, como granjeros, esquiladores y veterinarios, entre otros. En este trabajo se informa el primer caso humano de EC confirmado en Argentina. Un análisis filogenético basado en cuatro genes de la cepa responsable de este caso mostró que el aislamiento agrupa con otras secuencias de ORFV que causaron casos en ovinos en la misma provincia argentina. También se secuenció una muestra del caso de ectima humano reportado en Chile en 2017 y el análisis filogenético mostró que dicho aislamiento forma un grupo con otros aislamientos argentinos de localidades cercanas a la frontera con Chile. Palabras clave: Ectima contagioso; Dermatitis; Orf en humanos; Zoonosis; Caracterización molecular.
ABSTRACT
Objective To identify risk factors for a human orf disease outbreak in a village in Chongqing city. Methods Standardized case-definition was set and a case-finding program was conducted among all the residents of the village. All the patients were interviewed using a standardized questionnaire and collected fluids in the skin rash for laboratory testing. A retrospective cohort investigation was conducted among all the village residents who introduced the black goats to analyze the risk of orf infection, in relation to the mode and frequency of contacts to the infected goats. Results We found 18 cases (including 16 suspected cases and 2 confirmed cases) among the members of 10 families that introduced the black goats. Village residents who had ever used their legs to grip the goats were nearly five times as likely to develop orf disease as those who did not (RR=4.98, 95％CI: 1.34-75.27). Village residents who had ever washed and wiped the goats were three times as likely to develop orf disease as those who had not (RR = 3.09,95％CI: 0.98-45.38). The frequency of contacts with the infected goats was associated with the risk of developing orf disease in a dose-response fashion (x2 test for trends: P= 0.006).Frequently wearing long trousers when dealing with the goats appeared as a protective factor (RR=0.30,95％CI: 0.15-0.78). Conclusion This outbreak was caused by the introduced black goats which carried and infected by the orf virus. Direct physical contact with infected goats but without wearing protective clothing were risk factors for the development of human orf disease.