SPHENISCID ALPHAHERPESVIRUS 1 IN AFRICAN PENGUINS (SPHENISCUS DEMERSUS) WITHIN THE SPECIES SURVIVAL PLAN© MANAGED POPULATION IN THE US: INCIDENCE AND POPULATION IMPACT.

Abstract

Spheniscid alphaherpesvirus-1 (SpAHV-1) is associated with respiratory disease in juvenile African penguins (Spheniscus demersus). In 2020, this virus was detected in adult birds with clinical signs of respiratory disease in a previously asymptomatic colony of 21 birds following a recommended introduction of three new birds, including two with a history of herpesvirus as juveniles. Mild to moderate respiratory signs were noted in 33% (8/24) of the colony. SpAHV-1 DNA was detected in respiratory secreta by herpesvirus consensus PCR in three birds, although as the definitive source of the presentation, it could not be confirmed. Surveillance for SpAHV-1 was performed in all colony birds seven and 19 mo following resolution of respiratory disease signs. SpAHV-1 was detected via consensus herpesvirus PCR and sequencing in two apparently healthy individuals, including one which had clinical signs of respiratory disease and tested positive for SpAHV-1 during the original outbreak. Due to limited knowledge about this pathogen, a retrospective assessment regarding SpAHV-1 and respiratory disease was performed by analyzing survey data collected from 41 institutions holding African penguins in the Species Survival Plan^© (SSP) North American population from 2011-2021. From the 41 institutions that participated, 782 birds were evaluated and assessed, representing 70% of the total available population (n = 1,116). The majority (80%; 33/41) of participating institutions' veterinarians reported no knowledge of SpAHV-1 prior to this survey. Respiratory disease (e.g., sneezing, coughing, nasal discharge, oropharyngeal plaques, pulmonary auscultation changes) was reported in 21.2% of the surveyed cohort. Most clinical signs were resolved within 3-30 dy, with an average duration of illness of 13 dy. The odds of respiratory disease were significantly higher in males (p < 0.0001) and in non-transferred penguins as compared to those penguins transferred between institutions (p = 0.005). Only 5.6% of penguins (44/782) were tested for herpesviruses by PCR during the study period and of these birds, 18% (8/44) were positive for SpAHV-1. SpAHV-1 represents an important differential for respiratory disease in African penguins, but additional epidemiologic research is needed to determine the full impact of this pathogen.