A novel virus that spread through a California New World titi monkey colony in late 2009 has been shown to have also infected a human researcher and a household family member, in a documented example of an adenovirus “jumping” from one species to another and remaining contagious after the jump. Adenoviruses are known to cause a wide range of clinical illnesses in humans, from cold-like symptoms to diarrhea and pneumonia. Unlike influenza or coronaviruses, adenoviruses had previously not been known to spread from one species to another. Now adenoviruses can be added to the list of pathogens that have the ability to cross species.
The virus, which researchers have named titi monkey adenovirus (TMAdV), infected titi monkeys in the California National Primate Research Center (CNPRC) in 2009. At the time of the outbreak, a researcher caring for the sick monkeys also developed an upper respiratory infection with fever, as did two members of the researchers’ family who had no contact with the monkey colony. But which direction the virus spread – from monkeys to humans or vice versa – remains a mystery. The viral center is now conducting further studies in both humans and monkeys in Brazil and Africa to determine whether TMAdV is common in wild populations of monkeys, as well as whether it has crossed species in those settings to humans who live nearby.
Cross-Species Transmission of a Novel Adenovirus Associated with a Fulminant Pneumonia Outbreak in a New World Monkey Colony. (2011) PLoS Pathog 7(7): e1002155. doi:10.1371/journal.ppat.1002155
Adenoviruses are DNA viruses that naturally infect many vertebrates, including humans and monkeys, and cause a wide range of clinical illnesses in humans. Infection from individual strains has conventionally been thought to be species- specific. Here we applied the Virochip, a pan-viral microarray, to identify a novel adenovirus (TMAdV, titi monkey adenovirus) as the cause of a deadly outbreak in a closed colony of New World monkeys (titi monkeys; Callicebus cupreus) at
the California National Primate Research Center (CNPRC). Among 65 titi monkeys housed in a building, 23 (34%) developed upper respiratory symptoms that progressed to fulminant pneumonia and hepatitis, and 19 of 23 monkeys, or 83% of those infected, died or were humanely euthanized. Whole-genome sequencing of TMAdV revealed that this adenovirus is a new species and highly divergent, sharing ,57% pairwise nucleotide identity with other adenoviruses. Cultivation of TMAdV was successful in a human A549 lung adenocarcinoma cell line, but not in primary or established monkey kidney cells. At the onset of the outbreak, the researcher in closest contact with the monkeys developed an acute respiratory illness, with symptoms persisting for 4 weeks, and had a convalescent serum sample seropositive for TMAdV. A clinically ill family member, despite having no contact with the CNPRC, also tested positive, and screening of a set of 81 random adult blood donors from the Western United States detected TMAdV-specific neutralizing antibodies in 2 individuals (2/81, or 2.5%). These findings raise the possibility of zoonotic infection by TMAdV and human-to-human transmission of the virus in the population. Given the unusually high case fatality rate from the outbreak (83%), it is unlikely that titi monkeys are the native host species for TMAdV, and the natural reservoir of the virus is still unknown. The discovery of TMAdV, a novel adenovirus with the capacity to infect both monkeys and humans, suggests that adenoviruses should be monitored closely as potential causes of cross-species outbreaks.