VIRAL SURVEILLANCE DISCUSSION
During the most recent week with data, animal viral signals in Columbia wastewater showed a complex pattern. Several key livestock and companion animal viruses remained well below their long-term and seasonal averages, with some undetectable. However, a few viruses—most notably avian and swine pathogens—were detected at levels higher than recent weeks, and in some cases, substantially above historical baselines. Several pathogens were not detected at all, suggesting either a true absence or levels near the assay’s detection limit. The overall pattern suggests a mixed risk landscape for animal health, with some notable increases in certain avian and swine viruses.
DETAILED PATHOGEN DISCUSSION
Parvovirus aveparvovirus (bird)
Parvovirus aveparvovirus was detected at a markedly elevated level in the latest week with data, far exceeding both its long-term and seasonal averages, as well as the previous 4-week average. This virus primarily affects poultry, causing enteric and systemic disease, with transmission typically via fecal-oral routes and contaminated environments. Clinical signs in birds can include diarrhea, stunted growth, and increased mortality in young flocks. There are no widely available commercial vaccines for this virus, so biosecurity and sanitation remain the primary countermeasures. The current elevated signal may reflect increased shedding from local avian populations or agricultural runoff.
Enterovirus G (pig)
Enterovirus G was present at a moderate level in the latest week with data, below its long-term and seasonal averages but higher than the previous 4-week average. This virus is common in swine, often transmitted via the fecal-oral route, and can cause mild to moderate enteric disease, particularly in piglets. Outbreaks are usually managed through improved hygiene and supportive care, as no vaccines are currently licensed. The recent increase may warrant closer monitoring, especially in areas with dense pig populations.
Picornavirus sapelovirus A (pig)
Picornavirus sapelovirus A was detected at a moderate level, below long-term and seasonal averages but above the recent 4-week trend. This swine pathogen is transmitted primarily through fecal contamination and can cause a range of symptoms from subclinical infections to neurological disease and reproductive losses. No vaccines are available, so prevention relies on sanitation and limiting animal movement during outbreaks.
Astrovirus avian nephritis virus (bird)
Astrovirus avian nephritis virus was detected at a moderate level, slightly below historical averages but higher than the recent 4-week mean. This virus affects poultry, especially young chicks, causing nephritis, growth retardation, and increased mortality. Transmission is primarily fecal-oral. There are no commercial vaccines, so management focuses on hygiene and flock management.
Picornavirus teschovirus (pig)
Picornavirus teschovirus was present at a low-to-moderate level, below long-term and seasonal averages but above the recent 4-week average. This virus can cause neurological disease in pigs, ranging from mild to severe. Transmission is fecal-oral, and there are no specific vaccines. Control relies on biosecurity and supportive care.
Coronavirus tegacovirus (cat, dog, and pig)
Coronavirus tegacovirus was detected at a low level compared to historical and seasonal averages, and lower than the recent 4-week mean. This group includes viruses affecting cats, dogs, and pigs, typically causing mild enteric or respiratory symptoms. Transmission is primarily via close contact and contaminated surfaces. Some vaccines exist for related coronaviruses in companion animals, but not for all strains in this group.
Picornavirus ampivirus (unknown)
Picornavirus ampivirus was detected at a low level, well below long-term and seasonal averages but above the recent 4-week average. The host range and clinical impact of this virus remain unclear, but picornaviruses are generally transmitted via fecal-oral routes.
Distrovirus cripavirus (insect)
Distrovirus cripavirus was detected at a moderate level, above its long-term and seasonal averages and higher than the recent 4-week mean. This virus is associated with insects and is not known to cause disease in vertebrates. Its presence may reflect seasonal insect activity.
Flavivirus XiangYun virus (insect)
Flavivirus XiangYun virus was detected at a low level, below long-term and seasonal averages and much lower than the recent 4-week mean. This insect-associated virus is not known to impact livestock or pets.
Picornavirus harg calici-like virus (insect)
Picornavirus harg calici-like virus was detected at a low level, near the assay’s limit of detection, and with low confidence. This insect-associated virus is not believed to affect vertebrates.
NOT DETECTED OR BELOW DETECTION LIMIT
Several animal viruses, including PRRSV (pig), Calicivirus salovirus (fish), Calicivirus vesivirus (cat and dog), Coronavirus avian coronaviruses (bird), Coronavirus Luchacovirus (rodent), Coronavirus pedacovirus (pig), Coronavirus HKU15 (pig), Picornavirus megrivirus (bird), Picornavirus kobuvirus cebes (pig), Picornavirus cardiovirus C (rodent), Influenza D (cow and pig), Flavivirus pestivirus scrofae (pig), Rat astrovirus (rodent), Hepevirus flumine hepe-like virus (unknown), and Parvovirus flumine parvovirus (unknown) were not detected in the latest week with data. For several of these, the 4-week average was also at or near zero, suggesting sustained low or absent circulation in the community or levels below the assay’s detection limit.
SUMMARY AND IMPLICATIONS
The most recent wastewater surveillance indicates elevated levels of some avian and swine viruses, particularly Parvovirus aveparvovirus in birds and moderate signals for several swine enteric viruses. Livestock and poultry producers should maintain heightened biosecurity and sanitation practices, especially in light of increased viral shedding. Poultry operations should monitor for clinical signs of enteric disease in young flocks. Swine producers are advised to reinforce hygiene and monitor for gastrointestinal or neurological symptoms in herds. Companion animal and wildlife-associated viruses remain at low or undetectable levels, suggesting minimal current risk in those populations. Continued surveillance and prompt reporting of animal illness will help manage potential outbreaks and protect animal health.