The state epidemiologist said Wednesday that the discovery last week of avian influenza in Hilo wastewater samples is a “heads up” to poultry owners, but described ongoing wastewater testing — while important — as “a pretty blunt tool.”
“It can’t tell us exactly how avian flu got introduced, whether it is circulating actively in birds or other animals, or whether it might have infected any people,” said Dr. Sarah Kemble. “Knowing that H5N1 avian flu has been detected in wild birds on Oahu, the leading theory as to how it would most likely be introduced to the Big Island is still migratory wild birds, which we know can travel easily between the islands in our archipelago.”
The DOH has increased pre-treatment testing of wastewater at the county’s Hilo treatment facility to twice a week, according to Mayor Kimo Alameda.
“We want to assure our residents that we are working closely with the Department of Health and will provide updates as soon as they are available,” Alameda said.
The importance of testing, according to Kemble, is “an early warning indicator” to poultry owners “to take precautions to protect their flocks.”
Hawaii is the last among the 50 U.S. states to discover the presence of highly pathogenic avian influenza, or HPAI.
“We will continue to monitor wastewater testing results to see if we detect H5 persistently at the Hilo wastewater treatment plant location,” Kemble said. “Whether or not we find it on repeat testing, the best thing for the Department of Health and animal health focused state agencies to do is to continue to monitor for any new and unusual signs of disease.
“Front and center in this right now is animal health, because from what we know about the H5N1 strains we’ve seen worldwide in the past couple of years, certain birds and animals are far more likely to be infected, and to get very sick, than people. Spread of avian flu to humans is also a concern, but thankfully so far, we haven’t seen a lot of this spread happening.”
Detection of an H5N1 strain in two commercial poultry farms in Adair County, Nebraska, since Nov. 30 has led to more than 100,000 chickens being euthanized as a precautionary measure.
The U.S. Centers for Disease Control and Prevention said poultry and dairy farm workers have a higher risk of contracting the virus because of potential exposure to infected livestock, but it is rare that humans contract bird flu. And there have been no documented cases of human-to-human transmission of the virus in the U.S.
“In Hawaii, DOH tested over 30 people who had close, sometimes prolonged unprotected contact with birds that had confirmed H5N1 infection – the type of contact that we would consider to pose a very high risk for those people to become infected with the virus,” Kemble said. “None of those people tested positive for avian flu.
“Based on those results, I would say the strain of avian flu we detected here does not appear to be one that passes easily to or among people. That being said, the flu virus always has the potential to mutate and become more likely to infect people. That is why it is still important to take precautions to avoid unprotected contact with sick birds.”
A child in California reportedly contracted bird flu recently after drinking raw milk, according to health authorities there.
“First, I want to make clear that H5N1 has not been detected or suspected in any dairy cows in the state of Hawaii,” Kemble noted. “… Commercial poultry producers and residents with backyard flocks are strongly advised to increase biosecurity measures to reduce the likelihood of infection. HPAI can also infect dairy cows. While pasteurized milk is safe, raw milk should be avoided.”
According to CDC, there’s also no risk from consuming chicken or eggs, as long as both are cooked to an internal temperature of 165 Fahrenheit or higher.
“From a DOH standpoint, we will continue our multi-layered surveillance efforts to look for any evidence of spread of avian flu to humans in our state,” Kemble said. “Monitoring for avian flu in humans in Hawaii includes required reporting by providers of all influenza test results, and routine subtyping of a portion of specimens from patients who test positive for flu, to make sure we aren’t seeing any novel flu strains emerge.
“We also track overall human flu trends, such as test positivity for all clinical testing performed in the state, and the proportion of (emergency room) visits and hospital admissions that are attributable to flu.”
To report multiple or unusual illnesses in poultry, livestock, or other wild birds or animals, contact the state Department of Agriculture Animal Industry Division at (808) 483-7102, Monday to Friday from 7:45 a.m. to 4:30 p.m., or (808) 837-8092 during non-business hours and holidays.
“We ask the public to help with monitoring and report multiple or unusual illnesses in birds, livestock or other animals to the Hawaii Department of Agriculture,” said Alameda.
Residents who think they may have been exposed to sick birds or other wildlife should contact the Disease Outbreak Control Division Disease Reporting Line at (808) 586-4586 for additional guidance.
Email John Burnett at jburnett@hawaiitribune-herald.com.
