CNN
—
A third person in the United States has tested positive for H5 avian influenza linked to an outbreak in dairy cows, the Michigan Department of Health and Human Services said Thursday, the second case of the virus reported in the state and the fourth in the United States.
In addition to some of the eye symptoms seen in past H5N1 flu cases, farm workers reported coughing and other respiratory symptoms more typical of influenza infection in humans, health officials said.
“The individual presented with respiratory symptoms including cough, stuffy nose, sore throat and watery eyes,” Dr. Nirav Shah, principal deputy director of the US Centers for Disease Control and Prevention, said at a briefing on Thursday.
“What the respiratory symptoms tell us more than anything is that this virus, like many others, can manifest in multiple ways, so we need to remain vigilant and not fearful,” he added.
Experts say the addition of respiratory symptoms doesn’t necessarily make the virus more dangerous or easier to spread from person to person. Instead, they say, it’s more likely that the pulmonary symptoms were caused by a different route of infection — perhaps by inhaling infectious aerosols at the dairy instead of rubbing their eyes with contaminated hands.
“In Michigan’s first case, the individual developed eye symptoms after coming into direct contact with infected milk. In this case, the individual developed respiratory symptoms after direct contact with infected cows,” Dr. Natasha Bagdasarian, Michigan’s chief medical officer, said in a news release. “Neither individual was wearing full personal protective equipment (PPE), which indicates there is a risk to humans when in direct contact with infected livestock and that PPE is an important tool to prevent the spread of infection among people who work on dairy and poultry farms. There are no signs of sustained human-to-human transmission and the current health risk to the general public remains low.”
About 220 people in Michigan are being monitored for possible exposure to the virus, Shah said.
Michigan Highest number Dairy farms that manage herds with reported infections have also begun blood testing to determine how many workers have antibodies to the H5N1 virus, which would reflect past infection or exposure.
The CDC agreed that the risk to the general public remains low, but the case highlights the increased risk to people who handle infected animals.
CDC (Centers for Disease Control and Prevention) Recommended Dairy workers are required to wear personal protective equipment to reduce their risk, and the USDA is offering financial assistance to farms with infected animals to provide protective equipment for workers.
“Previously, we’ve focused on the importance of eye protection because of the conjunctivitis seen in the first two cases, but this case also highlights the importance of barrier protection such as masks and other protective measures, especially for dairy workers handling infected cows,” Shah said.
Research is ongoing into how the infection spreads between cows and from cows to people who handle them.
This is the third known human case of infection with the highly pathogenic avian influenza strain currently affecting dairy cows in the United States. All three had no contact with each other, but all worked with cattle, suggesting possible cases of cow-to-human transmission. The other two cases were eye infections, or conjunctivitis. The most recent employee had mild eye symptoms but was not diagnosed with conjunctivitis.
The individual had direct contact with the infected cows and reported feeling unwell to local health authorities, with symptoms described as mild.
The patient was given the antiviral drug oseltamivir, the same active ingredient in Tamiflu, and is in isolation at home. No other family members are showing symptoms but have been prescribed the antiviral drug as a precaution. No other employees at the dairy are sick and are being monitored, according to the CDC.
“Given the amount of contact between humans and dairy cows and with contaminated milking equipment, it’s not surprising that we’re seeing an increase in human infections,” said Dr. Seema Lakdawala, an infectious disease specialist at Emory University who has studied how the virus spreads in dairy barns.
“Every time the virus is able to replicate in the human body, it adapts to humans and acquires molecular characteristics that allow it to replicate in the respiratory system and potentially transmit from person to person,” Lakdawala said.
Influenza viruses are classified by two proteins found in their outer coat: the H (hemagglutinin) protein and the N (neuraminidase) protein. CDC testing confirmed that the third individual is carrying an influenza virus with an H5 protein, and the agency will be conducting further sequencing to determine if the N portion of the virus is N1 as suspected. Results are expected within the next few days.
The CDC confirmed Wednesday night that the person had H5 influenza and sent the results to the Michigan Department of Health and Human Services.
Get CNN Health’s weekly newsletter
The U.S. Department of Health and Human Services announced last week that it was moving forward with plans to repackage 4.8 million doses of the H5N1 vaccine held in bulk in the Strategic National Stockpile into multi-dose vials that will make them easier to distribute and administer.
Officials said Thursday that there are certain regulatory steps that must be followed before anyone can get the vaccine, and that there are no plans at this time to offer or recommend the vaccine to any specific groups.
The fill and finish process to repackage the vaccine will take at least two months, officials said at a news conference.
Meanwhile, the Michigan Department of Health is recommending that people who work on poultry and dairy farms get vaccinated against the seasonal flu.
“Although it cannot prevent infection with the avian influenza virus, it can reduce the risk of co-infection with the avian influenza virus,” the ministry said.
