About 20 homeless men considered at risk for hepatitis A trickled in to a circular arrangement of tables set up recently at the Salvation Army Center of Hope in Baton Rouge.

They were processed in assembly line fashion at the shelter off Airline Highway, moving through intake, medical screening, injection and observation. 

Each table was a step toward vaccination against a hepatitis A outbreak in Baton Rouge, New Orleans and other parts of the state that Louisiana public health workers have been struggling to keep from spreading.

Hepatitis A normally can lead to fever, fatigue, vomiting, abdominal pain, joint pain and jaundice. In more severe cases, renal disease, arthritis and anemia are possible. Though rarely causing death, populations with already compromised health can see more severe outcomes that can be fatal, federal health officials say.

Some men at the homeless shelter winced as one of two nurses slid a needle into their upper left arms. Other men stared off impassively as a nurse made quick work of their arms, a chance to sit during a hard scrabble period in their lives. 

Darren Longeuay, 48, formerly of Violet, took his turn through the line with a smile, a joke and some upbeat chitchat.

Longeuay, a former brick mason who describes himself as an optimist, has had some bad breaks in recent years. He lost his mother and other close family in and his career ended after his right leg had to be amputated due to a blood clot. 

He had recently left his home in St. Bernard Parish due to marital difficulties and has been at the shelter in Baton Rouge about two weeks preparing for a trip back to his native Ontario, Canada, to restart his life.

Longeuay said he didn't know there was a hepatitis A outbreak, how it was contracted or that the shelter was doing the vaccinations until he walked in the dining hall one day recently. But was willing to take the discomfort of the shot. 

"They're not fun, but if it's going to protect me from anything, I'm all for it," he said.

The department's Mobile Vaccination Strike Team visited Center of Hope recently in one of several efforts aimed at vaccinating people in what public health workers say are the most at risk populations for the potent, viral illness.

Before the Wednesday visit to the Salvation Army, the state strike team had vaccinated 392 people since Aug. 29, said Rubby  Douglas, the state department's public health emergency response coordinator.

In addition to other homeless shelters in Baton Rouge, the state team has vaccinated men in the East Baton Rouge Parish jail. The state department also has been working with the New Orleans Health Department to vaccinate at risk populations there since July, state health officials said.

Louisiana has had 89 cases of hepatitis A between Jan. 1, 2018 and March 22, a small number compared with the overall population but a figure that represents a large increase over annual totals that had hovered between 5 to 14 annually in the previous 10 years.

All but three of the cases since the beginning of 2018 are tied to the outbreak that the state Department of Health declared on Dec. 18, state health statistics say.

The most dense clusters of Louisiana cases have been in rural Morehouse Parish near Bastrop and in Livingston Parish, state health data show, but parishes encompassing or near Baton Rouge, New Orleans, Lafayette, Monroe and Shreveport also have had cases. 

Dr. Joseph Kanter, assistant state health officer for the state Health Department, said two-thirds of the cases in the current Louisiana outbreak have led to hospitalization, a high rate. Unlike those with hepatitis C who can face long-term liver damage, most patients with hepatitis A eventually recover.

In past years, some outbreaks have been linked to food.

In August 2016, an outbreak in Hawaii was tied to raw scallops in a restaurant chain. Another outbreak in the same month in several states were linked to frozen strawberries imported from Egypt and used by a chain smoothie business, the CDC says.

Kanter said hepatitis A isn't specifically a food-borne illness but lives in people and is transmitted through person-to-person contact. One way it can be contracted is when someone ingests food contaminated with the fecal material of a person who is infected with hepatitis A.

Sometimes infected restaurant workers can transmit the virus through food, Kanter said, but all the cases in Louisiana since January 2018, have been person to person or contracted it traveling abroad.

In all, 18 states have hepatitis A outbreaks, including next-door Arkansas where 303 cases have been reported since February 2018, according to Arkansas health officials and the U.S. Centers for Disease Control and Prevention.

The most recent national outbreak has been found most often in the homeless or intravenous drug users. Between January 2017 and April 2018, more than two-thirds of the 1,900 reported cases where risk factors were known were among people who were homeless, used drugs or both, a CDC health alert says.

The virus has an average incubation period of 28 days before symptoms show.

"And the challenge from a public health point view is a lot of people are in the beginning points of that phase — where they're sick and don't know why — and spreading Hep A before it gets diagnosed," Kanter said. 

That aspect of hepatitis A has led to proactive efforts to vaccinate the most high risk populations, like in Baton Rouge and through the city of New Orleans. 

So far, 550 people have been vaccinated, a city spokesperson said, including homeless people living in shelters or on the streets, injection drug users and previously incarcerated individuals.

"We encourage all New Orleanians to get the vaccine or check to see if they are already vaccinated," Dr. Jennifer Avegno, director of the City’s Health Department, said in a statement.

Follow David J. Mitchell on Twitter, @NewsieDave.