Mar 27, 2005
Fifteen people in Florida who visited agricultural fairs recently have developed a life-threatening kidney disease or are infected with bacteria that can cause it, Florida health officials said yesterday.
Eleven of those affected are children, and petting zoos at the two fairs are suspected, but Florida’s secretary of health said it was “too early to point to one single element, such as a petting zoo.”
Epidemiologists are “trying to triangulate the 15 cases and see if they can be associated with a single point source,” the secretary, Dr. John O. Agwunobi, said.
Officials at various Florida hospitals told The Associated Press that they knew of nine children with hemolytic uremic syndrome who had visited petting zoos at the Central Florida Fair in Orlando or the Florida Strawberry Festival in Plant City. One Florida television reporter described the death of a child who had visited a petting zoo, but it was unclear if there was any connection.
The virulent bacteria strain, known as E. coli 0157:H7, lives in the guts of cattle, sheep, goats and other ruminants, and can be picked up by petting or nuzzling the animals, or simply touching one’s shoes after walking through manure.
The bacteria can cause bloody diarrhea and, in a small number of cases, can lead to the syndrome, in which the kidneys, overwhelmed by toxins, shut down. In rare cases, it can require dialysis or a kidney transplant. Three percent to 5 percent of cases are fatal.
There were about 73,000 infections nationally with the E. coli strain last year; of those, 61, or less than one-tenth of 1 percent, were fatal.
There have been previous outbreaks associated with petting zoos, notably one at the North Carolina State Fair last year, in which 180 people were reported sick and 15 developed hemolytic uremic syndrome. After an investigation, the North Carolina health department recommended that direct contact with animals be restricted, especially for young children.
Many petting zoos now have hand-washing stations or staff members who squirt liquid sanitizer on visitors’ hands. Those measures were used in North Carolina, but some children still became infected, the state health department said.
Children who sat or fell on the ground were five times more likely to have been infected.
The disease is most dangerous to children under 5 and the elderly, and can be transmitted in many settings, Dr. Agwunobi said, including pony rides, rodeos, livestock displays, milking demonstrations, hayrides and pig races.
Bloody diarrhea is the most common first sign, followed by lethargy and failure to produce normal amounts of urine.
The bacteria can also be picked up from undercooked meat, said Dr. John Dunn, a veterinarian with the Centers for Disease Control and Prevention. It does not grow in the animal’s muscles, but may be splashed on in slaughterhouses when the animal is butchered.
There has been little testing of petting zoos, Dr. Dunn said, but the bacteria have been known to spread through whole cattle herds when they are penned closely together in feedlots. Cattle are often treated by giving them “probiotics,” bacteria that compete with the E. coli strain and reduce it.
A more likely remedy for petting zoo operations, he said, would be to keep all infected animals away from children.
Many other dangerous bacteria are found on petting animals and poultry. Snakes, for example, often have salmonella on their skins, and animal feces may contain campylobacter, shigella, giardia and cryptosporidium.
Young animals and birds – often handed to children because they are cute – are the most likely to transmit infections, according to C.D.C. guidelines.