For many people, summer is the prime time for barbecues
and swimming in lakes. Unfortunately, as a result of the popularity of these activities,
summer is also typically the peak time of the year for infection with a dangerous
strain of bacteria called E. coli O157:H7.
According to the Centers for Disease Control and Prevention,
every year about 73,000 people in the United States are infected with E. coli
O157:H7, leading to gastroenteritis, an acute inflammation of the lining of the
stomach and intestines. Every year, about 60 people die due to the infection.
"Most infections with E. coli O157:H7 cause severe
bloody diarrhea and abdominal cramps," says Jens Goebel, M.D., assistant
professor, Department of Pediatrics, Division of Pediatric Nephrology, University
of Kentucky College of Medicine.
Eating undercooked ground beef that was contaminated
during processing of the meat causes most infections. Infections can also be caused
by: drinking unpasteurized milk contaminated by bacteria from a cow's udder; eating
foods, such as alfalfa sprouts, that have been contaminated by fecal material
from infected cows; and swimming in or drinking natural water contaminated with
infected fecal matter. The bacteria can also be passed from person to person with
insufficient hand washing.
Antibiotics and antidiarrheal agents are not recommended
for treatment of illness caused by E. coli O157:H7.
"Illness from E. coli O157:H7 usually resolves
in five to 10 days, but in some cases hemolytic uremic syndrome, a very serious
kidney disease, develops," Goebel says.
"HUS is caused by a toxin released by E. coli
O157:H7," Goebel says. "The toxin is absorbed into the bloodstream from
the intestines and causes inflammation and blood clots in organs, particularly
the kidneys, leading to kidney failure and possibly damage to the heart, pancreas,
HUS frequently requires intensive care, sometimes including
blood transfusions and dialysis. Up to one-third of patients with acute HUS experience
incomplete recovery, leading to some degree of chronic renal insufficiency or,
less commonly, other long-term problems. Up to 5 percent of patients with HUS
"Currently, there is no treatment to prevent the
development of HUS in children with E. coli O157:H7 gastroenteritis," Goebel
says. "Also, recent research has shown that antibiotic therapy of E. coli
O157:H7-associated gastroenteritis likely increases the risk of HUS, so E. coli
O157:H7 infection should not be treated with antibiotics."
E. coli Safeguards
This summer, and throughout the year, keep in
mind these tips to prevent E. coli O157:H7 infection:
- Handle all ground beef carefully to prevent cross-contamination.
- Use within 48 hours of purchase.
- Store on the lowest refrigerator rack to prevent juices from dripping on
other foods, or freeze it.
- If frozen, defrost in the refrigerator or microwave, not on the countertop.
- Wash hands, surfaces, plates, and utensils after contact with raw ground
meat and before contact with other food.
- Do not eat undercooked (i.e., pink) ground beef.
- Wash all raw fruits and vegetables thoroughly.
- Wash hands thoroughly.
- Do not use or drink unpasteurized juices or unpasteurized milk and milk
- Avoid nonmunicipal, nonchlorinated water.
- Use appropriate precautions in pools for infants or toddlers in diapers
(i.e., waterproof swimwear).