Foodborne illnesses may lead to dehydration, hemolytic uremic syndrome (HUS), and other complications. Acute foodborne illnesses may also lead to chronicor long lastinghealth problems.
                
Dehydration
                
When someone does not drink enough fluids to replace those that are lost through vomiting and diarrhea, dehydration can result. When dehydrated, the body lacks enough fluid and electrolytesminerals in salts, including sodium, potassium, and chlorideto function properly. Infants, children, older adults, and people with weak immune systems have the greatest risk of becoming dehydrated.
                
Signs of dehydration are
                
- excessive thirst  - infrequent urination  - dark-colored urine  - lethargy, dizziness, or faintness
                
Signs of dehydration in infants and young children are
                
- dry mouth and tongue  - lack of tears when crying  - no wet diapers for 3 hours or more  - high fever  - unusually cranky or drowsy behavior  - sunken eyes, cheeks, or soft spot in the skull
                
Also, when people are dehydrated, their skin does not flatten back to normal right away after being gently pinched and released.
                
Severe dehydration may require intravenous fluids and hospitalization. Untreated severe dehydration can cause serious health problems such as organ damage, shock, or comaa sleeplike state in which a person is not conscious.
                
HUS
                
Hemolytic uremic syndrome is a rare disease that mostly affects children younger than 10 years of age. HUS develops when E. coli bacteria lodged in the digestive tract make toxins that enter the bloodstream. The toxins start to destroy red blood cells, which help the blood to clot, and the lining of the blood vessels.
                
In the United States, E. coli O157:H7 infection is the most common cause of HUS, but infection with other strains of E. coli, other bacteria, and viruses may also cause HUS. A recent study found that about 6 percent of people with E. coli O157:H7 infections developed HUS. Children younger than age 5 have the highest risk, but females and people age 60 and older also have increased risk.3
                
Symptoms of E. coli O157:H7 infection include diarrhea, which may be bloody, and abdominal pain, often accompanied by nausea, vomiting, and fever. Up to a week after E. coli symptoms appear, symptoms of HUS may develop, including irritability, paleness, and decreased urination. HUS may lead to acute renal failure, which is a sudden and temporary loss of kidney function. HUS may also affect other organs and the central nervous system. Most people who develop HUS recover with treatment. Research shows that in the United States between 2000 and 2006, fewer than 5 percent of people who developed HUS died of the disorder. Older adults had the highest mortality rateabout one-third of people age 60 and older who developed HUS died.3
                
Studies have shown that some children who recover from HUS develop chronic complications, including kidney problems, high blood pressure, and diabetes.
                
Other Complications
                
Some foodborne illnesses lead to other serious complications. For example, C. botulinum and certain chemicals in fish and seafood can paralyze the muscles that control breathing. L. monocytogenes can cause spontaneous abortion or stillbirth in pregnant women.
                
Research suggests that acute foodborne illnesses may lead to chronic disorders, including
                
- reactive arthritis, a type of joint inflammation that usually affects the knees, ankles, or feet. Some people develop this disorder following foodborne illnesses caused by certain bacteria, including C. jejuni and Salmonella. Reactive arthritis usually lasts fewer than 6 months, but this condition may recur or become chronic arthritis.4  - irritable bowel syndrome (IBS), a disorder of unknown cause that is associated with abdominal pain, bloating, and diarrhea or constipation or both. Foodborne illnesses caused by bacteria increase the risk of developing IBS.5  - Guillain-Barr syndrome, a disorder characterized by muscle weakness or paralysis that begins in the lower body and progresses to the upper body. This syndrome may occur after foodborne illnesses caused by bacteria, most commonly C. jejuni. Most people recover in 6 to 12 months.6
                
A recent study found that adults who had recovered from E. coli O157:H7 infections had increased risks of high blood pressure, kidney problems, and cardiovascular disease.7