Naturally, the symptoms you experience from an E. coli infection depend on what kind of infection occurs — and where in the body the infection is concentrated. (1) Here are the most common E. coli infections and their associated symptoms:
Intestinal E. Coli Infection Symptoms
There are numerous types of E. coli bacteria that can cause food poisoning. While each brings about similar symptoms, there are slight variations. Enterotoxigenic E. coli This uses hair-like appendages to attach to the intestine and attacks the body with toxins. These bacteria are often the cause of traveler’s diarrhea. Fever can occur with this E. coli infection, though it is not common. (2) Enteroinvasive E. coli This is a type that invades the cells lining the colon and results in diarrhea with fever, according to a paper published in the journal Frontiers in Microbiology. (3) Enteropathogenic E. coli This attaches to intestinal cells using a special protein. It’s a common culprit of infantile diarrhea in developing countries. This particular type of E. coli infection causes watery and sometimes bloody diarrhea, according to research. (4) Enteroaggregative E. coli This type lumps onto the cells lining the intestines. Then the toxin causes prolonged diarrhea, particularly in children, research has noted. (5) Shiga Toxin–Producing E. coli (STEC) STEC is the type most commonly heard about on the news because of the outbreaks it causes. An intestinal infection by STEC — which typically lives in cattle and migrates to humans after animal feces contaminate human food — results in:
NauseaSevere stomach crampsDiarrhea, which can be severe and bloodyFatigueVomiting (rare)Low-grade fever (rare)
While some fall seriously ill with a STEC infection, most people generally recover from this type of E. coli infection after about a week. (1) Those who are most likely to be impacted include children under age 5, the elderly, and those with compromised or weakened immune systems. (6) People who take antibiotics to treat an E. coli infection are also at an increased risk for developing HUS, according to a report published in the journal Toxins. (7) Usually, HUS emerges about seven days after E. coli symptoms first appear — and once diarrhea starts to subside. (6) Symptoms may include:
Bloody diarrheaAbdominal painDecreased urination or blood in urineVomitingFatigue and irritabilityFever (occasionally)PallorSmall, unexplained bruisingConfusion or seizuresIncreased blood pressureSwelling (face, hands, feet, body) (8)
It’s very important to immediately visit a healthcare professional if the affected individual doesn’t urinate for 12 hours or more, experiences bloody diarrhea, or has several days of nonbloody diarrhea followed by:
Decreased urine outputUnexplained bruisingUnusual bleeding (8)
Symptoms of E. Coli Infections in the Urinary Tract
The E. coli bacteria is behind 65 to 75 percent of all urinary tract infections (UTIs), according to research published in the journal Nature Reviews Microbiology. (9) UTIs occur when E. coli, which typically resides in the colon, enters the urinary system through the urethra. This can happen through improper hygiene (wiping from back to front after a bowel movement) or via sexual contact. A woman’s urethra is located next to the vagina and anus, making for an easy pathway for E. coli to enter the urinary tract. (10) With a urinary tract infection, you will likely experience at least one of the following signs:
Burning feeling during urinationIntense and persistent urges to urinatePassing frequent but small amounts of urineUnusual- or strong-smelling urineCloudy urineRed, bright pink, or cola-colored urine (these are an indication that blood is present in the urine)Fever or chillsPain in the lower back, hips, or flanksPelvic pain in women, rectal pain in men (10)
Symptoms of E. Coli Infections That Cause Neonatal Meningitis
It’s estimated that E. coli causes about 20 percent of all neonatal bacterial meningitis cases, but less than 2 percent of meningitis cases at all other ages. (11) Premature babies and those born at a low birth weight are at an increased risk of contracting this type of meningitis. An E. coli strain called K1 causes the vast majority of all E. coli–related neonatal meningitis cases, according to the Meningitis Research Foundation. (11) Newborns may become infected with E. coli K1 during birth, or from bacteria later acquired in the hospital or home. That said, bacterial meningitis is very rare in developed countries. A newborn with meningitis may experience one or more of the following symptoms:
Breathing troubleUnusually cold or warm skinJaundiceLethargySeizuresVomitingUnusual fussiness and irritability that does not subside when the baby is heldBulging soft spot at the top of the head (the fontanelle) (12)
Older children or adults with bacterial meningitis due to E. coli usually develop a stiff neck and have a headache as well. (12)
Symptoms of E. Coli Infections That Cause Sepsis
Beyond neonatal meningitis, E. coli (as well as listeria and certain strains of streptococcus) can also put newborns and babies at risk for sepsis, or blood poisoning. Infection of the blood is a common cause of neonatal sepsis, which occurs in babies less than 90 days old. The infection can be acquired from the mother before or during delivery (preterm delivery, early water breaking, and chorioamnionitis increase risk), or after delivery due to an extended hospital stay or extended catheter use. Signs and symptoms include:
Changes in body temperature and heart rateBreathing issuesDiarrhea or decreased bowel movementsLow blood sugarReduced movements and suckingSeizuresSwollen belly areaVomiting
Neonatal sepsis is a serious issue and a leading cause of infant death. The more quickly an infant gets diagnosed and treated with antibiotics, the better the outcome. (13)
Symptoms of E. Coli Infections That Cause Pneumonia
Streptococcus pneumoniae is the most common bacterial perpetrator of pneumonia, but E. coli can also sometimes cause the disease, according to the Centers for Disease Control and Prevention (CDC). (14) The most common symptoms of pneumonia include:
Chest pain when breathing or coughingCough with phlegmShortness of breathNausea, vomiting, or diarrheaFatigueFeverShaking chillsConfusion or changes in mental awareness (in those ages 65 and older)Lower than normal body temperature (in those ages 65 and older and in people with a weakened immune system) (15)
Additional reporting by Joseph Bennington-Castro.
