Shigellosis

Infectious diseases

Shigella picture



What is Shigella? Shigellosis is a diarrheal disease caused by a group of bacteria called Shigella. Shigella causes about 500,000 cases of diarrhea in the United States annually there are four different species of Shigella:

pathogenesis

number of bacteria

Toxicity

Invasiveness ( attachment, penetration,multiplication

immunity

The incubation period

Is 1-2 days (hours to 7 days)

Laboratory findings

1* Blood pictures WBC counts increased ,neutrophills increased
2* stool examination
1-gross stool: stool mixed with pus, mucous and blood
2-direct microscope :WBC, RBC, pus
3-bacteria culture PCR :DNA
3* sigmoidoscopy, shallow ulcer, scar, polyp

Complication of shigllosis

Post-infectious arthritis. About 2% of persons who are infected with Shigella flexneri later develop pains in their joints, irritation of the eyes, and painful urination. It can lead to chronic arthritis.
Blood stream infections. Although rare, blood stream infections are caused either by Shigella organisms or by other germs in the gut that get into the bloodstream when the lining of the intestines is damaged during shigellosis. Blood stream infections are most common among patients with weakened immune systems, such as those with HIV, cancer, or severe malnutrition .

Complication of shigllosis

• Seizures. Generalized seizures have been reported occasionally among young children with shigellosis, and usually resolve without treatment. Children who experience seizures while infected with Shigella typically have a high fever or abnormal blood electrolytes (salts), but it is not well understood why the seizures occur.

• Hemolytic-uremic syndrome or HUS. HUS occurs when bacteria enter the digestive system and produce a toxin that destroys red blood cells. Patients with HUS often have bloody diarrhea. HUS is only associated with Shiga-toxin producing Shigella, which is found most commonly in Shigella dysenteriae .

treatment

In 2013, CDC declared antibiotic-resistant Shigella an urgent threat in the United States .
Resistance to traditional first-line antibiotics like ampicillin and trimethoprim-sulfamethoxazole is common among Shigellaglobally, and resistance to some other important antibiotics is increasing. While travelers to the developing world are at particular risk of acquiring antibiotic-resistant shigellosis,
outbreaks of shigellosis resistant to ciprofloxacin or azithromycin—the two antibiotics most commonly used to treat shigellosis—have been reported recently within the United States and other industrialized countries

Cont. with treatment

. About 27,000 Shigella infections in the United States every year are resistant to one or both of these antibiotics.
When pathogens are resistant to common antibiotic medications, patients may need to be treated with medications that may be less effective, but more toxic and expensive