Shigella 11/25/14

November 25th, 2014

Locally we have seen an increase in the number of cases of Shigella.  Unfortunately we cannot establish a pattern of either food or location.  Please consider this when evaluating patients presenting with diarrhea and be sure to check a stool culture if they are a food handler, daycare worker or healthcare worker (see below).

Agent:

Four species of Shigella: sonnei, flexneri, dysenteriae, and boydii.

 Transmission:

Unfortunately only a small inoculum (10 to 200 organisms) is necessary to cause infection. As a result, spread can easily occur by the fecal-oral route and occurs in areas where hygiene is poor. Epidemics may be foodborne or waterborne. Shigella can also be transmitted by flies and sexual contact.

 Symptoms:

The incubation period ranges from one to seven days, with an average of three days. The disease typically begins with constitutional symptoms such as fever, anorexia, and malaise. Initially diarrhea is watery, but subsequently may contain blood and mucus. Tenesmus is a common complaint.

  • Abdominal pain – 70 to 93 percent
  • Fever – 30 to 40 percent
  • Mucoid diarrhea – 70 to 85 percent
  • Bloody diarrhea – 35 to 55 percent
  • Watery diarrhea – 30 to 40 percent
  • Vomiting – 35 percent

Diagnosis:  Stool culture (please check if patient is a food handler, daycare or healthcare worker)

Control Measures: (Per Indiana code) An investigation by the local health officer shall be performed immediately, include a five (5) day food consumption history, and determine if the case is part of an outbreak and if the case is a:

(A) food handler; (B) daycare worker;

(C) health care worker; or

(D) daycare, school, or other institution attendee.

Cases employed as food handlers, daycare workers, health care workers, or similar positions shall be excluded from employment involving food handling and direct care of children or hospitalized or institutionalized patients until all of the following have occurred:

(i) The case is asymptomatic for at least twenty-four (24) hours.

(ii) Two (2) successive negative stool specimens have been collected not less than twenty-four (24) hours apart and not sooner than forty-eight (48) hours after completion of antimicrobial therapy.

Cases shall be excluded from attending preschools and daycare facilities until all of the following have occurred:

(i) The case is asymptomatic for at least twenty-four (24) hours.

(ii) Completion of effective antimicrobial therapy supported by antimicrobial susceptibility testing or two (2) successive negative stool specimens collected not less than twenty-four (24) hours apart and not sooner than forty-eight (48) hours after cessation of antimicrobial therapy.

Cases shall be excluded from attending school until all of the following have occurred:

(i) The case is asymptomatic for at least twenty-four (24) hours.

(ii) The initiation of effective antimicrobial therapy for at least forty-eight (48) hours supported by antimicrobial susceptibility testing or two (2) successive negative stool specimens collected not less than twenty-four (24) hours apart and not sooner than forty-eight (48) hours after cessation of antimicrobial therapy.

 

Questions call Deb McMahan, MD,
Nikki Hartman, 449-4838