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Shigella Blog

Surveillance & Analysis on Shigella News & Outbreaks

Shigella in Iowa

Woodbury County Health officials are urging those sick with diarrhea to stay home from work and school to prevent the spread of shigellosis, an extremely contagious bacterial infection of the lining of the intestines.

Siouxland District Health Deputy Director Tyler Brock said 42 cases of the non-life-threatening illness transmitted through human contact have been reported recently in the county, and he only expects those numbers to grow. Last year Woodbury County recorded a single case of shigellosis.

Brock said only about 20 of the cases were diagnosed; the others, he said, were identified during phone interviews with family members suffering similar symptoms. Patients include school and daycare-age children, as well as adults. None of the patients have been hospitalized as a result of the illness.

North Carolina Seeing Shigella Uptick

The Cabarrus Health Alliance is continuing to investigate Shigella-related illnesses and officials are urging everyone to be aware of the symptoms and use precautionary measures.

As of Friday, October 25: 47 people have reported symptoms and 14 of those are confirmed Shigellosis. The non-confirmed cases have symptoms but lack a lab test with a positive or negative diagnosis.

The onset of Shigella began at Bethel Elementary and has spread to CC Griffin Middle School. While all 47 people are not students or staff at those schools, they do link back to the schools in some way.

Florida Health Officials Warn of Shigella Increase

Health officials at the Florida Department of Health in Broward County are advising parents, schools and daycare centers to take precautionary action to prevent the spread of Shigellosis. Shigellosis is a highly contagious form of diarrhea caused by Shigella bacteria. Shigella can spread through person to person contact and may cause severe diarrhea, fever and stomach cramps. Parents of children, or anyone with symptoms of Shigellosis should contact their healthcare provider for diagnosis and treatment. Careful attention to handwashing is the single most important measure to decrease transmission of Shigella bacteria. Symptoms may last from 48 to 72 hours, and frequently include diarrhea (may be watery or bloody), fever, and stomach cramps. School aged children and children in daycare should be excluded from school until symptoms have ceased and laboratory cultures test negative for Shigella.

Yellowstone sees increase in Shigella

Yellowstone County health officials warned Wednesday that the county has recently seen a noticeable increase in shigella infections.

Shigella is a bacteria found in the stool of infected people and is passed on via a fecal-oral route or by eating or drinking contaminated food or beverages, a news release from RiverStone Health, the county’s public health agency, said.

As of Wednesday, five cases had been confirmed and two more were pending. Typically, Yellowstone County sees only one or two cases annually.

“Five reported cases of shigella infection may not seem large, but we estimate that for every reported case, the actual number of cases could be 20 times greater,” said John Felton, RiverStone’s president and CEO and Yellowstone County’s health officer.

Eight more cases have been confirmed around the state by the Montana Department of Public Health and Human Services. Montana usually sees about 11 cases a year.

Symptoms can include bloody diarrhea, fever and stomach cramps and can appear 12 to 96 hours after infection, RiverStone said.

Shigella Bacteria Linked to Spring Lake Beach

A bacteria spread through contact with contaminated water is to blame for an illness that sickened 92 people at a July 4 event, state health officials said Tuesday.

Lab tests determined the culprit to be the shigella bacteria, which can cause gastrointestinal distress. Sixteen of those sickened at Spring Lake Beach in Burrillville were hospitalized and four remained in the hospital on Tuesday, but none of the illnesses was believed to be severe.

State Health Director Michael Fine said anyone who swam in the lake Thursday should seek medical attention if they develop gastrointestinal symptoms but that the illness often resolves on its own.

“We expect to see new cases over the next week — but not lots of new cases,” he said. “We know that no one is severely ill.”

The beach is expected to be reopened Wednesday. Tests of the water show no continuing shigella contamination.

Officials believe the illness was spread through contact with water contaminated with human feces. Most of those sickened are under 18, and Fine said the young are especially vulnerable. An estimated 2,000 people were in the lake on July 4.

CDC Reports California Shigella Outbreak is Antibiotic Resistant

The CDC in MMWR, reports that in May 2012, the Los Angeles County Department of Public Health’s Acute Communicable Disease Control Unit and Environmental Health, Food, and Milk Program investigated an outbreak of shigellosis associated with a private bridge club. This investigation documented the first known transmission of Shigella sonnei with decreased susceptibility to azithromycin in the United States.

Cases were defined as an illness clinically compatible with shigellosis in a patient or S. sonnei isolated from stool of a person with an epidemiologic link to the bridge club during May 22–26, 2012. Investigators attempted to interview all bridge club workers and members who had visited the bridge club during the week of May 22; they collected stool specimens from workers who handled food and from workers and members with diarrhea who had not already submitted a stool specimen for culture at a health facility. Thirty-nine cases were identified among club members with diarrhea and four among club workers; of the four workers, two, including one who handled food, reported no symptoms. The average age of affected persons was 75.3 years (range: 54–98 years); 55% were female. Among those with symptoms, the duration of illness averaged 5.9 days (range: 1–14 days). Common symptoms included diarrhea in 95% of patients, abdominal cramps in 70%, and fever in 56%. Thirty-one (72%) persons sought medical care, and 10 (23%) were hospitalized. No specific exposures implicated a source for the outbreak.

Among the 43 cases, 14 were culture-confirmed; 10 isolates underwent pulsed-field gel electrophoresis (PFGE), yielding indistinguishable patterns. Four isolates submitted to CDC’s National Antimicrobial Resistance Monitoring System (NARMS) displayed resistance to streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole. Unlike most Shigella isolates tested by NARMS, these isolates also showed elevated azithromycin minimum inhibitory concentrations (MICs) of >16 µg/mL and harbored a plasmid-encoded macrolide resistance gene, mphA.

CDC’s PulseNet identified two additional isolates indistinguishable from the outbreak PFGE pattern. One was from a man in Pennsylvania aged 23 years who had visited Los Angeles in April, and the other from a man in Hawaii aged 53 years who visited Los Angeles during April and May; both men were hospitalized with diarrhea. Neither case was epidemiologically linked to the bridge club or to each other.

Although sporadic cases of shigellosis caused by Shigella strains with increased azithromycin MICs have occurred, this is the first outbreak documented in the United States and might indicate increasing circulation of such strains. Illnesses in this outbreak tended to be severe; however, the affected population was much older than the general U.S. population. Clinical management of such illnesses is likely to be complex; although azithromycin currently is recommended for treatment of infections caused by multidrug-resistant Shigella, options for alternative treatment among children with such infections primarily include parenteral antimicrobial medications.

NIH-funded researchers begin trial of Shigella vaccine candidates – Aim to thwart a principal cause of diarrheal disease worldwide

Researchers have launched an early-stage human clinical trial of two related candidate vaccines to prevent infection with Shigella, bacteria that are a significant cause of diarrheal illness, particularly among children. The Phase I clinical trial, funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, will evaluate the vaccines for safety and their ability to induce immune responses among 90 healthy adults ages 18 to 45 years. The trial is being conducted at the Cincinnati Children’s Hospital Medical Center, one of the eight NIAID-funded Vaccine and Treatment Evaluation Units in the United States.

Shigella infection, called shigellosis, is an intestinal disease spread via contact with infected feces, by consumption of contaminated food or water or by contact with a contaminated surface. Symptoms include diarrhea, abdominal pain, fever, nausea and vomiting. In healthy adults, the infection generally clears on its own in five to seven days, but if left untreated, can lead to hospitalization or death, especially among young children and adults with weakened immune systems.

According to the World Health Organization, shigellosis causes roughly 90 million cases of severe disease each year and 108,000 deaths, most of which occur in the developing world and affect children under 5 years of age. In the United States, 14,000 shigellosis cases are reported annually, with most cases occurring among children ages 1 to 4 years.

Antibiotics are the standard treatment for patients with shigellosis, but drug-resistant strains of the bacterium are becoming more common.

“It seems that Shigella bacteria know our immune system better than we do,” said William Alexander, Ph.D., a program officer in NIAID’s Enteric and Hepatic Diseases Branch, Division of Microbiology and Infectious Diseases. “They’ve become very good at evading the human immune response and causing significant illness, so developing vaccines and better treatments is critical.”

Led by principal investigator Robert W. Frenck, Jr., M.D., director of clinical medicine at Cincinnati Children’s, the new clinical trial will evaluate two related candidate vaccines, known as WRSs2 and WRSs3, which have been found to be safe and effective when tested in guinea pigs and nonhuman primates. Both target Shigella sonnei, one of the bacteria’s four subtypes and the cause of most shigellosis outbreaks in developed and newly industrialized countries. Though neither candidate vaccine has been tested in humans, a precursor to both, known as WRSs1, was found to be safe and generated an immune response in small human trials in the United States and Israel. This early work was supported by NIAID, the U.S. Department of Defense and the Walter Reed Army Institute of Research. All three versions of the vaccine were developed by researchers at the Walter Reed institute.

WRSs2 and WRSs3 are live, attenuated vaccines, which means that the bacteria they contain are weakened such that they do not cause illness but still can induce an immune response. The weakened versions of S. sonnei used in WRSs2 and WRSs3 cannot spread between human cells, limiting their ability to cause disease. They are designed to improve upon WRSs1 by reducing the mild diarrhea associated with that vaccine in some patients. In addition, WRSs3 is designed to reduce the fever that accompanied some WRSs1 vaccinations.

After undergoing informed consent, study participants will be split into 10 groups of eight participants each, with each group receiving an increasing dose of WRSs2 or WRSs3. The remaining 10 participants will receive placebo. All doses will be given orally and will be preceded with a sodium bicarbonate (baking soda) suspension to neutralize stomach acid, which prevents the bacteria in the vaccine from being killed too quickly. Immediately after vaccination, participants will be admitted to inpatient care. Eight days later, or sooner if serious shigellosis symptoms occur, participants will begin a course of antibiotics until they pass two consecutive stools that test negative for S. sonnei. During the hospital stay, which can last up to 13 days, participants will be closely monitored and receive physical exams several times daily. Once discharged, participants are expected to collect and supply a stool sample at follow-up physical exams on study days 14, 28 and 56.

Additional information about the clinical trial is available at http://www.ClinicalTrials.gov under the identifier NCT01336699.

NIAID conducts and supports research — at NIH, throughout the United States, and worldwide — to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website at http://www.niaid.nih.gov.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

Shigella in Texas

Abilene Texas has seen a rise in Shigella cases since August, officials with the Abilene-Taylor County Public Health District report. Young children have been affected especially heavily.

Eighty cases have been reported since the first week of August, compared with about six cases per year on average.

A previous major outbreak occurred in 2002, when more than 200 cases were reported. By contrast, no cases were reported during 2010. Actual numbers will be higher, since not everyone experiences symptoms goes to a health care provider.

“Shigellosis is an infection of the intestines that causes diarrhea,” the report reads. “It is usually a mild, self-resolving illness (meaning the body will fight off the infection without treatment), and most people recover completely within 4 to 7 days.

Shigella is highly contagious and often begins with a victim swallowing something contaminated by the feces of an infected person. This usually happens when the infected person fails to properly wash hands after a bowel movement, then touches the hands or food of another person. Even a person without symptoms can pass on the bacteria.

Prevention methods include:

  • Hand-washing after bathroom visits, diaper changes or handling of pets or soil. Hands should be washed for at least 20 seconds using running water and soap. Hand sanitizer may be used as a substitute.
  • Children should wash hands frequently, with young children doing so under adult supervision.
  • Washing hands after diaper changes is especially important if the child has diarrhea.

More Shigella in Ohio

Columbus health officials are investigating what they call an “unprecedented large number of Shigella illness” in the area.

Since the start of the outbreak, 771 cases have been diagnosed.

That’s the largest number of cases in any year in the last decade.

Shigella is a bacterium that causes an infection of the intestine called Shigellosis. It causes diarrhea which may be bloody, and can cause severe dehydration and hospitalization. Found in human feces, this bacterium can get on hands when using the toilet or changing diapers.

Wisconsin Shigella Outbreak

Dane County health officials are dealing with an outbreak of bacterial infection.

Eighteen cases of Shigellosis have been reported in the county since Sept. 20. That’s one fewer case than all of last year.

The bacterial infection is associated with consuming water or food contaminated with fecal matter. Most of the Dane County cases are in children and young adults. Only one person sickened has been older than 40.