Shigellosis In The United States

Section: 309

ABSTRACT

Shigellosis is the cause of dysentery, and even though it has for the most part been isolated in developing countries around the world, it is beginning to spread throughout the Middle East, Asia and Latin America. Though research and study has gone on for decades there is to this day no known effective vaccine for this bacterial infection. Continuing research brings us closer to this point but as of right now we must continue to fight it with multiple types of antibiotics. Early detection is the key to successful recovery from this infection. If left unattended or treated it will lead to death in the person that has contracted it. It attacks the gastrointestinal area, destroys cells, it causes severe dehydration and
death among its victims.

PATHOGEN CHARACTERISTICS

Shigella spp., of the Enterobacteriaceae family, are gram-negative rod-shaped pathogenic bacteria. They are non-motile, non-encapsulated, and facultative anaerobes that do not ferment lactose, or do so slowly (Canada, 2010). These pathogens, once ingested, can survive the human body’s gastric acidity there for causing illness by infecting the mucosal lining of the colon. This bacterial infection can be anywhere from mild to no symptoms at all. Most people infected with shigellosis develop watery diarrhea, stomach cramps, vomiting and nausea. Further complications include Reiter’s Syndrome which has been associated with S. flexneri, severe dehydration, intestinal perforation, toxic mega colon, bacteremia, toxaemia, septicaemia, seizures, toxic encephalopathy with headache and alterations of consciousness, septic shock and convulsions (very rare), and haemolytic uremic syndrome, which have been liked to Shiga toxin (a potent cytotoxin produced by S. dysenteriae that can also cause other neurotoxic effects) (Canada, 2010). Though most infections are self-limiting, in patients that are elderly, very young or immunocompromised this infection can easily lead to death if not treated properly.

(Gen)

CLASSIFICATION
Genus: Shigella Species: dysenteriae Family: Enterobacteriaceae SubGroup: 1 (3)

ETIOLOGY

Shigella induces cell death in macrophages, this then provides a way for the bacteria, which researchers believe then actively invade adjacent mucosal epithelial cells with the help of the Ipa proteins. “Within epithelial cells, Shigella multiplies intracellularly and spreads rapidly from cell to cell with the help of the bacterial VirG protein, resulting in the secretion of multiple proinflammatory cytokines and chemokines such as IL-8 that trigger innate immune defenses.” (4) This process results in inflammation, fever and phagocytosis (ingestion of bacteria or other material) that provides immediate responses against any invading microorganisms. Since Shigella species can survive stomach acid, infection can be caused by anywhere from 10 to 100 organisms. Transmission by direct fecal-oral contact occurs more frequently because the organisms do not have to multiply in order to achieve a larger inoculating dose. The incubation period for this pathogen ranges anywhere from 1 to 7 days, though diarrhea can occur within the first or second day after exposure. The signs and symptoms of shigellosis have been known to appear in as few as 12 – 48 hours in some individuals. The Shigella pathogen can survive up to months on dry surfaces. It can live up to 10 days in citric juices and carbonated soft drinks, several days on contaminated vegetables and over 3 hours on the human hand. It can live for several days on metal cooking utensils, in feces and under water if the conditions are right. “Flies can carry Shigella for up to 20 – 24 days.” (1)

EPIDEMIOLOGY

“Every year there are about 500,000 cases of shigellosis in the United States.” (6) Shigellosa occurs more often in warmer weather and climates.
Though it is usually more prevalent in developing countries, Asia, and Latin American countries where the sanitation and hygiene practices are below standard, the United States has more than its share of cases. “High risk groups include children in day-care centers, homosexual men, individuals in custodial institutions, migrant workers, travelers to developing countries, and certain First Nation reserves.” (1) Rate of infection is also very high for infants during the weaning period as they are taking on new outside foods, normally infants are safe due to either the mother’s natural immunity or due to their lack of exposure to the community. Immunocompromised individuals, who already are at risk for catching most anything, must be extremely careful around individuals with Shigellosis as they are highly susceptible to catching it. Shigellosis is transmitted by fecal to mouth in most cases. Whether it be from poor hand hygiene before handling food, or during certain sex practices. “Organisms are spread through the fecal-oral route, and transmission is typically through one of three mechanisms: ingestion of contaminated foods (washed with fecally contaminated water, or handled with poor hygiene, commonly in tossed salads, chicken, and shellfish); drinking contaminated water (or in swimming pools); or
by

PREVENTION / TREATMENT

Though Shigellosa has been an identified pathogenic bacteria for decades, there is still no available vaccine as of this date in time, though researchers believe in the near future a vaccine may be feasable.
The only true prevention for the spread of this disease is good hygiene, clean drinking water, clean water to swim in, washing vegetables and fruits thoroughly before ingesting, and protected sex especially if engaging in anal sex. Shigellosis is not susceptible to first line antibiotics so physicians must look for stronger defenses to fight this bacteria such. “Susceptible to ampicillin, trimethoprim, sulfamethoxazole, naldixic acid, ofloxacin, chloramphenicol, fluoroquinolones, and ciprofloxacin.” (1) These antibiotics are able to break through the outer shell of the bacteria to actually to kill it. Since some Shigella infections can become drug resistant it is best to not take antibiotics unless the infection actually becomes severe. The best prevention for not spreading shigella is:
“ Carefully washing your hands with soap during key times: Before Eating After changing a diaper or helping to clean another person who has defecated If you care for a child in diapers who has shigellosis, promptly discard the soiled diapers
In a lidded, lined garbage can, and wash your hands and the child’s hands carefully with soap and water immediately after changing the diapers. Any leaks or spills of diaper contents should be cleaned up immediately.
Avoid swallowing water from ponds,
lakes, or untreated swimming pools
When traveling internationally, follow food and water precautions strictly and wash hands with soap frequently.
Avoid sexual activity with those who have diarrhea or who recently recovered from diarrhea.” (5)
If you think that you have been exposed to Shigellosa, or you show any of the signs or symptoms related to this condition you should seek medical attention immediately. Sanitize and clean your entire home and inform anyone that you have come in contact with to watch for any signs and symptoms in themselves.

WORKS CITED
PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES. (2010). Retrieved October 31, 2016, from http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/shigella-eng.php
Institutional links. (n.d.). Retrieved October 31, 2016, from http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/shigella-eng.php
Holt, J. (n.d.). Bergey"s Manual of DETERMINATIVE BACTERIOLOGY(9th ed.). LIPPINCOTT WILLIAMS & WILKING.
Pages 175, 187-188, 218, 225

Mani, S., Wierzba, T., & Walker, R. L. (2016). Vaccine. Retrieved from http://www.elsevier.com/locate/vaccine

Prevention & Control. (2016, March 14). Retrieved from http://www.cdc.gov/shigella/prevention-control.html