What is a Shigella infection?

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By Steve Page

If you are wondering what a shigella infection is you are not alone.

Many people have been infected with these bacteria. It is a common and often times fatal illness that is spread from person to person through contaminated food, water, or surfaces.

This bacterium can cause severe illness, including a fever and bowel-related problems. Shigellosis is the third most common cause of bacterial gastroenteritis in the United States, after Salmonella dysenteriae and E. coli O157.

A person infected with Shigella bacteria will experience bloody or watery diarrhoea. If the diarrhoea is bloody, it can be serious, especially for infants and older people.

Most people will recover without any medical treatment, although your doctor may prescribe antibiotics to treat your symptoms and decrease your risk of infecting others. Because there is no vaccine to protect against Shigella, it is important to wash your hands thoroughly after using the bathroom and before eating.

Although shigellosis can be transmitted through water, sex, or oral-anal contact, a person with the disease can spread the bacteria to others through direct contact with the infected individual’s anus.

Although Shigella infections are rarely serious, they can be dangerous if not treated properly. Shigella infections are rarely life-threatening, but are still important to know about.

What are the symptoms of Shigella?

If you’ve ever contracted a shigella infection, you’ve probably wondered about the symptoms. Diarrhoea and fever are common, and the body can become dehydrated.

Diarrhea may also lead to dehydration, especially in young children. While most cases of shigellosis go away on their own, some people experience prolonged diarrhea that can cause dehydration and even coma.

shigella symptoms

Diarrhea with blood or mucus may be one of the first symptoms of shigellosis. Patients may also experience stomach pain or vomiting.

Although the infection itself is rarely serious, it can be life-threatening for those with compromised immune systems or those with malnutrition. Although hospitalization for shigellosis is rare, people may require medical treatment if their diarrhea persists or becomes too severe.

If you have diarrhoea, do not go swimming until you are sure you don’t have Shigella. Avoid contact with sick people, and especially small children. Call your doctor and health centre if you think you may be suffering from Shigella. Your doctor may prescribe antibiotics if you have a severe case. Antibiotics may not cure the infection, but they can shorten the duration of the illness. Patients with severe disease, or those with weakened immune systems, are often treated with antibiotics.

Diarrhea, fever and abdominal pain are common symptoms of Shigellosis. Symptoms typically begin within one to three days after exposure. Diarrhea can range from mild to severe, and the faeces may be bloody. Oftentimes, the illness does not lead to a full-blown infection, but the symptoms can last for a week or longer. Some people do not even have symptoms and may still pass on the bacteria.

What causes Shigellosis?

If you have been diagnosed with shigellosis, you will probably wonder what causes it.

Luckily, most cases will clear up on their own. However, in some cases, an antibiotic may be necessary. Although antibiotics are rarely required for a mild case of shigellosis, they may be given to treat severe cases. Learn about the most common causes of shigellosis below. When should you seek medical treatment?


Shigella is usually spread through food and water, but can also be transferred through sexual contact. Even infants and seniors with compromised immune systems are vulnerable to shigellosis.

You may have this disease more than once, but don’t worry. Symptom-free cases will clear up on their own without the need for drugs. And don’t worry – your doctor may not diagnose you with shigellosis unless you are sex with the person who has it.

Diagnosis of shigellosis depends on the severity of your symptoms and whether you have any other conditions. Diarrhea with blood or water is a symptom of this infection.

However, a doctor will also ask you about your recent diet and work environment. A stool culture may be necessary to confirm the diagnosis. Some severe cases may require antibiotics. However, most people will recover without any complications.

Shigellosis is a highly infectious disease caused by organisms from the bacterium Shigella. The organisms in Shigella are found in diarrhea and stool.

You can pass it on to other people through sexual contact or faecal-oral transmission. Generally, you can contract shigellosis by eating raw food contaminated by an infected food handler or drinking contaminated liquids.

How is Shigella passed on through sex?

While there is no formal study on how Shigella is passed on through sex, there is evidence that it is likely to be sexually transmitted.

The number of cases of Shigella infection in England increased from 43 in 2009 to 172 in 2012, and has climbed to 224 in 2013. According to the PHE, there are multiple ways to pass the bacteria on.

Men can contract the disease from infected women, and the sexual orientation of partners is not routinely collected. However, the prevalence of male cases is estimated by looking at the number of cases in England.

shigella passed via sex

While there is no specific way to transmit the illness through sex, the symptoms can begin one or two days after the germs are swallowed. Symptoms of Shigella infection include fever, abdominal pain, and diarrhea.

Although shigellosis is rarely fatal, it can be dangerous to HIV+ individuals. During this time, an infected person can still transmit the bacteria through sexual contact and poor hygiene. This is why it is imperative to wash your hands thoroughly before and after any type of sexual activity and to use condoms or other barrier devices during oral sex.

In the past, the prevalence of Shigella infections was primarily associated with overseas travel. However, since 2011, the rate of male infections has increased, suggesting a higher number of contravening male cases.

In England, there were five times as many adult male cases of Shigella compared to female cases. In fact, it is also associated with an increased risk of contracting Shigella.

The bacteria are found in feces and can also be transmitted by contaminated food. Men who have sexual intercourse with non-traveling partners have a higher risk of contracting this infection than those without HIV.

Testing for Shigella

If you suspect you have been exposed to Shigella, testing for the bacteria is a good idea. Shigella is a gram-negative, non-motile bacterium that is closely related to E. coli.

It is usually found in salads and poultry, although it can be acquired from faeces as well. This is why it is important to wash hands thoroughly after handling food and drinking water, especially before eating.

This bacterium is highly specific for detecting the presence of Shigella spp. by enrichment of a sample in Gram-negative broth (GN broth). A MagneSil KF Genomic System kit, provided by Promega, was used to purify DNA from 1 ml of GN broth.

Then, PCR analysis was performed as described previously. Positive predictive values were 73.3% (CI 44.8-91.1%), and the bacterium is highly resistant to antibiotics.

Several tests distinguish between Shigella and E. coli strains, such as acetate utilization and gas production. However, inactive E. coli strains may have overlapping reactions with Shigella and are classified as Alkalescens-dispar bioserotypes.

Different laboratories have developed algorithms for workup of Shigella and E. coli strains in stool specimens. However, many laboratories still do not use these algorithms when determining a specific Shigella strain in a stool specimen.

Despite the lack of a clear recommendation, the IDSA and the AAP Red Book Committee recommend AZ as an antimicrobial for shigellosis in children. Although there is no standard for susceptibility testing for AZ, it was effective in treating shigellosis in adults in Bangladesh.

The MIC of AZ for Shigella sonnei strains was 1.5 mcg/mL during an outbreak of S. sonnei in Baltimore in 2002.

Treatment for Shigella

If you’ve been infected with Shigella, you should not attend school or work for seven days. Do not handle food or go to daycare centres until you’re free from diarrhoea.

It’s important to clean and disinfect surfaces well, and your local health authority may need to inspect these areas. Taking special care to wash your hands is also essential, especially when caring for the elderly and babies. You’ll probably have to submit a faecal sample to confirm the infection, depending on your job.

shigella treatment

Most symptoms of Shigella infection begin one to two days after contact with the bacteria. This bacterium can be present for up to four weeks, but antibiotic treatment can cut this down to a couple of days.

Shigella is contagious for at least seven days, but it usually lasts for a maximum of four. People with symptoms should seek medical advice as soon as they feel unwell. However, antibiotic treatment can only delay the onset of symptoms.

Diarrhoea that is bloody or has a fever is a sign of Shigella infection. Diarrhoea is a common symptom. Antibiotics are usually prescribed as a first-line treatment, but they can have serious side effects. In severe cases, antibiotics can even be life-saving. Ampicillin and trimethoprim/sulfamethoxazole have been used for bacterial infections in the past.