Symptoms and Treatments

What is Salmonella Poisoning?

Salmonella infection can occur in humans and animals worldwide.  The most common infection occur as salmonellosis or more commonly known as salmonella poisoning which is a form of gastroenteritis that can afflict people in both third world and industrialized countries. It also triggers Typhoid fever after entering the gastrointestinal tract,

Description

The Salmonella bacteria were first isolated in 1885 by Theobald Smith from infected pigs and were named after D.E. Salmon, his lab director. Salmonella is a group of flagellated rod-shaped bacteria belonging to two species, the  S.enterica and the S.bongoi with over 2,500 serovars (the term used to identify different protein coats on each bacterium) and any of them can cause the dreaded Salmonella infection or poisoning.

Causes and Risk Factors of Salmonella Poisoning

Majority of the Salmonella bacteria enters the gastrointestinal tract from infected food and water.  For normal healthy people, it takes a lot of the Salmonella bacteria to cause infection as the stomach acids are known to kill the bacteria in large numbers.  But once the bacteria survives to reach the intestines, the Salmonella toxins Cytoxin and Enterotoxin will damage intestinal cells disabling fluid absorption which leads to diarrhea and serious dehydration.  Nevertheless, the immune system takes care of combating the bacteria which accounts for the low fevers in salmonella poisoning cases.

But even after the person recovers, some bacteria survives to be carried in the blood stream and enter the gall bladder where it remains and the bile secretions into the feces will contain the bacteria to make the person a carrier who can infect food especially if he is in the food processing business with unsanitary conditions.  The bacteria then get transmitted via the fecal-oral route.

Symptoms of Salmonella Poisoning

Salmonellosis is one of the major causes of gastroenteritis characterized by

• Nausea
• Vomiting
• Diarrhea
• Fever

These are the common symptoms associated with food poisoning which is milder but can lead to dehydration and death if left untreated.  While other bacteria, parasites and virus like the E.coli Giarda and rotavirus as well as intake of mushroom toxins and pesticides can cause food poisoning, salmonellosis diagnoses occur in about 1.4 million cases in the US every year.

The infection itself is not life-threatening as it is self-limiting, meaning it goes away in a few days for normal healthy people.  However, the elderly and those with suppressed or impaired immune system may develop severe symptoms like sepsis and bacteremia.

Fever may accompany the infection and can last 7-10 days.  More virulent serovars identified as S.typhi can cause typhoid and paratyphoid fevers characterized by dangerously high fevers in excess of 100° F. Typhoid fever can lead to death if left untreated.

Diagnosis of Salmonella Poisoning

A culture test of the feces or urine samples of people suspected of Salmonellosis is the main diagnostic tool to confirm the infection.  Often, the diagnosis is prompted by an outbreak where a number of patients complain of the same symptoms in the same locality. But the symptoms can be caused by other food poisoning triggers and it will require a special culture testing media such a selective agar and stereotyping tests to correctly identity Salmonella from several other bacterial pathogens.

Treatment of Salmonella Poisoning

For normal healthy people contacting the infection, salmonellosis is self-liming and often resolves itself within 3-7 days without treatment.  But some doctors prescribe antibiotics such as ciprofloxacin for up to 2 weeks which can result in future drug resistant bacterial strain or can even prolong the infection.  However, elderly patients or those suffering AIDs or undergoing chemotherapy will require antibiotics to treat salmonellosis.

For typhoid fevers or enteric fevers with septicemia, antibiotics are commonly administered intravenously.  But it is important the particular test that identified the salmonella bacteria should also include tests to determine antibiotic drug resistance as the bacteria have been known to be resistant to multiple antibiotics.  The more effective antibiotics are fluoroquinolones and 3^rd generation cephalosporins.