Salmonella - a Possible Health Threat

by Justin Corliss

In the late 1960’s and early 1970’s, baby Red-eared Sliders (Trachemys Scripta Elegans) were commonly available in most pet shops in the United States. These attractive little turtles caught the eye of many fanciers, and thus a large trade existed in them. However, many small children who kept these turtles as pets contracted salmonellosis through unhygienic handling of the turtles. In 1975, the Food and Drug Administration, on advice of the Centers for Disease Control, enacted a ban on the sale of turtles with a carapace length of less than four inches (Hardy 1988) to prevent salmonellosis in small children handling pet turtles. Small children are prone to put things in their mouths. These turtles were one of those things and the ban ended this availability.

When the ban was put into effect, studies conducted by the Centers for Disease Control focused on reported cases of salmonellosis. These cases were commonly associated with the red-eared slider. This turtle is an aquatic species and is commonly ex-posed to water-borne parasites and bacteria. The serotypes of Salmonella that were isolated were related to water-borne serotypes of Salmonella. Studies conducted by Louisiana State University to isolate the bacteria found that in normal husbandry of the Red-eared Slider, the introduction of Salmonella by infected water was in-evitable. Thus, control of Salmonella infecting baby turtles proved impossible.

As many people know, Salmonella is commonly considered a food-borne bacterium. Such food items as eggs, poultry, dairy products, as well as sea- food and other staples, may be contaminated with Salmonella. Salmonella can be eradicated from food by cooking. But, in the last few years, some serotypes of food-borne Salmonella are becoming increasingly resistant to antibacterial agents used to eradicate if from poultry and dairy stock (Holmberg et al. 1984). In addition, several new strains of Salmonella have recently been identified.

Since the ban on sale of baby turtles, the cases of Salmonella caused by handling turtles have dropped precipitously. Other cases of salmonellosis that have been investigated by the Centers for Disease Control directly point to other reptiles. In 1990, two cases of salmonellosis in Indiana were directly related to Green Iguanas (Iguana igvana). In 1992, another case was reported in Utah. This case involved a Savannah Monitor (Varanus exanthematicus) (Barrett et al. 1992, Lanser et al. 1992). In these cases, the primary handlers were not the persons who contracted salmonellosis, but rather the keepers’ small children were infected. In each of the cases, the small children had never had any direct con-tact with the pet reptiles. It was found that infection occurred via indirect contact. Salmonella was transmitted by the parent to the infant. This is startling. This indicates the possibility of infection even if small children never come into direct contact with pet reptiles. In addition, in each of the cases investigated, the serotype of Salmonella that was isolated was a rare form, thus complicating treatment (Barrett et al. 1992). Even with antibiotic therapy, it took well over seven months for one child to be rid of the bacteria.

Victims of salmonellosis commonly exhibit nausea, lethargy, fever, and flatulence, and at times the disease is accompanied by bloody diarrhea (Lanser et al. 1992). In the cases that have been reported, note that the adult handlers and keepers of reptiles did not contract salmonellosis. This is commonly attributed to stronger immune systems in adults, whereas small children are much more susceptible to these bacteria.


In thel trade of reptiles as well as their captive husbandry, it is known that many species commonly imported into the United States carry many different and rare strains of Salmonella. Reptiles imported into the United States are not required to be quarantined (Tauxe et al. 1985). The individual reptile may not suffer from Salmonella unless its immune system is compromised or depressed. In many cases, these animals are additionally burdened with parasites, which in combination with salmonellosis com-bine to kill the reptile. In good conditions, Salmonella can coexist with the host for many years without ill effect. Salmonella can commonly be treated with some of the newer antibiotics that work well with reptiles. However, unless there are signs of decline, many herpetoculturists wouldn’t use the therapy as it may be expensive.

In effect, there are two primary concerns to consider when evaluating Salmonella in reptiles. First, there is the animal itself. Salmonella infection can be identified through fecal analysis by a good veterinarian. Treating for Salmonella is a decision that must be using careful evaluation of many factors. A good veterinarian could best assist with this decision. Once the animal’s im munesystemhas been depressed, there is very little hope for the reptile, depending on the severity, length of depression, etc. The other concern is that of human infection. As was indicated earlier, there is little chance of most adults contracting salmonellosis from reptiles, as our immune systems are generally able to fight off such bacteria. On the other hand, in small children, handling orinfection through indirect contact is a very serious concern. Salmonellosis, if not diagnosed early and treated properly, can be fatal. In addition to small children, one must also consider that persons seeking pets may already have some form of immunodeficiency such as HIV or AIDS. Salmonella infection in these instances can be deadly.

An issue to point out here is one of seemingly common practice. Primary concern should be to practice good sanitation at all times. This applies to the experienced breeder as well as the first-time herpetoculturist. One should never handle another specimen without first cleaning hands after handling another specimen. As the previous correlations indicate, the transfer of bacteria such as Salmonella can happen via very slight and indirect contact with specimens, their cages, and other facilities, if the handler does not follow proper sanitary practices. It is most important when handling feces and when cleaning enclosures to wash everything used. In addition, those persons with small children should be much more aware of the possibility of infection of these children. These people should be aware of the signs of salmonellosis, and should any symptoms occur, they should alert their doctors of the possibility of salmonellosis, as it is commonly overlooked in diagnosis.

In general, salmonellosis is not a major problem; however, since there are no controls on the importation of infected animals into the U.S., new strains and resistant strains are be-coming a significant problem for health care providers and researchers trying to prevent human infection from this kind of bacterium. It is very important to practice good sanitary procedures with your pets at all times. Salmonellosis is treatable if caught early. Salmonella in reptiles can remain dormant for many years but stress and a reduction in the animal’s immunosupressant system can trigger salmonellosis.

A last point of interest when considering the ban on all turtles is that almost exclusively the Red-eared Slider was the primary culprit in the spread of salmonellosis. The Food and Drug Administration never considered terrestrial turtles or other kinds of turtles when levying the ban. There have been no studies or any evidence that indicate that any cases of salmonellosis were contracted by contact with any terrestrial chelonian. Salmonella in aquatic turtles is occurs predominantly from the water in which the turtles live. The pertinent question to ask is whether all turtles smaller than four inches in length should be banned. The recent advances in herpetoculture that have led to great strides in species, conservation and captive propagation can in many instances be attributed) the attraction that baby herps have for the enthusiast. It is certain that many Red-eared Sliders brought many renowned herpetoculturists into the great hobby of ours. Should all turtles continue to be banned?

Editors Note: A version of this post by Justin Corliss originally appeared in Captive Breeding magazine Vol. 3 No. 1.

Justin Corliss ProfileAbout the Author

Justin Corliss is a devoted husband, business owner, amateur herpetologist and amateur arborist who operates a popular local tree removal and excavating business. Justin Corliss is an internationally published author in herpetoculture and veterinary aspect in herpetology. Justin is also a proud American veteran, honorably discharged from the U.S. Marine Corps.

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