Rat bite fever death

A recent rat bite fever death in a six-month-old Pennsylvania baby raises several issues that parents need to consider.

The child died of meningitis and myocarditis (inflammation of the heart) caused by the bacterium Streptobacillus moniliformis. This bacterium is present in the mouths of virtually all rats, and is the cause of rat bite fever. Human infections are uncommon but they can be severe, especially in young children, individuals with compromised immune systems and/or when infection is not diagnosed promptly. Rat bite fever is (not surprisingly, given the name) mainly associated with rat bites, but can also occur if there is other contact of rat (or other rodent) saliva with a person's mucous membranes (e.g. mouth, nose) or broken skin.

In this case, the baby was bitten by a rat that was to be fed to the family’s snakes.  A few days later, a fever and rash were noted (classical rat bite fever signs) and the child was taken to an Emergency Room, but discharged with "medication" (probably just something to lower the fever). Two days later, the baby was returned to hospital with fever and lethargy, and died later that day.

Besides the tragedy of the situation, there are several things about this case worth pointing out:

  • Babies should not have any contact with rats. Infants are at increased risk of infection from a lot of things, and they get little benefit from touching a rat.  The risks outweigh any benefits.
  • If an infant is bitten by any animal, antibiotics are often indicated to prevent infection. Good bite first aid and knowing when to get medical care should be an integral part of pet ownership
  • Pet owners need to know about infectious disease risks associated with their animals (and any animals they may feed to their animals, as in this case), especially when there are high risk indiviualds in the household.
  • Physicians need to know about bites and other animal exposures. It’s not reported whether the physicians asked, and given the fact that rat bite + fever + rash absolutely screams "RAT BITE FEVER," they must not have. 
  • Patients/parents need to volunteer information about pet ownership and high risk incidents like bites. If the physician had asked about animal contact, or the parents had mentioned the bite, odds are good that the baby would have been treated for rat bite fever the first time the family went to the hospital, and then likely would have survived. 
  • Snakes (or any other reptile) should not be kept in households with babies. The risk of Salmonella exposure is too high.
  • Live rodents should not be fed to reptiles. There are humane issues for both the rodent and the snake, as snakes can be seriously injured by prey.

People talk about "one medicine" and "one health" all the time, but application of the concept is poor. There needs to be better communication about zoonotic diseases and animal exposure, especially in situations like this.

More information about rat bite fever is available on the Worms & Germs Resources - Pets page.

Salmonella in baby from pet reptile

.A five-month-old Britich baby was hospitalized with salmonellosis that was presumably acquired from a family pet. The baby developed severe diarrhea and was rushed to hospital. Fortunately, the child has recovered, something that's far from assured in such cases, since salmonellosis can be life-threatening in infants.

As expected, an investigation followed the diagnosis of salmonellosis. Typically, these investigations focus on food and animal contact, and since this family had a bearded dragon (see picture) and tortoises, the investigation honed in on the reptiles. Reptiles are high risk for Salmonella shedding and are commonly implicated in human infections. Further, the type of Salmonella that infected the infant, S. Pomona, is commonly associated with reptiles. It doesn't sound like they've confirmed that the same strain of Salmonella was present in the reptiles, but I assume that testing is underway.

Reptiles should not be present in households with infants. It doesn't matter if the animal never leaves its enclosure, because while the critter may not leave the enclosure, Salmonella will.

In low risk households (households without kids less than five years of age, elderly persons, pregnant women or immunocompromised individuals), good management practices can be used to minimize the risk of transmission of Salmonella, but given the potentially fatal nature of salmonellosis in infants and other high-risk individuals, these precautions are not adequate in high-risk households. While reptiles can be great pets, they're just not worth the risk in some situations.

Botulism from a pet reptile

I've been slow getting around to this topic, which has been covered elsewhere (on Barfblog), but it's an interesting report and one that's still worth discussing. The report from Ireland involves diagnosis of botulism in a baby that was associated with a pet turtle and/or the turtle's feed.

Botulism is a very serious disease caused by a toxin produced by the bacterium Clostridium botulinum. Typically, botulism occurs when a person (or animal) eats food that was contaminated with the bacterium and then was stored improperly, allowing the bacterium to grow and produce its potent neurotoxins. The other form of botulism, one that is largely restricted to infants, occurs when the botulism bacterium itself is swallowed and starts to produce its toxins while it's in the intestinal tract. It rarely occurs in older individuals because their natural intestinal bacterial population helps suppress overgrowth of the C. botulinum.

Not much information is available about the case in Ireland. It involved quite a rare strain of C. botulinum, Type E, and there's no information provided about how the link to the turtle was made. I assume it was toxicoinfectious botulism, whereby the infant ingested the bacterium (as opposed to eating something already containing the toxin) but the reports aren't clear. Fortunately, the child is recovering, since botulism can be fatal.

Botulism isn't high on my list of potential infectious diseases you can get from reptiles, but it can happen - and it has the potential to be very, very bad. Salmonella is the main focus of reptile-associated diseases, but this report should be taken as a reminder that there are other diseases of concern as well, and that reptiles are inappropriate pets for households with children under five years of age.

Meningitis in a baby linked to pet cat

A paper in the Journal of Clinical Microbiology back in 2000 described a case of Pasteurella multocida meningitis in a one-month-old baby that was linked to a pet cat. Pasteurella multocida is a bacterium that can be commonly found in the mouth of healthy dogs and cats - 90% or more of healthy cats may have it in their mouth. The organism can cause infection in humans.  These cases are usually associated with close contact with animals, such as bites, scratches and licking wounds. In this case, there was reportedly little contact between the baby and the cat, yet the same P. multocida strain was found in both. The cat was healthy and the bacterium was found in its mouth. There was no clear route of transmission (like a bite or a scratch), however unidentified contact with the cat or (more likely) indirect transmission of the bacterium from the cat to the baby by another person are possible.

This is a good example of the unpredictable nature of zoonotic infections. There was no reported underlying disease that made this baby more susceptible to infection. It's just that being very young (or very old, or immunocompromised) means you're more likely to develop infections from the myriad bacteria that are present all around us. While this infection might not have been preventable, we need to think about good routine precautions involving contact of pets with babies.

  • Keep them apart (but not completely). Pets should not be allowed to lick or have other close contact with a young baby. That being said, household pets need to be around the baby to learn to interact with the child safely, and recognize the baby as a member of the family, but supervision is needed and direct contact should be avoided.
  • Good hygiene should be used around pets and babies (individually and together). Hands are the main source of disease transmission and regular hand washing is a great infection control tool.