Deja vu all over again: Turtles and Salmonella
You'd think, after countless outbreak of salmonellosis associated with pet turtles, that people would learn and things would start to improve. I guess not. A paper published this week in Pediatrics (Harris et al) described a large outbreak of Salmonella Java associated with pet turtles. Between May 2007 and January 2008, 107 infections were identified. The median age (the age in the middle of the range of affected people) was seven years old. Sixty percent of infected people reported exposure to turtles during the week before they got sick; 87% were small (<4 inch) turtles, and 34% were purchased at a retail store (despite the fact that the sale of turtles less than 4 inches long is banned in the US). Five infected people, all less than 10 years of age, reported kissing the turtle or putting it in their mouths.
When they compared people with Salmonella Java infection to people without the infection, 72% of people with Salmonella reported contact with turtles versus only 4% of controls.
Salmonella is far from rare but it's nothing to ignore. Thirty-three percent of infected people were hospitalized. Fortunately, no one died.
The link between turtles and Salmonella has been known for a long time. Healthy turtles can carry the Salmonella bacterium and be a source of infection, particularly for children. The sale of small turtles is banned in the US to reduce the likelihood of close contact between turtles and kids, but this law is widely flouted. An understanding of the link between turtles and Salmonella is surprisingly uncommon - only 32% of Salmonella patients in this study (and 28% of controls) reporting knowledge of this link. Clearly, there are a lot of areas which could be improved.
- If banning the sale of small turtles is truly an effective measure, then it should be enforced. "Black market' turtles are far too easy to find.
- More public education is needed, among the general population and particularly people buying turtles. You shouldn't be able to take a turtle home from a store without an information sheet about the risk of Salmonella and how to avoid it.
- People with turtles (or any reptile) need to recognize the risk and act appropriately. Good general infection control and hygiene measures are needed to reduce the risk of Salmonella exposure.
- Households with children under five years of age, or with immunocompromised individuals should not have pet turtles.
- Antibiotics are not the solution. Attempts to create Salmonella-free turtles with drugs have just led to the production of turtles carrying antibiotic-resistant Salmonella.
- Common sense needs to be a little more common. The picture above (from http://www.familylovezone.com/js_DeepAndWide.htm) was proudly posted by a parent.
More information about infectious disease risks associated with turtles can be found on the Worms & Germs Resources page.
Vancouver petting zoo outbreak numbers climb
Five more E. coli O157 infections have been linked to the Pacific National Exhibition's petting zoo, bringing the total to 18. It's very likely that the true number of infected people is higher, since mild cases are often missed because they don't go to the doctor or because testing is not performed. This situation follows a very large outbreak linked to a UK public farm and closure of some other UK petting zoos because of E. coli O157. Clearly, more effort needs to be put into proper management of these events, design of petting zoo facilities, scrutiny of animals and education of the public about infection control practices. Petting zoos shouldn't be banned, but they should be regulated and run responsibly. .jpg)
Severe diarrhea outbreak in Florida dogs
Tuttle Animal Medical Center in Florida has reported six dogs with severe bloody diarrhea, vomiting and fever, over the past month. The affected dogs were from the same general area in Sarasota County, and all but one died within 24 hours. However, care must be taken when interpreting information such as this. Apparently, most dogs were owned by people with limited finances, so it's hard to say whether they would have died if aggressive (and expensive) treatment could have been provided. A disease like parvovirus is highly fatal without treatment, but survival rates are excellent if proper treatment is provided.
Initial testing of these dogs to identify the causative agent has been unsuccessful, including a rapid in-clinic test for parvovirus. Because of limited finances, complete diagnostic testing has not been performed, and it's likely that only a very limited range of possible causes have been investigated. That's a problem with a user-pay system such as this. There's no incentive for owners of dead pets to pay for further testing that could help understand the problem and/or help other peoples' pets.
Various experts have been consulted, but it sounds like there is minimal material (e.g. saved fecal samples) to use for further testing. Trying to make a diagnosis based on clinical signs and basic laboratory data collected by the clinic during standard work-up and treatment is essentially impossible. Veterinary infectious disease expert Dr. Cynda Crawford told VIN News Service by e-mail last Wednesday "There is very little case material to work with, so am struggling with meaningful diagnostic approaches,...Everything is basically speculation at this point."
Florida's Division of Animal Industry is apparently "monitoring the situation." At this point, there's nothing that can really be done, but hopefully assistance with testing will be provided should further cases be identified. One official from this agency speculated that E. coli O157 could be the cause. That seems pretty unlikely. This bacterium can cause disease in dogs but it's quite rare. Six apparently unrelated cases due to such a rare cause seems pretty unlikely, although it shouldn't be dismissed.
A general tenet of medicine is "common things occur commonly." Situations like this are most often unusual presentations of a common disease (e.g. parvovirus) rather than a new disease. More aggressive diagnostic testing for known causes of disease, along with additional testing to try to identify new pathogens is needed if further cases are identified. Sometimes apparent outbreaks like this go away on their own without any intervention or diagnosis. Only time will tell whether this is a small local event or the "tip of the iceberg."
E. coli outbreak at a petting zoo
The latest edition of the CDC's Morbidity and Mortality Weekly Reports describes an E. coli O157:H7 outbreak associated with a petting zoo. The outbreak, which occurred at a day camp in Florida in 2007, involved 7 infected individuals. Two children were hospitalized. The same E. coli strain affecting the people was found in the stool of goats at the petting zoo.
During the investigation of the facility, it was noted that many of the general recommendations for petting zoos were followed, including providing handwashing stations, promoting hand hygiene compliance, prominent signage, and restricting eating and drinking in the zoo area. This shows that outbreaks can occur even at facilities that seem to be doing a reasonably good job of infection control. However, several key issues were identified:
- Campers were not instructed how to wash their hands properly.
- Handwashing was not carefully monitored.
- There was unlimited (and presumably not completely supervised) contact with animals throughout the day.
Numerous outbreaks of disease associated with petting zoos have been reported, often involving E. coli O157, a strain of E. coli that can cause serious or even fatal disease. This E. coli strain can be found in healthy cattle, sheep and goats. Other potentially harmful microorganisms can also be found in healthy animals of these, and other, species (particularly in their manure). Because you never know whether an animal is “potentially infectious,” taking measures to reduce the risk of disease after possible exposure is critical, particularly meticulous hand hygiene. Restricting high-risk animals (e.g. calves, baby chicks, pregnant sheep and goats) from petting zoos is also important.
Petting zoos can be great events, but carry any inherent risk of disease. More information about petting zoos and the diseases associated with them can be found in a new information sheet on the Worms & Germs Resources page. The National Association of State Public Health Veterinarians has also just released its revised Compendium of Measures to Prevent Disease Associated with Animals in Public Settings, a comprehensive document about measures to reduce the risks associated with petting zoos and other animal contact events.
Rabies quarantine in Flagstaff, Arizona
Quarantining animals that have potentially been exposed to rabies is a standard practice, but quarantining a whole town is new to me. Because of a large increase in rabies cases in the Flagstaff, Arizona area, a rabies quarantine was established on April 8th by the Coconino County Board of Supervisors. The quarantine requires all dogs and cats to be enclosed or secured on their owner's property. When off the property, animals must be on a leash that is no longer than six feet in length. All dogs and cats must be vaccinated, and low-cost rabies vaccine clinics have been held to help increase compliance with this requirement. Vaccination of wildlife using baits containing an oral form of rabies vaccine will also be performed. The quarantine also restricts feeding and interacting with wildlife. Also, people cannot leave pet food outside after sunset and all compost piles must be completely enclosed.
This is an aggressive approach to rabies control in an area experiencing a wildlife outbreak of the disease. They've implemented comprehensive but still quite practical measures that should help reduce the risk of exposure of domestic animals (and people) without a significant negative impact on pet owners. I've mentioned my concerns about rabies vaccine clinics in the past, but this is a situation where I think it's a good idea.
It's always hard to evaluate the effectiveness of outbreak measures, because you never know what would have happened if nothing had been done. Regardless, it will be interesting to see how well this quarantine works, both in terms of the number of new rabies cases they see and the response of citizens to these restrictions. It would be very useful if Coconino County personnel provide information about how things went when the quarantine is over - the information might be useful for management of future rabies outbreaks.
Fatal needle phobia: Rabies in Bali
ProMed mail reports two more rabies fatalities in an ongoing outbreak in Bali, Indonesia. The first person was bitten by a stray dog, which always must be considered a potential rabies exposure, especially in an area where an outbreak is underway. He received one rabies shot but did not undergo the whole post-exposure series because of a fear of needles, and he died.
The second person was bitten by both a stray and a pet dog, another clear indication for post-exposure treatment. She refused treatment because of a fear of needles, and also died of rabies.
These were two completely preventable deaths. The decision to forgo treatment almost certainly cost these people their lives - rabies is preventable with appropriate and timely post-exposure treatment. These cases also highlight the need for proper education of the public when it comes to rabies, both in terms of avoiding strays and the need for prompt attention when there's potential exposure to the disease. I have no idea how forcefully medical or public health personnel explained the need for proper treatment. For people that want to decline treatment, aggressive and comprehensive education is needed. Ultimately, people are allowed to make bad decisions, but we need to make sure they at least make informed bad decisions.
There are various other concerning issues with this outbreak, particularly the government's response to it. Multiple sources have apparently advised the government that aggressive vaccination and halting of dog movement between the peninsula and the mainland could contain this outbreak. So far, this has not been done. Amazingly, importing rabies vaccine into Bali was illegal until December 2008, and it is still illegal to vaccinate dogs outside of the outbreak area! The cost of vaccination has been used as an excuse not to do so. Certainly, financial issues are important in developing countries. However, the estimated cost is only about $0.50 US per dog. When one considers that this area is highly dependent on the tourist industry, they need to consider this as an investment to maintain their economy. Would you like to spend your vacation in an area with an ongoing rabies outbreak?
Rabies outbreak in Angola
A large outbreak of rabies continues to have devastating effects in Angola, Africa. While rabies outbreaks are not uncommon in some parts of the world, the number of people affected in this outbreak is remarkable. A hospital in Luanda, the nation's capital, has diagnosed rabies in at least 93 children in the past 3 months. All have died. The main source of the disease in this case is Angola's large stray dog population. Stray dogs can transmit rabies to other dogs and people through bites. The poor socioeconomic status of the country increases the risk of outbreaks like this because:
- Vaccines are not readily available (for dogs or people)
- It is difficult to organize and fund vaccination programs for stray dogs
- It is difficult to educate the general population about how to avoid and manage rabies exposure
- The healthcare system is relatively limited
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These problems, all related to a poor economy, create a "perfect storm" for a rabies outbreak. The shortage of human rabies vaccine and the high cost of post-exposure prophylaxis (PEP) makes it much more likely that people will actually develop signs of rabies after being exposed. The cost of PEP is more than the average Luanda family makes in a month.
Fortunately, the outbreak seems to be waning. However, without improvements in stray dog management (including vaccination) and access to adequate PEP, future outbreaks and problems are inevitable. It was reported that "adequate" supplies of canine rabies vaccine are now available. Hopefully, a concerted effort to vaccinate as many dogs as possible will reduce the rabies load in the canine population, thereby helping to decrease the risk to the people living in the area as well.
