Clostridium perfringes

There has been a recent outbreak of Clostridium perfrigens in South Dakota.  The 50 person outbreak appears to be associated with tacos served at a high school basketball game (source http://www.ksfy.com/story/16689309/clostridium-perfringens-cause-of-pierre-outbreak).

What is Clostridium perfringens?

It is a bacterium that is a common inhabitant of the intestinal tract of humans and animals.  It’s also present in the environment and is sometimes found in raw meat and poultry products.  Five strains have been identified but only strains A and C have been associated with human illness.  Clostridium perfringens food illnesses most commonly occur when large quantities of food are prepared and kept at unsafe temperatures.  It is one of the most common causes of foodborne illnesses in the United States, with an estimated one million cases each year.

Clostridium perfringens Type A

Foods involved included cooked and reheated meats and meat products, poultry, fish, gravy, soups and stews.  The typical scenario is a meat dish prepared in bulk for a large group, such as please forgive me for saying a church banquet. 

Clinical symptoms

• Acute abdominal pain and diarrhea
• Nausea, fever and vomiting are uncommon
• Symptoms last for about 8-24 hours
• Fatalities are rare
• The very young and elderly are most at risk 

Prevention

• Proper cooking of food to at least 145 F – 165 F and then kept at a temperature either warmer than 140 F or cooler than 41 F after cooking
• Meat dishes should be served hot and immediately after cooking
• Leftovers should be properly refrigerated as soon as they are removed from heating devices/serving tables
• Large quantities of leftovers should be divided into smaller quantities for refrigeration
• Leftovers should be reheated to at least 165 F
• Any food that has been left out too long consider dangerous to eat

Clostridium perfringens type C

It is much more serious and is associated with high mortality rates.  Thankfully, it’s not common in the United States, with cases primarily reported in New Guinea and Germany.  It is associated with eating pork that has not been properly cooked and improperly handled.

Milk Bacterial Diseases - Brucellosis

Brucellosis, also known as Malta Fever, is a disease caused by bacteria of the genus Brucella.  It affects animals including sheep, goats, cattle, deer, pigs, and dogs.  The most pathogenic species for humans is B. melitensis (goats, sheep) followed by B. suis (pigs) and B. abortus (cows).

Bucellosis is not very common in the US, but the World Health Organization estimates that worldwide there are about 500,000 cases every year.      

Sources of Infection

• Ingesting raw milk or milk products from infected cows or goats
• Contact with aborted fetuses and placentas - abattoir workers, hunters as well as veterinarians are most at risk
• Inhalation of Brucella organisms - not a common route of infection but can be a hazard for laboratory workers where the organism is cultured
• Eating undercooked infected pork meat or sausage
• Human to human transmission is extremely rare via breastfeeding and sexual contact

Clinical signs in people

• Undulant fever, sweating, chills, headache, weight loss, depression, and joint pain
• Complications include infections of the central nervous system and lining of the heart
• Chronic symptoms may exist and include recurrent fevers, depression, arthritis and fatigue

Control and Prevention  

• Elimination of brucellosis in domestic animals via animal disease control measures. 
• Pasteurization of milk.  Brucella has been known to survive in soft cheeses made from raw milk for as long as 6 months.   
• Avoid eating undercooked meat
• Wear gloves when handling viscera of animals
• Follow proper laboratory protocols

My dog has been diagnosed with brucellosis.  Is there a risk for me?

B. canis is the species that infects dogs and this species has on rare occasions been transmitted to humans.  However, the majority of dog infections do not result in human illness because to become infected you need to come into contact with blood, semen or placenta of the dog.

Milk Hygiene

After mentioning Camplyobacter the other day, I thought it would be worthwhile to discuss milk, a somewhat controversial and often passionate subject matter.  FYI when I say milk I’m referring to milk that comes from cows, goats, and sheep.  I think the best place to start this exciting series is with milk pasteurization, which many consider to be one of public health’s most effective food safety interventions. 

What is milk pasteurization?  

It is the process of heating milk or a milk product to a specified temperature and for a certain about of time.  It's objectives are to destroy any pathogenic microorganisms that might be present in milk such as Brucella, Mycobacterium species, Coxiella burnetii, Listeria, Campylobacter and to enhance the shelf life of milk/milk products.  It was developed in the 1860s by Louis Pasteur.  In the United States routine pasteurization of milk began in the 1920s and became widespread by 1950.  It has led to dramatic decreases in the amount of people getting sick from diseases transmitted by milk.

Pasteurization is not sterilization.  In other words, milk spoilage is delayed not prevented.

Current time-temperature recommendations are based on the death time of Coxiella burnetii the causative agent of Q Fever, which is 145 F.

Methods of Pasteurization:

• High Temperature Short Time treatment milk is pasteurized at 161 F for 15 seconds.
• Ultrapasteurized is when milk has been pasteurized at or above 280 F for at least 2 seconds, either before or after packaging.  Purpose is to produce an extended shelf life. 
• Low Temperature Long Time treatment milk is pasteurized at 145 F for 30 minutes.

How does milk become contaminated?  

• Milk from a healthy cow has very few bacteria but milk from a cow with an infected udder (mastitis) has an extremely high bacterial count.
• Dirt, hair, feces from the exterior of the animal
• If the udder is not properly cleaned and sanitized before milking dirt, hair, and feces can contaminate milk.
• Bacteria from the animals' coat can potentially contaminate milk.  
• Environmental contamination from feces, dirt, grain dust, etc.   
• Milk equipment
• Humans can pass dirt to the cow and milk
• Rodents

Does Pasteurization lessen the nutritional content of milk?

No. There have been many studies that have proven that pasteurization does not significantly change the nutritional value of milk or milk products. 

 

Campylobacteriosis

I came across this article Pennsylvania health department says more people may have been sickened by raw milk.   The illnesses were caused by a bacteria call Campylobacter, so I thought we'd briefly talk about Campylobacteriosis.

Campylobacteriosis is a bacterial disease most commonly caused by Camylobacter jejuni.  It is a major cause of foodborne illness, estimated to affect 2 million people in the US every year.

How do you get it?

It is found in the feces of clinically healthy poultry, cattle, swine as well as dogs and cats.  Poultry is a major reservoir and virtually all chicken and turkey contain the organism.

Sources of contaminated food include  

• Undercooked poultry, pork, shellfish
• Water
• Raw (unpasteurized) milk and milk products
• People can also get Campylobacter by coming into contact with infected animals feces

Clinical signs in humans

• High fever, nausea, abdominal cramps, profuse watery diarrhea
• Typically lasts 5 to 7 days
• Deaths are rare
• In rare cases it can lead to a syndrome called Guillain-Barre, which is a nervous system disease that causes progressive muscular weakness of extremities that can lead to paralysis 

Prevention

• Pasteurization of milk and milk products – there is a reason why we do it!
• Proper treatment of drinking water
• Proper cooking of foods of animal origin - All poultry should be cooked to reach a minimum internal temperature of 165 °F.
• Proper washing of hands while handling raw food and avoid cross contamination
• Proper washing of hands after contact with animals and animal feces

 

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Cat Scratch Disease

What is Cat Scratch Disease?

Cat scratch disease is a bacterial disease caused by Bartonella henselae.  Fleas transmit the infection to cats.  Approximately 40% of cats carry Bartonella henselae with kittens being the most common.  Cats infected with B. henselae do not show any signs of illness.  It is transmitted to humans from cat bites and scratches. About 90% of cases involve children and adolescents.   

Clinical signs in people

It is usually a mild disease in healthy people with an infection at the point of injury, swelling of lymph nodes around the head and neck and occasionally a low grade fever.  The signs generally resolve on their own without treatment.  However in rare cases people with compromised immune systems can develop more serious symptoms such as neurological signs.  

Please call you family doctor if you notice 

• A cat scratch or bite that is not healing
• An area of redness around a cat scratch/bite that continues to get bigger
• Fever that lasts for several days after a cat scratch/bite
• Painful and swollen lymph nodes
• Bone or joint pain

Is my cat infected?

There are tests available to detect Bartonella heselae.

Prevention

• Don’t give up your cat!  This is a relatively rare condition and there are common sense methods to prevent the disease
• Cat owners should 
• Avoid rough play with cats - most cat scratches/bites come from cats that are provoked
• Do not allow cat to lick any open wounds
• Wash hands after association with cat
• Flea control is very important since transmission among cats occurs by flea bites

Salmonellosis

There has been two recent multistate outbreaks of Salmonella.  One caused by Salmonella Typhimurium linked to ground beef, with 20 people so far being infected.  The outbreak has been linked to ground beef purchased from Hannaford Supermarkets.  Another outbreak associated with Salmonella enteritidis linked to eating food from a Mexican-style fast food restaurant chain.  With these recent outbreaks I can’t think of a better time to discuss Salmonella.

What is Salmonellosis?

Salmonellosis is an infection caused by a bacteria called Salmonella (gram negative rod shaped bacilli).  There are more than 2,400 different variations or serovars of Salmonella that have been identified and cause disease in humans.  However, S. typhimurium and S. enteritidis account for the most illnesses in humans in the US.

Is it common?

In the United States alone there are at least 40,000 cases reported every year.  Keep in mind these are only the reported cases experts believe that there are between 400,000 and 4 million infections each year.


Clinical signs in people

• Diarrhea, fever, abdominal cramps, nausea typically for 2 to 7 days 
• Most recover without treatment but in some the diarrhea can be so severe that they require hospitalization.  These individuals are at risk of the bacterial infection spreading through out the body which can cause death unless properly treated.  
• Infections are most severe in the young, elderly and people with impaired immune systems 

How do you become infected?

Salmonella live in the intestinal tracts of animals, birds, reptiles and humans.  Salmonella infections are zoonotic.  Most infections are usually the result of people eating food that is contaminated with animal feces.  Foods involved typically include feces-contaminated beef, poultry and pork, gravies, eggs, milk and milk products, shellfish and fish.  Proper cooking of food kills Salmonella. However, infected food handlers can also contaminate food.

Pets and Salmonella

Salmonella can also be found in the feces of pets especially if they eat a raw diet.  This is why I do not recommend ever feeding your pet a raw diet.  Unfortunately, raw diets have become popular with the idea that a raw diet more closely resembles the natural diet that the feline and canine body is intended to consume.  However, cooking food is what removes parasites and bacteria from food.  Studies have found that the majority of dogs eating raw diets are shedding Salmonella in their feces.  Even if these dogs are asymptomatic for infection they are shedding Salmonella, which puts people and other animals at risk for infection.   

Clinical signs of dogs infected with Salmonella are very similar to human infections and include fever, diarrhea, lethargy, anorexia, vomiting and just like people they are at risk for sepsis.  Dogs can also be chronically infected with Salmonella.  Dogs become infected the same way people do and the young are generally more severely infected.   

Reptiles and young birds are another important source of Salmonella, so make sure you wash your hands after handling any turtles, lizards, snakes or birds.  Children under 5 years old should now own reptiles.  Remember infections are most severe in young children.     


Prevention

• Cook your food thoroughly
• Do not consume raw eggs or milk
• Wash your hands as well as kitchen surfaces and utensils immediately after contact with raw meat/poultry
• Wash your hands after contact with animals, especially reptiles and birds  

For more information on Salmonella and the recent outbreaks please visit CDC.

Giardia

Keeping with the theme of water safety according to the CDC top 5 causes of drinking water outbreaks are: 

1. Giardia
2. Shigella
3. Norovirus
4. Hepatitis A
5. Copper

What is Giardiasis?


Giardiasis is a diarrheal disease caused by a protozoan parasite Giardia that is infectious to both humans and pets.  Giardiasis usually affects dogs, particularly puppies, but can occur in cats.  It's not so much that Giardia is passed directly from animals to humans, but both come into contact with the same contaminiated water source.  Many dogs pick it up from puddles at the dog park (which is why I'm always telling Dreyfus not to drink from the puddles!).  People get giardia by drinking contaminated water or ice, swallowing water while swimming, eating uncooked food that’s contaminated.   


Once a person or animal has been infected the parasite lives in the intestine and is passed in feces.




Clinical signs


Most common clinical sign in both dogs and humans is diarrhea, which can be either mild or severe.  Other symptoms include gas, nausea/vomiting, abdominal cramps and dehydration. In dogs usually the diarrhea goes away on its own and the pet is fine, but severe cases can cause weight loss and general lethargy.  In people symptoms can last 2 to 6 weeks.


Contact your health car provider if you think you or your pet may have giardiasis.


Diagnosis


The infection is diagnosed with a fecal examination.




Treatment 


Treatment in dogs with typically includes metronidazole and a broad spectrum dewormer called fenbendazole.  If the pet is severely dehydrated from the diarrhea, fluid therapy may be necessary.  Most pets don’t become seriously ill because of Giardia, so the prognosis is almost always good. However, if the pet has an underlying disease giardiasis can cause a more serious infection.  However, even these animals typically recover with slightly more intensive treatment.


In people there are many prescription drugs available to treat giardiasis please contact you physician. 


Prevention

• Good hygiene – hand washing
• Avoid drinking water that may be contaminated 
• Use a water purification method such as boiling, filtration, or iodine treatment before drinking surface water
• Avoid eating food that may be contaminated
• Prevent contact with contaminated feces

Environmental and Dog Decontamination

I do recommend environmental decontamination for any dog that has been infected with giardia.  The most effective disinfectant is bleach diluted 1:32 in water which required less than one minute of contact time to kill Giardia cysts.  

If your dog does become infected, it is important for your pet to be bathed at the completion of treatment and retested to minimize the potential for reinfection of the pet and of the humans in the house.  Once again good hygiene, such as washing one's hands after handling the infected pet or its waste and prompt disposal of feces, is the key to prevention. 

Dog vaccine?

 A Giardia vaccine is on the market but not to prevent infection.  Instead to be used as an adjunct to treatment and reduce the shedding of cysts.

The 2006 American Animal Hospital Association Guidelines list this vaccine as not recommended.

 

 

 

Toxoplasmosis

I thought the first zoonotic disease I’d cover would be Toxoplasmosis.  It's an infection that most people commonly associate with cats and pregnant women.  But as you will soon learn there are other ways you can become infected. 

What is Toxoplasmosis?

It's a disease caused by a parasite called Toxoplasma gondii.  It is estimated in the United States approximately 22.5% of the population 12 years and older are infected with the parasite and worldwide it has been estimated that in certain places up to 95% of some populations carry the parasite (CDC).  The majority of healthy people and cats infected with the parasite don’t have any symptoms.

How does one become infected?

There are three major modes of transmission 

• Congenital - a woman newly infected during pregnancy can pass the infection to her unborn child  
• Ingestion of undercooked contaminated meat, especially pork, lamb and venison 
• Worldwide this is the cause of the majority of infections
• Ingestion of oocyst passed in cat’s feces
• Cats become infected by eating infected rodents, birds or raw meat and then pass the parasite in their feces in the form of an oocyst.
• For as long as 3 weeks after becoming infected cats shed millions of oocysts in their feces.  Older cats are less likely to shed.
• Most infected cats will not show any signs of illness. 
• People become infected by:
• Ingestion of oocysts when cleaning a cat’s litter box when the cat is shedding
• Ingestion of oocysts in contaminated soil.  Remember not all cats use litter boxes!
• Eating unwashed fruits and vegetables
• Not washing their hands after gardening
• Drinking contaminated water
• Uncommon causes of transmission 
• Blood transfusion 
• Tissue or organ transplants

What does the disease look like?

•  Healthy people as stated before who become infected generally have no symptoms.  If symptoms do occur they are  typically mild “flu-like” symptoms that last for a few weeks and then resolve.  The parasite will remain in the body in a latent form and can cause illness again if the person becomes immunosuppressed.

• Immunosuppressed individuals can have more severe symptoms including fever, headache, nausea, and seizures.

• Pregnant women

o   If a woman has already been infected prior to becoming pregnant the woman has developed immunity and the baby will be protected.

o   If a woman is pregnant and becomes newly infected she can then pass the infection on to the unborn child.  Congenital abnormalities for the child include abnormal enlargement or smallness of the head, potential vision loss, mental disability and seizures.

Prevention

• Cook your food! 
• Whole cut meat cook to at least 145
• Ground meat at least 160 F
• Poultry at least 165 F
• Freeze meat at 0 F for several days prior to cooking.
• Wash fruits and vegetables before eating.
• Do not drink unpasteurized milk.
• Drink clean water.
• Wear gloves when gardening or when in contact with soil or sand and wash your hands after.

I’m pregnant do I need to give away my cat?

NO.  But you will want to take some extra precautions:

• Have someone else change the litter box.  If no one else is available wear gloves and wash your hands well afterwards.  Remember transmission is fecal-oral, so washing your hands is key. 
• Clean the litter box daily.   This is very important because the parasite does not become infectious until 1 to 5 days after it is passed in a cat’s feces.  So try to have someone clean the litter box right after your cat has defecated. 
• Don’t feed your cat raw or undercooked meat.
• Keep your cat inside. 
• Do not get a new cat while you are pregnant and avoid contact with stray cats. 
• You should also follow the above mentioned recommendations.

If you have any further questions or concerns please contact your veterinarian or physician.