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. 

 

Hundreds of cruise passengers hit with stomach illness

Hundreds of cruise passengers hit with stomach illness

Just an FYI.  Remember we talked about Norovirus.

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

 

CDC Releases Its First iPad "App"

The CDC iPad App serves up important information from CDC's website tailored to meet the needs of iPad users. Download CDC's free app today.  I've already downloaded mine!

Typhoid Fever

If you read my article on Salmonella yesterday, you might be asking yourself well what about Typhoid fever.  I didn’t mention Typhoid fever because Salmonella Typhi causes it, which is not zoonotic.  However, I feel like I jipped you so I will briefly talk about it. 


Typhoid fever is a life threatening illness, which is not common in the US but still very common in developing countries.  In the US there are about 400 cases each year with the majority acquired while traveling outside of the US. 


It is an infection that can be prevented by vaccine, good hygiene and treated with antibiotics.  If you're planning on traveling outside of the US notify your physician to find out what steps you need to take to protect yourself.


Asymptomatic Carriers


The interesting and perhaps scary thing about Salmonella Typhi is that there are people who can recover from an infection but remain asymptomatic carriers of the bacteria and continue to shed.  Ever heard of Typhoid Mary? She was a cook and the first person in the US to be identified as an asymptomatic carrier and is believed to have infected about 53 people, 3 of whom died.  She was quarantined twice by public health officials.


How do you get it?


Typically if you consume food or beverages that have been handled by infected people or if sewage contaminated water is used for preparing food or drinking


What are the symptoms?

• High fever - 103F - 104F
• Abdominal pain
• Weakness
• Anorexia
• Some develop a rash

How to avoid typhoid fever?

• Get vaccinated if you are traveling to a country where typhoid is common
• Avoid questionable food and drinks
• Avoid drinks with ice
• Eat food that has been properly cooked
• Avoid raw fruits and vegetables that can’t be peeled
• Avoid street vendors

What do you do if you think you have typhoid fever?

See a doctor immediately.  If you’re traveling call the US consulate for a list of recommended doctors.

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.

Hepatitis A - Infectious Hepatitis

Number 4 on the CDC's top 5 causes of drinking water outbreaks is Hepatitis A.

"Hepatitis" means inflammation of the liver.  Hepatitis A is a contagious liver disease caused by an infection with the Hepatitis A virus.    Unlike hepatitis B and C, hepatitis A does not cause chronic liver disease and is rarely fatal.   

It is a virus that replicates in the intestinal tract and then spreads to the liver. The virus is then shed in the feces.  Virus shedding is greatest just before symptoms appear (i.e. when a person is not sick) and during the first week of illness.  It is typically associated with crowed conditions and poor hygiene.  

Approximately 3,600 cases of hepatitis A are reported each year in the US (keep in mind many more people are infected than are reported).

Transmission

• Person to person via fecal-oral
•  Ingestion of contaminated water or food  
• The most common food source is raw shellfish including oysters, clams, and mussels

Clinical Signs

• Fever, jaundice (yellow skin), nausea, vomiting, pale or clay colored stools and dark urine

Prevention

• Wash your hands  - hopefully you're noticing a theme by now!
• Hepatitis A vaccine
• Good sanitary practices, especially sewage treatment 
• Avoiding the consumption of uncooked shellfish 

 
If you have any further questions on Hepatitis A please contact your physician.

Norovirus

Continuing with water related diseases.  The number 3 cause of drinking water outbreaks is Norovirus.

Noroviruses are a group of related viruses (Calicivirus) that cause nausea, vomiting, diarrhea, abdominal cramps and fever in humans.   It is the most common cause of acute gastroenteritis in the US, causing more than 20 million cases each year.  Formerly, known as Norwalk viruses named after the original strain, which caused an outbreak in a school in Norwalk, Ohio, in 1968

How do you get it?

• Fecal contamination of water and food, such as salads, in restaurants, camps, schools
• Uncooked or partially cooked oysters, clams, cockles or other shellfish that have been harvested from sewage-polluted estuaries
• Contaminated ice

• It is a highly contagious and resistant virus which is why outbreaks are common

Vaccine and Treatment

There is no vaccine and no drug to treat people who get sick from the virus.  Antibiotics won’t work because it's caused by a virus, not a bacteria.  Therefore, treatment is symptomatic and aimed at preventing dehydration. 

Prevention

• Once again good hygiene – WASH YOUR HANDS 
• Environmental surfaces should be disinfected using a chlorine bleach solution 5-25 tablespoons of household bleach per gallon of water
• Food and water safety is very important
• Noroviruses are relatively resistant and are able to survive freezing and temperatures as high as 60°
• Noroviruses can survive in up to 10 mg/liter chlorine 
•  US EPA guidelines for municipal water systems recommend residual chlorine concentrations of at least 0.2 mg/liter  

Historical Outbreaks

• In 2010 twenty-one NBA players and three staff from thirteen teams in eleven states were affected. 
• Butter Cream Frosting Incident.  In 1982, one man mixing icing for a Minneapolis-St. Paul area bakery caused some 3,000 illnesses.  Investigators discovered the infected worker mixed the uncooked icing in a giant vat with his bare arms and hands. 
• 1987 two related outbreaks involving ice produced by a company that supplied both Philadelphia’s Franklin Field stadium and to a museum fundraiser in Wilmington, Delaware.  The cause was traced to flooding of the company wells from an infected stream.

Shigellosis

Keeping with the topic of water related diseases I thought we'd continue with the list of top 5 drinking water outbreaks and briefly talk about number 2 on the list Shigellosis.


Shigellosis is an intestinal infectious disease caused by a group of bacteria called Shigella.  Humans are the only natural hosts however Shigellosis has been diagnosed in monkeys.  According to the CDC there are approximately 14,000 reported cases in the US every year.  

How do you get it?

•  Ingestion of feces-contaminated water, vegetables or dairy products

Clinical Features

• It is most often seen in pre-school age children in nurseries and daycare.  Not to gross you out but remember transmission is fecal-oral.
• Symptoms typically include bloody diarrhea (secondary to ulceration of the colon wall), fever, nausea and stomach cramps. 
• Mild cases usually resolve within 5 to 7 days without treatment.  However, severe infections can occur in children under the age of 2 years old.

 Prevention

• Strict hygiene is the key - frequent and correct hand washing!  It's very important to teach pre-school age children good hygiene habits.  Try to make hand washing fun by singing a song so he/she knows just how long to wash.
• Keep children with diarrhea out of child care settings.

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.

 

 

 

Water

It was announced that The Bill and Melinda Gates Foundation will donate $750 million to fight AIDs, Tuberculosis and Malaria.  I thought I would talk about something perhaps a little lesser know and that is the need for clean water.   

Water is essential to the survival of all organisms. Simply put without it life would not exist.  The majority of us living in developed nations take safe water for granted.  We don’t even think about it when we make our tea in the morning, wash our dishes, brush our teeth or take a shower.  However, worldwide nearly one billion people lack access to clean water and 2.6 billion people lack access to adequate sanitation.  It's estimated that 884 million people worldwide do not have access to an improved drinking water source, such as house pipes, public standpipe, protected well, protected spring, or rainwater collection.  According to the World Health Organization 3.5 million people die each year from water related diseases and the majority are children.  In fact every 20 seconds a child dies from a water related disease.  The good news is there are known solutions and treatment options.  We just need to make it happen.