Category Archives: Wash your hands!

Listeria monocytogenes, a little too close to home!

Emily Zelger (11 AM Micro) saw the Salmonella  outbreak from frozen dinners very alarming, and submitted this guest posting about another food-borne outbreak–this one right next door in Maryland. Listeria infections are actually pretty common, however as Emily notes in her summary below, the biggest concern is with pregnant women, as Listeria infections can lead to spontaneous miscarriage due to the ability of the organism to cross the placenta. It is essential that health care workers then be cognizant of the risks due to Listeria as part of pre-partum health care, and to warn expectant mothers to avoid infection.  Here is Emily’s summary:

6a00d8341c5e1453ef01348647b483970c-800wiSeven people of Hispanic descent in the state of Maryland have been diagnosed with listeriosis, an infection caused by the Listeria monocytogenes bacteria. One person in California was also infected, but has since died from the infection. The outbreak had occurred from August to November of 2013.

The Maryland patients reported that they had all eaten a Hispanic-style soft cheese manufactured by Roos Foods in Delaware. In each of these cases, the patients bought the cheese from the same grocery store chain. A laboratory in Virginia collected samples of the cheese and confirmed the presence of Listeria monocytogenes in it. All consumers were warned by the Maryland Department of Health and Mental Hygiene not to eat any Roos Foods cheese products, in order to prevent a possible further spread of the outbreak.

Listeriosis is typically caused by eating contaminated food, such as the soft cheese mentioned above. Symptoms of listeriosis can include head ache, stiff neck, confusion, loss of balance, fever, muscle aches, and convulsions. If an infection is caused in a pregnant woman, it can lead to miscarriage, still birth, premature delivery or a serious infection to the newborn child. Five of the cases in Maryland were related to a pregnancy. Three of these include newborn children and the other two cases related to pregnancy were mothers of two of the children that had contracted the infection. Typically, infants, the elderly, and people with a weak immune system pose the greatest risk for developing listeriosis.


Case count map of listeriosis, as of Feb. 21, 2014

Case count map of listeriosis, as of Feb. 21, 2014; 80% of the cases have been in Maryland

Listeriosis can be diagnosed by isolation from blood, spinal fluid, or amniotic fluid in a clinical laboratory on a selective media plate to determine the presence of L. monocytogenes in the body. If the diagnosis is confirmed, listeriosis can be treated with antibiotics such as ampicillin.

Listeria monocytogenes is a low G and C, Gram positive, bacillus shaped bacteria that is also a facultative anaerobe. It can survive in an environment with or without the presence of oxygen. L. monocytogenes can reproduce inside human body cells and destroy red blood cells. L. monocytogenes moves by way of peritrichous flagella at room temperature, but at human body temperature, the bacterium does not make any flagella. Because it doesn’t make any flagella at body temperature, the bacterium can move within host cells by way of actin rockets, produced by the polymerization of actin filaments. L. monocytogenes has thirteen serotypes that are capable of causing disease in humans, but 90% of diseases come from just three of the thirteen serotypes. The infection this bacterium causes is responsible for the most deaths among food related bacterial pathogens. Recent outbreaks of listeriosis due to Listeria monocytogenes have come from foods such as cabbage, cheese, and cantaloupes. These outbreaks often come from a single manufacturer.

It is possible to take a few precautions to prevent contracting listeriosis. All food should be washed and handled carefully, cooked thoroughly, and stored properly to ensure its safety. Choosing safer foods (pasteurized milk as opposed to raw milk or avoiding soft cheeses, for example) can also help prevent a listeriosis infection.



Who, me?

New Picture (9)Stefi Holtzer (12:00 Micro) found another article of general health care interest. This one focuses on the best practices of the health care worker in helping to block the transmission of nosocomial infections. Here is Stefi’s summary:

Recently in class we have been discussing the prevalence of nosocomial infections and how we as future nurses can help prevent them. In the article, “The health professional’s role in preventing nosocomial infections,” different approaches are looked at in means of healthcare handling of patients today, as well as future prevention strategies are discussed.

Specifically, this article discusses how the most significant risk in nosocomial infection spread is the amount of time a patient spends in the hospital. In addition to this the article claims that the practice of hand washing is, “the single most important measure in infection control” (Saloojee &Steenhoff, 2001). The article goes on to discuss the affects of sanitizers as opposed to soap hand washing methods. The fact that it takes less time to wash one’s hands with sanitizer than soap can contribute to the fact that hand washing will be performed more frequently and effectively. The article also discusses the various forms of fomites, or inanimate objects that transmit infectious pathogens. Some of these fomites include items healthcare professional would not consider as being particularly unsanitary. These include, lab coats, rings and jewelry, and  stethoscopes. In conclusion the article states that it is important to continue to educate healthcare professionals on nosocomial infections and their roles in transmission of them.

This article was very interesting to me because as a student going into the healthcare field I am very curious about the ways in which infections are spread. I was surprised to learn about the prevalence of nosocomial infections and how easily they can be spread even when healthcare professionals take such cautious measures to maintain sanitary conditions. I am glad to have learned even more about nosocomial infections by reading this article. While, I was aware that infections can be spread throughout the hospital setting, I never gave too much thought to the fact that a simple thing such as wearing a ring while dealing with patients can spread infections. Overall, my growing knowledge on nosocomial infections has lead me to be even more cautious about my actions in staying sanitary in everyday life and has further sparked my interests in the field of microbial control.

Being clean is crucial

Courtney Gladstone (12:00 Micro) realizes the importance of hand washing. She found an article from Live Science that perhaps warnings on passing on infections to our patients are having an effect on health care workers; this is great news, but we cannot become complacent. Here is what Courtney found out:

As we discuss in class and lab especially, there are microorganisms everywhere.  They’re on the door handle, the hand railing in the stair case and the most obvious place for microorganisms to be would be in the hospital. For most of the people taking this microbiology class their jobs are most likely going to have them working hands on with these microorganisms in a hospital, an assisted living facility, the list goes  on and on. It can be scary working hands on with these types of microorganisms but with the proper cleaning and disinfecting techniques it can be controlled and cases of these infections can even be decreased!

MRSA which stands for Methicillin Resistant Staphylococcus aureus is exactly what it sounds like, it is resistant to the antibiotic methicillin which makes it very hard to treat. This microorganism can range anywhere from mild to potentially fatal. There are different types of Staphylococcus that can infect the body but the most common in the body is the Staphylococcus aureus which is what we are dealing with in this article.

This disease can be acquired by skin to skin contact. Some examples of this can be in contact sports like wrestling. In the article it was brought up that MRSA has been a problem in jails and homeless shelters because of the close quarters and the unsanitary environment. However it’s not just places like shelters and jails that can be a risky place for this, its hospitals too! However as shown in the article proper hand washing and other sanitary techniques can prevent the spread of MRSA and even decrease the rate of infection!

There were a lot of neat statistics stated in the article that showed how these steps towards more sanitary environments can prevent and lower the rate of infection.  “The number of deaths associated with MRSA has also dropped. In 2005, more than 21,000 people in the U.S. were infected with MRSA at the time of their death, Dantes said. By 2011, the number had fallen to slightly more than 11,000 — a 47 percent drop. In total, there were 80,461 invasive MRSA cases nationwide in 2011, compared with 111,261 MRSA cases in 2005, according to the study.” All of these statistics were said to be the aftermath of proper education about keeping yourself sanitary with all of the correct hand washing methods. “The decline of MRSA is likely due to hospital programs that encourage hand washing, and the wider use of sterile techniques to keep catheters and intravenous lines clean, Dantes said.” Dr. Eli Perencevich, an epidemiologist at the University of Iowa who was mentioned in this article as well said that healthcare workers can prevent all of these antibiotic resistant just by practicing great hand hygiene and following other guidelines in their facility.

This doesn’t just have to be followed in places like the hospital; these precautions should be taken everywhere. You never really know what could be lurking on the lab bench or on the elevator buttons. It’s better to be safe than sorry, especially in this case. Something to take from this…. WASH YOUR HANDS PEOPLE!

Notes from the Field: Salmonella from Microbiology lab

CaptureWe have a two-fer in this week’s CDC Morbidity and Mortality Weekly Report; several “Notes from the Field,” and an outbreak of Salmonella. Imagine my surprise to see that the Salmonella outbreak was from a college microbiology laboratory.  Actually, I wasn’t surprised at all, and BIO230 students will recall that I warned of these dangers in our very first class meeting this semester. The CDC reports that a case of salmonellosis was verified by the Maine Center for Disease Control in May 2013, and a second case was additionally reported shortly thereafter. Both patients complained of diarrhea, fever, and nausea, after attending Microbiology lab at a local community college. Molecular characterization of the patient isolates were identical, and further matched the isolate used in the class laboratory exercises.

Members of the Maine state testing laboratory visited the community college lab, and interviewed faculty and students to determine what infection control practices were in place. Survey results indicated that erratic personal protection methods were in place, including inconsistent and improper use of gloves, as well as inconsistent hand washing. Examination of control practices in the laboratory were unable to pinpoint the source of the infection, which may have resulted from direct handling of Salmonella cultures, a spill, or lab equipment that may have become contaminated. Recommendations from review of policies were much in line with the recommendations from the prior Salmonella outbreak. First, personal protective equipment including gloves, proper clothing, lab coats, and safety goggles should be used under all conditions where infection risk exists. Second, lab coats must remain in the laboratory, and can only leave the laboratory after being autoclaved. Third, all personal items such as cell phones must remain outside of the laboratory. Infectious agents may remain viable for extended periods of time, and are easily removed from the controlled laboratory setting on these items. Forth, hand hygiene remains one of the most effective methods for controlling infection in and out of the lab. Adherence to these rules of Microbiology Club will ensure that we have happy students, and happy instructors!

Salmonella from government shutdown!


Via io9, a news alert about a huge multistate outbreak due to Salmonella. I’d be snarky in any summary I would put up, but is is unlikely that I would do as good of a job, so I will just refer everyone there. Please go read it! I would say that we can rest easy because the professionals are handling it, but that is not the case today. Wash your hands an extra time.

Update! Via CBSNews, apparently food monitoring workers at the CDC have been called back to work to deal with this. I only hope they will get paid.

Update 2! I have put up a placeholder post for the current flu season. As you might be able to tell, we don’t know how much flu there is, or where it is.

New news on cat urine


“Mr. Pickels, we should get that nice Professor Singleton to change your litter box”

I was over at the vet’s office on Friday, and while I was waiting for Happy the Hamster to finish up with her exam, I noted this news alert from up on the office wall, with the intriguing headline “Good kitty, Good science, Bad journalism”.  The editorial took the national news media to task for their reporting of an extensive behavioral study from the journal JAMA Psychiatry (note: free access to the article if you get to it via the YCP Library page). The study followed a cohort of over 45,000 women in Denmark over the period of time from 1992 to 2006, and examined the question as to whether Toxoplasm gondii infected women were at any higher risk for self-directed violence or suicide. The story was widely reported when it came out, and according to, inappropriately slanted the findings of the study to overemphasize the potential risks due to Toxoplasma infection. My interest in this story reflects both my role as a litter-box cleaner, and as a student of the dangers of Toxoplasma

Here is the Danish study in a nutshell: 45,778 Danish women were enrolled in a study from between 1992 and 1995, shortly after giving birth. At this time, blood was drawn from the infant to determine whether the subject was asymptomatically infected with the protozoan parasite Toxoplasma gondii. Because newborn babies do not produce antibody themselves at this time, the presence of Toxoplasma specific antibodies in the baby’s circulation result from the passage of antibody from the mother across the placenta prior to birth. Subjects were followed through a blinded study (investigators never knew the identity of any of the subjects), and assessed for self-directed violence, suicide attempts, and suicide.

The study found that approximately one quarter (26.8%) of the population was seropositive for Toxoplasma antibodies, suggesting potentially sub-clinical infection. Of the 45,000 subjects followed through the study period (over half a million person years), researchers found that 488 had a first contact for some indication of self-directed violence. These subjects were then followed up through the remainder of the study period regardless of their serological status to Toxoplasma. When seropositive and seronegative subjects were finally compared at the end of the study, it was found that seropositive subjects (i.e. those who had a positive titer of antibody to Toxomplasm gondii at the time of their child’s delivery) had a 1.53-fold higher risk of committing a violent act against themselves. The authors of the study propose a potential mechanism to explain the results, and suggest that an inflammatory response designed to keep the pathogen in check might cause activation of certain neuronal cells and lead to behavioral changes. The authors note that the study cannot distinguish between the direction of causation–an alternative hypothesis might be that a preexisting neuroimmune abnormality might make an individual more susceptible to Toxoplasma infection.

Note: women can safely change the litter box after they are no longer pregnant

Toxoplasma infection (over one quarter of the women enrolled in the study!), it makes no attempt to identify the source of their infections. Cat feces are certainly an important route of transmission, and indeed if you go to the Centers for Disease Control and Prevention’s site on toxoplasmosis, cats are the first animal mentioned on the page, and they explicitly recommend that if you are pregnant you should have someone else clean the cat box. However, with such a high rate of infection, a more significant risk of infection are other environmental sources such as gardening in soil that is contaminated with the organism.

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