#37: PCR Testing for Bacteria

Improving management and patient outcomes should be, and I believe is, the main goal of most health care providers.  The odds of accomplishing this when faced with Urinary Tract Infections, the most common type of bacterial infection,  increase by using the most efficacious and sensitive type of bacterial testing available.  For years we tested for UTIs using standard culture plates looking for the presence of bacteria and elevated white blood cells, and many providers still do.  Research and evidence-based care have revealed the standard culture plate is inferior to Polymerase Chain Reaction (PCR) testing.  PCR testing captures a DNA sequence of bacterial (or viral) pathogens present and amplifies (multiplies) it many times over to verify the presence of the pathogen.  Over this past year, PCR has become a household name made famous by COVID-19.  The history of PCR started in 1976 with the discovery of TAQ Polymerase, an enzyme found in the bacteria Thermus AQuaticus, which lived in the hot springs of Yellowstone Park.  In the early 1980s, a biochemist named Kary Mullis discovered how to put this thermally resistant enzyme (able to withstand temps up to 95 degrees C) to use and invented the PCR technique.  He was awarded the Nobel prize in chemistry in 1993.  

As the number of pathogens discovered over the years increased it became evident how plate-dominate E. Coli was on standard agar culture plates.  E. Coli grew therefore we knew it was present, but what about the other pathogens that take longer to grow, or pathogens dominated by E. coli and therefore unseen, or the ones that just simply could not grow in the nutritional environment E. coli thrived in?  We know there are fastidious organisms (organisms with very complicated nutritional requirements) that will not grow on a standard culture plate.

Gram-Positive bacteria will not grow on a standard agar plate, and although they are easier to kill than Gram-negative bacteria, isn’t it important to know exactly what bacteria exists in the UTI being treated?  Staphylococcus saprophyticus and Enterococcus facecalis are the two most prevalent Gram-positive uropathogens seen.   Although most UTIs are caused by Gram-negative bacteria, the prevalence of polymicrobial infections has increased significantly in the past decade or two prompting the question, “ Does E. Coli cause 70 percent of all UTIs or are we missing other pathogens present?”

Waking long-dormant nightmares of microbiology class may cause uncontrolled fever and chills in some of you however knowledge is power.  PCR testing is fast becoming the industry standard and in addition to our urinary panels we have respiratory panels and are validating several other panels.  Using PCR testing will help decrease the overuse of antibiotics which we all know is a relevant problem today.  We appreciate all of you and thank you for your business.

Lance Benedict

President/CEO Industry Lab Diagnostic Partners 

#36: Immunity Takes Time

Last week we had a patient test positive for COVID-19 weeks after receiving two doses of a vaccine. This patient was also positive for COVID-19 in September/October of 2020 and has had several negative tests since recovering.  Oh my goodness, “Ma, hide the kids!”  Everyone take a deep breath.  There are several reasons this could happen.  

First and foremost, none of the vaccines out there (and there are many more than Moderna and Pfizer) are 100 percent effective.  There will always be a small percentage of the population who will still acquire the disease they are being vaccinated for.  Additionally, you do not receive the second dose of the vaccination one day and become COVID invincible the next.  Vaccinations work by making your body believe some type of foreign invader has gotten inside the gates and it reacts by building up immunity against the invader.  This takes time.  Experts say anywhere from 14 days to two months along with the caveat that “everyone is different”, which means it may be longer for some to develop a sufficient immune response. 

The purpose of the vaccine is to cause your body to develop immunity to the virus, it does not prevent you from coming in contact with the virus.  The patient we tested is asymptomatic this time after being very sick the first time.  Perhaps the natural immunity from the first episode in October, or early vaccine developed immunity, may help ward off any symptoms.  We know that some people get exposed to the virus before they receive the vaccination and display symptoms after.  The vaccines being used in the US do not contain any live virus.  You will not test positive for the virus on a RT-PCR test because you had the vaccine.  However, if one was to have an antibody test several months after having the vaccination, there is a chance the test may be positive.  We still do not know definitively how the vaccine will affect antibody tests. 

Finally, although the experts feel confident that the vaccines are very effective against preventing the disease, they do not know how effective they are against preventing infection.  In other words, you may still be able to have the SARS-CoV-2 virus in your nares and potentially spread it, without having the COVID-19 disease.  The bottom line is, nobody knows for sure at this time if a vaccinated individual can still spread the disease.  Therefore continuing preventative measures, as if you have not been vaccinated, is recommended.  Masks, social distancing, avoiding gatherings, and GREAT hygiene are still the norm.  You will notice I use a lot of non-definitive words. “We think, experts feel, there is the chance, you may, etc.”  As I have stated prior, COVID-19 is an ever-changing target and the quickly developed vaccinations are no exception.

Remember to take one day at a time.  Think, read and educate yourself daily.  Please stay safe and do something nice for someone today.  Thank you all for your business.

Lance Benedict

President/CEO Industry Lab Diagnostic Partners 

 

#35: A Healthy Respect of Covid-19

 In March of 1933 our 32^nd President spoke these words, “..the only thing we have to fear, is fear itself--nameless, unreasoning, unjustified terror which paralyzes needed efforts to convert retreat into advance.”  The disease COVID-19, caused by the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) has produced this effect on much of the world today.  FDR was not referring to a world pandemic during his inauguration speech, however, I submit his words can be applied to our present-day circumstance.  I propose the term “healthy respect” should be substituted for the term fear regarding COVID-19.  Most of those reading this are involved with healthcare in some fashion and your best weapon against developing paralyzing fear is knowledge. 

Through worldwide study and collaboration, experts generally accept the infectious period (the period in which one who has the virus may spread it) to be 10 days after the onset of infection.  However, it has been determined a small fraction of persons with severe COVID-19 may shed replication-competent virus for up to 20 days.  Additionally, if one practices excellent hygiene (washing hands thoroughly, keeping hands away from the face, coughing and sneezing into elbow creases, etc) and is not within 6 feet for at least 15 minutes of someone who is infected with SARS-CoV-2 the odds are one would not get it.  Currently based on existing literature, the incubation time (time from exposure to development of symptoms) is anywhere from 2-14 days.  This is important as I have fielded multiple questions regarding someone testing RT-PCR negative a day or two after being exposed and then developing symptoms and testing positive several days later. 

Another frequently asked question involves the wearing of face masks.  Although I, just like many of you, am not a fan of face masks there is undeniable evidence the appropriate use of them will decrease the spread of this disease.  From our knowledge of the incubation period as well as what has been learned about SARS-CoV-2 positive patients who are asymptomatic, many people walk around capable of spreading the disease without anyone’s knowledge.  If you are that person, wearing a mask along with the other previously mentioned hygienic practices will decrease your odds of spreading it significantly.  Those that don’t have the disease will improve their chances of not contracting it by wearing a mask as well. 

Look, COVID-19 is an ever-changing target.  Respect it but dig into any new information from credible sources as soon as it comes out and your comfort level in dealing with it will rise.  Next time I will discuss the patient who recently had both doses of the vaccine, after having COVID several months ago, and tested positive last week.  Until then, stay safe, hug your loved ones daily, and as always thank you for your business.

 

Lance Benedict

President/CEO Industry Lab Diagnostic Partners