Bordetella Pertusis

Bordetella PertussisAuthor: Katie McCorkle
Date: May 13, 2009

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en.wikipedia.org/wiki/Bordetella_pertussis


Abstract:

I chose to research Bordetella Pertussis because it the causive microbe of whooping cough, a potentially life threatening childhood disease. I am pursuing a career in Nursing, so what caught my interests was what results from exposure to Bordetella Pertussis? Some questions that I had were: What is the progression of the infection? What can be done to treat an infection? And what are the preventative measures? Bordetella Petussis is a fairly well understood pathogen and treatment and preventative measures are well developed and widely used.

Introduction:

B. Pertussis is something that we do not often have to think about because many of us are vaccinated against it as children. However with the rising fear of vaccines, perhaps we need to be better educated of what exactly the vaccine is trying to prevent. I will not be commenting on vaccine issues. However, my desire it to better educate you, the reader, about B. Pertussis.
My hope is to dicuss common questions relating to this bacterium and the infection that follows. If we are not aware of the harm that this bacterium can do we are more likely to ignore it. In the case of children, ignoring such a pathogen can have serious repercussions. I'm not a doctor, so if you think you have any symptoms consult your healthcare professional. Only they will be able to determine what is going on in your specific case.


Discussion:

What is Bordetella Pertussis?:
Before we can discuss what results from Bordetella Pertussis, we must first discuss its own characteristics. B. Pertussis is a gram negative coccobacillus that appear singly or in pairs. It is obligate anerobic, meaning that it requires molecular oxygen to live. The strain that is pathogenic has a capsule and is known to colonize in mammals respiratory epithelium, eventually causing whooping cough (Tortora, p. 718-719).
Virulent (pathogenic) B. Pertussis adhears itself to the a mammal's trachea via filamentous hemagglutinin (FHA), which are fimbrae like structures that help the bacteria to hang on to the environment. Cell-bound pertussis toxin is responsible for interfering and killing the cilia of the trachea, which allows a colony of B.pertussis to grow better (Todar).
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What results from exposure to B. Pertussis?
The short answer to this question is: whooping cough is the result of exposure to B. Pertussis. However, before the diagnosis of whooping cough is able to be made the bacteria has already done much damage. After Cell-bound pertussis toxin and other toxins have broken down the cilia and wounds are exposed, the body then wants to rid of the drainage from the wounds. At first it is nothing more than slightly productive cough, but as the bacteria continue to colonize there is more and more drainage. The increased need to expel the drainage results in violent, uncontrollable coughing, with a distinct gasp of air following. This gasp of air is described as a whooping noise, thus we get the term whooping cough (medlineplus.gov).
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Whooping cough can affect anyone, in any age group, but it is more severe for those who are in their first six months of life or who are otherwise immunocompromised. B. pertussis is highly contagious because it transmission is through the air. When an infected person cough, sneezes or even breathes, tiny droplets are released and can easily be inhaled by other people. This type of transmission is refered to as aerosol transportation (Wendelboe).

What is the progression of whooping cough, in an infected person?
There are three classic stages to the progression of whooping cough.
1. Catarrhal Stage: This stage is often misdiagnosed as the common cold. Symptoms include: mild to moderate rhinoherra (aka a runny nose) and a slight fever (CDPH). At this point the body is beginning its immune response. This is the stage where it is very easy for the bacteria to spread due to the fact that the patient is unaware of what they have and they may continue with their normal daily life.
2. Paroxysmal Stage: This is the stage in which the severeity of the infection is at its greatest. The coughing, sneezing and runny nose increase in severeity and occurence. Chest spasms that result in coughing are followed by a large intake of air, causing the whooping sound. Vomitting after bronciole spasm (coughing)episode is common because the violent shaking in the chest cavity. Attacks are most commonly seen at night and sleep apnea (not breathing while sleeping) often follows an episode. In between episodes the patient may appear normal and healthy. This stage lasts one to three weeks and begins subsiding in severity after two to three weeks (CDPH).
3. Convalescent Stage: This stage lasts aproximently two to six weeks, but can last up to several months. During this time the number and severity of the coughing episodes decrease, until they are completely gone (CDPH).

Complications of whooping cough can be severe. They include: pneumonia, bradycardia (heart beat of less than 50 beats per minute), apnea, conjunctivitis (infection of the membrane around the eye), loss of weight, ear infection, dehydration, collapsed lung, burst capillaries in the eyes, nose and face (causing nosebleeds, bruising around the eyes, etc.), cerebral hemorrhaging, and brain damage due to oxygen (convulsions, retardation, etc.). Some of these side effects are potentially fatal, particularly in infants (medlineplus.gov, Stojanov,S).

What is the treatment of Whooping Cough?
Normally antibiotics are perscribed once it is confirmed that a person has whooping. There are a wide variety of antibiotics types that could be used, but it depends on the patient and the doctor's preference. Particularly infants are hospitalized because they are too young to recieve the vaccine, and therefore at greater risk of having a full manifistation of the whooping cough (NCHS). As seen in the chart below, infants less than 6 months of age are more likely to be hospitalized.
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What are some preventative measures?
Currently the Centers for Disease Control (CDC) recommend that children be given the Diptheria, Tetnus and Pertussis (DTaP) vaccine as early as 6 weeks old, but no later than 6 years old. The vaccine is a requirement for many public and private schools prior to entry. Now there is discussion if there needs to be a booster vaccine given around age 12. This is due to the increase in occurences of adolescent whooping cough in recent years. The thought is that this booster would provide 'touch up' to the immune power of the infant vaccine (CDC.gov).
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The Food and Drug Administration (FDA) is responsible for monitoring the standards relating to the vaccine. While there are several brands of the DTaP vaccine, they all held to the same standards. The pertussis portion of the DTaP is created from lab grown strains of B. pertussis that are then modified chemically to not produce more than fifty endotoxins per one mililiter of solution. Thus, the vaccine contains a culture of B. pertussis, but not one that is strong enough to have damaging effects (FDA.gov).
Of course good hygiene is the best way to prevent the spread of any bacteria.
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Literature Cited:
• CDC. Recommended Immunization Schedule of Persons Aged 0 through 6 Years. Centers for Disease Control. 2009. http://www.cdc.gov/vaccines/recs/schedules/downloads/child/2009/09_0-6yrs_schedule_pr.pdf
• CDPH. Investigation and Control of Pertussis Cases and Outbreaks--pgs.3-5. California Department of Health. 2006. http://ww2.cdph.ca.gov/programs/immunize/Documents/B.%20Pertussis_Guidelines%2011-06%20cdph.pdf
• FDA. Diptheria and Tetanus Toxiods and Acellular Pertussis Vaccine Adsorbed Tripedia. Food and Drug Administration. 2005. http://www.fda.gov/cber/label/tripedialb.pdf
• Medlineplus.gov. Medline Plus Medical Encyclopedia--pertussis. http://www.nlm.nih.gov/medlineplus/ency/article/001561.htm 2007
• Sirkus, Leah, et.al. NCHS Data on Pertussis Hospitalization in Young Children. National Center of Health Statistics. 2007 http://www.cdc.gov/nchs/products/pubs/pubd/hestats/pertussis/pertussis.htm
• Stojanov, S, et.al. Hospitalization and Complications in Children under 2 Years of Age with Bordetella pertussis Infection. Infection. 2000. http://www.springerlink.com/content/q7xr4tg9jwpfrcf8/
• Todar, Kenneth. Online Textbook of Bacteriology. http://www.textbookofbacteriology.net/pertussis.html 2008
• Tortora, Gerard J. Microbiology: an introduction 9th ed. Peason Benjamin Cummings. 2007. pgs. 718-719
• Wendelboe, Aaron M, et.al. Transmission of Bordetella Pertusis to Young Infants. The Pediatric Infectious Disease Journal. 2007. http://journals.lww.com/pidj/pages/articleviewer.aspx?year=2007&issue=04000&article=00005&type=abstract