Pertussis and Diphtheria


by Brian Gee and Laura PerryPertussis.png

PERTUSSIS
by B. Gee

Pertussis is a respiratory infection caused by a bacteria called Bordetella pertussis. This illness, known most commonly as whooping cough was considered one of the most frequent and severe diseases in the United States until immunization was introduced in the 1930's. According to the Department of Heath and Human Services between 5,000 and 10,000 people each year are reported with Pertussis and the number is steadily increasing with our growing population. The US incidence rate in 2007 was roughly 3.6/100,000 with over 10,000 reported cases. Although a vaccination for B. pertussis is given to adolescents the effects wear off around the teenage years. Not only is this B. pertussis a danger in the US, it is even more prevalent in developing countries such like Africa. Researchers such as K. Nagalo are studing the absolute rate of lymphocytes as an alternative method to identify whooping cough.

Pertussis affects both humans and higher primates specifically. It is most commonly found/cultivated on rich media with an ample supply of blood. While both adults and children are susceptible to B. pertussis the infant mortality rate is much higher because children are unable to cope with the stress of coughing to keep their airways open. This limits oxygen flow to the brain and can cause irreversible dammage. (Tortora & Funke 2007)

The reason for this pathogen’s efficiency of invading the respiratory tract is because of two characteristics. It uses filamentous hemagglutinin, resembling fimbriae allow it to "stick" and colonize the respiratory epithelium. B. pertussis also releases PTx (cell-bound pertussis toxin) which enhances its adherence to the tracheal epithelium. When the degredation of the cilary action, mucus begins to accumulate which ultimately results in a coughing spasm of the infected individual in an attempt to dislodge the mucus. Such intense coughing in small children can often result in broken bones. (Tortora & Funke 2007)

Scientifically defined, Bordetella pertussis is a gram-negative aerobic coccobacillus belonging to the genus Bordetella. However unless you are working in a microbiology laboratory and are able to examine your blood, it is highly unlikely for an individual to identify this pathogen. A much more realistic method of identifying Pertussis is by recognizing some of its symptoms. There are three stages of Pertussis, the catarrhal, paroxysmal and convalescence stages. Each has unique characteristics which distinguish it from tho others.

Catarrhal Stage
Colonization in the upper respiratory tract causes a fever, paroxysmal spasms, malaise and coughing. These symptoms will resemble the common cold. (Tortora & Funke 2007)

Paroxysmal Stage
Coughing becomes prolonged ending with its characteristic gasp or whoop. Occuring several times a day for 1 to 6 weeks. (Tortora & Funke 2007)

Convalescence Stage
The recovery period of Pertussis which can last for months before completely subsiding. (Tortora & Funke 2007)


diagram_of_bordetella_pertussis.gif

If you suspect yourself or another of having Pertussis based on the above characteristics, it is important to know that only the FIRST stage is treatable with antibiotics. Once the illness moves to the second stage, it is resistant to antibiotics and generally unresponsive to treatment. This places extra importance to early identification and examination by a health care professional. The following website is just one of many that list other possible symptoms of Pertussis.

Helpful Websites
Symptom Identification
Todar's Online Textbook of Bacteriology
Listen to Whooping Cough

References

Bordetella pertussis [online image] (n.d.). Retrieved May 9, 2009 from google images.
http://www.cdc.jknsabah.gov.my/Images/Diseases/Pertussis.png

Bordetella pertussis [online image] (n.d.). Retrieved May 9, 2009 from googleimages.
images.google.com/imgres?imgurl=http://www.infectieziektebulletin.be/uploadedImages/figuur-1-bordetella-pertuss.gif&imgrefurl=http://www.infectieziektebulletin.be/defaultSubsite.aspx%3Fid%3D11990&usg=__J0IsJH_bf9DsP87xRzbbgCeTTcI=&h=321&w=337&sz=13&hl=en&start=40&um=1&tbnid=_kYScTe2D2rV6M:&tbnh=113&tbnw=119&prev

C Locht and JM Keith. "Pertussis Toxin Gene: Nucelotide Sequence and Genetic Organization." Science Volume: 232, Issue 4755 (1986) 1258-1264

Emrah Altindis, Burcu E. Tefon, Volkan Yildirim, Erkan Ozcengiz, Dorte Becher, Michael Hecker and Gulay Ozcengiz. "Immunoproteomic Analysis of Bordetella pertussis and Identification of New Immunogenic Proteins." Vaccine Volume: 27, Issue 4 (2009) 542-548

M Pizza, A Covacci, A Bartoloni, M Perugini, L Nencioni, MT De Magistris, L Villa, D Nucci, R Manetti, M Bugnoli, and al. et. "Mutants of Pertussis Toxin Suitable for Vaccine Development." Science Volume 246, Issue 4929 (1989) 497-500

Pertussis. 5 May. 2009. Department of Heath and Human Services Center for Disease Control and Prevention. 25 March. 2009
<http://www.cdc.gov/ncidod/dbmd/diseaseinfo/pertussis_t.htm>

Tortora, Funke and Case. Microbiology an Introduction 9th ed. California: Pearson Education. (2007) 718-719


DIPHTHERIA
by L. Perry
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What is diphtheria?
Diphtheria is an acute bacterial infection characterized by the formation of a grey-ish membrane over the throat and nasal passages, which, in severe cases, can cause suffocation. It is a potentially fatal infection caused by Corynebacterium diphtheriae, a gram-positive bacillus. This bacterium can affect any of the mucous membranes of the body, but most often causes an infection of the upper respiratory tract with "90 percent of cases affecting the larynx (voice box), pharynx, or tonsils" (Kagan & Gall, 2007) C. diphtheriae produces a toxin that is responsible for killing cells within the mucous membrane. In some cases this toxin can spread to the heart and nervous system of the person infected causing an enlarged heart or paralysis. Symptoms of C. diphtheriae include cough, low-grade fever, swelling and tenderness of the neck, throat, and tonsils, and a thick, grey-ish covering on the throat and tonsils.



Who is affected?
At one time diphtheria was a major childhood disease. In the early 20th century it was one of the leading causes of death among infants and children. In the 1920s there were about 100,000 to 200,000 cases in the U.S. per year. In 1942 a vaccine was discovered and virtually wiped out the disease in industrialized countries. C. diphtheriae is highly infectious but at this point in time is more likely to be endemic in less developed countries where poverty, poor sanitation, over crowding and low vaccination rates are common.

How is it transmitted?
Diphtheria is usually transmitted by contact with infected droplets from the respiratory tract through couching or sneezing as well as through contaminated objects or food. People who are untreated will remain infectious for two to three weeks after exposure.



How is it treated?
The vaccine was introduced in 1942. It is administered in combination with the tetanus and pertussis (whooping cough) vaccines, collectively known as DTaP. In the United States this vaccine is given in five doses, including two booster shots, to children under the age of seven. The timeline for the vaccination may vary but usually goes as follows: The first dose at two months old, a dose at four months old, a dose at six months old, a booster shot at 15 to 18 months old, and another booster shot at 4 to 6 years old (Frey & Longe, 2006). Boosters are given to increase the number of protective antibodies in the blood because over time your body will lose it’s immunity to the disease.


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If the person in not vaccinated they are treated with antitoxin, which neutralizes the toxin produced by C. diphtheriae before it can do too much damage to the body. The antitoxin works by causing the membrane covering the airways to recede dramatically. Antibiotics are also given, the two most common being erythromycin and penicillin (Lerner & Lerner, 2008).



References

Diptheria is deadly [online image]. (n.d.). Retrieved May 11, 2009, from hubpages.com.
http://hubpages.com/hub/Causes-and-Prevention-of-Diphtheria

Corynebacterium diphtheriae [online image]. (n.d.). Retrieved May 11, 2009, from googleimages.
http://202.114.65.51/fzjx/wsw/newindex/tuku/MYPER/zxj/97287c.htm

Kagan, J., & Gall, S., B. (Eds.). (2007). Diphtheria. In The gale encyclopedia of childhood and adolescence. Detroit, MI: Gale.

Lerner, B., W. & Lerner, K., L. (Eds.). (2008). Diphtheria. In Infectious diseases: In context. (Vol. 1, pg. 242-248). Detroit, MI: Gale.

Longe, J., L. (Ed.). (2006) Diphtheria. In The gale encyclopedia. (Vol. 3). Detroit, MI: Gale.