! Scarlet Fever  

Scarlet Fever By Lori Carpenter

Causative agent Scarlet fever is caused by the genus Streptococcus, which is a diverse group of gram-positive bacteria. Strepto is Greek for twisted chain and kokkos means kernel or berry. As such, these bacteria are usually arranged in pairs or chains. There are a large variety of diseases caused by the genus, but Strep. pyogenes specifically is responsible for Scarlet fever. Strep. pyogenes are facultative anaerobes, beta hemolytic, catalase negative, and characterized as Lancefield group A. (9). The name Streptococcus was chosen by Theodor Billroth, a surgeon from Vienna, Austria. He elected the name in 1874 because of the group’s spherical chain morphology and tendency to link together (9). Taxonomic Group Kingdom: Bacteria Phylum: Firmicutes Class: Bacilli Order: Lactobacillales Family: Streptococcaceae Genus: Streptococcus Species: pyogenes Historical significance Streptococcus pyogenes produced multiple epidemics throughout history. The first occurred in Sicily during 1543 and was mainly a sequela of strep throat. However, more serious infections were reported across the United States from 1830-1880 (9). More recently, severe cases have occurred in the United Kingdom in 2003-2004, resulting from the use of illegal, injectable drugs (11). Epidemiology and Public Health

 

 ! Scarlet Fever  

The many species of the Streptococcus genus are found all over the world in nature and as commensals in many mammals. Strep. pyogenes has been responsible for more than 10 million infections since its discovery. A century ago, more than 150,000 cases were reported yearly. Although not as common today, annually, approximately 9,000 cases are found in the United States alone. In Texas, 333 cases were reported in 2012 with 125 of those infected were of 60 years or older (10). Currently, the United Kingdom has been experiencing recent outbreaks. In 2013, 3,548 cases were seen, as compared with a previous average of only 1,420 in the last decade (13).

(a). (b).

(a). Examination of colony morphology shown after Gram-staining. Note tendency to form pairs and chains (6). (b). Red bumps shown around throat and tonsils, characteristic of Scarlet fever (2). Transmission Since Streptococcus bacteria are part of the normal flora of humans and animals, they can be transmitted in different ways (9). Strep. pyogenes can live in a person’s nose or throat and is spread via aerosol droplets resulting from a cough or sneeze from an infected person. These bacteria can be inhaled through the nose, swallowed from introduction into the mouth, or absorb from mucous membranes, such as the conjunctiva of the eye (1). Transmission may also occur from contact with infected wounds or sores on the skin (10).

 

 ! Scarlet Fever  

Scarlet fever can be seen at any age, but is seen most commonly in children, ages 5-15. Crowded environments such as those that can be seen in day care or military settings can also increase risk factors. Infections are more prevalent in the spring and fall, but can occur year round (11). Pathogenesis and Virulence Factors Diseases caused by Streptococcus pyogenes can be further classified as: Strep throat, Scarlet fever, Impetigo, Streptococcal toxic shock syndrome, and necrotizing fasciitis. Their development will depend on several factors, including body system affected and bacterial port of entry. When Strep. pyogenes enter human tissue, a systemic inflammatory response is initiated causing vasodilation and neutrophil invasion. However, when neutrophils phagocytize invading bacteria, bacteria resist neutrophillic enzymes and will multiply inside the white blood cell. In response to toxins produced by enzymes released after the death of the neutrophil, dead tissue becomes liquefied. The ability to produce this thick pus from the nuclei of dead cells is a key part of the pathogenesis of Strep. pyogenes (9). Strep.pyogenes produces an exotoxin when it is infected with a bacteriophage, called T12. This converts the bacteria it from its original, non-toxic form, into Streptococcus erythrotoxin type A, which is directly responsible for Scarlet fever, and the red rash associated with it (15).

(c). (d).

 

 ! Scarlet Fever  

(c). Skin rash present on the neck, arms, and trunk (7). (d). Typical quarantine sign posted on houses containing infected persons with Scarlet fever. Posted in Field Township, 1922 (4). Symptomology Streptococcus pyogenes is responsible for both invasive and non-invasive disease (10). The incubation period for Scarlet fever, a non-invasive infection, is generally 1-2 days and begins with a sore throat and fever, but may include abdominal pain, chills, and vomiting (11),(1). A rash, will quickly develop on the neck and chest, later spreading all over the body (5). The rash usually appears as small, flat red blotches that eventually will become bumpy and feel like sandpaper to the touch (1),(12). The tongue of infected patients is also red and bumpy, with the characteristic “strawberry-like” appearance, along with the tonsils and throat. These bumps will make eating and swallowing very painful (1). The rash will fade after around seven days, causing the fingertips, toes, and groin area to peel for several weeks (1). Diagnosis A presumptive diagnosis of Strep. pyogenes can be made from samples obtained from biopsies, smears, wound aspirates, pharyngeal secretions, blood, or CSF if gram-positive cocci are observed in chains or pairs. Other, more specific diagnoses are confirmed via culture and identification from blood agar or from serology with antigen detection. A PYR reaction and susceptibility to bacitracin, antistreptolysin O and antihyaluronidaste titers, or anti-D Nase B will all prove positive for Strep. pyogenes (9). Recently, newer and more rapid diagnostic tests, including direct carbohydrate antigen and nucleic acid probe detection, are now available (14).

(e). (f).

 

 ! Scarlet Fever  

(e). Necrotizing fasciitis attacking the forearm after surgical debridement (8). (f). “Strawberry” tongue seen in a child with Scarlet fever (3).

Treatment In humans, infections caused by Streptococcus pyogenes are treated with great success using a variety of antibiotics. Penicillin, amoxicillin, ampicillin, cephalosporins, vancomycin, and clindamycin all prove efficacious (6),(9), (12). Management and Control Early identification and treatment are best to control the spread of infection. The Center for Disease Control also recommends limited contact with those suffering from sore throat, maintaining good personal hygiene such as covering the mouth or nose while coughing or sneezing, and washing hands frequently (5). Bibliography

1. Center for Disease Control. “Scarlet Fever: A Group A Streptococcal Infection.”

Updated: Jan 6, 2014. Accessed: March 8, 2014. Web.

http://www.cdc.gov/features/scarletfever/

2. Davis, Charles Patrick, MD, PhD. Medicine Net onhealth.com: “Streptococcal

Infections.” Edited: May 9, 2012. Accessed: March 8, 2014. Web:

http://www.onhealth.com/streptococcal_infections/article.htm

14. Fox, James W. Journal of Clinical Microbiology. “Diagnosis of Streptococcal

Pharyngitis by Detection of Streptococcus pyogenes in Posterior Pharyngeal versus Oral

Cavity Specimens.” Published: July, 2006. Accessed: March 24, 2014. Web.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489465/#__ffn_sectitle

 

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3. Habif, Thomas P. Clinical dermatology: A color guide to diagnosis & therapy.

Publication date: 2004. Accessed: March 8, 2014. Web:

http://hardinmd.lib.uiowa.edu/dermnet/scarlet3.html

4. McKay, Maddie. Museum of Health Care. “Would I have died? Scarlet Fever.”

Posted: July 6, 2012. Accessed: March 8, 2014.

http://museumofhealthcare.wordpress.com/2012/07/06/would-i-have-died-scarlet-

fever/

13. Meikle, James. The Guardian. Posted: March 21, 2014. Accessed: March 24, 2014.

Web. http://www.theguardian.com/society/2014/mar/21/scarlet-fever-cases-children-

england-highest-level-1990.

5. New York City Department of Health and Mental Hygeine. “Scarlet Fever.”

Updated: March 2003. Accessed: March 8, 2014. Web.

http://www.nyc.gov/html/doh/html/diseases/cdscarlet.shtml

6. ProProfs Flashcards. Streptococcus pyogenes. Created: December 12, 2010.

Accessed: March 8, 2014. Web:

http://www.proprofs.com/flashcards/story.php?title=medical-bugs_1

 

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7. Reese, Charlotte. “Streptococcus pyogenes: A Microbiology Project.” Publication

date not listed. Accessed: March 8, 2014. Web: http://pyogenesgonewild.com/

8. Rodriguez, Laura V. “Group A Streptococcus.” Publication date not listed.

Accessed: March 8, 2014. Web: http://www.austincc.edu/microbio/2993q/sp.htm.

 

9.    Rominch, Janet Amundson. Understanding Zoonotic Diseases. Canada: Delmar

Learning Corporation, 2008. p. 196-205. Print.

10. Texas Department of State Health Services. “Infeccious Disease Control:

Streptococcal Diseases.” Updated: February 11, 2014. Accessed: March 8, 2014.

Web. https://www.dshs.state.tx.us/idcu/disease/strep/groupa/

11. United States National Library of Medicine. Pub Med Health: “Scarlet Fever.”

Updated: March 15, 2012. Accessed: March 8, 2014. Web.

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001969/

 

12. Vorvick, Linda, MD. National Institute of Health. Medline Plus: “Scarlet Fever.”

Updated: May 12, 2012. Accessed: March 8, 2014. Web.

http://www.nlm.nih.gov/medlineplus/ency/article/000974.htm

15. Weeks, C.R. American Society of Microbiology: Infection and Immunity. “The gene

for type A streptococcal exotoxin (erythrogenic toxin) is located in bacteriophage T12.”

 

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Published: November, 1984. Accessed: March 24, 2014. Web.

http://iai.asm.org/content/46/2/531