Editing Streptococcus pyogenes (section)

==Epidemiology==
[[File:Streptococcus pyogenes.jpg|thumb|Chains of ''S. pyogenes'' bacteria (orange) at 900× magnification]]
[[File:Gram stain of Streptococcus pyogenes.jpg|thumb|[[Gram stain]] of ''Streptococcus pyogenes''.]]
Unlike most bacterial pathogens, ''S. pyogenes'' only infects humans. Thus, [[Zoonosis|zoonotic transmission]] from an animal (or animal products) to a human is rare.<ref>{{cite journal | vauthors = Gera K, McIver KS | title = Laboratory growth and maintenance of Streptococcus pyogenes (the Group A Streptococcus, GAS) | journal = Current Protocols in Microbiology | volume = 30 | pages = 9D.2.1–9D.2.13 | date = October 2013 | pmid = 24510893 | pmc = 3920295 | doi = 10.1002/9780471729259.mc09d02s30 }}</ref>

''S. pyogenes'' typically colonizes the throat, genital mucosa, [[rectum]], and skin. Of healthy adults, 1% to 5% have throat, vaginal, or rectal carriage, with children being more common carriers. Most frequently, transmission from one person to another occurs due to inhalation of [[respiratory droplet]]s, produced by sneezing and coughing from an infected person. Skin contact, contact with [[Fomite|objects]] harboring the bacterium, and consumption of contaminated food are possible but uncommon modes of transmission. [[Streptococcal pharyngitis]] occurs most frequently in late winter to early spring in most countries as indoor spaces are used more often and thus more crowded. Disease cases are the lowest during autumn.<ref name="epidemiology">{{cite book| vauthors = Androulla E, Theresa L |chapter=Epidemiology of Streptococcus pyogenes |title=Streptococcus pyogenes : Basic Biology to Clinical Manifestations|date=February 10, 2016|publisher=University of Oklahoma Health Sciences Center |location=Oklahoma City, United States |chapter-url= https://www.ncbi.nlm.nih.gov/books/NBK343616/ |access-date=February 24, 2018 |pmid=26866237 }}</ref>

Maternal ''S. pyogenes'' infection usually happens in late pregnancy, at more than 30 weeks of [[Gestational age|gestation]] to four weeks [[postpartum]]. Maternal infections account for 2 to 4% of all clinically diagnosed ''S. pyogenes'' infections.<ref name="epidemiology" /> The risk of [[sepsis]] is relatively high compared to other bacterial infections acquired during pregnancy, and ''S. pyogenes'' is a leading cause of [[septic shock]] and death in pregnant and postpartum women.<ref>{{cite journal | vauthors = Tanaka H, Katsuragi S, Hasegawa J, Tanaka K, Osato K, Nakata M, Murakoshi T, Sekizawa A, Kanayama N, Ishiwata I, Ikeda T | display-authors = 6 | title = The most common causative bacteria in maternal sepsis-related deaths in Japan were group A Streptococcus: A nationwide survey | journal = Journal of Infection and Chemotherapy | volume = 25 | issue = 1 | pages = 41–44 | date = January 2019 | pmid = 30377069 | doi = 10.1016/j.jiac.2018.10.004 }}</ref>