Editing Plague (disease) (section)

===Bubonic plague===
{{Main|Bubonic plague}}

[[File:Plague -buboes.jpg|thumb|Swollen inguinal lymph glands on a person infected with the bubonic plague. The swollen lymph glands are termed ''buboes'' from the Greek word for groin, swollen gland: ''bubo''.]]

When a flea bites a human and contaminates the wound with regurgitated blood, the plague-causing bacteria are passed into the tissue. ''Y. pestis'' can reproduce inside cells, so even if [[phagocytosis|phagocytosed]], they can still survive. Once in the body, the bacteria can enter the [[lymphatic system]], which drains [[interstitial fluid]]. Plague bacteria secrete several [[toxin]]s, one of which is known to cause [[beta blocker|beta-adrenergic blockade]].<ref>{{cite journal |last1=Brown |first1=SD |last2=Montie |first2=TC |title=Beta-adrenergic blocking activity of Yersinia pestis murine toxin |journal=[[Infection and Immunity]] |volume=18 |issue=1 |pages=85–93 |year=1977 |doi=10.1128/IAI.18.1.85-93.1977 |pmid=198377 |pmc=421197 |url=}}</ref>

''Y. pestis'' spreads through the [[lymphatic vessels]] of the infected human until it reaches a [[lymph node]], where it causes acute [[lymphadenopathy|lymphadenitis]].<ref>{{cite journal|last1=Sebbane|first1=F|last2=Jarret|first2=C.O.|last3=Gardner|first3=D|last4=Long|first4=D|last5=Hinnebusch|first5=B.J.|title=Role of ''Yersinia pestis'' plasminogen activator in the incidence of distinct septicemic and bubonic forms of flea-borne plague|journal=Proc Natl Acad Sci U S A|volume=103|issue=14|pages=5526–5530|doi=10.1073/pnas.0509544103|pmid=16567636|pmc=1414629|year=2006|bibcode=2006PNAS..103.5526S|doi-access=free}}</ref> The swollen lymph nodes form the characteristic [[bubo]]es associated with the disease,<ref>{{cite web|title=Symptoms &#124; Plague|url=https://www.cdc.gov/plague/symptoms/|website=Centers for Disease Control and Prevention|access-date=18 April 2017|date=14 September 2015}}</ref> and autopsies of these buboes have revealed them to be mostly [[bleeding|hemorrhagic]] or [[necrosis|necrotic]].<ref>{{cite journal|last1=Sebbane|first1=F|last2=Gardner|first2=D|last3=Long|first3=D|last4=Gowen|first4=B.B.|last5=Hinnebusch|first5=B.J.|title=Kinetics of Disease Progression and Host Response in a Rat Model of Bubonic Plague|journal=Am J Pathol|volume=166|issue=5|pages=1427–1439|doi=10.1016/S0002-9440(10)62360-7|pmid=15855643|pmc=1606397|year=2005}}</ref>

If the lymph node is overwhelmed, the infection can pass into the bloodstream, causing ''secondary septicemic plague'' and if the lungs are seeded, it can cause ''secondary pneumonic plague''.<ref>{{cite web|title=Plague|publisher=Centers for Disease Control and Prevention|url=https://www.cdc.gov/plague/healthcare/clinicians.html|access-date=2014-08-05}}</ref>