Editing Clade (section)

==Viruses==
[[File:HIV-SIV-phylogenetic-tree straight.svg|right|thumb|[[Phylogenetic tree]] of the SIV and HIV viruses showing clades (subtypes) of the virus.]]
[[Viruses]], and particularly [[RNA viruses]] form clades.<ref name="Yamaji-2020">{{cite journal |vauthors=Yamaji R, Saad MD, Davis CT, Swayne DE, Wang D, Wong FY, McCauley JW, Peiris JS, Webby RJ, Fouchier RA, Kawaoka Y, Zhang W |title=Pandemic potential of highly pathogenic avian influenza clade 2.3.4.4 A(H5) viruses |journal=Reviews in Medical Virology |volume=30 |issue=3 |pages=e2099 |date=May 2020 |pmid=32135031 |pmc=9285678 |doi=10.1002/rmv.2099 |url=}}</ref> These are useful in [[epidemiology|tracking the spread of viral infections]]. [[HIV]], for example, has clades called subtypes, which vary in geographical prevalence.<ref name="Stebbing-2003">{{cite journal |vauthors=Stebbing J, Moyle G |title=The clades of HIV: their origins and clinical significance |journal=AIDS Reviews |volume=5 |issue=4 |pages=205–13 |date=2003 |pmid=15011999 |doi= |url=}}</ref> HIV subtype (clade) B, for example is predominant in Europe, the Americas and Japan, whereas subtype A is more common in east Africa.<ref name="Sarabia-2019">{{cite journal |vauthors=Sarabia I, Bosque A |title=HIV-1 Latency and Latency Reversal: Does Subtype Matter? |journal=Viruses |volume=11 |issue=12 |date=November 2019 |page=1104 |pmid=31795223 |pmc=6950696 |doi=10.3390/v11121104 |url= |doi-access=free }}</ref>