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gue
Plague
– A z o o no sis caused by the G ram -negative bacillus Yersinia pestis th at m ainly affects
wild and d o m estic ro d ents.
– P lague is transm itted to m an by the bite o f an infected flea vecto r o r thro ugh a break
in the sk in by co ntact with a ro d ent. H um an-to -hum an transm issio n o ccurs thro ugh
the bites o f hum an fleas, o r, in the case o f p neum o nic p lague, by inhaling infected
d ro p lets exp elled by co ughing.
– V ast fo ci o f infectio n rem ain in C entral and S o utheast A sia, A frica, M ad agascar, and
in No rth and S o uth A m erica.
Clinical features and progress
T here are 3 m ain clinical fo rm s:
– Bubonic plague is the m o st co m m o n fo rm : high fever, chills, head ache, asso ciated with
o ne ( o r m o re) very p ainful ly m p h no d e, usually inguinal ( b ubo ) . F requent
gastro intestinal signs: abd o m inal p ain, vo m iting, d iarrho ea, etc. T he m o rtality rate in
untreated p atients is ap p ro xim ately 5 0 % as a result o f sep ticaem ia.
– Septicaemic plague is a co m p licatio n o f untreated bubo nic p lague and is a fulm inant
illness.
– Pneumonic plague is a very co ntagio us fo rm : h igh fever, chills, head ach e, m y algia
asso ciated with p aro xy sm al co ugh ing, haem o p ty sis and resp irato ry d istress. T his
fo rm p ro gresses rap id ly , and is fatal unless treated . I t o ccurs either as a co m p licatio n
o f bubo nic p lague o r as the result o f a p rim ary infectio n.
O ccasio nally , the d isease can tak e the fo rm o f meningitic plague.
Laboratory
– I so latio n o f Y. pestis ( d irect exam inatio n and culture) fro m ly m p h no d e asp irate,
blo o d , sp utum , cerebro sp inal fluid , d ep end ing o n the fo rm invo lved .
– S ero d iagno sis: E L IS A read s p o sitive so o n after the o nset o f the illness.
– T ransp o rtatio n o f th e sam p les requires a co ld ch ain (failing that, th e tem p erature
m ust be k ep t belo w 3 0 °C ).
Management and treatment
– W hen p lague is susp ected : tak e sam p les fo r cultures and antibio tic sensitivity testing
and then treat im m ed iately witho ut waiting fo r the d iagno sis to be co nfirm ed . I nfo rm
the health autho rities as so o n as the d iagno sis has been co nfirm ed .
– I so latio n:
• P atients suffering fro m bubo nic p lague d o no t have to be iso lated . T reat the p atient
and his/ her bed d ing and clo thing with an insecticid e (e.g. permethrin 0.5% p o wd er;
see Pediculoses, p age 1 0 1 ). O bserve elem entary rules o f hy giene (wash hand s, wear
go wns, glo ves etc.).
• P atients with p rim ary o r seco nd ary p neum o nic p lague m ust be strictly iso lated .
T heir bed d ing, clo thing, sp utum and excreta m ust be d isinfected with a chlo rinated
so lutio n. O bserve elem entary rules o f hy giene (wash hand s, wear ho sp ital lab co ats,
glo ves etc.) and bo th the p atient and carers sho uld wear facem ask s.
178
Plague
– A z o o no sis caused by the G ram -negative bacillus Yersinia pestis th at m ainly affects
wild and d o m estic ro d ents.
– P lague is transm itted to m an by the bite o f an infected flea vecto r o r thro ugh a break
in the sk in by co ntact with a ro d ent. H um an-to -hum an transm issio n o ccurs thro ugh
the bites o f hum an fleas, o r, in the case o f p neum o nic p lague, by inhaling infected
d ro p lets exp elled by co ughing.
– V ast fo ci o f infectio n rem ain in C entral and S o utheast A sia, A frica, M ad agascar, and
in No rth and S o uth A m erica.
Clinical features and progress
T here are 3 m ain clinical fo rm s:
– Bubonic plague is the m o st co m m o n fo rm : high fever, chills, head ache, asso ciated with
o ne ( o r m o re) very p ainful ly m p h no d e, usually inguinal ( b ubo ) . F requent
gastro intestinal signs: abd o m inal p ain, vo m iting, d iarrho ea, etc. T he m o rtality rate in
untreated p atients is ap p ro xim ately 5 0 % as a result o f sep ticaem ia.
– Septicaemic plague is a co m p licatio n o f untreated bubo nic p lague and is a fulm inant
illness.
– Pneumonic plague is a very co ntagio us fo rm : h igh fever, chills, head ach e, m y algia
asso ciated with p aro xy sm al co ugh ing, haem o p ty sis and resp irato ry d istress. T his
fo rm p ro gresses rap id ly , and is fatal unless treated . I t o ccurs either as a co m p licatio n
o f bubo nic p lague o r as the result o f a p rim ary infectio n.
O ccasio nally , the d isease can tak e the fo rm o f meningitic plague.
Laboratory
– I so latio n o f Y. pestis ( d irect exam inatio n and culture) fro m ly m p h no d e asp irate,
blo o d , sp utum , cerebro sp inal fluid , d ep end ing o n the fo rm invo lved .
– S ero d iagno sis: E L IS A read s p o sitive so o n after the o nset o f the illness.
– T ransp o rtatio n o f th e sam p les requires a co ld ch ain (failing that, th e tem p erature
m ust be k ep t belo w 3 0 °C ).
Management and treatment
– W hen p lague is susp ected : tak e sam p les fo r cultures and antibio tic sensitivity testing
and then treat im m ed iately witho ut waiting fo r the d iagno sis to be co nfirm ed . I nfo rm
the health autho rities as so o n as the d iagno sis has been co nfirm ed .
– I so latio n:
• P atients suffering fro m bubo nic p lague d o no t have to be iso lated . T reat the p atient
and his/ her bed d ing and clo thing with an insecticid e (e.g. permethrin 0.5% p o wd er;
see Pediculoses, p age 1 0 1 ). O bserve elem entary rules o f hy giene (wash hand s, wear
go wns, glo ves etc.).
• P atients with p rim ary o r seco nd ary p neum o nic p lague m ust be strictly iso lated .
T heir bed d ing, clo thing, sp utum and excreta m ust be d isinfected with a chlo rinated
so lutio n. O bserve elem entary rules o f hy giene (wash hand s, wear ho sp ital lab co ats,
glo ves etc.) and bo th the p atient and carers sho uld wear facem ask s.
178
