PAHO releases new clinical guidelines for severe yellow fever patients

The Pan Amer­i­can Health Or­ga­ni­za­tion (PA­HO) has re­leased new clin­i­cal guide­lines for the man­age­ment of pa­tients with se­vere yel­low fever in the Amer­i­c­as, in­clud­ing the Caribbean.

The guide­lines come amidst the con­cerns that the dis­ease has re-emerged as a grow­ing pub­lic health mat­ter, with PA­HO not­ing that since 2024, out­breaks have been re­port­ed in sev­er­al coun­tries—in­clud­ing in ar­eas out­side the tra­di­tion­al Ama­zon basin—con­firm­ing an ex­pan­sion of risk zones.

Last year, PA­HO said a to­tal of 346 con­firmed cas­es and 143 deaths were re­port­ed across sev­en coun­tries in the re­gion, name­ly Bo­livia, Brazil, Colom­bia, Ecuador, Guyana, Pe­ru, and Venezuela.

In the first sev­en weeks of this year, PA­HO said 34 hu­man cas­es and 15 deaths have al­ready been con­firmed in Bo­livia, Colom­bia, Pe­ru and Venezuela and that while there is no spe­cif­ic treat­ment for yel­low fever, vac­ci­na­tion re­mains the most ef­fec­tive pre­ven­tive mea­sure.

It said a sin­gle dose pro­vides life­long im­mu­ni­ty and that most con­firmed cas­es and deaths re­port­ed in 2025 and 2026 oc­curred among un­vac­ci­nat­ed in­di­vid­u­als.

The health or­ga­ni­za­tion said it con­tin­ues to sup­port coun­tries in strength­en­ing epi­demi­o­log­i­cal sur­veil­lance, ex­pand­ing vac­ci­na­tion cov­er­age among at-risk pop­u­la­tions, and im­prov­ing the ca­pac­i­ty of health ser­vices for ear­ly de­tec­tion and time­ly clin­i­cal man­age­ment of se­vere cas­es.

“The new guide­lines aim to con­tribute to these ef­forts by pro­vid­ing health teams with a prac­ti­cal, ev­i­dence-based tool to de­liv­er safe, stan­dard­ized care and re­duce mor­tal­i­ty as­so­ci­at­ed with the dis­ease,” PA­HO said, adding that the guide­lines aim to strength­en the ca­pac­i­ty of health work­ers and sup­port time­ly, life-sav­ing care.

“Yel­low fever is a mos­qui­to-borne vi­ral dis­ease that can cause out­breaks with a high num­ber of cas­es and deaths in a short pe­ri­od of time. As there is no spe­cif­ic treat­ment, ear­ly de­tec­tion of sus­pect­ed cas­es, iden­ti­fi­ca­tion and close mon­i­tor­ing of pa­tients at high­er risk of se­vere dis­ease, and time­ly re­fer­ral to in­ten­sive care units are crit­i­cal to re­duc­ing com­pli­ca­tions and sav­ing lives,” PA­HO said.

PA­HO’s ad­vi­sor on clin­i­cal man­age­ment of emerg­ing dis­eases, Án­gel Ro­dríguez, said that the guide­line pro­vides “ev­i­dence-based clin­i­cal rec­om­men­da­tions to sup­port de­ci­sion-mak­ing and im­prove the care of se­vere yel­low fever cas­es.”

“It al­so serves as a key tool to strength­en pre­pared­ness and re­sponse across health ser­vices in the Amer­i­c­as,” he added.

PA­HO said the new guid­ance com­ple­ments its 2023 clin­i­cal man­age­ment guide­lines and is part of the health or­ga­ni­za­tion’s re­gion­al re­sponse to the pub­lic health emer­gency record­ed be­tween 2024 and 2025, when the av­er­age case fa­tal­i­ty rate for yel­low fever reached 45 per­cent.

“It brings to­geth­er up­dat­ed clin­i­cal and epi­demi­o­log­i­cal in­for­ma­tion, along with prac­ti­cal rec­om­men­da­tions on case de­tec­tion, di­ag­no­sis, ini­tial man­age­ment, sever­i­ty clas­si­fi­ca­tion, and com­pre­hen­sive pa­tient care,” PA­HO said, adding yel­low fever is caused by a virus of the Fla­vivirus genus and is trans­mit­ted through mos­qui­to bites.

PA­HO said the syl­vat­ic (jun­gle) cy­cle pri­mar­i­ly in­volves mos­qui­toes of the Haem­a­gogus and Sa­bethes gen­era, while ur­ban trans­mis­sion can oc­cur through Aedes ae­gyp­ti and Aedes al­bopic­tus.

It said se­vere cas­es can rapid­ly progress to se­ri­ous com­pli­ca­tions such as acute liv­er fail­ure, re­quir­ing spe­cial­ized in­ten­sive care. —WASH­ING­TON D.C. (CMC)