Lessons learned about pneumonic plague diagnosis from two outbreaks, Democratic Republic of the Congo

Abstract

Pneumonic plague is a highly transmissible infectious disease for which fatality rates can be high if untreated; it is considered extremely lethal. Without prompt diagnosis and treatment, disease management can be problematic. In the Democratic Republic of the Congo, 2 outbreaks of pneumonic plague occurred during 2005 and 2006. In 2005, because of limitations in laboratory capabilities, etiology was confirmed only through retrospective serologic studies. This prompted modifications in diagnostic strategies, resulting in isolation of Yersinia pestis during the second outbreak. Results from these outbreaks demonstrate the utility of a rapid diagnostic test detecting F1 antigen for initial diagnosis and public health management, as well as the need for specialized sampling kits and trained personnel for quality specimen collection and appropriate specimen handling and preservation for plague confirmation and Y. pestis isolation. Efficient frontline management and a streamlined diagnostic strategy are essential for confirming plague, especially in remote areas.

Figure 1

Transport routes of clinical specimens from 2 pneumonic plague outbreaks, Democratic Republic of the Congo, 2005 and 2006.

Figure 2

Flow of sample processing for specimens for pneumonic plague outbreaks in Zobia, Democratic Republic of the Congo (DRC), 2005 (A), and Bolebole, DRC, 2006 (B). PBS, phosphate-buffered saline; RDT, rapid diagnostic test; RT, reverse transcription; CB, Cary Blair; BHI/CIN, brain–heart infusion; cefsulodin-Irgasan-novobiocin; INRB, Institut National pour la Recherche Biologique; IPM/NICD/CRSSA, Institut Pasteur de Madagascar/National Institute for Communicable Diseases/Centre de Recherche du Service de Santé des Armées; DFA, direct fluorescent antibody.