The Use of a Mobile Laboratory Unit in Support of Patient Management and Epidemiological Surveillance during the 2005 Marburg Outbreak in Angola

Abstract

BackgroundMarburg virus (MARV), a zoonotic pathogen causing severe hemorrhagic fever in man, has emerged in Angola resulting in the largest outbreak of Marburg hemorrhagic fever (MHF) with the highest case fatality rate to date.Methodology/Principal FindingsA mobile laboratory unit (MLU) was deployed as part of the World Health Organization outbreak response. Utilizing quantitative real-time PCR assays, this laboratory provided specific MARV diagnostics in Uige, the epicentre of the outbreak. The MLU operated over a period of 88 days and tested 620 specimens from 388 individuals. Specimens included mainly oral swabs and EDTA blood. Following establishing on site, the MLU operation allowed a diagnostic response in <4 hours from sample receiving. Most cases were found among females in the child-bearing age and in children less than five years of age. The outbreak had a high number of paediatric cases and breastfeeding may have been a factor in MARV transmission as indicated by the epidemiology and MARV positive breast milk specimens. Oral swabs were a useful alternative specimen source to whole blood/serum allowing testing of patients in circumstances of resistance to invasive procedures but limited diagnostic testing to molecular approaches. There was a high concordance in test results between the MLU and the reference laboratory in Luanda operated by the US Centers for Disease Control and Prevention.Conclusions/SignificanceThe MLU was an important outbreak response asset providing support in patient management and epidemiological surveillance. Field laboratory capacity should be expanded and made an essential part of any future outbreak investigation.

Ebola Virus Disease Diagnostics, Sierra Leone: Analysis of Real-time Reverse Transcription–Polymerase Chain Reaction Values for Clinical Blood and Oral Swab Specimens

“…However, the data set from paired blood and oral swab specimens (Figure 1A) demonstrate consistently higher Ct values for the Ebola target genes (by up to 14 Cts) in swabs compared to blood specimens, indicating that swabs are considerably less sensitive. This is consistent with findings from previous filovirus outbreaks in Republic of Congo and Angola and several animal studies [5–8], which indicated that swabs are suitable specimens only for severely ill patients and corpses. Especially for deceased patients, the anticipated high virus load [5–8] and safety concerns with performing cardiac puncture in field settings also support the continued use of swabs; however using swabs for the diagnosis of live patients will lead to false negative results.…”

Diagnostic schemes for reducing epidemic size of african viral hemorrhagic fever outbreaks

“…WHO-recommended clinical case diagnoses for Ebola and Marburg VHFs require epidemiological connection to a confirmed case [44,45]. When laboratory testing is not performed, there are inevitably extended delays to initial outbreak identification.…”

Mobile diagnostics in outbreak response, not only for Ebola: a blueprint for a modular and robust field laboratory

“…coverall suits, goggles and FFP-3 face masks within a designated 'hot zone' [6]. However, this option has a number of disadvantages: (i) the time laboratory personnel can work in full protective gear is very limited especially in tropical climate, (ii) a designated separate 'hot zone' is needed, adding another factor to the already complex task of setting up a field laboratory, and (iii) this 'hot zone' has to be considered as contaminated until it has been completely disinfected.…”

“…malaria, dengue, leptospirosis and typhus [4]. Therefore, accurate identification of the causative agents is critical for effective containment of the outbreaks and provision of appropriate supportive care to the patients [5][6][7][8][9]. In preparedness for rapid, global response to naturally occurring and emerging infectious disease outbreaks, the International Cooperation and Development Office of the European Commission (DG DevCo) launched the European Mobile field laboratory (EMLab, www.emlab.…”