Treatment of Marburg and Ebola hemorrhagic fevers: a strategy for testing new drugs and vaccines under outbreak conditions.

The filoviruses, Marburg and Ebola, have the dubious distinction of being associated with some of the highest case-fatality rates of any known infectious disease--approaching 90% in many outbreaks. In recent years, laboratory research on the filoviruses has produced treatments and vaccines that are effective in laboratory animals and that could potentially drastically reduce case-fatality rates and curtail outbreaks in humans. However, there are significant challenges in clinical testing of these products and eventual delivery to populations in need. Most cases of filovirus infection are recognized only in the setting of large outbreaks, often in the most remote and resource-poor areas of sub-Saharan Africa, with little infrastructure and few personnel experienced in clinical research. Significant political, legal, and socio-cultural barriers also exist. Here, we review the present research priorities and environment for field study of the filovirus hemorrhagic fevers and outline a strategy for future prospective clinical research on treatment and vaccine prevention.

Detection of Ebola virus in oral fluid specimens during outbreaks of Ebola virus hemorrhagic fever in the Republic of Congo.

BACKGROUND: Patients who have refused to provide blood samples has meant that there have been significant delays in confirming outbreaks of Ebola virus hemorrhagic fever (EVHF). During the 2 EVHF outbreaks in the Republic of Congo in 2003, we assessed the use of oral fluid specimens versus serum samples for laboratory confirmation of cases of EVHF. METHODS: Serum and oral fluid specimens were obtained from 24 patients with suspected Ebola and 10 healthy control subjects. Specimens were analyzed for immunoglobulin G antibodies by enzyme-linked immunosorbent assay (ELISA) and for Ebola virus by antigen detection ELISA and reverse-transcriptase polymerase chain reaction (RT-PCR). Oral fluid specimens were collected with a commercially available collection device. RESULTS: We failed to detect antibodies against Ebola in the oral fluid specimens obtained from patients whose serum samples were seropositive. All patients with positive serum RT-PCR results also had positive results for their oral fluid specimens. CONCLUSIONS: This study demonstrates the usefulness of oral fluid samples for the investigation of Ebola outbreaks, but further development in antibodies and antigen detection in oral fluid specimens is needed before these samples are used for filovirus surveillance activities in Africa.

Lessons learned during active epidemiological surveillance of Ebola and Marburg viral hemorrhagic fever epidemics in Africa.

OBJECTIVE: To review epidemiological surveillance approaches used during Ebola and Marburg hemorrhagic fever epidemics in Africa in the past fifteen years. Overall, 26 hemorrhagic epidemic outbreaks have been registered in 12 countries; 18 caused by the Ebola virus and eight by the Marburg virus. About 2551 cases have been reported, among which 268 were health workers (9,3%). METHODS: Based on articles and epidemic management reports, this review analyses surveillance approaches, route of introduction of the virus into the population (urban and rural), the collaboration between the human health sector and the wildlife sector and factors that have affected epidemic management. FINDINGS: Several factors affecting the epidemiological surveillance during Ebola and Marburg viruses hemorrhagic epidemics have been observed. During epidemics in rural settings, outbreak investigations have shown multiple introductions of the virus into the human population through wildlife. In contrast, during epidemics in urban settings a single introduction of the virus in the community was responsible for the epidemic. Active surveillance is key to containing outbreaks of Ebola and Marburg viruses CONCLUSIONS: Collaboration with those in charge of the conservation of wildlife is essential for the early detection of viral hemorrhagic fever epidemics. Hemorrhagic fever epidemics caused by Ebola and Marburg viruses are occurring more and more frequently in Sub-Saharan Africa and only an adapted epidemiological surveillance system will allow for early detection and effective response.

Outbreaks of filovirus hemorrhagic fever: time to refocus on the patient.

In the 40 years since the recognition of filoviruses as agents of lethal human disease, there have been no specific advances in antiviral therapies or vaccines and few clinical studies on the efficacy of supportive care. On 20 September 2006, experts from 14 countries representing 68 institutions integrally involved in the response to outbreaks of filovirus hemorrhagic fever gathered at the National Microbiology Laboratory of the Public Health Agency of Canada in Winnipeg to discuss possible remedies for this grim situation, in a unique workshop entitled "Marburg and Ebola Hemorrhagic Fever: Feasibility of Prophylaxis and Therapy." A summary of the opportunities for and challenges to improving treatment of filovirus hemorrhagic fevers is presented here.