Ebola Virus Disease in Guinea

The outbreak of Ebola virus disease in western Africa has consumed the news in both healthcare-related and public forums. Such attention is fitting for a disease with an extremely high case-fatality rate and an exponentially increasing number of cases. As noted in an accompanying editorial, the magnitude of the current outbreak already exceeds that of all previous Ebola outbreaks combined. Researchers now report results of their investigation into early cases of the disease in Guinea.

In March 2014, the WHO received reports of a severe transmissible disease in Guinea. Characterized by fever, severe diarrhea, and vomiting, the disease had a high fatality rate. Blood samples collected from 20 patients were tested by polymerase chain reaction, electron microscopy, and cell culture for suspected viruses; data on possible transmission chains were collected from hospital records and by interviews with patients, their families, contacts, and authorities.

Epidemiologic investigation suggested that the first case of the outbreak involved a 2-year-old child who died in December 2013. Within 13 weeks, 111 clinically suspected cases had occurred with 79 deaths; the median patient age was 35 years. Testing revealed Zaire ebolavirus as the causative agent; genomic sequencing and phylogenetic analysis demonstrated a viral strain different from those identified from other outbreaks.