The recent large outbreak of Ebola virus disease (EVD) in Western Africa resulted in greatly increased accumulation of human genotypic, phenotypic and clinical data, and improved our understanding of the spectrum of clinical manifestations. As a result, the WHO disease classification of EVD underwent major revision. The recent large outbreak of Ebola virus disease (EVD) in Western Africa resulted in greatly increased accumulation of human genotypic, phenotypic and clinical data, and improved our understanding of the spectrum of clinical manifestations. As a result, the WHO disease classification of EVD underwent major revision.

In October 2012, a cluster of illnesses and deaths was reported in Uganda and was confirmed to be an outbreak of Marburg virus disease (MVD). Patients meeting the case criteria were interviewed using a standard investigation form, and blood specimens were tested for evidence of acute or recent Marburg virus infection by reverse transcription–polymerase chain reaction (RT-PCR) and antibody enzyme-linked immunosorbent assay. The total count of confirmed and probable MVD cases was 26, of which 15 (58%) were fatal. Four of 15 laboratory-confirmed cases (27%) were fatal. Case patients were located in 4 different districts in Uganda, although all chains of transmission originated in Ibanda District, and the earliest case detected had an onset in July 2012. No zoonotic exposures were identified. Symptoms significantly associated with being a MVD case included hiccups, anorexia, fatigue, vomiting, sore throat, and difficulty swallowing. Contact with a case patient and attending a funeral were also significantly associated with being a case. Average RT-PCR cycle threshold values for fatal cases during the acute phase of illness were significantly lower than those for nonfatal cases. Following the institution of contact tracing, active case surveillance, care of patients with isolation precautions, community mobilization, and rapid diagnostic testing, the outbreak was successfully contained 14 days after its initial detection.

On 28 March, 2016, the Ministry of Health received a report on three deaths from an unknown disease characterized by fever, jaundice, and hemorrhage which occurred within a one-month period in the same family in central Uganda. We started an investigation to determine its nature and scope, identify risk factors, and to recommend eventually control measures for future prevention. We defined a probable case as onset of unexplained fever plus ≥1 of the following unexplained symptoms: jaundice, unexplained bleeding, or liver function abnormalities. A confirmed case was a probable case with IgM or PCR positivity for yellow fever. We reviewed medical records and conducted active community case-finding. In a case-control study, we compared risk factors between case-patients and asymptomatic control-persons, frequency-matched by age, sex, and village. We used multivariate conditional logistic regression to evaluate risk factors. We also conducted entomological studies and environmental assessments. From February to May, we identified 42 case-persons (35 probable and seven confirmed), of whom 14 (33%) died. The attack rate (AR) was 2.6/100,000 for all affected districts, and highest in Masaka District (AR = 6.0/100,000). Men (AR = 4.0/100,000) were more affected than women (AR = 1.1/100,000) (p = 0.00016). Persons aged 30–39 years (AR = 14/100,000) were the most affected. Only 32 case-patients and 128 controls were used in the case control study. Twenty three case-persons (72%) and 32 control-persons (25%) farmed in swampy areas (OR_adj = 7.5; 95%CI = 2.3–24); 20 case-patients (63%) and 32 control-persons (25%) who farmed reported presence of monkeys in agriculture fields (OR_adj = 3.1, 95%CI = 1.1–8.6); and 20 case-patients (63%) and 35 control-persons (27%) farmed in forest areas (OR_adj = 3.2; 95%CI = 0.93–11). No study participants reported yellow fever vaccination. Sylvatic monkeys and Aedes mosquitoes were identified in the nearby forest areas. This yellow fever outbreak was likely sylvatic and transmitted to a susceptible population probably by mosquito bites during farming in forest and swampy areas. A reactive vaccination campaign was conducted in the affected districts after the outbreak. We recommended introduction of yellow fever vaccine into the routine Uganda National Expanded Program on Immunization and enhanced yellow fever surveillance.

As the outbreak of Ebola virus disease (EVD) in West Africa continues, clinical preparedness is needed in countries at risk for EVD (e.g., United States) and more fully equipped and supported clinical teams in those countries with epidemic spread of EVD in Africa. Clinical staff must approach the patient with a very deliberate focus on providing effective care while assuring personal safety. To do this, both individual health care providers and health systems must improve EVD care. Although formal guidance toward these goals exists from the World Health Organization, Medecin Sans Frontières, the Centers for Disease Control and Prevention, and other groups, some of the most critical lessons come from personal experience. In this narrative, clinicians deployed by the World Health Organization into a wide range of clinical settings in West Africa distill key, practical considerations for working safely and effectively with patients with EVD.