Anatomy of a Hotspot: Chain and Seroepidemiology of Ebola Virus Transmission, Sukudu, Sierra Leone, 2015-16.

Studies have yet to include minimally symptomatic Ebola virus (EBOV) infections and unrecognized Ebola virus disease (EVD) in Ebola-related transmission chains and epidemiologic risk estimates. We conducted a cross-sectional, sero-epidemiological survey from October 2015 to January 2016 among 221 individuals living in quarantined households from November 2014 to February 2015 during the Ebola outbreak in the village of Sukudu, Sierra Leone. Of 48 EBOV-infected persons, 25% (95% confidence interval [CI], 14%-40%) had minimally symptomatic EBOV infections and 4% (95% CI, 1%-14%) were unrecognized EVD cases. The pattern of minimally symptomatic EBOV infections in the transmission chain was nonrandom (P < .001, permutation test). Not having lived in the same house as an EVD case was significantly associated with minimally symptomatic infection. This is the first study to investigate a chain of EBOV transmission inclusive of minimally symptomatic EBOV infections and unrecognized EVD. Our findings provide new insights into Ebola transmission dynamics and quarantine practices.

The Majority of the Pre-Antiretroviral Population Who Were Lost to Follow-Up Stopped Their Care in Freetown, Sierra Leone: A 12-Month Prospective Cohort Study Starting with HIV Diagnosis.

BACKGROUND: The heterogeneity of the pre-antiretroviral (pre-ART) population calls for more granular depictions of the cascade of HIV care. METHODS: We studied a prospective cohort of persons newly diagnosed with HIV infection from a single center in Freetown, Sierra Leone, over a 12-month period and then traced those persons who were lost to follow-up (LTFU) during pre-ART care (before ART initiation). ART eligibility was based on a CD4 cell count result of ≤ 350 mm/cells and/or WHO clinical stage 3 or 4. Persons who attended an appointment in the final three months were considered to be retained in care. Adherence to ART was measured using pharmacy refill dates. "Effective HIV care" was defined as completion of the cascade of care at 12-months regardless of whether patients are on ART. Tracing outcomes were obtained for those who were LTFU during pre-ART care. RESULTS: 408 persons newly diagnosed with HIV infection were screened, 338 were enrolled, and 255 persons were staged for ART. ART-ineligible persons had higher retention rates than ART-eligible persons (59.6% vs 41.8%, p = 0.03). 77 (22.8%) of 338 persons received effective HIV care. Most attrition (61.9%) occurred with persons during pre-ART care. 123 of 138 persons (89.1%) who were LTFU prior to ART initiation were found, and 91 of those 123 (74.0%) were alive. Of the 74 persons who were alive and described their engagement in care, 40 (54.1%) stopped care. Nearly half (42.5%) of those 40 stopped after assessment of ART-eligibility but before ART initiation. The main limitation of this study was the lack of tracing outcomes for those lost during ART care. CONCLUSIONS: The majority of the pre-ART LTFU population stopped their care, particularly after ART-eligibility but before ART initiation. Interventions to hasten ART initiation and retain this at-risk group may have significant downstream impact on effective HIV care.