Ebola Virus-Specific Neutralizing Antibody Persists at High Levels in Survivors 2 Years After Resolution of Disease in a Sierra Leonean Cohort.

Ebola virus (EBOV) infection results in Ebola virus disease (EVD), an often severe disease with a nonspecific presentation. Since its recognition, periodic outbreaks of EVD continue to occur in sub-Saharan Africa. The 2013-2016 West African EVD outbreak was the largest recorded, resulting in a substantial cohort of EVD survivors with persistent health complaints and variable immune responses. In this study, we characterize humoral immune responses in EVD survivors and their contacts in Eastern Sierra Leone. We found high levels of EBOV IgG in EVD survivors and lower yet substantial antibody levels in household contacts, suggesting subclinical transmission. Neutralizing antibody function was prevalent but variable in EVD survivors, raising questions about the durability of immune responses from natural infection with EBOV. Additionally, we found that certain discrete symptoms-ophthalmologic and auditory-are associated with EBOV IgG seropositivity, while an array of symptoms are associated with the presence of neutralizing antibody.

Seroprevalence of anti-Lassa Virus IgG antibodies in three districts of Sierra Leone: A cross-sectional, population-based study.

BACKGROUND: Lassa virus (LASV), the cause of the acute viral hemorrhagic illness Lassa fever (LF), is endemic in West Africa. Infections in humans occur mainly after exposure to infected excrement or urine of the rodent-host, Mastomys natalensis. The prevalence of exposure to LASV in Sierra Leone is crudely estimated and largely unknown. This cross-sectional study aimed to establish a baseline point seroprevalence of IgG antibodies to LASV in three administrative districts of Sierra Leone and identify potential risk factors for seropositivity and LASV exposure. METHODOLOGY AND PRINCIPAL FINDINGS: Between 2015 and 2018, over 10,642 participants from Kenema, Tonkolili, and Port Loko Districts were enrolled in this cross-sectional study. Previous LASV and LF epidemiological studies support classification of these districts as "endemic," "emerging," and "non-endemic", respectively. Dried blood spot samples were tested for LASV antibodies by ELISA to determine the seropositivity of participants, indicating previous exposure to LASV. Surveys were administered to each participant to assess demographic and environmental factors associated with a higher risk of exposure to LASV. Overall seroprevalence for antibodies to LASV was 16.0%. In Kenema, Port Loko, and Tonkolili Districts, seroprevalences were 20.1%, 14.1%, and 10.6%, respectively. In a multivariate analysis, individuals were more likely to be LASV seropositive if they were living in Kenema District, regardless of sex, age, or occupation. Environmental factors contributed to an increased risk of LASV exposure, including poor housing construction and proximity to bushland, forested areas, and refuse. CONCLUSIONS AND SIGNIFICANCE: In this study we determine a baseline LASV seroprevalence in three districts which will inform future epidemiological, ecological, and clinical studies on LF and the LASV in Sierra Leone. The heterogeneity of the distribution of LASV and LF over both space, and time, can make the design of efficacy trials and intervention programs difficult. Having more studies on the prevalence of LASV and identifying potential hyper-endemic areas will greatly increase the awareness of LF and improve targeted control programs related to LASV.

The prevalence of Post-Ebola Syndrome hearing loss, Sierra Leone.

BACKGROUND: Globally, hearing loss is the second leading cause of disability, affecting approximately 18.7% of the world's population. However, the burden of hearing loss is unequally distributed, with the majority of affected individuals located in Asia or Sub-Saharan Africa. Following the 2014 West African Ebola Outbreak, disease survivors began to describe hearing loss as part of the constellation of symptoms known as Post-Ebola Syndrome. The goal of this study was to more fully characterize hearing loss among Ebola Virus Disease (EVD) survivors. METHODOLOGY AND PRINCIPAL FINDINGS: EVD survivors and their household contacts were recruited (n = 1,12) from Eastern Sierra Leone. Each individual completed a symptom questionnaire, physical exam, and a two-step audiometry process measuring both air and bone conduction thresholds. In comparison to contacts, EVD survivors were more likely to have complaints or abnormal findings affecting every organ system. A significantly greater percentage of EVD survivors were found to have hearing loss in comparison to contacts (23% vs. 9%, p < 0.001). Additionally, survivors were more likely to have bilateral hearing loss of a mixed etiology. Logistic regression revealed that the presence of any symptoms of middle or inner ear (p < 0.001), eye (p = 0.005), psychiatric (p = 0.019), and nervous system (p = 0.037) increased the odds of developing hearing loss. CONCLUSIONS AND SIGNIFICANCE: This study is the first to use an objective and standardized measurement to report hearing loss among EVD survivors in a clinically meaningful manner. In this study it was found that greater than 1/5th of EVD survivors develop hearing loss. The association between hearing impairment and symptoms affecting the eye and nervous system may indicate a similar mechanism of pathogenesis, which should be investigated further. Due to the quality of life and socioeconomic detriments associated with untreated hearing loss, a greater emphasis must be placed on understanding and mitigating hearing loss following survival to aid in economic recovery following infectious disease epidemics.

Lassa Fever Induced Hearing Loss: The Neglected Disability of Hemorrhagic Fever.

OBJECTIVE: Lassa fever (LF) a hemorrhagic fever endemic to Western has an incidence of approximately 500,000 cases per year. Here, we evaluate hearing loss and other sequelae following LF. METHODS: This case-control study enrolled laboratory confirmed LF survivors, non-LF Febrile controls and Matched Community controls with no history of LF or recent hospitalization for a febrile illness. Study participants completed a symptom questionnaire. Pure-tone audiometry was completed by a subset of participants. RESULTS: One hundred forty-seven subjects were enrolled aged from 3-66 years (mean = 23.3). LF survivors were significantly more likely to report balance difficulties (55% vs 20%, p < 0.001), hair loss (32% vs 7%, p < 0.001), difficulty speaking (19% vs 1%, p < 0.001), social isolation (50% vs 0%, p < 0.001), and hearing loss (17% vs 1%, p = 0.002) in comparison to Matched-Community Controls. Similar trends were noted in comparison to Febrile Controls, although these findings were non-significant. Fifty subjects completed audiometry. Audiometry found that LF survivors had significantly more bilateral hearing loss in comparison to Matched-Community Controls (30% vs 4%, p = 0.029). CONCLUSION: This study characterizes the sequelae of LF and highlights the need for increased access to hearing care in West Africa.

A Review of Hearing Loss Associated with Zika, Ebola, and Lassa Fever.

The neglected tropical diseases Zika, Ebola, and Lassa fever (LF) have all been noted to cause some degree of hearing loss (HL). Hearing loss is a chronic disability that can lead to a variety of detrimental effects, including speech and language delays in children, decreased economic productivity in adults, and accelerated cognitive decline in older adults. The objective of this review is to summarize what is known regarding HL secondary to these viruses. Literature for this review was gathered using the PubMed database. Articles were excluded if there were no data of the respective viruses, postinfectious complications, or conditions related to survivorship. A total of 50 articles were included in this review. Fourteen articles discussing Zika virus and subsequent complications were included. Across these studies, 56 (21.2%) of 264 Zika-infected individuals were found to have HL. Twenty-one articles discussing Ebola virus and subsequent complications were included, with 190 (5.7%) of 3,350 Ebola survivors found to have HL. Fifteen additional articles discussing LF and subsequent complications were included. Of 926 individuals with LF, 79 (8.5%) were found to have HL. These results demonstrate a relationship between HL and infection. The true prevalence is likely underestimated, however, because of lack of standardization of reporting and measurement. Future studies of viral sequelae would benefit from including audiometric evaluation. This information is critical to understanding pathophysiology, preventing future cases of this disability, and improving quality of life after survival of infection.

Acute Calcific Tendonitis of the Longus Colli.

BACKGROUND: Acute calcific tendonitis of the longus colli (ACTLC) is an aseptic inflammatory response to deposition of calcium in the longus colli muscle tendons. Although reports in the literature are scarce, ACTLC likely represents an underreported disease process that routinely goes misdiagnosed. We report a case of ACTLC and provide a brief review of the literature. CASE REPORT: A 45-year-old otherwise healthy female presented with a 3-day history of progressive neck pain, decreased neck mobility, and odynophagia. She exhibited tenderness over the right posterolateral neck with limited neck flexion and rotation. Flexible fiber-optic laryngoscopy revealed moderate posterior pharyngeal wall edema extending from the palatal-pharyngeal sphincter down to the level of the epiglottis. A computed tomography (CT) scan of the neck with contrast revealed an amorphous calcification in the longus colli muscle and a prevertebral fluid collection without rim enhancement. A diagnosis of ACTLC was presumed. The patient was successfully managed with nonsteroidal antiinflammatory drugs, corticosteroids, and antibiotics and reported complete resolution of symptoms on follow-up. CONCLUSION: The clinical presentation and laboratory findings of ACTLC are nonspecific; however, a CT scan revealing a calcific deposition in the retropharyngeal space confirms the diagnosis. Spontaneous resolution during the course of several weeks warrants conservative treatment with analgesia and antiinflammatory medications. Awareness of ACTLC must be increased to avoid diagnostic errors and prevent unnecessary medical interventions.