An Evaluation of the Performance, Patient Acceptability and Feasibility of a Point-of-Care HIV-Syphilis Assay in an Urban Emergency Department.

BACKGROUND: Point-of-care (POC) tests for sexually transmitted infections (STIs) permit delivery of results during the patient's emergency department (ED) encounter. We evaluated performance, patient acceptability, and feasibility of a new duplex POC test, Chembio DPP® HIV-Syphilis Assay in an urban ED setting. METHODS: Convenience sampling approach prioritizing those considered at increased risk for an STI and/or with a history of HIV. For the performance evaluation, participants were tested for HIV/syphilis with the Chembio POC assay, and the reference laboratory tests; sensitivity and specificity were determined. For the patient acceptability evaluation, participants completed pre- and post-user surveys. For the feasibility evaluation, ED clinical technicians completed a survey evaluating their perceptions regarding feasibility of use of this POC test. RESULTS: 327 patients were consented and enrolled. The diagnostic sensitivity and specificity of the Chembio POC assay for HIV was 96.5% (95% CI: 90.1%, 99.3%) and 99.6% (95% CI: 97.7%, 100.0%), respectively, and for syphilis was 93.9% (95% CI: 85.0%, 98.3%) and 99.6% (95% CI: 97.9%, 100.0%), respectively. Regarding patient acceptability: 87% trusted the result; and 93% reported they were more likely to seek treatment if they received a positive STI test result in the ED rather than after the ED visit. Regarding feasibility: 90% of the technicians reported they would recommend using the test in EDs. CONCLUSIONS: The Chembio DPP® HIV-Syphilis POC assay had excellent performance characteristics when evaluated in an ED population, as well as high perceived acceptability from patients, and feasibility for ED use from clinical technicians. The test may have utility for HIV-syphilis screening among high-risk ED patients.

A Tale of 3 Pandemics: Severe Acute Respiratory Syndrome Coronavirus 2, Hepatitis C Virus, and Human Immunodeficiency Virus in an Urban Emergency Department in Baltimore, Maryland.

Background: We sought to determine the prevalence and sociodemographic and clinical correlates of acute and convalescent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections among emergency department (ED) patients in Baltimore. Methods: Remnant blood samples from 7450 unique patients were collected over 4 months in 2020 for SARS-CoV-2 antibody (Ab), HCV Ab, and HIV-1/2 antigen and Ab. Among them, 5012 patients were tested by polymerase chain reaction for SARS-CoV-2 based on clinical suspicion. Sociodemographics, ED clinical presentations, and outcomes associated with coinfections were assessed. Results: Overall, 729 (9.8%) patients had SARS-CoV-2 (acute or convalescent), 934 (12.5%) HCV, 372 (5.0%) HIV infection, and 211 patients (2.8%) had evidence of any coinfection (HCV/HIV, 1.5%; SARS-CoV-2/HCV, 0.7%; SARS-CoV-2/HIV, 0.3%; SARS-CoV-2/HCV/HIV, 0.3%). The prevalence of SARS-CoV-2 (acute or convalescent) was significantly higher in those with HCV or HIV vs those without (13.6% vs 9.1%, P < .001). Key sociodemographic disparities (race, ethnicity, and poverty) and specific ED clinical characteristics were significantly correlated with having any coinfections vs no infection or individual monoinfection. Among those with HCV or HIV, aged 18-34 years, Black race, Hispanic ethnicity, and a cardiovascular-related chief complaint had a significantly higher odds of having SARS-CoV-2 (prevalence ratios: 2.02, 2.37, 5.81, and 2.07, respectively). Conclusions: The burden of SARS-CoV-2, HCV, and HIV co-pandemics and their associations with specific sociodemographic disparities, clinical presentations, and outcomes suggest that urban EDs should consider implementing integrated screening and linkage-to-care programs for these 3 infections.

Clinical Utility of the Signal-to-Cutoff Ratio of Reactive HIV Antigen/Antibody Screening Tests in Guiding Emergency Physician Management.

BACKGROUND: The signal-to-cutoff (S/CO) ratio of the HIV antigen/antibody test may help immediately to differentiate true-positive results from false-positive results, which may be particularly useful in time-sensitive circumstances, such as when providing emergency department (ED) care. SETTING: Seven US EDs with HIV screening programs using HIV antigen/antibody assays. METHODS: This cross-sectional study of existing data correlated S/CO ratios with confirmed HIV status. Test characteristics at predetermined S/CO ratios and the S/CO ratio with the best performance by receiver operator characteristic (ROC) curve were calculated. RESULTS: Of 1035 patients with a reactive HIV antigen/antibody test, 232 (22.4%) were confirmed HIV-negative and 803 (77.6%) were confirmed HIV-positive. Of the 803 patients, 713 (88.8%) experienced chronic infections and 90 (11.2%) experienced acute infections. S/CO ratios were greater for HIV-positive (median 539.2) than for HIV-negative patients (median 1.93) (P < 0.001) and lower for acute infection (median 22.8) than for chronic infection (median 605.7) (P < 0.001). All patients with an S/CO ratio < 1.58 (n = 93) were HIV-negative (NPV 100%), and nearly all with an S/CO ≥ 20.7 (n = 760) (optimal level by ROC analysis) were HIV-positive (PPV 98.6%). Of patients with S/CO values between 1.58 and 20.7 (n = 182), 29.7% were HIV-positive. CONCLUSIONS: The S/CO ratio may be used in real time to classify most ED patients as almost certain to be either HIV-positive or HIV-negative long before nucleic acid confirmatory testing is available. When combined with clinical judgment, this could guide preliminary result disclosure and management.

Differentiation of Individuals Previously Infected with and Vaccinated for SARS-CoV-2 in an Inner-City Emergency Department.

Emergency departments (EDs) can serve as surveillance sites for infectious diseases. The objective of this study was to determine the burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to monitor the prevalence of vaccination against coronavirus disease 2019 (COVID-19) among patients attending an urban ED in Baltimore City. Using 1,914 samples of known exposure status, we developed an algorithm to differentiate previously infected, vaccinated, and unexposed individuals using a combination of antibody assays. We applied this testing algorithm to 4,360 samples from ED patients obtained in the spring of 2020 and 2021. Using multinomial logistic regression, we determined factors associated with infection and vaccination. For the algorithm, sensitivity and specificity for identifying vaccinated individuals were 100% and 99%, respectively, and 84% and 100% for previously infected individuals. Among the ED subjects, seroprevalence to SARS-CoV-2 increased from 2% to 24% between April 2020 and March 2021. Vaccination prevalence rose to 11% by mid-March 2021. Marked differences in burden of disease and vaccination coverage were seen by sex, race, and ethnicity. Hispanic patients, though accounting for 7% of the study population, had the highest relative burden of disease (17% of total infections) but with similar vaccination rates. Women and white individuals were more likely to be vaccinated than men or Black individuals. Individuals previously infected with SARS-CoV-2 can often be differentiated from vaccinated individuals using a serologic testing algorithm. The utility of this algorithm can aid in monitoring SARS-CoV-2 exposure and vaccination uptake frequencies and can potentially reflect gender, race, and ethnic health disparities.

Differentiation of SARS-CoV-2 naturally infected and vaccinated individuals in an inner-city emergency department.

BACKGROUND: Emergency Departments (EDs) can serve as surveillance sites for infectious diseases. Our purpose was to determine the burden of SARS-CoV-2 infection and prevalence of vaccination against COVID-19 among patients attending an urban ED in Baltimore City. METHODS: Using 1914 samples of known exposure status, we developed an algorithm to differentiate previously infected, vaccinated, and unexposed individuals using a combination of antibody assays. We applied this testing algorithm to 4360 samples ED patients obtained in the springs of 2020 and 2021. Using multinomial logistic regression, we determined factors associated with infection and vaccination. RESULTS: For the algorithm, sensitivity and specificity for identifying vaccinated individuals was 100% and 99%, respectively, and 84% and 100% for naturally infected individuals. Among the ED subjects, seroprevalence to SARS-CoV-2 increased from 2% to 24% between April 2020 and March 2021. Vaccination prevalence rose to 11% by mid-March 2021. Marked differences in burden of disease and vaccination coverage were seen by sex, race, and ethnicity. Hispanic patients, though 7% of the study population, had the highest relative burden of disease (17% of total infections) but similar vaccination rates. Women and White individuals were more likely to be vaccinated than men or Black individuals (adjusted odds ratios [aOR] 1.35 [95% CI: 1.02, 1.80] and aOR 2.26 [95% CI: 1.67, 3.07], respectively). CONCLUSIONS: Individuals previously infected with SARS-CoV-2 can be differentiated from vaccinated individuals using a serologic testing algorithm. SARS-CoV-2 exposure and vaccination uptake frequencies reflect gender, race and ethnic health disparities in this urban context. SUMMARY: Using an antibody testing algorithm, we distinguished between immune responses from SARS-CoV-2-infected and vaccinated individuals. When applied to blood samples from an emergency department in Baltimore, disparities in disease burden and vaccine uptake by sex, race, and ethnicity were identified.

Demographic and clinical correlates of acute and convalescent SARS-CoV-2 infection among patients of a U.S. emergency department.

BACKGROUND: Emergency Departments (EDs) have served as critical surveillance sites for infectious diseases. We sought to determine the prevalence and temporal trends of acute (by PCR) and convalescent (by antibody [Ab]) SARS-CoV-2 infection during the earliest phase of the pandemic among patients in an urban ED in Baltimore City. METHODS: We tested remnant blood samples from 3255 unique ED patients, collected between March 16th and May 31st 2020 for SARS-CoV-2 Ab. PCR for acute SARS-CoV-2 infection from nasopharyngeal swabs was obtained on any patients based on clinical suspicion. Hospital records were abstracted and factors associated with SARS-CoV-2 infection were assessed. RESULTS: Of 3255 ED patients, 8.2% (95%CI: 7.3%, 9.2%) individuals had evidence of SARS-CoV-2 infection; 155 PCR+, 78 Ab+, and 35 who were both PCR+ and Ab+. Prevalence of disease increased throughout the study period, ranging from 3.2% (95%CI: 1.8%, 5.2%) PCR+ and 0.6% (95%CI: 0.1%, 1.8%) Ab+ in March, to 6.2% (95%CI: 5.1%, 7.4%) PCR+ and 4.2% (95%CI: 3.3%, 5.3%) Ab+ in May. The highest SARS-CoV-2 prevalence was found in Hispanic individuals who made up 8.4% (95%CI: 7.4%, 9.4%) of individuals screened, but 35% (95%CI: 29%, 41%) of infections (PCR and/or Ab+). Demographic and clinical factors independently associated with acute infection included Hispanic ethnicity, loss of smell or taste, subjective fever, cough, muscle ache and fever. Factors independently associated with convalescent infection were Hispanic ethnicity and low oxygen saturation. CONCLUSIONS: The burden of COVID-19 in Baltimore City increased dramatically over the 11-week study period and was disproportionately higher among Hispanic individuals. ED-based surveillance methods are important for identifying both acute and convalescent SARS-CoV-2 infections and provides important information regarding demographic and clinical correlates of disease in the local community.