Rapid, Round-the-Clock HIV Screening in the ED
Rapid, Round-the-Clock HIV Screening in the ED
Objective: To describe the prevalence and location of new and acute HIV diagnoses in a large urban medical center. Secondary objectives were to evaluate rapid HIV test performance, the added yield of acute HIV screening, and linkage-to-care outcomes.
Design: Cross-sectional study from November 1, 2008, to April 30, 2009.
Methods: The hospital laboratory performed round-the-clock rapid HIV antibody testing on venipuncture specimens from patients undergoing HIV testing in hospital and community clinics, inpatient settings, and the emergency department (ED). For patients with negative results, a public health laboratory conducted pooled HIV RNA testing for acute HIV infection. The laboratories communicated positive results from the hospital campus to a linkage team. Linkage was defined as 1 outpatient HIV-related visit.
Results: Among 7927 patients, 8550 rapid tests resulted in 137 cases of HIV infection [1.7%, 95% confidence interval (CI): 1.5% to 2.0%], of whom 46 were new HIV diagnoses (0.58%, 95% CI: 0.43% to 0.77%). Pooled HIV RNA testing of 6704 specimens (78.4%) resulted in 3 cases of acute HIV infection (0.05%, 95% CI: 0.01% to 0.14%) and increased HIV case detection by 3.5%. Half of new HIV diagnoses and two thirds of acute infections were detected in the ED and urgent care clinic. Rapid test sensitivity was 98.9% (95% CI: 93.8% to 99.8%) and the specificity 99.9% (95% CI: 99.7% to 99.9%). More than 95% of newly diagnosed and out-of-care HIV-infected patients were linked to care.
Conclusions: Patients undergoing HIV testing in EDs and urgent care clinics may benefit from being simultaneously screened for acute HIV infection.
In 2006, the Centers for Disease Control and Prevention recommended routine screening for HIV infection in patients aged 13–64 years in all health care settings where the prevalence of HIV infection is >0.1%. HIV-infected persons who do not know their status often present to medical settings and fail to be diagnosed, leading to late detection, higher morbidity, and prolonged transmission risk. Hospitals and their satellite clinics, therefore, are ideal settings to scale up HIV testing, especially because access to on-site HIV specialists has been shown to improve linkage to care for newly diagnosed and out-of-care HIV-infected patients.
Historically, a significant barrier to expanding HIV testing in the medical center setting has been the use of testing technologies with long turnaround time, for example, enzyme immunoassay (EIA) testing. EIA testing, conducted in "batches" several times a week, is not well suited to settings with rapid patient turnover, as it may delay appropriate clinical management and has been associated with high failure-to-notify rates.
Rapid HIV testing has the potential to increase testing in medical settings. Indeed, rapid HIV testing has been implemented successfully in medical settings such as labor and delivery, the emergency department (ED), and the inpatient wards. To date, however, the use of rapid HIV testing in medical settings has been limited to specific hospital departments. In addition, these initiatives have generally relied on point-of-care technology requiring ancillary staff, curtailing the ability to provide round-the-clock testing for large numbers of patients. As yet, a system for the effective application of rapid HIV testing across all care settings of a hospital and its satellite clinics has not been demonstrated.
An additional point regarding the adoption of rapid HIV testing is that the optimal testing technology for identifying HIV infection in medical settings has not been determined, especially because acute HIV infection may be relatively common in certain clinical venues, such as the urgent care clinic. Persons with acute HIV infection are highly infectious and may unknowingly transmit HIV infection if they remain unaware of their status. Fourth-generation immunoassays that can detect both HIV antibody and p24 antigen are a potentially appealing option. In addition, these assays can be run on automated platforms (as opposed to manual third-generation EIAs). However, few data exist on the prevalence of acute HIV infection across all inpatient and outpatient medical settings to justify a universal shift to this more sensitive testing format.
We therefore sought to investigate the potential contribution of acute HIV infection to hospital-wide HIV diagnosis. We drew upon a unique testing system developed at San Francisco General Hospital (SFGH) to execute this project. Key features of this testing system were laboratory-based, round-the-clock, rapid HIV testing on venipuncture specimens from all medical center care settings closely integrated with the services of an HIV clinic–based linkage-to-care team. Building on this system, we developed and implemented a program to screen rapid test–negative specimens for HIV RNA and link acutely HIV-infected individuals to care. Thus, the primary objective of this study was to describe the prevalence of all HIV cases, new HIV diagnoses, and acute HIV infections across medical center sites. Secondary objectives were to (1) determine the increase in HIV case detection conferred by screening for acute HIV infection, (2) calculate rapid test performance characteristics against a "gold standard" of pooled HIV RNA screening, and (3) ascertain disclosure and linkage-to-care outcomes.
Abstract and Introduction
Abstract
Objective: To describe the prevalence and location of new and acute HIV diagnoses in a large urban medical center. Secondary objectives were to evaluate rapid HIV test performance, the added yield of acute HIV screening, and linkage-to-care outcomes.
Design: Cross-sectional study from November 1, 2008, to April 30, 2009.
Methods: The hospital laboratory performed round-the-clock rapid HIV antibody testing on venipuncture specimens from patients undergoing HIV testing in hospital and community clinics, inpatient settings, and the emergency department (ED). For patients with negative results, a public health laboratory conducted pooled HIV RNA testing for acute HIV infection. The laboratories communicated positive results from the hospital campus to a linkage team. Linkage was defined as 1 outpatient HIV-related visit.
Results: Among 7927 patients, 8550 rapid tests resulted in 137 cases of HIV infection [1.7%, 95% confidence interval (CI): 1.5% to 2.0%], of whom 46 were new HIV diagnoses (0.58%, 95% CI: 0.43% to 0.77%). Pooled HIV RNA testing of 6704 specimens (78.4%) resulted in 3 cases of acute HIV infection (0.05%, 95% CI: 0.01% to 0.14%) and increased HIV case detection by 3.5%. Half of new HIV diagnoses and two thirds of acute infections were detected in the ED and urgent care clinic. Rapid test sensitivity was 98.9% (95% CI: 93.8% to 99.8%) and the specificity 99.9% (95% CI: 99.7% to 99.9%). More than 95% of newly diagnosed and out-of-care HIV-infected patients were linked to care.
Conclusions: Patients undergoing HIV testing in EDs and urgent care clinics may benefit from being simultaneously screened for acute HIV infection.
Introduction
In 2006, the Centers for Disease Control and Prevention recommended routine screening for HIV infection in patients aged 13–64 years in all health care settings where the prevalence of HIV infection is >0.1%. HIV-infected persons who do not know their status often present to medical settings and fail to be diagnosed, leading to late detection, higher morbidity, and prolonged transmission risk. Hospitals and their satellite clinics, therefore, are ideal settings to scale up HIV testing, especially because access to on-site HIV specialists has been shown to improve linkage to care for newly diagnosed and out-of-care HIV-infected patients.
Historically, a significant barrier to expanding HIV testing in the medical center setting has been the use of testing technologies with long turnaround time, for example, enzyme immunoassay (EIA) testing. EIA testing, conducted in "batches" several times a week, is not well suited to settings with rapid patient turnover, as it may delay appropriate clinical management and has been associated with high failure-to-notify rates.
Rapid HIV testing has the potential to increase testing in medical settings. Indeed, rapid HIV testing has been implemented successfully in medical settings such as labor and delivery, the emergency department (ED), and the inpatient wards. To date, however, the use of rapid HIV testing in medical settings has been limited to specific hospital departments. In addition, these initiatives have generally relied on point-of-care technology requiring ancillary staff, curtailing the ability to provide round-the-clock testing for large numbers of patients. As yet, a system for the effective application of rapid HIV testing across all care settings of a hospital and its satellite clinics has not been demonstrated.
An additional point regarding the adoption of rapid HIV testing is that the optimal testing technology for identifying HIV infection in medical settings has not been determined, especially because acute HIV infection may be relatively common in certain clinical venues, such as the urgent care clinic. Persons with acute HIV infection are highly infectious and may unknowingly transmit HIV infection if they remain unaware of their status. Fourth-generation immunoassays that can detect both HIV antibody and p24 antigen are a potentially appealing option. In addition, these assays can be run on automated platforms (as opposed to manual third-generation EIAs). However, few data exist on the prevalence of acute HIV infection across all inpatient and outpatient medical settings to justify a universal shift to this more sensitive testing format.
We therefore sought to investigate the potential contribution of acute HIV infection to hospital-wide HIV diagnosis. We drew upon a unique testing system developed at San Francisco General Hospital (SFGH) to execute this project. Key features of this testing system were laboratory-based, round-the-clock, rapid HIV testing on venipuncture specimens from all medical center care settings closely integrated with the services of an HIV clinic–based linkage-to-care team. Building on this system, we developed and implemented a program to screen rapid test–negative specimens for HIV RNA and link acutely HIV-infected individuals to care. Thus, the primary objective of this study was to describe the prevalence of all HIV cases, new HIV diagnoses, and acute HIV infections across medical center sites. Secondary objectives were to (1) determine the increase in HIV case detection conferred by screening for acute HIV infection, (2) calculate rapid test performance characteristics against a "gold standard" of pooled HIV RNA screening, and (3) ascertain disclosure and linkage-to-care outcomes.
