It is estimated that up to a third of HIV-infected patients aware of their infection are not receiving specialized HIV medical care in the U.S., and a similar proportion of those receiving care do not enter medical services until reaching a stage of advanced immunosuppression [1, 2]. Clinically, early entry into care after diagnosis is associated with better health outcomes, as patients benefit maximally from timely initiation of highly active antiretroviral therapy (HAART), immunizations, and screening and prophylaxis for opportunistic infections and sexually transmitted diseases (STDs) . Public health benefits of early linkage to care include access to risk-reduction interventions, possibly decreased HIV transmission due to reduced plasma and genital HIV viral load as a result of HAART, and possibly lower health care costs .
While case management and referral has been advocated as a method of decreasing unmet needs for supportive services and increasing utilization and adherence to HIV therapy [4, 5], its role in linkage to care after HIV diagnosis remains poorly understood. At the public health level, collecting initial CD4 T cell counts and plasma HIV viral loads can determine the stage of HIV infection at diagnosis and serve as a measure of entry into medical care. Although several studies have used CD4 T cell count tests or plasma HIV viral load results as markers of care, those studies have not used provider or laboratory-reported test results as surveillance measures to assess entry to HIV medical care in the public health setting [2, 5, 6]. Surveillance of laboratory reports of CD4 T cell counts and plasma HIV viral loads could be used by public health departments as valid surrogates for entry into HIV medical care after diagnosis, allowing the design, evaluation, and improvement of HIV testing and linkage to care programs. Currently, few local public health departments are using CD4 T cell count data collected for these purposes and many states have not yet established mandatory laboratory reporting of CD4 T cell counts and plasma HIV viral loads.
Recently, the Centers for Disease Control and Prevention (CDC) prioritized linkage to care as a primary strategic prevention objective of the National Advancing HIV Prevention plan . Current recommendations include the report of ongoing CD4 T cell count results to the local health jurisdiction, beginning at the time of HIV diagnosis . CD4 T cell counts and plasma HIV viral load are used clinically to determine the stage of disease and indications for initiating antiretroviral therapy. Those tests are commonly obtained on the first visit for HIV medical care. Therefore, CD4 T cell counts and plasma HIV viral load could potentially serve as surrogate markers to evaluate entry into care, and determine unmet health needs in various communities.
In this report we describe the characteristics of patients having a newly diagnosed HIV infection between July 1, 2006 and June 30, 2007 who entered into HIV medical care. Secondly, we demonstrate the additional yield obtained by using laboratory surveillance of CD4 T cell tests and plasma HIV viral loads as markers for entry into HIV medical care after initial diagnosis. Lastly, we show the effect of having had a public health investigator interview after a first positive HIV test on the likelihood of entering medical care within 3 months of the initial HIV diagnosis.