BACKGROUND: The Houston Health Department (HHD) is responsible for the public health follow-up of HIV-positive individuals who have become infected with either Chlamydia or Gonorrhea (co-infected patients). Compared to other HIV patients, coinfected patients are associated with a higher risk of HIV transmission. The number of coinfected patients has been increasing, but HHD’s limited resources are unable to meet the growth. The purpose of this study was to identify a prioritization method that reduces the number of coinfected patients needing follow-up. The literature shows that the strongest predictor of HIV transmission is plasma viral load (VL). A low VL is 20x less likely to transmit as shown in the HPTN 052 Study, which evaluated 1,800 couples, mostly heterosexual. The PARTNER Study is currently evaluating 1,110 couples, 40% MSM, and has thus far showed no cases of HIV transmission by a VL less than 200.
METHODS: For the exclusion of follow-up of patients with low VLs to effectively reduce HHD’s workload, a substantial number of these patients was needed. To predict the number of these patients in the upcoming years, data from previous years was examined. A single dataset was created by matching a dataset of coinfected patients and their coinfection diagnosis date, ranging from 2011-2015, to a dataset of HIV/AIDS patients and their plasma VLs collected during 2006-2015. Of this single dataset, patients that had a VL within 3 months of coinfection diagnosis were used. For each year during 2011-2015, patients with a suppressed VL (<200) and an undetectable VL (≤50) were counted. Because most patients had more than one VL within the 3 month period, the evaluation was conducted in two ways, the most recent and greatest VL.
RESULTS: The results showed a substantial number of patients with an undetectable VL in the years 2013-2015, using greatest or most recent VL. Based on 2014 data, excluding those with an undetectable VL results in 9 less cases per month that require follow-up.
CONCLUSIONS: With this insight, HHD formally proposed exclusion of patients with an undetectable VL from follow-up. In addition, this exclusion policy is to be reevaluated after the PARTNER Study is complete, to inform us of expanding exclusion to those with a suppressed VL (<200). Though, this proposal was not accepted by HHD leadership, it can be an effective strategy for other public health agencies that face resource limitations and must continue to prevent the transmission of HIV.