Figure 1.

Psychosocial stress increases the plasma and cerebrospinal fluid (CSF) viral load in acute simian immunodeficiency virus (SIV) infection. Simian immunodeficiency virus viral load in plasma (A) and CSF (B) were quantified utilizing quantitative reverse-transcriptase polymerase chain reaction. Linear-mixed effects regression model. Statistics depicted in figure represent significance of difference between singly and socially housed animals at each time point. *, P ≤ .05; **, P ≤ .01; and ***, P ≤ .001. Circles connected by a solid line (red) indicate socially housed animals (N = 41 for all time points), whereas squares connected by a dashed line (blue) represent singly housed animals (N = 35 for the preinoculation and days 7 and 10 postinoculation; N = 17 for plasma viral load and N = 14 for CSF viral load for day 14 postinoculation). Error bars represent the standard error of the least square mean estimates generated by the linear mixed-effects regression model. Antiretroviral therapy initiated on day 12 postinoculation.