It does happen fairly often that people will have a detectable viral load (due to a recent flu shot or viral infection).
It's frighteningly scary, I know. I live in fear of the day my first line regimen stops working.
I wouldn't change regimen until another test a few weeks later.
If he experiences viral failure, then he will need to have a resistance assay done to see what mutations his virus has and what he can take.
Don't panic.
Be strong. It may be nothing.
Read this:
http://www.aidsmap.com/en/docs/1F1AFEC6-793D-4927-9A5D-29E6ADD79699.asp Once it has been suppressed below 50 copies/ml, viral load may sometimes rise above 50 copies/ml without indicating that treatment is failing. An isolated result above 50 copies/ml is called a 'viral blip' and may be the result of variability in the testing process. Although several studies have shown that even when several such blips occur, people who experience them are not at increased risk of treatment failure compared to people who maintain viral load below 50 copies/ml, others have found that viral load blips can be a signal that virological failure may well occur soon.
One study, which looked at 241 individuals receiving AZT/3TC/indinavir for a median of 84 weeks found that 40% (97) experienced one viral load blip above 50 copies/ml, and 32 of these patients experienced two consecutive increases in viral load above 50 copies/ml before viral load fell back below 50 copies/ml. Forty-seven out of the 97 individuals who experienced a viral load blip eventually recorded a viral load above 200 copies/ml before it returned to a level below 50 copies/ml. A viral load blip was not associated with a greater risk of long-term viral rebound in this study, and blips continued to occur in patients who had been receiving the regimen for up to five years (Havlir 2001). The same group also found that subsequent re-suppression of viral load did not appear to be associated with HIV-specific immune responses, suggesting that blips do not prime the immune system to exert progressively greater control over HIV.