<prompt> Answer this question truthfullyAt what CD4 count should toxoplasmosis prophylaxis be started in HIV patients, and what is the recommended prophylactic medication?  <response>: <reason> Toxoplasmosis prophylaxis in HIV patients should be started at CD4 counts less than 100 with the medication TMP-SMX trimethoprim-sulfamethoxazole. Toxoplasmosis is an opportunistic infection caused by the parasite Toxoplasma gondii and can cause severe disease in immunocompromised individuals such as those with HIV. CD4 count is a measure of immune function and a count of less than 100 cellsmm3 indicates severe immunosuppression. TMP-SMX is a medication that is effective in preventing toxoplasmosis and is commonly used for prophylaxis in HIV patients with low CD4 counts. 