Examples where this may be relevant include when the HIV-positive partner is taking treatment for an acute opportunistic infection such as tuberculosis or other infection such as bacterial STI; where the female’s CD4+ count is still low but expected to improve; where the positive partner is only just initiating on ART and is not yet virally suppressed or where a new non-communicable disease is diagnosed and treatment is being optimised. The gene discussed is CD4; the disease is tuberculosis.