Two studies [44, 58] evaluated the effectiveness of SMS on the uptake of HIV testing compared to standard care, one study [53] examined the effectiveness of SMS on the uptake of STI testing in the past 6 months compared to standard care, one study [74] examined those undergoing chlamydia test of cure, and two others examined CD4 testing before 26 weeks gestation [45] and viral load testing in infants by 8 weeks postpartum [62]. Here, CD4 is linked to chlamydia trachomatis infectious disease.