To evaluate the prevalence of primary and secondary phenotypic resistance to nevirupine among the infected patients at the comprehensive clinic of the Kenyatta National Hospital.

Abstract

Objective: while transmission of nevirapine resistance when given as monotherapy in PMTCT is well established, prevalence of nevirapine resistance in drug naive and nevirapine experienced is not known in the presence of the above setting and thus we evaluated the prevalence of primary and secondary phenotypic resistance to nevirapine among HIV positive patients attending the Comprehensive Care Clinic at the Kenyatta National Hospital. Design: cross sectional descriptive study of patients who are ARV naive and nevirapine experienced among HIV positive patients attending the Comprehensive Care Clinic of the Kenyatta National Hospital. Setting: Kenyatta National Hospital. Subjects: fifty one (51) patients who are ARV naive and one hundred and thirty eight (138) patients who are nevirapine experienced attending the CCC of the Kenyatta National Hospital. Methods: Plasma was obtained from 51 patients who were ARV naive and 138 patients who had been on nevirapine based regimen for at least one year. Phenotypic resistance using the Cavidi test kit was done at IC50 and compared to that of the reference wild type virus. Results: fifty one patients and one hundred and thirty eight patients for primary and secondary resistance respectively completed the study. In primary resistance group four (7.8%) were resistant and nine (17.8%) had reduced susceptibility to nevirapine. In the secondary resistance group four (2.9%) were resistant and two (1.4%) had reduced susceptibility to nevirapine. Conclusion: a substantial frequency of resistance to nevirapine was identified in HIV patients who had been ARV naive and nevirapine experienced. This data suggests the need of optimization of treatment guidelines based on the current estimates of the prevalence of nevirapine resistance in HIV seroconverters and those who are nevirapine experienced.