Comparison of the ScreenFire and Xpert HPV assays for the detection of human papillomavirus and cervical precancer among women living with HIV in Malawi

Table 1 Agreement between Xpert and ScreenFire HPV assays on provider-collected specimens among HIV-positive women in Malawi^*

HPV HPV positivity	Xpert provider-collected N = 315 N (%)	ScreenFire provider-collected N = 315 N (%)	Percent agreement on positives	Unweighted Kappa (95% CI)
Any HPV	221 (70%)	236 (75%)	80%	0.59 (0.50–0.69)
HPV 16	45 (14%)	42 (13%)	64%	0.75 (0.64–0.86)
HPV 18/45	35 (11%)	45 (14%)	60%	0.71 (0.60–0.83)
HPV 31/33/52/58/35	129 (41%)	133 (42%)	72%	0.73 (0.65–0.80)
Channels 4/5^†	Channel 4: HPV 51/59 37 (12%)	Channel 4: HPV 39/51/56/59/68 62 (20%)	NA	NA
Channels 4/5^†	Channel 5: HPV 39/56/66/68 50 (16%)	Channel 4: HPV 39/51/56/59/68 62 (20%)	NA	NA
HPV Negative Participants	94 (30%)	79 (25%)	NA	NA

*At baseline, all specimens were self-collected, followed by pelvic exam and provider-collected specimens
Participants can be HPV-positive for more than one channel; hence, the totals may add up to more than N = 315. Provider-collected specimens were collected between July 2020 and February 2022 and divided into aliquots for freezer storage. Some of the aliquots were then thawed and tested with Xpert 1–2 years after collection, between September 2021 and June 2022. Remaining aliquots were thawed and tested with ScreenFire between November 2022 and January 2023
^†Xpert Channel 4 (HPV 51/59) & Channel 5 (HPV 39/68/56/66) and ScreenFire Channel 4 (HPV 39/51/59/56/68) differ and cannot be directly compared. Could not calculate Kappa for Channels 4 & 5

ISSN: 1750-9378