[MoPeD3680] Superiority of An "Ultra short" Zidovudine (ZDV) regimen in the prevention of perinatal HIV transmission in rural Zimbabwe

14th International AIDS Conference

Barcelona, Spain — July 7-12, 2002

[TITLE:] Superiority of An "Ultra short" Zidovudine (ZDV) regimen in the prevention of perinatal HIV transmission in rural Zimbabwe

[AUTHOR(S):] M.S. Silverman, G. Arbess, R. Glazier, A. Simor¹, P. Thistle², I. Chitsikie, I. Chipato³, R. Pilon⁴

Int Conf AIDS. 2002 Jul 7-12;14:Abstract No. MoPeD3680

BACKGROUND: A 4-week course of ZDV at the end of pregnancy was demonstrated to decrease Perinatal transmission by 51% in Thailand. This abbreviated regimen became the WHO recommendation for resource poor countries. Unfortunately due to cost, even this abbreviated regimen is not available in most of Africa. Longer courses are likely more effective, but also are more expensive and impractical. As in many countries, Nevaripine is not yet licensed for routine use in Zimbabwe. Retrospective studies suggest that the most important portion of the ZDV prevention protocol is that given to the neonate, within the first 48 hours.

METHODS: Between Nov 1999 and Dec 2000, 223 patients were enrolled in a prospective randomized double-blind trial in a rural hospital in Zimbabwe. After informed consent, HIV seropositive expectant mothers were randomized at 36 weeks to A (THAI Protocol): ZDV 300mg PO BID to start at 36 weeks and continue until labour onset, then 300mg PO Q3H until delivery, with Placebo given to the neonate; or B (ultra-short): Placebo until the onset of labour, then ZDV 300mg PO Q3H while in labour, and ZDV 2mg/kg Q6H PO to the neonate for 72 hours postpartum. Sequential infant heel prick blood samples were collected on filter blot paper and assessed for HIV-1 viral RNA by the Nuclisens QL assay. Counselling regarding breast-feeding was carried out as per Zimbabwe National Guidelines. 99% of women decided to breast feed.

Results (see table): PCR results are available for the first 191 infants.

Group	A			B
	#infected	n	%infected	#infected	n	%infected
Birth	5	95	5.3	6	96	6.3
2weeks	12	90	13.3	10	88	11.4
6weeks	18	87	20.7	14	86	16.3
3months	21	81	25.9	16	77	20.8
6months	22	73	30.1	17	70	24.3

Discussion: There is a trend towards less perinatal transmission in B and this advantage persisted for 6 months. Transmission beyond 6 weeks is likely due to breast feeding, which was similar in both groups. B is also less expensive (4$ vs 110$US), easier to administer and due to it's brevity, is less likely to induce drug resistance and helps to maintain patient confidentiality.

Conclusion: Overall, in rural Africa, Ultrashort(B) is superior to Thai(A).

Presenting Author: Michael Silverman

1University of Toronto, 95 Bayly St #200, Ajax, Ontario, 11S7K8, Canada.

2Howard Hospital, Glendale, Zimbabwe.

3University of Zimbabwe, Harare, Zimbabwe.

5Health Canada, Ottawa, Canada.

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