Access to highly active antiretroviral therapy (HAART) for persons infected with HIV in sub-Saharan Africa has greatly improved over the past few years. However, data on long-term clinical outcomes of Africans receiving HAART, patterns of HIV resistance to antiretroviral drugs and implications of HIV type-1 (HIV-1) subtype diversity in Africa for resistance, are limited. In resource-limited settings, concerns have been raised that deficiencies in health systems could create the conditions for accelerated development of resistance. Coordinated surveillance systems are being established to assess the emergence of resistance and the factors associated with resistance development, and to create the possibility for adjusting treatment guidelines as necessary. The purpose of this report is to review the literature on HIV-1 resistance to antiretroviral drugs in sub-Saharan Africa, in relation to the drug regimens used in Africa, HIV-1 subtype diversity and overall prevalence of resistance. The report focuses on resistance associated with treatment, prevention of mother-to-child transmission and transmitted resistance. It also outlines priorities for public health action and research.
References
1.
PalellaF.J.Jr., DelaneyK.M., MoormanA.C.Declining morbidity and mortality among patients with advanced human immunodeficiency virus infection. HIV Outpatient Study Investigators.N Engl J Med1998; 338: 853–860.
DerdelinckxI., VanL.K., MaesB.Current levels of drug resistance among therapy-naive HIV-infected patients have significant impact on treatment response.J Acquir Immune Defic Syndr2004; 37: 1664–1666.
5.
LittleS.J., HolteS., RoutyJ.P.Antiretroviral-drug resistance among patients recently infected with HIV.N Engl J Med2002; 347: 385–394.
6.
WensingA.M., van de VijverD.A., AngaranoG.Prevalence of drug-resistant HIV-1 variants in untreated individuals in Europe: implications for clinical management.J Infect Dis2005; 192: 958–966.
7.
HemelaarJ., GouwsE., GhysP.D., OsmanovS.Global and regional distribution of HIV-1 genetic subtypes and recombinants in 2004.AIDS2006; 20: W13–W23.
8.
PrestonB.D., PoieszB.J., LoebL.A.Fidelity of HIV-1 reverse transcriptase.Science1988; 242: 1168–1171.
9.
RobertsJ.D., BebenekK., KunkelT.A.The accuracy of reverse transcriptase from HIV-1.Science1988; 242: 1171–1173.
10.
HoD.D., NeumannA.U., PerelsonA.S., ChenW., LeonardJ.M., MarkowitzM.Rapid turnover of plasma virions and CD4 lymphocytes in HIV-1 infection.Nature1995; 373: 123–126.
11.
WeiX., GhoshS.K., TaylorM.E.Viral dynamics in human immunodeficiency virus type 1 infection.Nature1995; 373: 117–122.
12.
NijhuisM., DeeksS., BoucherC.Implications of antiretroviral resistance on viral fitness.Curr Opin Infect Dis2001; 14: 23–28.
13.
JohnsonV.A., Brun-VezinetF., ClotetB.Update of the drug resistance mutations in HIV-1: 2007.Top HIV Med2007; 15: 119–125.
14.
World Health Organization.Antiretroviral therapy for HIV infection in adults and adolescents: recommendations for a public health approach, 2006 revision. (Accessed 1 November 2007). Available from http://www.who.int/hiv/pub/guidelines/artadultguidelines.pdf. Geneva, 2006.
15.
GilksC.F., CrowleyS., EkpiniR.The WHO public-health approach to antiretroviral treatment against HIV in resource-limited settings.Lancet2006; 368: 505–510.
16.
RenjifoB.HIV-1 subtypes and recombinants. In AIDS in Africa, 2nd edn. Edited by EssexM., MboupS., KankiP.J., MarlinkR.G., and TlouS.D.. New York: Springer2002; pp. 138–157.
17.
FonjungoP.N., DashB.C., MpoudiE.N.Molecular screening for HIV-1 group N and simian immunodeficiency virus cpz-like virus infections in Cameroon.AIDS2000; 14: 750–752.
18.
JaffeH.W., SchochetmanG.Group O human immunodeficiency virus-1 infections.Infect Dis Clin North Am1998; 12: 39–46.
GroblerJ., GrayC.M., RademeyerC.Incidence of HIV-1 dual infection and its association with increased viral load set point in a cohort of HIV-1 subtype C-infected female sex workers.J Infect Dis2004; 190: 1355–1359.
21.
HuD.J., SubbaraoS., VanichseniS.Frequency of HIV-1 dual subtype infections, including intersubtype superinfections, among injection drug users in Bangkok, Thailand.AIDS2005; 19: 303–308.
22.
BraitsteinP., BrinkhofM.W., DabisF.Mortality of HIV-1-infected patients in the first year of antiretroviral therapy: comparison between low-income and high-income countries.Lancet2006; 367: 817–824.
23.
IversL.C., KendrickD., DoucetteK.Efficacy of antiretroviral therapy programs in resource-poor settings: a meta-analysis of the published literature.Clin Infect Dis2005; 41: 217–224.
24.
DumansA.T., SoaresM.A., MachadoE.S.Synonymous genetic polymorphisms within Brazilian human immunodeficiency virus Type 1 subtypes may influence mutational routes to drug resistance.J Infect Dis2004; 189: 1232–1238.
25.
GonzalezL.M., BrindeiroR.M., AguiarR.S.Impact of nelfinavir resistance mutations on in vitro phenotype, fitness, and replication capacity of human immunodeficiency virus type 1 with subtype B and C proteases.Antimicrob Agents Chemother2004; 48: 3552–3555.
26.
KantorR., KatzensteinD.A., EfronB.Impact of HIV-1 subtype and antiretroviral therapy on protease and reverse transcriptase genotype: results of a global collaboration.PLoS Med2005; 2: e112.
27.
KantorR., KatzensteinD.Polymorphism in HIV-1 non-subtype B protease and reverse transcriptase and its potential impact on drug susceptibility and drug resistance evolution.AIDS Rev2003; 5: 25–35.
28.
VergneL., PeetersM., Mpoudi-NgoleE.Genetic diversity of protease and reverse transcriptase sequences in non-subtype-B human immunodeficiency virus type 1 strains: evidence of many minor drug resistance mutations in treatment-naive patients.J Clin Microbiol2000; 38: 3919–3925.
29.
DescampsD., CollinG., LetourneurF.Susceptibility of human immunodeficiency virus type 1 group O isolates to antiretroviral agents: in vitro phenotypic and genotypic analyses.J Virol1997; 71: 8893–8898.
30.
WitvrouwM., PannecouqueC., VanL.K., DesmyterJ., DeC.E., VandammeA.M.Activity of non-nucleoside reverse transcriptase inhibitors against HIV-2 and SIV.AIDS1999; 13: 1477–1483.
31.
HolguinA., SuneC., HamyF., SorianoV., KlimkaitT.Natural polymorphisms in the protease gene modulate the replicative capacity of non-B HIV-1 variants in the absence of drug pressure.J Clin Virol2006; 36: 264–271.
32.
DescampsD., ApetreiC., CollinG., DamondF., SimonF., Brun-VezinetF.Naturally occurring decreased susceptibility of HIV-1 subtype G to protease inhibitors.AIDS1998; 12: 1109–1111.
33.
KinomotoM., Appiah-OpongR., BrandfulJ.A.HIV-1 proteases from drug-naive West African patients are differentially less susceptible to protease inhibitors.Clin Infect Dis2005; 41: 243–251.
34.
PalmerS., AlaeusA., AlbertJ., CoxS.Drug susceptibility of subtypes A, B,C, D, and E human immunodeficiency virus type 1 primary isolates.AIDS Res Hum Retroviruses1998; 14: 157–162.
35.
Velazquez-CampoyA., ToddM.J., VegaS., FreireE.Catalytic efficiency and vitality of HIV-1 proteases from African viral subtypes.Proc Natl Acad Sci U S A2001; 98: 6062–6067.
36.
Velazquez-CampoyA., VegaS., FreireE.Amplification of the effects of drug resistance mutations by background polymorphisms in HIV-1 protease from African subtypes.Biochemistry2002; 41: 8613–8619.
37.
VergneL., StuyverL., VanH.M., ButelC., DelaporteE., PeetersM.Natural polymorphism in protease and reverse transcriptase genes and in vitro antiretroviral drug susceptibilities of non-B HIV-1 strains from treatment-naive patients.J Clin Virol2006; 36: 43–49.
38.
van de VijverD.A., WensingA.M., AngaranoG.The calculated genetic barrier for antiretroviral drug resistance substitutions is largely similar for different HIV-1 subtypes.J Acquir Immune Defic Syndr2006; 41: 352–360.
39.
BrennerB.G., OliveiraM., Doualla-BellF.HIV-1 subtype C viruses rapidly develop K65R resistance to tenofovir in cell culture.AIDS2006; 20: F9–F13.
40.
Doualla-BellF., AvalosA., BrennerB.High prevalence of the K65R mutation in human immunodeficiency virus type 1 subtype C isolates from infected patients in Botswana treated with didanosine-based regimens.Antimicrob Agents Chemother2006; 50: 4182–4185.
41.
EshlemanS.H., GuayL.A., WangJ.Distinct patterns of emergence and fading of K103N and Y181C in women with subtype A vs. D after single-dose nevirapine: HIVNET 012.J Acquir Immune Defic Syndr2005; 40: 24–29.
42.
EshlemanS.H., HooverD.R., ChenS.Nevirapine (NVP) resistance in women with HIV-1 subtype C, compared with subtypes A and D, after the administration of single-dose NVP.J Infect Dis2005; 192: 30–36.
43.
FlysT., NissleyD.V., ClaasenC.W.Sensitive drug-resistance assays reveal long-term persistence of HIV-1 variants with the K103N nevirapine (NVP) resistance mutation in some women and infants after the administration of single-dose NVP: HIVNET 012.J Infect Dis2005; 192: 24–29.
44.
EshlemanS.H., HooverD.R., ChenS.Resistance after single-dose nevirapine prophylaxis emerges in a high proportion of Malawian newborns.AIDS2005; 19: 2167–2169.
45.
BrennerB., TurnerD., OliveiraM.A V106M mutation in HIV-1 clade C viruses exposed to efavirenz confers cross-resistance to non-nucleoside reverse transcriptase inhibitors.AIDS2003; 17: F1–F5.
46.
SnoeckJ., KantorR., ShaferR.W.Discordances between interpretation algorithms for genotypic resistance to protease and reverse transcriptase inhibitors of human immunodeficiency virus are subtype dependent.Antimicrob Agents Chemother2006; 50: 694–701.
47.
VergneL., SnoeckJ., AghokengA.Genotypic drug resistance interpretation algorithms display high levels of discordance when applied to non-B strains from HIV-1 naive and treated patients.FEMS Immunol Med Microbiol2006; 46: 53–62.
48.
BourgeoisA., LaurentC., MougnutouR.Field assessment of generic antiretroviral drugs: a prospective cohort study in Cameroon.Antivir Ther2005; 10: 335–341.
49.
FischerA., KarasiJ.C., KibibiD.Antiviral efficacy and resistance in patients on antiretroviral therapy in Kigali, Rwanda: the real-life situation in 2002.HIV Med2006; 7: 64–66.
50.
LaurentC., DiakhateN., GueyeN.F.The Senegalese government's highly active antiretroviral therapy initiative: an 18-month follow-up study.AIDS2002; 16: 1363–1370.
51.
LaurentC., Ngom GueyeN.F., NdourC.T.Long-term benefits of highly active antiretroviral therapy in Senegalese HIV-1-infected adults.J Acquir Immune Defic Syndr2005; 38: 14–17.
52.
LaurentC., KouanfackC., VergneL.Antiretroviral drug resistance and routine therapy, Cameroon.Emerg Infect Dis2006; 12: 1001–1004.
53.
SpacekL.A., ShihabH.M., KamyaM.R.Response to antiretroviral therapy in HIV-infected patients attending a public, urban clinic in Kampala, Uganda.Clin Infect Dis2006; 42: 252–259.
54.
DART Virology Group and Trial Team virological response to a triple nucleoside/nucleotide analogue regimen over 48 weeks in HIV-1-infected adults in Africa.AIDS2006; 20: 1391–1399.
55.
SeylerC., dje-ToureC., MessouE.Impact of genotypic drug resistance mutations on clinical and immunological outcomes in HIV-infected adults on HAART in West Africa.AIDS2007; 21: 1157–1164.
56.
WeidleP.J., MalambaS., MwebazeR.Assessment of a pilot antiretroviral drug therapy programme in Uganda: patients’ response, survival, and drug resistance.Lancet2002; 360: 34–40.
57.
RamadhaniH.O., ThielmanN.M., LandmanK.Z.Predictors of incomplete adherence, virologic failure, and antiviral drug resistance among HIV-infected adults receiving antiretroviral therapy in Tanzania.Clin Infect Dis2007; 45: 1492–1498.
58.
KantorR., ZijenahL.S., ShaferR.W.HIV-1 subtype C reverse transcriptase and protease genotypes in Zimbabwean patients failing antiretroviral therapy.AIDS Res Hum Retroviruses2002; 18: 1407–1413.
59.
AdjeC., CheingsongR., RoelsT.H.High prevalence of genotypic and phenotypic HIV-1 drug-resistant strains among patients receiving antiretroviral therapy in Abidjan, Cote d'Ivoire.J Acquir Immune Defic Syndr2001; 26: 501–506.
60.
VergneL., Malonga-MouelletG., MistoulI.Resistance to antiretroviral treatment in Gabon: need for implementation of guidelines on antiretroviral therapy use and HIV-1 drug resistance monitoring in developing countries.J Acquir Immune Defic Syndr2002; 29: 165–168.
61.
PhillipsA.N., DunnD., SabinC.Long term probability of detection of HIV-1 drug resistance after starting antiretroviral therapy in routine clinical practice.AIDS2005; 19: 487–494.
62.
ChaixM.L., RouetF., KouakoussuiK.A.Genotypic human immunodeficiency virus type 1 drug resistance in highly active antiretroviral therapy-treated children in Abidjan, Cote d'Ivoire.Pediatr Infect Dis J2005; 24: 1072–1076.
63.
KamyaM.R., Mayanja-KizzaH., KambuguA.Predictors of long-term viral failure among Ugandan children and adults treated with antiretroviral therapy.J Acquir Immune Defic Syndr2007; 46: 187–193.
64.
LwembeR., OchiengW., PanikulamA.Anti-retroviral drug resistance-associated mutations among non-subtype B HIV-1-infected Kenyan children with treatment failure.J Med Virol2007; 79: 865–872.
65.
CohenG.M.Access to diagnostics in support of HIV/AIDS and tuberculosis treatment in developing countries.AIDS2007; 21Suppl 4: S81–S87.
66.
NugentR., PickettJ., BackE.Drug resistance as a global health policy priority.Center for Global Development. Washington, January 2008. (Accessed 15 January 2008). Available from http://www.cgdev.org/doc/ghprn/Concept%20Paper.pdf.
HarriganP.R., HoggR.S., DongW.W.Predictors of HIV drug-resistance mutations in a large antiretroviral-naive cohort initiating triple antiretroviral therapy.J Infect Dis2005; 191: 339–347.
69.
PatersonD.L., SwindellsS., MohrJ.Adherence to protease inhibitor therapy and outcomes in patients with HIV infection.Ann Intern Med2000; 133: 21–30.
70.
SethiA.K., CelentanoD.D., GangeS.J., MooreR.D., GallantJ.E.Association between adherence to antiretroviral therapy and human immunodeficiency virus drug resistance.Clin Infect Dis2003; 37: 1112–1118.
71.
BissonG.P., FrankI., GrossR.Out-of-pocket costs of HAART limit HIV treatment responses in Botswana's private sector.AIDS2006; 20: 1333–1336.
72.
GillC.J., HamerD.H., SimonJ.L., TheaD.M., SabinL.L.No room for complacency about adherence to antiretroviral therapy in sub-Saharan Africa.AIDS2005; 19: 1243–1249.
73.
BreenR.A., SwadenL., BallingerJ., LipmanM.C.Tuberculosis and HIV co-infection: a practical therapeutic approach.Drugs2006; 66: 2299–2308.
74.
WallisC.L., BellC., BoulméR.Emerging ART Drug Resistance in Subtype C: Experience from the 2 Clinics in Johannesburg, South Africa.14th Conference on Retroviruses and Opportunistic Infections. 25–28 February 2007, Los Angeles, CA, USA. Abstract 661.
75.
Cozzi-LepriA., PhillipsA.N., RuizL.Evolution of drug resistance in HIV-infected patients remaining on a virologically failing combination antiretroviral therapy regimen.AIDS2007; 21: 721–732.
76.
WensingA.M., VercauterenJ., van de VijverD.First representative prospective surveillance data on HIV baseline drug resistance from 17 countries in Europe: the SPREAD programme.4th European HIV Drug Resistance Workshop. 29–31 March 2006, Monte Carlo, Monaco. Abstract 1.
77.
LittleS.J., MayS., HechtF.Increase in transmitted NNRTI drug resistance among recently HIV infected patients from North America and Australia.Antivir Ther2006; 11Suppl 1: S110.
78.
RossL.L., FloranceA., WineB.Prevalence of HIV-1 drug resistance-associated mutations in a large cohort of antiretroviral therapy (ART) naive HIV-infected individuals in the United States from 2000–2004.Antivir Ther2006; 11Suppl 1: S120.
79.
BowlesE., WensingA.M., van de VijverD.A., BoulméR., SchuurmanR., BoucherC.A.WATCH: a worldwide database for collecting and analysing data on transmission of drug resistant HIV using standardized methods.XVIth International AIDS Conference. 3–8 August 2006, Toronto, Canada. Abstract MOPE0388.
80.
Adje-ToureC., BileC.E., BorgetM.Y.Polymorphism in protease and reverse transcriptase and phenotypic drug resistance of HIV-1 recombinant CRF02_AG isolates from patients with no prior use of antiretroviral drugs in Abidjan, Cote d'Ivoire.J Acquir Immune Defic Syndr2003; 34: 111–113.
81.
BellocchiM.C., ForbiciF., PalombiL.Subtype analysis and mutations to antiviral drugs in HIV-1-infected patients from Mozambique before initiation of antiretroviral therapy: results from the DREAM programme.J Med Virol2005; 76: 452–458.
82.
BussmannH., NovitskyV., WesterW.HIV-1 subtype C drug-resistance background among ARV-naive adults in Botswana.Antivir Chem Chemother2005; 16: 103–115.
83.
GordonM., de OliveiraT., BishopK.Molecular characteristics of human immunodeficiency virus type 1 subtype C viruses from KwaZulu-Natal, South Africa: implications for vaccine and antiretroviral control strategies.J Virol2003; 77: 2587–2599.
84.
HandemaR., TerunumaH., KasoloF.Prevalence of drug-resistance-associated mutations in antiretroviral drug-naive Zambians infected with subtype C HIV-1.AIDS Res Hum Retroviruses2003; 19: 151–160.
85.
KoizumiY., NdembiN., MiyashitaM.Emergence of antiretroviral therapy resistance-associated primary mutations among drug-naive HIV-1-infected individuals in rural western Cameroon.J Acquir Immune Defic Syndr2006; 43: 15–22.
86.
KoningsF.A., ZhongP., AgwaraM.Protease mutations in HIV-1 non-B strains infecting drug-naive villagers in Cameroon.AIDS Res Hum Retroviruses2004; 20: 105–109.
87.
MaslinJ., RogierC., CaronM., GrandadamM., KoeckJ.L., NicandE.Antiretroviral drug resistance among drug-naive HIV-1-infected individuals in Djibouti (Horn of Africa).Antivir Ther2005; 10: 855–859.
88.
PetchL.A., HoffmanI.F., JereC.S.Genotypic analysis of the protease and reverse transcriptase of HIV type 1 subtype C isolates from antiretroviral drug-naive adults in Malawi.AIDS Res Hum Retroviruses2005; 21: 799–805.
89.
PillayC., BredellH., McIntyreJ., GrayG., MorrisL.HIV-1 subtype C reverse transcriptase sequences from drug-naive pregnant women in South Africa.AIDS Res Hum Retroviruses2002; 18: 605–610.
90.
SomiG., KibukaT., DialloK.Surveillance of transmitted HIV drug resistance among women attending antenatal clinics in Dar Es Salaam, Tanzania.14th Conference on Retroviruses and Opportunistic Infections. 25–28 February 2007, Los Angeles, CA, USA. Abstract 655.
91.
ToniT., MasquelierB., BonardD.Primary HIV-1 drug resistance in Abidjan (Cote d'Ivoire): a genotypic and phenotypic study.AIDS2002; 16: 488–491.
92.
ToniT.D., Recordon-PinsonP., MingaA.Presence of key drug resistance mutations in isolates from untreated patients of Abidjan, Cote d'Ivoire: ANRS 1257 study.AIDS Res Hum Retroviruses2003; 19: 713–717.
93.
VergneL., KaneC.T., LaurentC.Low rate of genotypic HIV-1 drug-resistant strains in the Senegalese government initiative of access to antiretroviral therapy.AIDS2003; 17Suppl 3: S31–S38.
94.
VergneL., DiagbougaS., KouanfackC.HIV-1 drug-resistance mutations among newly diagnosed patients before scaling-up programmes in Burkina Faso and Cameroon.Antivir Ther2006; 11: 575–579.
95.
VessiereA., NerrienetE., KfutwahA.HIV-1 pol gene polymorphism and antiretroviral resistance mutations in drug-naive pregnant women in Yaounde, Cameroon.J Acquir Immune Defic Syndr2006; 42: 256–258.
96.
VidalN., MulangaC., BazepeoS.E.HIV type 1 pol gene diversity and antiretroviral drug resistance mutations in the Democratic Republic of Congo (DRC).AIDS Res Hum Retroviruses2006; 22: 202–206.
97.
VidalN., NiyongaboT., NduwimanaJ.HIV type 1 diversity and antiretroviral drug resistance mutations in Burundi.AIDS Res Hum Retroviruses2007; 23: 175–180.
98.
BlowerS., BodineE., KahnJ., McFarlandW.The antiretroviral rollout and drug-resistant HIV in Africa: insights from empirical data and theoretical models.AIDS2005; 19: 1–14.
99.
HastingsI.M., LallooD., KhooS.H.Will ART rollout in Africa drive an epidemic of drug resistant HIV?AIDS2006; 20: 1354–1356.
100.
VardavasR., BlowerS.The emergence of HIV transmitted resistance in Botswana: “When will the WHO detection threshold be exceeded?”PLoS ONE2007; 2: e152.
101.
BarbourJ.D., HechtF.M., WrinT.Persistence of primary drug resistance among recently HIV-1 infected adults.AIDS2004; 18: 1683–1689.
102.
GhosnJ., PellegrinI., GoujardC.HIV-1 resistant strains acquired at the time of primary infection massively fuel the cellular reservoir and persist for lengthy periods of time.AIDS2006; 20: 159–170.
103.
HIV-infected pregnant women and vertical transmission in Europe since 1986.European collaborative study.AIDS2001; 15: 761–770.
104.
DorenbaumA., CunninghamC.K., GelberR.D.Two-dose intrapartum/newborn nevirapine and standard antiretroviral therapy to reduce perinatal HIV transmission: a randomized trial.JAMA2002; 288: 189–198.
105.
MandelbrotL., Landreau-MascaroA., RekacewiczC.Lamivudine-zidovudine combination for prevention of maternal-infant transmission of HIV-1.JAMA2001; 285: 2083–2093.
106.
GuayL.A., MusokeP., FlemingT.Intrapartum and neonatal single-dose nevirapine compared with zidovudine for prevention of mother-to-child transmission of HIV-1 in Kampala, Uganda: HIVNET 012 randomised trial.Lancet1999; 354: 795–802.
107.
JacksonJ.B., MusokeP., FlemingT.Intrapartum and neonatal single-dose nevirapine compared with zidovudine for prevention of mother-to-child transmission of HIV-1 in Kampala, Uganda: 18-month follow-up of the HIVNET 012 randomised trial.Lancet2003; 362: 859–868.
108.
EshlemanS.H., MracnaM., GuayL.A.Selection and fading of resistance mutations in women and infants receiving nevirapine to prevent HIV-1 vertical transmission (HIVNET 012).AIDS2001; 15: 1951–1957.
109.
EshlemanS.H., GuayL.A., MwathaA.Comparison of nevirapine (NVP) resistance in Ugandan women 7 days vs. 6-8 weeks after single-dose nvp prophylaxis: HIVNET 012.AIDS Res Hum Retroviruses2004; 20: 595–599.
110.
EshlemanS.H., GuayL.A., MwathaA.Characterization of nevirapine resistance mutations in women with subtype A vs. D HIV-1 6-8 weeks after single-dose nevirapine (HIVNET 012).J Acquir Immune Defic Syndr2004; 35: 126–130.
111.
GordonM., GrahamN., BlandR.Surveillance of resistance in KZN South Africa, including mother-infant pairs 6 weeks after single-dose NVP.Antivir Ther2004; 9: S80.
112.
LeeE.J., KantorR., ZijenahL.Breast-milk shedding of drug-resistant HIV-1 subtype C in women exposed to single-dose nevirapine.J Infect Dis2005; 192: 1260–1264.
113.
MartinsonN., MorrisL., GrayG.HIV resistance and transmission following single-dose nevirapine in a PMTCT cohort.11th Conference on Retroviruses and Opportunistic Infections. 8–11 February 2004, San Francisco, LA, USA. Abstract 38.
114.
McIntyreJ., MartinsonN., GrayG.E.Addition of short course Combivir (CBV) to single dose viramune (sdNVP) for the prevention of mother to child transmission (MTCT) of HIV-1 can significantly decrease the subsequent development of maternal and paediatric NNRTI-resistant virus.3rd IAS Conference on HIV Pathogenesis and Treatment. 24–27 July 2005, Rio de Janeiro, Brazil. Abstract TuFo0204.
115.
MorrisL., MartinsonN., PillayC.Persistence of nevirapine resistance mutations 6 months following single dose nevirapine.XVth International AIDS Conference. 11–16 July 2004, Bangkok, Thailand. Abstract ThOrB1353.
116.
SullivanJ.South African Nevirapine Trial: Selection of resistance mutations.XIVth International AIDS Conference. 7–12 July 2002, Barcelona, Spain. Abstract LbPeB9024.
117.
ToniT.D., MasquelierB., LazaroE.Characterization of nevirapine (NVP) resistance mutations and HIV type 1 subtype in women from Abidjan (Cote d'Ivoire) after NVP single-dose prophylaxis of HIV type 1 mother-to-child transmission.AIDS Res Hum Retroviruses2005; 21: 1031–1034.
118.
ChaixM.L., EkoueviD.K., RouetF.Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire.J Infect Dis2006; 193: 482–487.
119.
World Health Organization.Antiretroviral drugs for treating pregnant women and preventing HIV infection in infants in resource-limited settings: towards universal access: recommendations for a public health approach. (Accessed 1 September 2007). Available from http://www.who.int/hiv/pub/mtct/guidelines/en. Geneva, 2006.
120.
ChiB.H., SinkalaM., MbeweF.Single-dose tenofovir and emtricitabine for reduction of viral resistance to non-nucleoside reverse transcriptase inhibitor drugs in women given intrapartum nevirapine for perinatal HIV prevention: an open-label randomised trial.Lancet2007; 370: 1698–1705.
121.
ArriveE., NewellM.L., EkoueviD.K.Prevalence of resistance to nevirapine in mothers and children after single-dose exposure to prevent vertical transmission of HIV-1: a meta-analysis.Int J Epidemiol2007; 36: 1009–1021.
122.
TroyerR., LalondeM., KyeyuneF.High frequency of nevirapine resistant mutations in the HIV quasi species found in NVP-treated participants of an MTCT Ugandan cohort.Antivir Ther2005; 10: S14.
123.
EshlemanS.H., HooverD.R., HudelsonS.E.Development of nevirapine resistance in infants is reduced by use of infant-only single-dose nevirapine plus zidovudine postexposure prophylaxis for the prevention of mother-to-child transmission of HIV-1.J Infect Dis2006; 193: 479–481.
124.
JourdainG., Ngo-Giang-HuongN., Le CoeurS.Intrapartum exposure to nevirapine and subsequent maternal responses to nevirapine-based antiretroviral therapy.N Engl J Med2004; 351: 229–240.
125.
LockmanS., ShapiroR.L., SmeatonL.M.Response to antiretroviral therapy after a single, peripartum dose of nevirapine.N Engl J Med2007; 356: 135–147.
126.
CovaadiaA., MaraisB., AbramsE.Virologic reponse to NNRTi treatment among women who took single-dose nevirapine 18 to 36 months earlier.13th Conference on Retroviruses and Opportunistic Infections. 5–8 February 2006, Denver, CO, USA. Abstract 641.
127.
KuhnL., SinkalaM., KankasaM.P., KasondeP., TheaD.M., AldrovandiG.M.Nevirapine resistance viral mutations after repeat use of nevirapine for prevention of perinatal HIV transmission.J Acquir Immune Defic Syndr2006; 42: 260–262.
128.
MartinsonN.A., EkoueviD.K., DabisF.Transmission rates in consecutive pregnancies exposed to single-dose nevirapine in Soweto, South Africa and Abidjan, Cote d'Ivoire.J Acquir Immune Defic Syndr2007; 45: 206–209.
129.
EureC., BakakiP., McConnellM.Effectiveness of repeat single-dose nevirapine in subsequent pregnancies among Uganda women.13th Conference on Retroviruses and Opportunistic Infections. 5–8 February, 2006, Denver, CO, USA. Abstract 125.
130.
KatabiraE.T., OelrichsR.B.Scaling up antiretroviral treatment in resource-limited settings: successes and challenges.AIDS2007; 21Suppl 4: S5–S10.
131.
KoenigS.P., KuritzkesD.R., HirschM.S.Monitoring HIV treatment in developing countries.BMJ2006; 332: 602–604.
Linking African and Asian Societies for an Enhanced Response to HIV/AIDS (LAASER). (Accessed 1 December 2007). Available from http://www.laaserhivaids.org/.
134.
GallantJ.E.Antiretroviral drug resistance and resistance testing.Top HIV Med2005; 13: 138–142.
