***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: CONTEXT Antenatal counseling and human immunodeficiency virus ( HIV ) testing are not universal in Africa ; thus , women often present in labor with unknown HIV status without receiving the HIVNET 012 nevirapine ( NVP ) regimen ( a single oral dose of NVP to the mother at the start of labor and to the infant within 72 hours of birth ) . OBJECTIVE To determine risk of mother-to-child transmission of HIV when either st and ard use of NVP alone or in combination with zidovudine ( ZDV ) was administered to infants of women tested at delivery . DESIGN , SETTING , AND PARTICIPANTS A r and omized , open-label , phase 3 trial conducted between April 1 , 2000 , and March 15 , 2003 , at 6 clinics in Blantyre , Malawi , Africa . The trial included all infants born to 894 women who were HIV positive , received NVP intrapartum , and were previously antiretroviral treatment-naive . Infants were r and omly assigned to NVP ( n = 448 ) and NVP plus ZDV ( n = 446 ) . Infants were enrolled at birth , observed at 6 to 8 weeks , and followed up through 3 to 18 months . The HIV status of 90 % of all infants was established at 6 to 8 weeks . INTERVENTION Mothers received a 200-mg single oral dose of NVP intrapartum and infants received either 2-mg/kg oral dose of NVP or NVP ( same dose ) plus 4 mg/kg of ZDV twice per day for a week . MAIN OUTCOME MEASURES HIV infection of infant at birth and 6 to 8 weeks , and adverse events . RESULTS The mother-to-child transmission of HIV at birth was 8.1 % ( 36/445 ) in infants administered NVP only and 10.1 % ( 45/444 ) in those administered NVP plus ZDV ( P = .30 ) . A life table estimate of transmission at 6 to 8 weeks was 14.1 % ( 95 % confidence interval [ CI ] , 10.7%-17.4 % ) in infants who received NVP and 16.3 % ( 95 % CI , 12.7%-19.8 % ) in those who received NVP plus ZDV ( P = .36 ) . For infants not infected at birth and retested at 6 to 8 weeks , transmission was 6.5 % ( 23/353 ) in those who received NVP only and 6.9 % ( 25/363 ) in those who received NVP plus ZDV ( P = .88 ) . Almost all infants ( 99%-100 % ) were breastfed at 1 week and 6 to 8 weeks . Grade s 3 and 4 adverse events were comparable ; 4.9 % ( 22/448 ) and 5.4 % ( 24/446 ) in infants receiving NVP only and NVP plus ZDV , respectively ( P = .76 ) . CONCLUSIONS The frequency of mother-to-child HIV transmission at 6 to 8 weeks in our 2 study groups was comparable with that observed for other perinatal HIV intervention studies among breastfeeding women in Africa . The safety of the regimen containing neonatal ZDV was similar to that of a st and ard NVP regimen Almost all childhood HIV-1 is now acquired through vertical transmission . Identifying factors that affect the rate of transmission may lead to the initiation of specific preventive strategies . In this study , antibody levels against different neutralizing epitopes on the envelope glycoprotein of HIV-1 ( gp120 ) were measured in HIV-1-infected pregnant women that either transmitted HIV-1 to their infants ( 18 women ) or did not ( 29 women ) . Differences in levels of antibodies directed against the monomeric gp120 molecule and against the V3 loop region of gp120 were not significantly different between the two groups studied . However , significant differences were observed in the levels of CD4 binding site antibodies , as determined by the ability of diluted maternal plasma to inhibit binding of the CD4 binding site monoclonal antibody F105 ( mAb F105 ) to monomeric gp120 . In addition , more nontransmitting mothers had low viral load as defined by having two or more negative HIV-1 viral cultures during pregnancy compared with transmitters . This pilot study suggests that in addition to higher viral load , low levels of CD4 binding site antibodies correlate with increased risk of HIV-1 vertical transmission . Passive immunotherapy with broadly neutralizing CD4 binding site antibodies should be considered as a strategy to reduce this risk Objectives To study mortality in African children born to HIV-1-infected mothers exposed peripartum to zidovudine .  Methods A r and omized placebo-controlled trial in Abidjan and Bobo-Dioulasso . Pregnant women received either 300 mg zidovudine twice daily from 36–38 weeks ’ gestation , 600 mg during labour , and 300 mg twice daily for 7 days post-partum or a matching placebo . Determinants of mortality were studied up to 18 months , overall and among the infected children : treatment , centre , timing of infection , mother and child HIV disease . Results There were 75 infant deaths among 407 live births .  The risk of death at 18 months was 176/1000 in the zidovudine arm and 221 for placebo . Relative hazard ( RH , zidovudine versus placebo ) was 0.47 [ 95 % confidence interval ( CI ) 0.2–1.0 ] up to 230 days of life . Maternal CD4 lymphocyte count < 200/mm3 ( RH 2.92 ; CI 1.4–6.1 ) and child HIV-1 infection ( RH 12.6 ; CI 6.6–24.3 ) increased mortality of all children born to HIV-1-infected mothers . There were 101 children infected ( 40 in the zidovudine group ) , and 51 died . Their 18 month probability of death was 590/1000 in the zidovudine group and 510 in the placebo group . Among infected children , maternal zidovudine reduced the risk of death on or before day 230 ( RH 0.18 ; CI 0.1–0.5 ) . Maternal CD4 lymphocyte count < 200/mm3 ( RH 3.25 ; CI 1.3–8.4 ) , maternal death ( RH 9.65 ; CI 1.7–56.0 ) , diagnosis of paediatric infection on or before day 12 ( RH 18.1 ; CI 4.8–69.0 ) and between days 13 and 45 ( RH 7.63 ; CI 2.0–29.5 ) , clinical paediatric AIDS ( RH 5.37 ; CI 2.3–12.7 ) were risk factors for death in HIV-1-infected children . Conclusion Mother-to-child transmission reduction by zidovudine is safe and beneficial to African children . The mortality of HIV-1-infected children is high . Peripartum maternal zidovudine exerts a protective effect for at least 8 months BACKGROUND The AIDS Clinical Trials Group protocol 076 zidovudine prophylaxis regimen for HIV-1-infected pregnant women and their babies has been associated with a significant decrease in vertical HIV-1 transmission in non-breastfeeding women in developed countries . We compared the safety and efficacy of short-course nevirapine or zidovudine during labour and the first week of life . METHODS From November , 1997 , to April , 1999 , we enrolled 626 HIV-1-infected pregnant women at Mulago Hospital in Kampala , Ug and a. We r and omly assigned mothers nevirapine 200 mg orally at onset of labour and 2 mg/kg to babies within 72 h of birth , or zidovudine 600 mg orally to the mother at onset of labour and 300 mg every 3 h until delivery , and 4 mg/kg orally twice daily to babies for 7 days after birth . We tested babies for HIV-1 infection at birth , 6 - 8 weeks , and 14 - 16 weeks by HIV-1 RNA PCR . We assessed HIV-1 transmission and HIV-1-free survival with Kaplan-Meier analysis . FINDINGS Nearly all babies ( 98.8 % ) were breastfed , and 95.6 % were still breastfeeding at age 14 - 16 weeks . The estimated risks of HIV-1 transmission in the zidovudine and nevirapine groups were : 10.4 % and 8.2 % at birth ( p=0.354 ) ; 21.3 % and 11.9 % by age 6 - 8 weeks ( p=0.0027 ) ; and 25.1 % and 13.1 % by age 14 - 16 weeks ( p=0.0006 ) . The efficacy of nevirapine compared with zidovudine was 47 % ( 95 % CI 20 - 64 ) up to age 14 - 16 weeks . The two regimens were well tolerated and adverse events were similar in the two groups . INTERPRETATION Nevirapine lowered the risk of HIV-1 transmission during the first 14 - 16 weeks of life by nearly 50 % in a breastfeeding population . This simple and inexpensive regimen could decrease mother-to-child HIV-1 transmission in less-developed countries BACKGROUND Short-course zidovudine ( ZDV ) given in the late antenatal period can reduce mother-infant human immunodeficiency virus ( HIV ) transmission by one half . Because this intervention is being implemented in developing countries , evidence of its safety is needed . METHODS In a r and omized , double-blinded , placebo-controlled trial in Bangkok , HIV-infected pregnant women received either ZDV ( 300 mg twice daily from 36 weeks ' gestation until labor , then every 3 hours until delivery ) or an identical placebo regimen . Infants were evaluated at birth and at 1 , 2 , 4 , 6 , 9 , 12 , 15 , and 18 months of age . Growth , clinical events , and hematologic and immunologic measurements were compared between treatment groups . RESULTS Of the 395 children born ( 196 in ZDV group and 199 in placebo group ) , 330 were uninfected , 55 were infected , and 10 had indeterminate infection status . Overall , 319 children ( 81 % ) completed 18 months of follow-up , and 14 ( 4 % ) died before 18 months of age . Among uninfected children , the mean hematocrit was lower in the ZDV group at birth ( 49.1 % vs 51.5 % ) but not at later ages ; mean weight , height , head circumference , and CD4(+ ) and CD8(+ ) T lymphocyte counts were similar in both groups at all ages . Five uninfected children in the ZDV group but only one in the placebo group had a febrile convulsion . No other signs suggestive of mitochondrial dysfunction and no tumors were observed . Among infected children , an estimated 62 % in the ZDV group and 77 % in the placebo group survived free of Centers for Disease Control and Prevention class C disease during the 18-month follow-up . CONCLUSIONS No significant adverse events were associated with short-course ZDV during 18 months of follow-up in this population BACKGROUND The clinical presentation of HIV-1 related diseases could have changed after the introduction of highly active antiretroviral treatment ( HAART ) . We aim ed to assess changes over time in the incidence of ADIs overall and within CD4 lymphocyte count strata , the relationship with treatment and degree of immunodeficiency at diagnosis of ADIs . METHODS We did a prospect i ve observational multicentre study of over 7300 patients in 52 European HIV-1 outpatient clinics . Incidence rates per 100 patient-years of observation were calculated . FINDINGS In total , we recorded 1667 new ADIs ; the incidence of ADIs declined from 30.7 per 100 patient-years of observation during 1994 ( 95 % CI 28.0 - 33.4 ) to 2.5 per 100 patient-years of observation during 1998 ( 95 % CI 2.0 - 3.0 , p<0.0001 , test for trend ) . Median CD4 lymphocyte count at diagnosis of a new ADI increased from 28 cells/microL to 125 cells/microL between 1994 and 1998 ( p<0.0001 ) , yet a steep decline in the rate of ADIs was seen after stratification by latest CD4 lymphocyte count within each year ( < or = 50 , 51 - 200 , and > 200 cells/microL ) . Patients on HAART had a lower rate of ADIs than patients not on this treatment within each CD4 lymphocyte count strata . The proportion of ADIs attributable to cytomegalov 
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REVIEW ER 'S CONCLUSIONS Implication s for practice The r and omised trials included in this review provide evidence that short course zidovudine and single-dose nevirapine are effective therapies for reducing mother-to-child transmission of HIV .