***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: BACKGROUND Recent evidence suggests that decreases in morbidity and mortality in cohorts of adults infected with human immunodeficiency virus ( HIV ) are showing signs of reversal . We describe changes over time in these characteristics and in the response to treatment among children in the United Kingdom and Irel and with perinatally acquired HIV infection , many of whom are now adolescents . METHODS We analyzed prospect i ve cohort data reported to the National Study of HIV in Pregnancy and Childhood ( NSHPC ) and the Collaborative HIV Paediatric Study . RESULTS By mid 2006 , 1441 HIV-infected children were reported to NSHPC ; 40 % were > or = 10 years old at their most recent follow-up visit , and 34 % were receiving care outside London . The proportion of children born abroad increased from 24 % during 1994 - 1996 to 64 % during 2003 - 2006 . The percentage of total child time during which children received  highly active antiretroviral therapy ( HAART )  increased from 36 % during 1997 - 1999 to 61 % during 2000 - 2002 and 63 % during 2003 - 2006 . Of children who were naive to antiretroviral  therapy  at the start of HAART , the percentage with an HIV-1 RNA load of < 400 copies/mL after 12 months increased from 52 % during 1997 - 1999 to 79 % during 2003 - 2006 . In multivariate analysis , only calendar time predicted virological response , whereas both younger age and lower CD4 cell percentage at HAART initiation predicted increases of > 10 % in the CD4 cell percentage . A total of 31 % of children aged 5 - 14 years and 38 % aged > or = 15 years at their most recent follow-up visit had been exposed to drugs from each of the 3 main HAART classes . The rate of AIDS and mortality combined decreased from 13.3 cases per 100 person-years before 1997 to 3.1 and 2.5 cases per 100 person-years , respectively , during 2000 - 2002 and 2003 - 2006 ; rates of hospital admission also declined during this interval . Of 18 children known to have  died since 2003 , 9 died within 1 month after presentation . CONCLUSIONS Morbidity and mortality rates among HIV-infected children continue to decrease over time . Because these children are increasingly dispersed outside London , specialist care is now provided in national clinical networks . Transition pathways to adolescent and adult services and long-term observation to monitor the effects of prolonged exposure to both HIV and HAART are required Objective To evaluate the feasibility of a large immediate versus deferred antiretroviral therapy ( ART )  study in children . Methods We conducted an open-label pilot r and omized clinical trial study in 43 Thai children with CD4 15 to 24 % of starting generic AZT/3TC/NVP immediately ( Arm 1 ) or deferring until CD4 < 15 % or CDC C ( Arm 2 ) . Primary endpoints were recruitment rate , adherence to r and omized treatment and retention in trial . Secondary endpoints were % with CDC C or CD4 < 15 % . Children were in the trial until the last child reached 108 weeks . Intention to treat and on treatment analyses were performed . Results Recruitment took 15 months . Twenty-six of 69 ( 37.7 % ) were not eligible due mainly to low CD4 % . Twenty four and 19 were r and omized to arms 1 and 2 respectively . All accepted the r and omized arm ; however , 3 in arm 1 stopped ART and 1 in arm 2 refused to start ART . Ten/19 ( 53 % ) in arm 2 started ART . At baseline , median age was 4.8 yrs , CDC A : B were 36:7 , median CD4 was 19 % and viral load was 4.8 log . All in arm 1 and 17/19 in arm 2 completed the study ( median of 134 weeks ) . No one had AIDS or death . Four in immediate arm had tuberculosis . Once started on ART , deferred arm children achieved similar CD4 and viral load response as the immediate arm . Adverse events were similar between arms . The deferred arm had a 26 % ART saving . Conclusion Almost 40 % of children were not eligible due mainly to low CD4 % but adherence to r and omized treatment and retention in trial were excellent . A larger study to evaluate when to start ART is feasible Objectives : Infants infected with HIV-1 perinatally despite single-dose nevirapine progress rapidly . Data on treatment outcome in sub-Saharan African infants exposed to single-dose nevirapine  are urgently required . This feasibility study addresses efficacy of infant antiretroviral therapy in this setting . Methods : HIV-infected infants in Durban , South Africa , received r and omized immediate or deferred ( when CD4 cell count reached < 20 % ) four-drug antiretroviral therapy ( zidovudine/lamivudine/nelfinavir/nevirapine ) .  Genotyping for non-nucleoside reverse transcriptase inhibitor ( NNRTI ) resistance was undertaken pre-antiretroviral therapy . Monthly follow-up to 1-year post-antiretroviral therapy included viral load , CD4 cell count and verbal/measured adherence monitoring . Results : All 63 infants were exposed to single-dose nevirapine .  Twenty-one out of 51 ( 39 % ) infants with baseline genotyping results had NNRTI resistance ( most frequently Y181C ; 20 % ) . Forty-three infants were r and omized to immediate antiretroviral therapy ( ART ) : three withdrew pre-antiretroviral therapy ; 36 out of 40 completed 1-year of ART . Twenty infants received deferred ART : 17 reached CD4 cell counts less than 20 % ( median d99 ) and 13 out of 17 started antiretroviral therapy in year 1 . Verbal and measured adherence was 99 % and 95 % , respectively . One-year post-ART , 49 out of 49 ( 100 % ) infants had a viral load less than 400 copies/ml ; 46 out of 49 ( 94 % ) had viral load less than 50 copies/ml . Ten infants ( 20 % ) required second-line ART due to virological failure or tuberculosis treatment , therefore 39 out of 49 ( 80 % ) achieved viral load less than 400 copies/ml by intention-to-treat . Time to viral load less than 50 copies/ml correlated with maternal CD4 cell count ( r = −0.42 ; P = 0.005 ) and infant pre-ART viral load ( r = 0.64 ; P < 0.001 ) . NNRTI mutations had no significant effect on virological suppression . Infants starting immediate compared with deferred ART had fewer illness episodes ( P = 0.003 ) , but no significant difference in virological suppression . Conclusion : Excellent adherence and virological suppression are achievable in infants , despite high-frequency NNRTI mutations and rapid disease progression . Infants remain relatively neglected in roll-out programmes and ART provision must be exp and ed ABSTRACT Studies of potent antiretroviral combination regimens were undertaken in young infants to evaluate the potential for long-term suppression of viral replication and to evaluate the immune consequences of such therapies . Early combination antiretroviral therapy led to a loss of plasma viremia , cultivable virus , and labile extrachromosomal replication intermediates . Despite preservation of immune function , persistent human immunodeficiency type 1 (HIV-1)-specific immune responses were not detected in most infants . The absence of detectable , persisting immune responses in most HIV-1-infected infants treated early contrasts with what is typically seen in adults who are treated early . These results are consistent with the notion that early combination antiretroviral therapy  of HIV-1-infected infants allows the long-term suppression of viral replication OBJECTIVE To investigate the outcome in children perinatally infected with HIV-1 whose mothers received zidovudine ( ZDV ) monotherapy in pregnancy . DESIGN Observational retrospective study of a prospect ively recruited cohort . SETTING Italian Register for HIV Infection in Children . PATIENTS A group of 216 children perinatally infected with HIV-1 , born in 1992 - 1997 and derived prospect ively from birth : 38 children had mothers receiving ZDV monotherapy and for 178 children the mothers received no antiretroviral treatment during pregnancy . MAIN OUTCOME MEASURES The estimated probability of developing severe disease or severe immune suppression , survival probability [ 95 % confidence interval ( CI ) ] within 3 years , and the hazard ratio ( 95 % CI ) , adjusted for year of birth , maternal clinical condition at delivery , birthweight and treatments ( Pneumocystis carinii pneumonia chemoprophylaxis and /or antiretroviral therapy before the onset of severe disease , severe immune suppression or death ) were compared . RESULTS Comparison of HIV-1-infected children whose mothers were treated with ZDV with children whose mothers were not treated showed that the former group had a higher probability of developing severe disease [ 57.3 % ( 95 % CI 40.9 - 74.3 ) versus 37.2 % ( 95 % CI 30.0 - 45.4 ) ; log-rank test 7.83 , P = 0.005 ; adjusted hazard ratio 1.8 ( 95 % CI 1.1 - 3.1 ) ] or severe immune suppression [ 53.9 % ( 95 % CI 36.3 - 73.5 ) versus 37.5 % ( 95 % CI 30.0 - 46.2 ) ; log-rank test 5.58 , P = 0.018 ; adjusted hazard ratio 2.4 , ( 95 % CI : 1.3 - 4.3 ) ] and a lower survival [ 72.2 % ( 95 % CI 50.4 - 85.7 ) versus 81.0 % ( 95 % CI 73.7 - 86.5 ) ; log-rank test 4.23 , P = 0.039 ; adjusted hazard ratio of death 1.9 ( 95 % CI 1.1 - 3.6 ) ] . CONCLUSIONS This epidemiological observation could stimulate virologic studies to eluci date whether this rapid progression depends on in utero infection or transmission of resistant virus . Findings may suggest a need to hasten HIV-1 diagnosis in infants of ZDV-treated mothers and undertake an aggressive antiretroviral therapy in those found to be infected BACKGROUND Single-dose nevirapine is the cornerstone of the regimen for prevention of mother-to-child transmission of human immunodeficiency virus ( HIV ) in re source -limited setting s , but nevirapine frequently selects for resistant virus in mothers and children who become infected despite prophylaxis . The optimal antiretroviral treatment strategy for children who have had prior exposure to single-dose nevirapine  is unknown . METHODS We conducted a r and omized trial of initial therapy with zidovudine and lamivudine plus either nevirapine or ritonavir-boosted lopinavir in HIV-infected children 6 to 36 months of age , in six African countries , who qualified for treatment according to World Health Organization ( WHO ) criteria . Results are reported for the cohort that included children exposed to single-dose nevirapine prophylaxis . The primary end point was virologic failure or discontinuation of treatment by study week 24 . Enrollment in this cohort was terminated early on the recommendation of the data and safety monitoring board . RESULTS A total of 164 children were enrolled . The median percentage of CD4 + lymphocytes was 19 % ; a total of 56 % of the children had WHO stage 3 or 4 disease . More children in the nevirapine group than in the ritonavir-boosted lopinavir group reached a primary end point ( 39.6 % vs. 21.7 % ; weighted difference , 18.6 percentage-points ; 95 % confidence interval , 3.7 to 33.6 ; nominal P=0.02 ) . Baseline resistance to  nevirapine was detected in 18 of 148 children ( 12 % ) and was predictive of treatment failure . No significant between-group differences were seen in the rate of adverse events . CONCLUSIONS Among children with prior exposure to single-dose nevirapine  for perinatal prevention of HIV transmission , antiretroviral treatment consisting of zidovudine and lamivudine plus ritonavir-boosted lopinavir result ed in better outcomes than did treatment with zidovudine and lamivudine plus nevirapine . Since nevirapine is used for both treatment and perinatal prevention of HIV infection in re source -limited setting s , alternative strategies for the prevention of HIV transmission from mother to child , as well as for the treatment of HIV infection , are urgently required . ( Funded by 
    Output:
    
Immediate ART reduces morbidity and mortality among infants and may improve neurodevelopmental outcome .
The available evidence suggests that a LPV/r-based first-line regimen is more potent than NVP , regardless of PMTCT exposure status .
This strategy looked promising in the one trial undertaken , but may be difficult to implement in the absence of VL testing .