Vertically acquired paediatric HIV infection: the challenges of providing comprehensive packages of care in resource-limited settings

Mutations in HIV-1 gag and pol compensate for the loss of viral fitness caused by a highly mutated protease

During the last few decades, the treatment of HIV-infected patients by highly active antiretroviral therapy, including protease inhibitors (PIs), has become standard. Here, we present results of analysis of a patient-derived, multiresistant HIV-1 CRF02_AG recombinant strain with a highly mutated protease (PR) coding sequence, where up to 19 coding mutations have accumulated in the PR. The results of biochemical analysis in vitro showed that the patient-derived PR is highly resistant to most of the currently used PIs and that it also exhibits very poor catalytic activity. Determination of the crystal structure revealed prominent changes in the flap elbow region and S1/S1' active site subsites. While viral loads in the patient were found to be high, the insertion of the patient-derived PR into a HIV-1 subtype B backbone resulted in reduction of infectivity by 3 orders of magnitude. Fitness compensation was not achieved by elevated polymerase (Pol) expression, but the introduction of patient-derived gag and pol sequences in a CRF02_AG backbone rescued viral infectivity to near wild-type (wt) levels. The mutations that accumulated in the vicinity of the processing sites spanning the p2/NC, NC/p1, and p6pol/PR proteins lead to much more efficient hydrolysis of corresponding peptides by patient-derived PR in comparison to the wt enzyme. This indicates a very efficient coevolution of enzyme and substrate maintaining high viral loads in vivo under constant drug pressure.

Improving survival in children with AIDS in Brazil: results of the second national study, 1999-2002

The objective of this study is to characterize survival in children with AIDS diagnosed in Brazil between 1999-2002, compared with the first national study (1983-1998). This national retrospective cohort study examined a representative sample of Brazilian children exposed to HIV from mother-to-child transmission and followed through 2007. The survival probability after 60 months was analyzed by sex, year of birth and death, clinical classification, use of antiretroviral therapy (ART) and prophylaxis for opportunistic diseases. 920 children were included. The survival probability increased: comparing cases diagnosed before 1988 with those diagnosed from 2001-2002 it increased by 3.5-fold (from 25% to 86.3%). Use of ART, initial clinical classification, and final classification were significant (p < 0.001) predictors of survival. Issues regarding quality of records and care were identified. The results point to the success of the Brazilian policy of providing ART. The improvement of clinical status contributes to quality of life, while indicating challenges, particularly practices to improve long-term care.

Survival of HIV-infected children: a cohort study from the Asia-Pacific region

BACKGROUND

Combination antiretroviral therapy (ART) has been used for HIV-infected children in many Asian countries since 2002. This study describes survival outcomes among HIV-infected children in a multicenter regional cohort in Asia.

PATIENTS AND METHODS

Retrospective and prospective data collected through March 2009 from children in 5 countries enrolled in TREAT Asia's Pediatric HIV Observational Database were analysed. Multivariate Cox proportional hazard models were used to assess factors associated with mortality in children who received ART.

RESULTS

Among 2280 children, 1752 (77%) had received ART. During a median follow-up of 3.1 years after ART, 115 (6.6%) deaths occurred, giving a crude mortality rate of 1.9 per 100 child-years [95% confidence interval (CI): 1.6 to 2.4]. The mortality rate was highest in the first 3 months of ART (10.2 per 100 child-years; 95% CI: 7.5 to 13.7) and declined after 12 months (0.9 per 100 child-years; 95% CI: 0.7 to 1.3). Those with a low recent CD4 percentage, who started ART with lower baseline weight-for-age Z score, or with WHO clinical stage 4 had an increased risk of death. Of 528 (23%) children who never received ART, 36 (6.8%) died after presenting to care, giving a crude mortality rate of 4.1 per 100 child-years (95% CI: 3.0 to 5.7), with a lost-to-program rate of 31.5 per 100 child-years (95% CI: 28.0 to 35.5).

CONCLUSIONS

The high mortality during the first 3 months of ART and in those with low CD4 percentage support the implementation of early diagnosis and ART initiation.

[Fate of children born to HIV positive mothers followed in the context of preventing mother-to-child transmission of HIV in Togo. Study of 1042 infants]

The purpose of this study is to analyze the fate of children born to HIV-positive mothers and to determine the impact of feeding options on the HIV status of the children in preventing mother-to-child transmission sites (PMTCT) in Togo. It was a retrospective and descriptive study, focused on medical files of 1042 children of both sexes aged from 0 to 59 months born to HIV-positive mothers and registered in the PMTCT sites between January 2004 and December 2008. Our study was conducted in seven PMTCT sites located in four of the six health regions in the country. We analyzed a total of 1042 medical files in seven PMTCT sites selected. The majority of children were born vaginally (77.4%). Antiretroviral prophylaxis most used in the mothers and/or the children was nevirapine in 86% of the cases. Breastfeeding (49%) was dominated by milk substitutes (50%). Globally, dropout rate was 52.2% (525), with 44.9% (408) at six months and 65.09% (483) at 12 months. At 12 months, 196 of 742 children (26.4%) had their retroviral serology. Among them, we have 5.6% overall rate of HIV infection. The transmission rate in the group of children breastfed was 5.9% (six children infected out of 102) and 8.5% in the group of children fed by formula milk (seven children out of 82). Death occurred in half of the cases (8 of 16) during the first two months of life. Follow-up was the major issue in monitoring children born to HIV-infected mothers. The HIV transmission rate is very high, irrespective of the feeding method.

Potential impact of viral load and genetic makeup of HIV type 1 on mother-to-child transmission: characterization of env-C2V3C3 and nef sequences

HIV-1 mother-to-child transmission (MTCT) was evaluated in terms of the molecular characterization of the env and nef genomic regions and quantification of maternal RNA viral loads. Assignment of viral subtype was achieved by direct sequencing of PCR 1172 products amplified from proviral DNA in 45 HIV-1-nontransmitting mothers (NTM), along with 13 pairs of HIV-1-transmitting mothers (TM) and their infected children (C). Analysis of the env C2V3C3 and nef sequences revealed that subtypes G and B, and their genetic combinations (AG, BG), accounted for over 84.5% of all viruses identified. The genetic structure form envA-nefG was the most commonly observed, with a lower frequency in the NTM (13.3%) compared to the TM (23.1%) group. A greater number of genetic forms was observed among NTM, namely the presence of sequences assigned to subtypes D and F, as well as the intergenetic A/J, and C/U, recombinant forms, along with a mosaic provirus with a complex putative envA-nefEGE genetic structure. No significant differences were found when RNA viral loads were evaluated as a function of the viral subtypes. Nevertheless, a relatively high quantification of HIV-1 RNA was obtained in the NTM group, emphasizing the importance of the compliance and effectiveness of therapeutic schemes to control viral replication and reduce the risk of HIV vertical transmission. V3 sequences displaying features associated with the R5 phenotype dominated in both groups. Both C2V3C3 and Nef's functional domains were conserved during HIV-1 vertical transmission.

Ethical and practical challenges in implementing informed consent in HIV/AIDS clinical trials in developing or resource-limited countries

BACKGROUND/RATIONALE

Ethical issues regarding HIV/AIDS human research in the developing world remain under continuous evaluation; a critical area of concern includes informed consent. This paper reviews several of the most important ethical and practical aspects of informed consent in HIV research in developing countries. Enhancement of overall understanding of such key issues might promote higher ethical standards of future research.

OBJECTIVES

The major objective was to address informed consent in human research in non-Western societies, and specifically in HIV clinical trials of affected adults. Secondary end-points included the consent complexities in HIV research involving vulnerable patient populations in resource-limited nations, such as children, adolescents and women.

METHODS

A systematic review of the published literature using MEDLINE and EMBASE from 1998 until December 2008 was performed, using the search terms 'HIV/AIDS', 'informed consent', 'clinical trials', 'developing world'.

RESULTS

Ethical complexities such as participants' diminished autonomy, coercion or monetary inducement, language difficulties, illiteracy or lack of true understanding of the entire study, cultural barriers mainly due to communitarianism and social diversities were identified in the 44 studies reviewed. Informed consent of vulnerable patient populations must be tailored to their sex and developmental age, while counselling is fundamental. Children and adolescents' assent must be ensured. Local language is to be used, while trusted community leaders and local cultural representatives may convey information.

DISCUSSION

Despite the heterogeneity of studies, similarities were identified. Providing adequate and comprehensive information and assessing the true understanding of the research represent fundamental prerequisites. Potential solutions to the critical areas of concern include peer counselling and meetings with local community leaders or local cultural representatives.

CONCLUSIONS

International investigators of HIV human research should bear in mind these ethical issues and their potential solutions, when trying to ensure ethical research conduct, based on a truly informed and culturally relevant consent.

A package of primary health care services for comprehensive family-centred HIV/AIDS care and treatment programs in low-income settings

Particularly in resource-limited settings, HIV/AIDS is a family concern. Separate services for children and adults may make accessing care more difficult for families than services where family members can be cared for together. Implicit in comprehensive, family-centred approaches to care are the broader notions of longitudinal primary care and linkages to other services, including those based in communities. As highly-active antiretroviral therapy becomes more available, and the direct burden of HIV-associated morbidity diminishes, HIV-infected individuals require primary care that goes beyond exclusive management of HIV and related conditions, including preventive services and the management of common medical issues. The prevention of tuberculosis, diarrhoea, and, in endemic regions, malaria; the addressing of debilitating depression; cervical screening; and the management of chronic cardiovascular disease and its risk factors are all of benefit to patients accessing HIV/AIDS care. Packaging such services is an effective means both of standardizing care within a program and of ensuring patients receives a full roster of available interventions. As family-centred care models develop in resource-limited settings, the availability of evidence-based service packages such as presented here will help program designers prioritize available human and materiel resources toward those interventions that improve patients' global health and well being.