Recent advances in the neurological and neurodevelopmental impact of HIV
Abstract
This wide-ranging new book takes us through the neurologi-cal and neurodevelopmental impact of HIV through the lens of pediatrics. Compiled and written by clinician-research-ers from sub-Saharan Africa predominantly, the chapters provide comprehensive, well-written reviews of the major research findings in this field – informative for both novice and expert alike. Importantly, the chapters also convey the authors' considerable experience in applying these research findings in real-world clinical settings, particularly in the low-resource health systems where the impact of the HIV pandemic is most felt. This gives the book a richness and immediacy beyond simply providing information.The first half of the book discusses the clinical manifesta-tions of HIV infection in children and young people. Severe HIV encephalopathy in infants is one of the more tragic hall-marks of an era when HIV infection was a devastating, rapidly progressing disease. This was before the advent of effective an-tiretroviral treatment (ART). Effective ART changed this dis-ease profile into one of a complex chronic disease. Children respond equally well to ART and have the most to gain from treatment, but many challenges in diagnosis and access lead to treatment coverage for children that lags behind that of adults. Infants and young children are also entirely dependent on their caregivers for medication adherence. Social stigma and the practical difficulties of daily medication adherence with mul-tiple medications (often not optimally formulated) translates to generally worse ART outcomes in children. Primarily for these reasons, a spectrum of HIV-associated neurological and neurodevelopmental complications continues to occur. In ad-dition, antiretroviral drugs mostly do not penetrate the central nervous system where HIV can persist. This may be one of the reasons for the continued occurrence of neurological disorders in otherwise well-treated children and young people.The second half of the book includes a series of chapters that take a developmental perspective. These chapters start with birth to 3 years, then move on to school age, then to adolescence, and finally to the growing cohorts who acquired perinatal infection but, thanks to ART, are now surviving into adulthood. Cognitive and behavioral problems take center stage here and the intimate tangle of biological and social vulnerabilities become apparent. The HIV pandemic leads directly to some social factors that have an adverse impact on neurodevelopmental conditions. These include parental mortality and morbidity, familial instability, parental depres-sion, substance use, and fear of disclosure amongst others. The HIV pandemic is also superimposed on existing social determinants of health (such as poverty, discrimination, un-employment, etc.) that contribute to a vicious cycle of adverse outcomes. It is this context that makes one greatly appreciate the careful attention this book gives to interventions. Several of these interventions have now been proved to alleviate some of the consequences of this vicious viral–social interaction.Finally, the book considers neurodevelopment of children who are born to women living with HIV but who escape from acquiring infection themselves, so-called HIV-exposed unin-fected. With universal ART for adults, the vast majority of chil-dren born to mothers with HIV do not acquire infection. Prior to the ART era, infants who escaped HIV infection appeared to have immune abnormalities putting them at increased risk of morbidity and mortality. The verdict is still out on whether these and other risks, including neurodevelopmental prob-lems, persist into the current era, but the situation offers a fas-cinating research opportunity to study the effects of maternal viral infections on neurodevelopmental outcomes in offspring. Overall, this book has something for everyone, regardless of the extent of their past engagement with this topic