Pediatric HIV infection: diagnostic laboratory methods

Nanoplasmonic quantitative detection of intact viruses from unprocessed whole blood

Infectious diseases such as HIV and hepatitis B pose an omnipresent threat to global health. Reliable, fast, accurate, and sensitive platforms that can be deployed at the point-of-care (POC) in multiple settings, such as airports and offices, for detection of infectious pathogens are essential for the management of epidemics and possible biological attacks. To the best of our knowledge, no viral load technology adaptable to the POC settings exists today due to critical technical and biological challenges. Here, we present for the first time a broadly applicable technology for quantitative, nanoplasmonic-based intact virus detection at clinically relevant concentrations. The sensing platform is based on unique nanoplasmonic properties of nanoparticles utilizing immobilized antibodies to selectively capture rapidly evolving viral subtypes. We demonstrate the capture, detection, and quantification of multiple HIV subtypes (A, B, C, D, E, G, and subtype panel) with high repeatability, sensitivity, and specificity down to 98 ± 39 copies/mL (i.e., HIV subtype D) using spiked whole blood samples and clinical discarded HIV-infected patient whole blood samples validated by the gold standard, i.e., RT-qPCR. This platform technology offers an assay time of 1 h and 10 min (1 h for capture, 10 min for detection and data analysis). The presented platform is also able to capture intact viruses at high efficiency using immuno-surface chemistry approaches directly from whole blood samples without any sample preprocessing steps such as spin-down or sorting. Evidence is presented showing the system to be accurate, repeatable, and reliable. Additionally, the presented platform technology can be broadly adapted to detect other pathogens having reasonably well-described biomarkers by adapting the surface chemistry. Thus, this broadly applicable detection platform holds great promise to be implemented at POC settings, hospitals, and primary care settings.

Impact of HIV/Aids on Child Mortality before the Highly Active Antiretroviral Therapy Era: A Study in Pointe-Noire, Republic of Congo

Few studies have documented the contribution of HIV/AIDS to mortality among children under 15 years. From June 30 to October 19, 2001, all child deaths (n = 588) registered to the morgue and/or hospitals of the city of Pointe-Noire, Congo, were investigated using a combined approach including an interview of relatives and postmortem clinical and biological HIV diagnosis. Twenty-one percent of children were HIV positive, while 10.5% of deaths were attributed to AIDS. The most common causes of death in HIV-infected children were pneumonia (30%), pyrexia (22%), diarrhoea (16%) and wasting syndrome (16%). Infant mortality rate was estimated 6.3 times higher in children born to HIV-infected mothers compared to HIV-uninfected mothers. This study provides a direct measure of HIV/AIDS as impact on child mortality using a rapid and reliable method. A significant number of deaths could be prevented if HIV infection was diagnosed earlier and infants were provided with antiretroviral treatments.

Clinical practice treatment of HIV infection in children

Perinatal transmission remains the main cause of HIV infection in the pediatric population. Treatment of HIV-infected children has become less of a problem in resource-rich countries with a remarkable decrease of perinatal infections, resulting in an effective prevention of mother-to-child transmission and antiretroviral treatment of HIV infection in pediatrics because of differences in drug pharmacokinetics, the lack of available licensed drugs, the use of different immunologic markers and age-related adherence issues. This review, for the general pediatrician, summarizes the most recent pediatric data and guidelines for treatment of HIV. Recommendations for when to initiate therapy are more aggressive in children than in adults, particularly in infants because disease progression in children is more rapid. The indications to start therapy differ by age and are based on international immunologic and clinical classification system for HIV infection. At present, combination regimens of at least three drugs are recommended. Moreover, therapies must also consider the potential complications in these children currently treated for a long time.

Pediatric HIV infection: the state of antiretroviral therapy

Pediatric HIV/AIDS has become less of a problem in resource-rich countries as the number of perinatal infections has reduced dramatically since the advent of antiretrovirals, resulting in the effective prevention of mother-to-child transmission. In resource-limited settings, however, pediatric HIV infection remains a colossal problem; a separate review in this same issue of Expert Review of Anti-Infective Therapy examines the international aspects of pediatric HIV/AIDS. Treatment of HIV infection in children differs from that in adults in the use of immunologic markers and owing to drug pharmacokinetics and age-related adherence issues. This review, geared for the general pediatrician or family practitioner who may see the HIV-positive child in the clinic or the hospital, summarizes the most recent pediatric data and guidelines for the testing and treatment of HIV, including the US NIH guidelines released in February 2008. Treatment-experienced patients, who should be cared for by pediatric HIV specialists, are not addressed here specifically. Adolescents, infected either perinatally or sexually, with their own unique issues, deserve a separate review.

Clinical management of HIV infection in children

PURPOSE OF REVIEW

The aim of this article is to review recent advances in the clinical care of HIV-infected children.

RECENT FINDINGS

Obstacles to diagnosing HIV in children and providing clinical care to those HIV infected relate to a number of technical and operational factors. Most countries now have antiretroviral treatment guidelines and have incorporated co-trimoxazole prophylaxis for infected and exposed infants and children. Implementation lags behind policy and technical recommendations. Optimal early infant feeding remains difficult and, while breastfeeding remains the safest feeding option for child survival, it carries with it the risk of HIV acquisition. Recent data suggest HIV-free survival at 18 months is comparable in infants who are replacement-fed or exclusively breastfed for the first 6 months of life. Antiretroviral treatment efficacy in children is now well documented. Optimal timing of initiation of antiretroviral treatment remains uncertain; in general it is started earlier, especially in infants. Children starting treatment in infancy are surviving and reaching adulthood; new problems of managing the highly treatment-experienced and adolescents are emerging.

SUMMARY

New antiretroviral drugs and classes will be needed for the future; research is urgently required to characterize optimal nutritional interventions, interpretation of immunological and virological parameters, and develop diagnostic tools for use in health services with limited infrastructure and capacity.