HIV infection and malnutrition

HIV Infection, Viral Load, Low Birth Weight, and Nevirapine Are Independent Influences on Growth Velocity in HIV-Exposed South African Infants

Ramokolo V, Lombard C, Fadnes LT, Doherty T, Jackson DJ, Goga AE, Chhagan M, Van den Broeck J.
The Journal of Nutrition, 2013 Nov 

First growth velocity report using 2009 WHO growth chart
Due to the large number of deaths, prevention and management of malnutrition is a public health priority. In 2009 the World Health Organization (WHO) published new growth velocity standards which constitute a new tool for investigating the effect of HIV exposure and infection on infant growth velocity.

PhD student Vundli Ramokolo is the first author of a new article where the researchers uses the WHO velocity standards when studying growth patterns data from an earlier study of HIV-exposed and HIV-unexposed infants. The original study, called Good Start 1, took place in three South African sites, Paarl, Rietvlei and Umlazi in 2002-2004.

The report, now published in the Journal of Nutrition, is the first on growth velocity among HIV-exposed and -unexposed infants that uses the 2009 WHO growth velocity standards.

Nearly 900 mother-baby pairs recruited
In the Good Start 1 study, a total of 883 mother–infant pairs were recruited and followed up until 36 weeks after giving birth. Trained field staff collected interview data on socioeconomic status, infant feeding practices, medicine use, infant sickness and other health-related factors during regular home visits. They also measured infant weight and length at 3, 24, and 36 weeks.

The infants were categorized in three groups as HIV-infected infants, HIV-negative infants born to HIV-positive mothers (HEU: HIV-exposed uninfected), or HIV-negative infants born to HIV-negative mothers (unexposed).

Lower birth weight and slower growth among HIV-infected infants
In the study Ramokolo and her colleagues demonstrate that HIV infection in infants is associated with lower birth weight and also related to poorer weight velocity Z-score and slower growth, i.e. length velocity Z-score in the first 6 months of life. Z-Score (standard deviation score) is the deviation of an individual’s anthropometric value from the median value of the reference population divided by the standard deviation of the reference population value. Anthropometry is the science of measuring bodily dimensions using non-invasive instruments, scoring the measurement values and making inferences about the nutritional or health status of individuals or groups. The scoring enables the researchers to place individual values within an expected ‘normal’ distribution obtained from normally growing children so they can meaningfully classify the value as high, low, extreme, normal etc.

HIV-exposed infants with poor growth velocities and an unknown or previously negative HIV test result should be referred for HIV testing and counseling and additional care as needed. Great gains have been made in scaling up HIV prevention and treatment interventions. Single-dose nevirapine prophylaxis given to both the HIV positive women and their babies was associated with higher length velocity Z-score in this study, highlighting the importance of strengthening this service.

In conclusion, HIV infection, and not exposure, was associated with low weight velocity Z-score and length velocity Z-score. Eliminating infant HIV infection is a critical component in averting HIV-related poor growth patterns in infants in the first 6 months of life.

Read the full article here: http://jn.nutrition.org/content/early/2013/11/06/jn.113.178616.long