As I write, our annual clinic on the Meaningful Modelling of Epidemiological Data (MMED) is in progress, so is the 7th SA AIDS conference, and I just returned from a meeting in Geneva how best to provide advice to teams planning to estimate HIV incidence from large household surveys. In short, it seems to be a time to reflect, to reconsider what we are trying to do, and whether we are making any useful contributions. We hope these quarterly epidemiological update offerings are food for thought.
Malaria kills between 70,000 and 100,000 children every year in Uganda. In order to apply successful interventions to eradicate malaria, there is a continuous need to understand the epidemiology and risk factors associated with the disease. The Malaria Indicator Survey (MIS) in 2009 was the first nationally representative survey of malaria conducted in Uganda. The aim of the study presented here was to use this MIS to investigate the distribution of malaria infection in children under the age of 5 years old, as well as to investigate the relationship with selected socio-economic, demographic and environmental factors.
Agent-based modelling, also called microsimulation, is a way of modelling epidemics that is growing in popularity. Instead of the traditional way of modelling using differential equations, an agent-based model consists of, perhaps, thousands of agents, each representing a person, and each behaving according to a simple set of rules. Instead of outputs such as infection and mortality rates being derived from equations, they are derived from the interactions of the agents over many iterations. These models are providing rich insights into the HIV epidemic.
South Africa is the unenviable epicentre of the HIV pandemic with 0.7% of the global population sadly amassing 18% of the global prevalence. The government has expanded interventions over the years to quell the epidemic. Sadly however, 58% of South Africans eligible for ARV treatment remain unable to access it. Despite the strides made by government to alleviate the HIV burden, high HIV incidence rates of 16% were reported in 2013. We can gauge from this that the current prevention and treatment processes are failing. The question is: what alternatives do we have at our disposal? And could we gauge the potential success of these?
UNAIDS has reported that the prevalence of people infected with HIV but who are not on ART, the incidence of HIV, and AIDS related mortality are falling. The Health Metrics Institute recently made their own, semi-independent, assessment of the trends in each of these indicators and reached similar conclusions with small differences arising from the use of somewhat different assumptions. Both analyses suggest that the world is on track to end AIDS by 2030, but this will depend on continued expansion of treatment at about the present rate together with supportive prevention efforts in Sub-Saharan Africa. Unfortunately, the data on which these analyses are based is weak in almost all places and better data on patient monitoring, follow-up and support, including drug procurement, supply and delivery, and better routing surveillance are needed.
SACEMA hosted its ‘Annual Research Days’ meeting in Stellenbosch on 24 and 25 March 2015 showcasing the research conducted by SACEMA funded postgraduate students. The Research Days have become a hallmark of the postgraduate development undertaken by SACEMA and serves to integrate the multitude of individual projects into the wider research aims of SACEMA.
The recent HSRC household survey reports that the HIV prevalence among adolescents and young people is declining. Although the decline is important, the focus needs to be on the fact that the reported HIV prevalence levels are still very high, together with alarmingly high levels of HIV incidence. Prevention methods have demonstrated effectiveness in reducing the risk of HIV acquisition among many of the most-at-risk populations. More research is needed, however, into how HIV is spread among the adolescent population and how to decrease this spread.
Scientists offering papers for publication will be becoming increasingly aware of a significant change in the attitude of journals to the publication of the data used to reach conclusions drawn in their manuscript. New regulations are moving rapidly and uncompromisingly towards a policy where all of the data, and related metadata, required to replicate the reported findings must be made freely available to the world at large. There is much to be said in favour of this argument, but one wonders whether journals have thought through some of the ramifications of the new policy.
Africa and Asia have the highest prevalence of Hepatitis B virus (HBV) worldwide. Mother-to-child transmission (MTCT) is the most common route of transmission in high prevalence areas. There are three different prevention strategies available to prevent HBV MTCT: Vaccine, Hepatitis B Immunoglobulin and Antiviral therapy during pregnancy. Strategic investment now could see the eradication of HBV MTCT in Africa and ultimately potentially the elimination of this major public health problem.
As coverage of paediatric ART increases and guidelines for ART initiation change, it will be necessary to determine how best to monitor ART. Routine monitoring of HIV viral load is common practice in ART programmes in high-income countries, but, in sub-Saharan Africa, most ART programmes rely on CD4 cell measurements or clinical monitoring to detect treatment failure. We conducted a computer simulation of HIV-positive children to predict the effect of different ART monitoring strategies.