Another of his odd beliefs is that:
It has become increasingly clear over the years that only a very few HIV positive people ever become ill .This statement summarises Bauer’s basic misapprehension of the natural history of HIV infection, or as he would put it the natural history of the "HIV positive" state. The natural history of a disease or condition is what happens between initial exposure to the causative agent until either death or resolution of the condition occur, without interruption by treatment. Understanding the natural history of a disease is absolutely foundational to making sense of its epidemiology. But Bauer’s grasp of the natural history of HIV is a completely false, as even a cursory examination of US epidemiological surveillance reports reveals.
- “Demographic Characteristics of HIV:II. What Determines the Frequency of Positive HIV Tests?” page 82
By 2006, of the approximately 1.6 million Americans infected with HIV since the beginning of the epidemic (including those diagnosed with AIDS prior to the availability of diagnostic testing) 566,000 had died and 449,000 were then living with AIDS.
More than one million out of 1.6 million is not “only a very few”. Of the remaining 600,000 there are undoubtedly some who have maintained good general health without treatment for two decades or more, but the majority have been infected too recently for AIDS to have developed given the median latency between infection and AIDS of a decade or so, or else are maintaining their immune health using antiretrovirals.
WHEN THE FIRST HIV tests became widely available in the West in the mid 1980s, it became possible to begin to answer two very important questions about HIV’s natural history: what proportion of people infected with HIV will go on to get AIDS, and over what time period? By the late 1980s it was possible to provide some basic answers: about half of young adults with untreated HIV infection develop AIDS within about a decade of seroconversion.
The natural history of AIDS untreated by antiretroviral therapy was well known before that: annual mortality was 62-70% following a diagnosis of AIDS between 1982 and 1986, and few survived more than two years, with the exception of a small number whose AIDS defining condition was the more indolent forms of Kaposi’s sarcoma that can appear in relatively immunocompetent individuals.
There are various ways of modeling the period between seroconversion and AIDS, but the most reliable is to take a cohort whose time of seroconversion is known and follow them year by year to see what proportion have developed AIDS within what particular timeframe. It was possible to produce 10 year data within a few years of the development of the HIV antibody tests, because there existed banks of stored blood samples from studies of various populations going back many years: it was possible to restrospectively identify seroconversions that occurred 5 to 7 years before the tests were developed. One of the best known of such studies examined blood samples from gay men recruited to a study in San Francisco between 1978 and 1980. Other similar natural history studies have followed cohorts with a variety of risk factors for HIV infection and in a variety of countries.
From 1987 on there was increasing use of the antiretroviral zidovudine (AZT) initially to treat AIDS and then in subsequent years to try to delay the progression to AIDS – recall that “natural history of a disease” means the course uninterrupted by treatment. 1987 saw an appreciable drop in annual risk of mortality from HIV/AIDS and an increase in survival with AIDS. The introduction of AZT monotherapy was not the only reason for this, and even its most ardent defenders acknowledge that monotherapy in itself had only a modest survival benefit: also of importance were earlier diagnosis and better prophylaxis and treatment of opportunistic disease.
However the claims by Duesberg, Bauer and other denialists that AZT monotherapy was both a major cause of AIDS and hastened death in people with AIDS is contrary to the basic facts: the roughly ten year median AIDS-free survival was established prior to the introduction of AZT, AIDS mortality was substantially higher before than after 1987, and in the early years at least, AZT was mostly reserved for people already diagnosed with AIDS or ARC.
THE TEN YEAR MEDIAN AIDS-free survival period following infection and serconversion and without antiretroviral treatment is of course a ballpark figure, and varies from population to population. Untreated perinatally infected infants typically progress much faster, as do older adults. The natural history also varies somewhat from study to study and country to country: for example the median latency from seroconversion to AIDS has often been found to be shorter in Thailand than in other countries, for as yet unknown reasons, but perhaps related to the prevalence of different subtypes in different parts of the world.
A “median” latency of ten years does not mean that everyone develops AIDS at ten years, or even that ten years is necessarily the average “latent” period between infection and the development of AIDS. What it means is that half of infected people will have developed AIDS by ten years, and half won’t have. The half that don’t may develop AIDS after 10 to 15 years, or between 15 and 20 years after infection, or later, or possibly never. Over time, the proportion of HIV infected people who progress to AIDS continues to increase. By fifteen years it is of the order of 75 to 80%.
Even after many years there is a small group of people with HIV (perhaps a few per cent) who show little sign of progressing toward AIDS, either clinically or on measurements of immune function. The reasons for long term non progression have not been fully established, but in some cases there is defective virus , or fortuitous mutations in the cell receptors that inhibit HIV binding and entry, or unusually potent cell mediated and humoral immune responses. What is known about the small proportion of long term non-progressors confirms rather than refutes the role of HIV in the development of AIDS.
BAUER’S SOLITARY REFERENCE supporting his claim that “very few [untreated] HIV positive people ever become ill ” is not an epidemiological study: it is Christine Maggiore’s “What if everything you thought you knew about AIDS was wrong”. It is grossly and patently incorrect.
Further reading: It's about ten years old now, but the HIV Insite page on the Epidemiology of Disease Progression in HIV is detailed and well referenced.