Of all violations of a human's space, infection is the most nefarious. Aliens grow within us, subverting our bodies for their own ends. Antibiotics and public health measures to keep microbial contact to a minimum appeared to herald the end of the "age of infection" in the middle of this century. But now we are in danger of entering a post-antibiotic era, especially as antibiotics are being routinely used as "growth promoters" in farming and for keeping infection levels low, allowing livestock to grow without competition from microbial intruders. The trouble is that growth promoters are given with far fewer regulations on their use than their counterparts in human use.
In 1998, reporting on resistance to antibiotics, the House of Lords Select Committee on Science and Technology concluded that the imprudent use of antibacterial wonder drugs had led to the development of resistance, rendering many of them useless. The Lords committee recommended that the only way to ensure that new drugs don't also become obsolete is to restrict their use. But where will these new drugs come from? The pharmaceutical industry will produce drugs only if the market price is right. Prudent use equates to unequal use - in effect, drugs reserved for the rich.
The situation regarding Aids therapy is already growing ugly; $20,000 will secure a year's supply of drugs to hold the disease in check. Most of the world's 30 million HIV-infected people live in developing countries. The South African government, confronted with a catastrophic Aids epidemic, has pleaded for the costs of drugs to be reduced. Against this, the US vice-president, Al Gore, has personally led efforts to quash any attempted violation of intellectual property rights held by the western pharmaceutical companies, which dictate prices. To vilify the pharmaceutical industry, however, is to forget that without their investment most drugs would have never emerged in the first place. So ultimately it must fall on "society" to produce not-for-profit drugs.
Paul Farmer, a medical anthropologist, works extensively on Aids and tuberculosis. He is angry. Angry that the afflicted are blamed for their own condition. But dividing disease susceptibility between "them" and "us" seems to be deeply ingrained. The first recognised Aids cases occurred in homosexual men. Those in conventional relationships felt comforted by the notion that the spread of infection required anal sex.
The reality that heterosexual HIV infection was rife in Africa should have worried the conventionalists. But the comforters were quick to blame Africans for their heterosexual epidemic. Myths such as the idea that widows were ritually sodomised by the siblings of their deceased husbands were widely reported. Conrad's brutes were exterminating themselves through their own bestial excesses. Aids promised to be a disease of the "other". All of this is, of course, complete nonsense.
Farmer's work focuses on Haiti, where gay sex tourism in the late 1970s was supposedly linked to the original Californian Aids epidemic. The disease was apocryphally linked, too, to voodoo rituals, with all the accompanying gory titillation to comfort Mr Average. It's not clear how Aids reached Haiti, but Farmer's descriptions of the unremitting misery of the poor there provide compelling evidence of how inequality led to its spread. Coercive prostitution, violence, lack of healthcare, depression, drug addiction, ignorance and superstition all conspired to keep the poor ill.
Aids and tuberculosis are not confined to Haiti's poor. The streets of London and New York are laden with the victims of inequality. They, too, provide shelter for the HIV virus and tuberculosis bacterium. New York City was compelled to pay around $1 billion to rein in a serious problem of multi-drug-resistant tuberculosis in the early 1990s, having allowed its relatively modest expenditure on disease surveillance to wane over the preceding two decades.
Infections are like inundations: all too willing to return whenever defences drop. And yet governments behave no more prudently than the GPs and patients attacked by the Lords select committee. As soon as the overt symptoms cease, we stop the medication. Prudent policies on international public health must accompany prudent use of antibiotics if we are to realise our dream of an infection-free society.
Michael Barrett is a lecturer at the Institute of Biomedical and Life Sciences, University of Glasgow