By Nick Bryant
BBC News correspondent in Sydney
Imagine being the health minister of Papua New Guinea, a poor country confronting one of the fastest growing Aids epidemics but which can call on the services of fewer than 300 doctors.
Many still cannot access HIV drugs
Or of Ethiopia, which has one doctor for every 100,000 people.
In many sub-Saharan countries, the public health infrastructure is so inadequate and incomplete that they do not have anywhere near enough refrigerated storage facilities.
This means vital drugs can expire even before they are administered.
Without proper coordination, it is hard to conduct proper research, the precursor of proper policy.
Then, to compound the problem even further, local doctors often grow so exasperated by their dysfunctional health systems that they apply for more lucrative jobs abroad, thus accelerating a "brain drain" at home.
Cycles do not come much more vicious.
No wonder the World Bank has recently warned that the biggest challenge in the fight against HIV infection and Aids is no longer the shortage of research funding, prevention strategies or treatments, but a chronic lack of basic health services in the countries worst affected by the pandemic.
It spoke of a "desperate shortage" of doctors, health care workers and researchers.
Safe sex is still key to avoiding infection
The global goal, as expressed in a 2005 UN General Assembly resolution, is to make treatments and preventions universally available by 2010.
But right now the world is "losing the numbers game," in the carefully chosen words of Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases in the US and one of the Bush administration's foremost advisors on the disease.
Even a cursory glance at the headline figures shows why: 11,000 people are being infected with HIV every day, and more than 3 million are dying each year.
But fewer than a third of the people with HIV who live in developing countries have access to life-saving medications and the means of prevention, such as condoms and sterile syringes.
Still, any global Aids audit has to take in a number of welcome developments on the positive side of the ledger, which provided a measure of optimism at a gathering in Sydney this month of 5,000 delegates from 133 countries for an international Aids conference.
Access to drugs
A significant increase in access to antiretroviral therapy in developing countries.
According to UNAIDS, more than a million people were getting ART by June 2006, a tenfold increase since December 2003. The number of people receiving ART doubled in 2005 alone.
New and better drugs
New classes of antiretroviral drugs can offer treatment to HIV-positive people who have grown resistant to first-line drugs.
"It means that people who've exhausted their treatment options now have new ones they can try which can keep them alive and healthy," according to Craig McClure, the executive director of the International Aids Society.
"The more treatment options we have, the more you can tailor treatments to a persons individual needs."
Effective forms of prevention
A welter of evidence gathered in Kenya and Uganda confirms what experts have long suspected: that male circumcision in young men can reduce HIV infection rates by 60%.
This could prevent 2 million new HIV cases and 300,000 Aids-related deaths in sub-Saharan Africa over the next decade.
But experts stress that the procedure has to be carried out by experienced surgeons and accompanied by a strong safe sex message.
"Circumcision gives you some protective benefit," says Professor David Cooper, an Australia-based expert.
"But you still have to keep up safe sex."
Female prevention strategies
Females need to be able to protect themselves against HIV infection, with forms of prevention they can control themselves - especially when their partners refuse to practice safe sex.
It was hoped that diaphragms might offer some protection, but a trial in South Africa yielded disappointing results.
It suggested there was no added protective benefit when the diaphragm and lubricant gel were provided in addition to condoms and a comprehensive HIV prevention package.
"It could be that it doesn't work and maybe we should never look at it again," said Nancy Padian, of the University of California.
"Or it may be we just need to sort out what was really going on in the trial."
Safe Sex fatigue and treatment optimism in developed countries
In Australia, for instance, HIV infection rates have doubled over the past seven years, a rise which experts think is partly due to what they call "safe sex fatigue" - a reluctance to use condoms.
They have also identified a phenomenon called "treatment optimism," whereby people engage in less safe forms of sex confident that, if they become infected, their lives will ultimately be saved by antiretroviral drugs.
"Life on antiretrovirals is definitely no party," says Professor Cooper.
Ice and other methamphetamines
A US study is one of the first to establish a strong link between the use of methamphetamines, like speed and the more powerful Ice, with HIV infection.
The study showed that between 2000 and 2005, the number of HIV positive young men taking club drugs tripled.
Drugs like ice have the effect of increasing sexual desire and of encouraging more dangerous forms of sex because the drugs numb any pain.