In push-up bras and sassy hair, Kinshasa's upper-class prostitutes get down to business at le Trente-Six Quinze. The prostitutes, known as the Londoners because they dress like British girls on a Saturday night out, sup Cokes by the Congo and gaze through blue-tinted contact lenses at Russian pilots and Chinese businessmen grabbing fat slices of pizza. Towards midnight, four women pair off with a table of white expats; they might make $100 (£57) by dawn.
In the east end of the Democratic Republic of Congo's capital, Doris Bilonda takes a filthy 200-franc note (25p) and is pushed in her wheelchair into her bamboo partition. Living in a breezeblock barn built by the government "pour handicaps physiques sinistres", it is the best price Doris, 34, a pregnant mother of four, can get in the circumstances: one foot was ruined by polio and, worse, she insists on using a condom.
The next morning the Londoners, together with older women such as Doris wait, by a shabby white building in the slums. Run by Médecins sans Frontières, the clinic at Matonge is the only one for thousands of sex workers among the seven million people of Kinshasa, a city both ruined and terribly alive. Clutching cheap handbags, they tell tales of exploitation. Two prostitutes aged nine and 10 accept less money than the usual $1 because they haven't yet developed breasts; pupils at a school get good grades if they sleep with their teacher: 8/10 if they agree not to use a condom but only 6/10 with protection.
Kinshasa in the wet season is forbidding. Stinking rubbish and rough plots of maize border the army barracks. Green weeds choke half-built roundabouts; orange Kombi vans with portholes hacked in the sides are crammed with passengers. Bindweed runs over walls by tower blocks while mosquitoes hover over fetid creeks.
But sweaty expat subcontractors sizing up young girls apart, this is not the moral ruin of Joseph Conrad. It is economic ruin. After decades of dictatorship and a civil war that killed 3.8 million people, there is no sign of any public money anywhere in Congo. Outside cocoons of private affluence such as the golf club, millions have no jobs and no cash and yet must pay for schooling and healthcare. Everything is for sale, piled into pyramids by the road: rocks, maize, phone cards, inner tubes, pineapples, coffins, antelope heads, fanbelts, flip-flops and sex.
In the Savannah bar, the stereo plays Ebony and Ivory. Like an obscene school disco, white men slump in chairs while black women hover at the bar. "I lost my parents, I had no one to support me," said Judith, 21, who could be a student and once was. "I met another girl who told me: 'You are pretty, I will show you where you can get money easily.' That's when I began what I do here. Unfortunately I am not happy but it's my life."
As a Londoner, Judith can earn good money letting expats do what they want with her each night. She tips open her handbag and eight condoms fall out. She claims she always makes her clients wear them. So does Blandine Ketuange-Mawete. But the 24-year-old, who looks like a demure British clubber in her white vest and hoop earrings, is receiving treatment at Matonge for a sexually transmitted disease. Around 12% of the sex workers test positive for HIV at the MSF clinic. Officially, 4.2% of Congo's adult population has HIV/Aids. Health workers fear the true figure is much higher. Soldiers and sexual violence help speed its spread.
"I've never met anyone who says they have chosen prostitution for reasons other than poverty, and the sex worker population is growing because of it," said Françoise Louis, HIV programme coordinator for MSF in Kinshasa. "Many sex workers are hidden - students and housewives who have sex for food. Their family does not know they are sex workers."
Dr Louis and the MSF staff first offer free care for the sex workers, the most vulnerable and stigmatised group in a traumatised city. "We also have to empower the Congolese. They are used to being led by NGOs. Little by little, those living with HIV understand they need to take on this issue themselves."
A key player in the transmission of HIV in Kinshasa is "the Love", the boyfriend/pimp who lives with many of the working girls. Natalie Mangassa, 24, and Safia Bahavu, 26, are among 60 young women who use grubby mattresses laid on the concrete floors of Hotel Muma in the city's east end. The narrow corridor smells of urine. Two brothers who own the hotel say they simply charge clients $5 for a room, but one admits he also has sex with the girls.
Natalie and Safia use packs of Prudence condoms supplied by MSF with their predominantly Congolese punters but admit they don't use them with their Love. Most Loves keep four or five prostitutes and sleep around.
Next year a new MSF project in Kinshasa will treat around 1,000 prostitutes and target their Loves, urging both to use condoms. "If HIV prevalence decreases among sex workers, it will help everybody in the town," said Dr Aimé Loando, the doctor in charge of Matonge clinic.
MSF will also expand the provision of antiretroviral drugs to sex workers with HIV. Seven prostitutes have recently been put on ARVs. Several of them are now well enough to seek new jobs and a way out of prostitution. Still, there are obstacles. With its small staff, including HIV-positive counsellors and former sex workers, MSF cannot educate, test or supply every sex worker with condoms in Kinshasa. While working girls are snapping up the free condoms, the resolve of self-confident Londoners such as Judith is limited when customers resort to money or violence.
Pregnant, disabled prostitutes such as Doris Bilonda have even less power. "If a client comes I suggest a condom but they give me less money," she said. She claims to insist on condoms but most of the 30 sex workers among the limbless women living in Kinshasa's disabled barn cannot make such a demand. So they continue to dice with death to earn "big money" - $2.