Sex work is legal here. But only if you register with the police

Binta didn't think twice about joining the program, convinced that it would help safeguard her from sexually transmitted diseases and abuse.

Senegal's legalization and regulation of sex work has been applauded for controlling the nation's HIV rate. At 0.4%, HIV prevalence in the country is significantly lower than many of its West and Central African neighbors; the average for the region is 1.5%, per UNAIDS. That figure is even higher in East and Southern Africa, where HIV prevalence is 7.1%.

It's also the only nation on the continent where sex work is legal and regulated by health policy, according to the Global Network of Sex Work Projects (NSWP), which advocates for decriminalization of the profession.

Some public health experts suggest that Senegal's registration system opened dialogue about sexual behavior and laid the groundwork for future HIV prevention programs targeting vulnerable populations.

But questions remain about the policy's efficacy in controlling the HIV/AIDS epidemic. Sex work is still criminalized in Senegal for those who are unregistered, which effectively creates a two-tiered system in which "clandestine" prostitutes fall through the cracks.

And signing up for the legal scheme is not such a simple choice in Senegal, a 96% Muslim-majority nation where sex workers face enormous social stigma and discrimination. NSWP says that leaves sex workers open to exploitation by police. Plus, the system only applies to women over 21, leaving male sex workers without support (homosexuality is illegal under Senegalese law).

These factors combined are cited by researchers to explain the low level of registration -- only 20% of sex workers across Senegal and 43% in Dakar have signed up to get the card.

"Right now, the system doesn't work," says Khady Gueye, program coordinator for the HIV division of Senegal's Ministry of Health, who provides support to both registered and unregistered women through outreach programs.

Senegal's Ministry of Health and civil society groups are hoping to change that, particularly because sex workers are still the main contributor to the HIV epidemic: with a prevalence of 6.6%, they are up to 16 times more likely to be infected than the general population.

Although the registration law was first introduced in 1969 -- inherited from French colonial legislation that stuck around even after Senegal declared independence -- there was little evidence of its impact on sex workers until recently.

Aurelia Lepine, a development economist at University College London, published a report last year in collaboration with Professor Cheikh Tidiane Ndour, director of the AIDS and STI division of Senegal's Ministry of Health, which revealed that the registration system has a crippling impact on sex worker's mental well-being.

"In Senegal, there is this idea ... that the low HIV rate is due to this policy," said Lepine, explaining that this was part of the reason she wanted to study the system. But while she found registration led to a 38% decrease in STI prevalence, it also dramatically reduced the well-being of sex workers.

"It's a good policy in terms of public health. The problem is the card. So, it's not the policy itself, but it's the way it is materialized," Lepine said.

Women who are registered live in fear that family members will discover their identification cards, or somehow see their name on a registration database. To avoid detection, they go out of their way to visit remote health clinics like Sébikhotane.

Awa, a 28-year-old registered sex worker who spoke with CNN after her appointment at the clinic, worries constantly that her 11-year-old son will find her ID.

"At home I made a little hole in my mattress where I hide the card, because my son is old enough to understand," Awa said, wiping away tears. "Registering has helped me on one side because I never have any health issues, and when I need medication I can get it. But in other ways it doesn't help at all."

In her report, Lepine suggests that the card could be replaced by a mobile application to track appointments, or with a quick response (QR) code issued at each medical visit. She recently received a grant from the UK Medical Research Council to explore these alternatives with the Ministry of Health.

Over ataya tea in his office at Dakar's Polyclinique hospital, Ndour said it would be difficult to change the card, but acknowledged that the current system was problematic.

"When you are registered, you are registered for life," said Ndour, referring to the database of registered sex workers, which is easily available to police forces and healthcare workers. "That, I think, needs to change. The duration. There is no limitation, and somewhere, even if you stop pursuing this profession, your great-grandchildren can find your name somewhere, and that is a problem."

"This opens the door to certain infringements," Ndour added, explaining that exploitation of sex workers by police forces is alleged to take place in some parts of the country.

The Director-General of Senegal's National Police did not respond to CNN's request for comment.

If registered sex workers miss their monthly appointments they can face up to six months in jail, Lepine found in her research, which puts police officers in a position to abuse their power.

The study found that registered sex workers were more likely than unregistered prostitutes to experience violence at the hands of police officers.

"We heard stories from women who were telling us that because a policeman knew she was a sex worker, they will go to their place asking for money, or if they refuse to give them money they will reveal to her family that she's a sex worker ... this type of blackmail," Lepine said.

But registered sex workers are also more willing to report clients' violence to police, according to Lepine's findings, an aspect of the system that is praised by women like Binta.

"If a registered worker has a problem with a client, they can get justice with their card," Binta said, explaining that unregistered prostitutes have no means of legal recourse.

Khadija, a 37-year-old unregistered sex worker who lives in a concrete compound in one of Dakar's poorest districts, said that if she had an ID card she would have reported being raped to police.

Sitting in her bedroom, a news broadcast playing on the muted television behind her, Khadija recalled the night she was assaulted by a client. She said she was robbed by the man, who forced himself on her without a condom.

But, she said, she would rather risk the consequences of not having a card -- which include arrest -- than face the stigma associated with it. She's been locked up twice for soliciting sex without an ID. The second time, she spent 45 days in jail. Now she's more cautious about where she meets clients.

"When you don't have the card, the stigma is there, but with the card it's even more," Khadija said, underlining the double-edged sword of the legal system that so many women describe.

Khadija recalled an incident from several years ago, when she went to a nearby police station to resolve a dispute with her landlord, and a man came in to report that he was robbed by a prostitute. The police, she said, showed him a booklet of photos of registered women working in the area.

CNN reached out to Senegal's National Police about the incident, but they did not respond.

Khadija said she couldn't face the possibility of her profession being so easily revealed.

"My main concern is my family. I don't want them to know. I don't care about anything else," said Khadija, who lives with her elderly mother, as well as a friend, who also works clandestinely.

Khadija is among a group of women that serve as peer-to-peer educators, working with non-profit organization Enda Santé to organize meetings, distribute free condoms, and share advice with other sex workers in Dakar.

Daouda Diouf, director of Enda Santé, says that leaders like Khadija have been instrumental in building trust within the community, allowing them to reach unregistered women. He says that, since Enda started operating its grassroots program 15 years ago, the prevalence of HIV in Senegal's sex work population has dropped from more than 20% to 5-6%. Diouf credits that success to the nonprofit's mobile clinic, which treats women on their own terms, providing services at night in the neighborhoods where they meet clients.

"Working with sex workers is the thing that is keeping Senegal in control of the (HIV) epidemic," Diouf said. "But the reality is not only on the public health and technical approach side, it's also society, religion, and community that has to be taken into account."

For both registered and unregistered women, the realities they face are often the same: juggling jobs, caring for children alone, supporting aging parents, navigating nights out,meeting new clients and trying to stay safe.

On a Saturday evening, many of the seaside bars in Almadies, Dakar's nightlife district, are packed with sex workers and their clients. Some women are carrying cards, and some are not.

When Binta works there on the weekend she always takes her ID card, concealing it in a secret compartment of her purse.

"If I could change one thing, it would be to remove the photo and my residence from the card," says Binta, who is saving up money to open a multi-service shop for fixing computers.

She says she doesn't want it to define who she is.