Josee Nyiraneza was in her prime, twenty years ago, when she was diagnosed with HIV. Now 42, the then young Nyiranzeza had resigned herself to a life of loneliness. Twenty years ago, stigma was itself a harrowing ordeal, so she had found herself rejected from every side of the society.

However, she lived on and would later embrace anti-retrovirals when the HIV drugs became more accessible in the country.

Seven years ago, Nyiraneza met a man with whom she would later fall in love. Jean Hategekimana, 60, living positively with HIV; his first wife had passed on earlier.

Nyiraneza and Hategekimana agreed to start a new life together, and, in 2007, despite protests from their community and opposition from their relatives, walked down the aisle. Today, Nyiraneza and her husband still live together and both are on anti-retroviral (ARV) treatment.

Their life story, published in The New Times on December 16, had a caution from a specialist at the end of it. Dr Sabin Nsanzimana, the head of HIV division at the Rwanda Biomedical Centre, said although it was okay for HIV-positive couple to have ‘unprotected sex,’ to avoid more problems, it would be recommendable that the couple have a similar viral strain.

"They have to screen to confirm their virus types. If found different, they have to stick to condom use to avoid re-infection that complicates treatment,” he said.

Dr Nsanzimana’s caution is one of the most ignored issues in HIV/Aids prevention, treatment and care today.

You have probably heard of people who, when they realise they are HIV-positive, claim they would let loose so as to "die with someone” by infecting as many people as possible.

Such attitudes then lead to recklessness and exposure to different virus strains from other infected persons one would have unprotected sex with.

It is that scary.

The US National Library of Medicine, on September 14, 2002, reported on their web site that doctors have reported a rare case of HIV ‘superinfection,’ in which a person already infected with HIV became reinfected with a different strain of the virus.

The article said the finding proves the importance of consistently practising safer sex, even between two HIV positive people, they say. But they warn that HIV superinfection could be another obstacle to developing an effective Aids vaccine.

The patient, a 38-year-old man whose blood counts of HIV had fallen sharply after drug treatment, had a resurgent viral load after stopping his medication during an Aids vaccine trial. Tests showed that the cause was a new strain of HIV that had replaced the one he had had contracted two years earlier.

Weeks earlier the man had had unprotected sex several times while in Brazil. The new strain in his blood, known as subtype B, is endemic in Brazil. The patient’s initial strain, called AE, is prevalent in South East Asia.

"If you aren’t careful you [might] catch it twice,” said Dr Bernard Hirschel, of the University of Geneva, one of the case report’s authors.

So what does this mean?

In addition to sexually transmitted infections, unprotected sex can carry other health risks for HIV-positive people, says AidsMap, an agency dedicated to fight the disease burden.

Although reinfection appears to be rare, there seem to be some factors that might increase the risk of it happening. Nearly all the reported cases of reinfection occurred in the first few years after infection, and in people who were not on HIV treatment. However, there have been some case reports of reinfection in people who had long-term HIV infection.

"People should be more careful about the infection nowadays more than ever,” says Dr Narine Netov, a paediatrician at Midas Medical Centre in Kanombe.

According to the health expert, the fact that someone is already HIV-positive is no guarantee to engage in randomised sexual behaviour or any other kind promiscuity.

 "Even when you already have the virus, it is very possible for you to acquire another strain of the virus which may further weaken your immune system.” She explains.

Dr Netov also explains how the situation worsens when individuals already taking ARVs have intercourse with other people who may not even be on the drugs.

"First the virus has been exposed to drugs implying that chances of drug resistance are very high in the new individual suppose there is transmission of infection,” Dr Nestov said.

Superinfection, also known as reinfection, is the acquisition of different HIV strains from multiple partners if the second virus is acquired after seroconversion, that is, very early before any HIV infection is recognised.

While dual infection is when a person is infected with two or more strains of HIV. That person may have acquired both strains simultaneously from a dually infected partner or from multiple partners. A different strain of the virus is one that can be genetically distinguished from the first in a "family,” or phylogenetic tree. Acquisition of HIV strains from multiple partners is often called coinfection if all the strains were acquired prior to your seroconversion.

Experts say in some cases, reinfection has resulted in the person’s HIV viral load increasing and CD4 cell count falling. In addition, their treatment options have been limited because the type of HIV they were reinfected with was resistant to some or all of the anti-HIV drugs they were taking, as well as to others they had never taken.

However, generally, reinfection does not seem to cause serious health problems for most people with HIV.

Dr Rachna Pande an internist at Ruhengeri hospital says that: "since HIV virus is secreted in body fluids including semen and vaginal fluid. Concentration in genital fluids is not very high, as compared to blood. But since sex is a repetitive activity, the risk of transmission of virus increases manifold.”

For Rachna, safe sex is the one where one uses a good quality latex condom which will not rupture. Sex with one partner, whose HIV status is known, is safe, instead of having sex with multiple partners.

"With a very good HIV programme being run by government, down to health center level (including sensitization, early detection, counseling and treatment) very cachexic people with oral lesions are not commonly seen as before,” Rachna adds.

Writing in an accompanying editorial to the US National Library of Medicine finding, Dr Philip Goulder and Dr Bruce Walker of Massachusetts General Hospital, Boston, said the fact that natural infection does not necessarily protect against a range of HIV strains challenges the hope that one vaccine might do so.

Vaccine researchers have for the last decade been working on the premise that it will be difficult to develop a single vaccine that fights several strains of HIV. But it is becoming clearer that a fully protective vaccine will potentially have to contain hundreds or thousands of viral samples.