Discordant HIV Couple: Analysis of the Possible Contributing Factors.

Several intricacies still abound with respect to HIV infection. Discordance is one such intriguing aspect of HIV infection. Out of 35 discordant couples included in the study. husbands were positive in 29 couples and wives in 6. Pre/extramarital affairs was the probable reason for HIV infection in 23 out of 29 discordant males, and 2 out of 6 discordant females. Even though, decreased frequency of sexual acts between the couple was the reason for discordance in a few, but in majority of the couples who had regular sexual contact for many years, the exact cause for discordance could not be ascertained. inherent resistance to HIV in some individuals may be the reasons for the discordance.

What was known?

Discordant couples are at high risk of HIV transmission, and therefore are increasingly becoming a focus of HIV prevention research.

Several complex issues still exist with regards to HIV infection. It is often seen that some people have repeated unprotected sexual intercourse with their infected partners and yet they do not contact the infection. This is HIV discordance.[1] Discordant couples are definitely at high risk of HIV transmission, and therefore are increasingly becoming a focus of HIV prevention research. We conducted this study with the aim of analyzing the possible reasons for the presence of such discordance.

Among the married couple visiting our ART center, we recruited those discordant couples who had been married for a minimum of one year. The negativity of the HIV negative partner was confirmed by HIV testing two times at least three months apart. Each participant completed a brief self-administered questionnaire. In addition, an in-depth semi-structured interview was conducted to gain an understanding of sexual behaviour especially regarding their sexual habits, frequency of sexual contact with spouses and history of any premarital/extramarital sexual relationships. The frequency of sexual contacts with their spouses was graded in to three categories for the purpose of convenience; Average, above average and below average.

Average means one to three sexual contacts per week

Above average means more than three sexual contacts per week and

Below average means less than one sexual contact per week.

Duration of positivity (the time between the person detected to be HIV positive and their entry time in to the study) was also recorded. In addition, history of tattooing or any surgical procedures undergone in the past, and history of blood transfusion in the past were recorded. Informed consent was taken from both the partners. Ethical permission was obtained from the independent research ethical committee of the institute.

There were totally thirty five discordant couples, out of which husbands were positive in 29 couples and wives in six. Average duration of marriage was 10.7 years (Range; one year three months to twenty six years). Mean duration of positivity was 1.5 years (Range; one week to five years). Out of 29 discordant males, probable reasons for HIV infection were pre/extramarital affairs in 23, blood transfusion in one, surgical operation in one and acquiring the infection from the previous wife in two. In spite of our detailed assessment, we could not find any obvious reasons in the remaining two. Similarly out of six discordant females, probable reasons for HIV infection were pre/extramarital affairs in two, acquiring the infection from the previous husbands in two and two claimed that they must have got it after hysterectomy operation they had undergone many years back.

As per our grading, 25 of the discordant males and 4 of the discordant females had average or above average sexual frequency with their spouses. Twenty three out of these 25 males and two out of these four females had extramarital affairs. The mean duration of HIV positivity was 1.5 years. But, they would have been positive much earlier than this before testing for HIV as the average duration of marriage was 10.7 years. That means majority of the couple had regular unprotected sexual contact with their infected spouses more than three times a week for a minimum of 1.5 years, still they did not get the infection. Therefore, with regards to why the negative partner continued to be negative in spite of regular unprotected sexual contact with their infected spouses for at least 1.5 years, one reason could be that the sexual frequencies between the couple might not have been sufficient enough to transmit the infection. Published estimates of HIV transmission probabilities per coital act vary from γ = 0.0001 to 0.0014 in studies of discordant couples.[2]

Another reason for the continued discordance could be that some people may be inherently resistant to the infection. Several studies have suggested that cellular immunity and viral characteristics may be associated with HIV-discordance.[3] Resistance to HIV infection is especially demonstrated among individuals bearing mutant alleles of CCR-5.[4] It is believed that there are other mutations like CCR-5 which may be responsible for some people showing resistance to HIV infection. Variations in CCR5 are associated with resistance or susceptibility to immunodeficiency virus.[5] We did not have the facility to measure CCR-5 or any other gene mutations. The other drawbacks in our study were that we had a small population sample with only 35 discordant couples and we relied mainly on what the patients reported about their sexual behaviours even though we knew that the self reported sexual behaviours are not always reliable. Therefore we recommend further studies in this regard overcoming these drawbacks to explore this intriguing aspect of HIV.

What is new ?

An attempt is made in this study to analyze the possible reasons for the existence of HIV discordance. Sexual promiscuity resulting in decreased sexual frequencies between the couple and inherent resistance to HIV in some individuals may be the reasons for the discordance