Three-fold increase in new HIV cases amongst UK Caribbeans between 1997 - 2001

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The number of new HIV diagnoses amongst black Caribbeans living in the UK increased three-fold between 1997 and 2001, according to an editorial published in the February edition of Sexually Transmitted Infections. An editorial accompanying this article argues that high rates of gonorrhoea amongst the UK Caribbean population are “proving fuel for an explosive epidemic” of HIV.

Another study published in the same edition of Sexually Transmitted Infections describes an increase of new HIV diagnoses of similar magnitude to that seen in UK Caribbeans amongst south Asians in London.

Public health investigators wished to establish the epidemiology of HIV amongst the UK’s Caribbean population. Several factors suggesting an increased susceptibility of this population to HIV formed the background to the study. UNAIDS estimates that over 420,000 people in the Caribbean are HIV-positive, giving the region the highest HIV prevalence outside southern Africa. Immigration from the Caribbean to the UK continues and there is frequent travel between the UK’s Caribbean population and the region. In addition, the rate of the bacterial sexually transmitted infection (STI) gonorrhoea is estimated to be between 12 and 13 times higher in the UK’s Caribbean population than the UK white population.

Glossary

epidemiology

The study of the causes of a disease, its distribution within a population, and measures for control and prevention. Epidemiology focuses on groups rather than individuals.

UNAIDS

The Joint United Nations Programme on HIV/AIDS (UNAIDS) brings together the resources of ten United Nations organisations in response to HIV and AIDS.

p-value

The result of a statistical test which tells us whether the results of a study are likely to be due to chance and would not be confirmed if the study was repeated. All p-values are between 0 and 1; the most reliable studies have p-values very close to 0. A p-value of 0.001 means that there is a 1 in 1000 probability that the results are due to chance and do not reflect a real difference. A p-value of 0.05 means there is a 1 in 20 probability that the results are due to chance. When a p-value is 0.05 or below, the result is considered to be ‘statistically significant’. Confidence intervals give similar information to p-values but are easier to interpret. 

Accordingly, investigators reviewed HIV surveillance data held by the UK’s Communicable Disease Surveillance Centre between 1997 and 2001.

Between 1997 and 2001, 528 adult black Caribbeans were newly diagnosed HIV-positive, representing 3.3% of all new HIV cases reporting during this period. A 2.8-fold increase in cases amongst this ethnic group occurred between 1997 and 2001, “the largest proportional increase within an ethnic group after black Africans”. In 1997, 62 black Caribbeans received a positive HIV test result, increasing to 176 in 2001.

Heterosexual sex accounted for 63% of all HIV cases amongst Caribbeans in this period, compared to 50% of total new HIV cases. Sex between men accounted for a total of 32% of infections amongst Caribbeans, and fell significantly from 44% of all new infections in 1997 to 29% in 2001 (p=0.02).

Almost equal numbers of heterosexual men and women were infected (161 men and 174 women), with the median age of men at infection being 35 years against 32.8 years for women. The majority of heterosexual men (63%) were probably infected with HIV in the Caribbean. By comparison only 44% of women are thought to have been infected in the Caribbean.

The median age of men who had sex with another men as the cause of their HIV infection was 32.3 years, and the majority (62%) were infected with HIV in the UK, with a little under a third probably infected in the Caribbean.

Between 1997 and 2001, the number of Caribbeans accessing HIV care in the UK increased 2.4 fold. In 1997 294 (2% of total) Caribbeans were receiving HIV care in the UK, increasing to 691 (2.8% of total HIV-positive individuals seen) in 2001. This was the greatest increase for any ethnic group observed during this period other than black Africans.

Caribbeans were just as likely to access HIV treatment and care as Africans or UK whites.

South London is focus of UK Carribean HIV

A distinct residential pattern emerged, with 76% of all Caribbeans diagnosed with HIV living in London, mainly in the south London boroughs of Lambeth, Southwark and Lewisham.

The prevalence of undiagnosed HIV infection amongst Caribbean-born attenders of sexual health services was 0.7% for heterosexual men and 0.6% for women, contrasting to 0.16% and 0.12% for UK white heterosexual men and women and 2.9% for African-born heterosexual men and 4.7% for African-born women.

The percentage of Caribbean-born women giving birth in the London regions who were HIV-positive remained steady at 0.31% between 1997 and 2001. This contrasted to 0.03% of white British women and 1.5% of African-born women.

Both Caribbean-born heterosexuals and gay men diagnosed with HIV through sexual health services were more likely than white British heterosexuals and gay men to have an STI at the time of their HIV diagnosis (41% and 42% for Caribbeans versus 29% and 21% of white British).

”Our data confirm,” note the investigators, “that numbers of new diagnoses among black Caribbeans and the number of black Caribbeans HIV infected and accessing HIV treatment and care services…have increased rapidly in recent years.” The investigators conclude that “as HIV spreads among the black Caribbean communities…the emerging surveillance data must be used to ensure that prevention and services are targeted towards those who need them most, and that widespread HIV among this ethnic group is averted.”

An accompanying editorial draws attention to the rates of gonorrhoea and other sexually transmitted infections amongst the UK Caribbean population. The author notes “the rate of newly diagnosed HIV infections is 12 times higher in black Caribbeans than in the white population. This is about the same difference in gonorrhoea rates that has generated widespread alarm.” The editorial concludes “the challenge is to get across the message that the rates of HIV among black Caribbeans are currently modest but that persistently high gonorrhoea rates are providing fuel for an explosive epidemic. The issue of HIV must first be taken on by black Caribbean communities so that partnerships for research and prevention can find out what works.”

Threefold growth in HIV amongst South Asians in UK

A similar epidemiological pattern to that observed amongst Caribbeans was also seen amongst south Asians, according to a small study published in the same edition of the journal. Investigators studied the notes of patients receiving HIV care at four London centres between 1985 and 2002 and identified patients describing themselves as Indian, Pakistani, Bangladeshi, or Sri Lankan. A total of 117 individuals were identified, 87 being men. There was a threefold increase in new HIV diagnoses amongst south Asians attending these hospitals between 1996 and 2002 (25 diagnoses pre-1996 and 90 diagnoses 1996 – 2002).

Interestingly, the majority of patients (38%) originated in Africa, with 24% coming from India, and 18% the UK. Most cases (62%) involved heterosexual transmission, and 31% sex between men. The majority, 39%, identified Africa as the probable location of infection. A total of 44% of men who had sex with another man as their HIV-risk activity were diagnosed through routine HIV testing at a sexual health clinic.

Amongst heterosexual men, the existence of symptoms of HIV disease was the reason for HIV testing in most cases (60%), whereas heterosexual women were most often tested after contact tracing (44%). Median CD4 cell count at the time of diagnosis was 300 cells/mm3, but heterosexual men had lower median CD4 cell counts (178 cells/mm3 than either gay men (381 cells/mm3) or women (377 cells/mm3).

Further information on this website

UNAIDS: HIV prevalence increases 10% in South America and Caribbean - news story

About the epidemic: south and south east Asia

References

Dougan S et al. Black Caribbean adults with HIV in England, Wales, and Northern Ireland: an emerging epidemic? Sexually Transmitted Infections 80: 18 – 25, 2004

Low N. HIV infection in black Caribbeans in the United Kingdom. Sexually Transmitted Infections 80: 2 – 3, 2004

Lacey G S et al. South Asians with HIV in London: is it time to rethink sexual health service delivery to meet the needs of heterosexual minorities. Sexually Transmitted Infections 80: 75 – 76, 2004.