364
highly recommended beach on the north shore of Java. If there were signs warning of pollution, they had no effect on the multitude of bathers. My stay in the water was very brief for I was propelled out by the grossest evidence of untreated sewage. My neighbour, a skilled Indonesian physician, was unconcerned ("things have always been so"); his school-age daughter came down with typhoid
HIV SEROPREVALENCE IN 4097 ANTENATAL CLINIC ATTENDERS, ST THOMAS’ HOSPITAL, LONDON, 1990
fever about a week later.
give the impression that all my recollections of Indonesia bowel-related, let me say that the store of memories include the infinite grace of the people of Indonesia and her dancers, gamelan music, shadow plays, and batik. Lest I
are
4911 N E 65th Street, Seattle, Washington 98115, USA
WILLIAM PARSON
HIV seroprevalence among women attending antenatal clinics in London SIR,-Using unlinked anonymous testing we found a nine-fold increase in the prevalence of HIV infection among women attending antenatal clinics at St Thomas’ Hospital between 1988 and 1990.1 Among these patients there was a high proportion of women classified in their notes as being from ethnic minority groups, including women originating from west or central Africa. An increase in HIV prevalence in inner London was also reported by the Public Health Laboratory Service (PHLS).2 This has been interpreted as providing evidence of spread of HI V infection among the heterosexual population in London.3 A Ministerial AIDS Action Group was formed to look at local services and at prevention and educational initiatives and to identify means of reaching women, children, and ethnic minorities. HIV-related resources must be targeted accurately, so we have attempted to identify the risk factors involved. We obtained local ethical approval to re-examine the serum collected from women attending antenatal clinics in 1990, retaining anonymity but linking serum to such factors as ethnic origin, age, and history of injecting drug use (IDU) of patient or partner. In addition we assessed malarial antibodies (Launch Diagnostics, Longfield, Kent) and hepatitis B virus (HBV) core antibodies as surrogate markers of either recent travel to, or of having been raised in, endemic areas. Throughout the analysis we have ensured the impossibility of deductive disclosure of HIV positivity by removing all identifying data (name and hospital number) from serum before testing, and maintaining subgroup sizes of more than 20. This study is complementary to but distinct from the anonymous unlinked study by the PHLS. Records were available for 2931 (72%) of the 4097 patients collected in 1990. Ethnic origins (A African; E = European [Caucasian]; 0 other, including Asian) are given in the table. Of these 2931 patients, 13 (0-4%) were HIV-1 positive, of whom 10 (77%) were in ethnic group A. The remaining 3 (23%) were in group E, 2 being sexual partners of IDU. 10 (2%) of 489 patients in group A but only 3 (0-2%) of 1566 patients in group E were HIV-1 positive (and only 1 of these 3 had no recorded HIV risk factor). No patient in group 0 was HIV positive. Of the 1158 patients for whom no notes were available, 5 (0-4%) were HIV-1 positive. However, the fact that all 5 had malarial antibodies suggested that they had recently visited or been resident in a tropical country. In total, HIV-1 prevalence was 18 (0-4%) of 4097. No HIV-2 was detected. Malarial antibodies were detected in only 1 % of those in group E, infrequently in group 0, but commonly (75%) in group A. Although the serology of malarial infection is complex, antibodies are time dependent and our results suggest that many patients in group A had lately visited or been resident in tropical Africa. That malarial antibodies were detected in 9 of 10 (90%) HIV-positive patients in group A suggests that these patients may have acquired their HIV infection in Africa rather than in the UK. We also tested for antibodies to hepatitis B core antigen. The higher seroprevalence in group A (42%) and in patients from the Far East (45%) compared with group E (2%) suggests that such antibodies may be of some use as a marker of former residence in HBV-endemic areas. Since it may not always be possible to distinguish patients travelling to London for their confinement from patients normally =
=
*Not all sera tested for malarial antibodies. tAntenatal booking at > 20 weeks’ gestation $All HIV-1.
resident in the UK, we have attempted to determine whether late antenatal booking (at more than 20 weeks’ gestation) can be used as a surrogate marker of travel to London. Late booking was more common among patients in group A (25%) (p < 0-05) and Asians (30%) than in group E (14%). We have now completed anonymous unlinked testing of sera collected during 1991, during which time only 7 (0-2%) of 4112 women were HIV positive. The reasons for this decline are unclear but it is not reflected elsewhere in London (PHLS, unpublished). Further extensive and detailed prospective studies should be done in inner London to identify risk categories and to monitor the spread of HIV outside them, if it occurs, so that preventive measures may be targeted accurately. The diagnosis of HIV infection is now thought to be of clinical benefit. For instance, it is only by identifying HIV-positive patients that proper counselling can be given both with regard to the desirability of continuation of pregnancy and diagnosis of HIV infection in and treatment of babies. This, coupled with the high prevalance of infection reported by ourselves and others in parts of London and the rapid spread of HIV infection in other tropical areas from which many of our patients originate, leads us to suggest that consideration be given to initiating testing on a named basis. It would be invidious to target HIV testing at specific ethnic categories. Not only would such a policy fail to identify any spread of infection outside known risk categories but also our experience with HBV infection has demonstrated the inefficiency of selective screening.’ Thus, screening of antenatal clinic patients for HIV infection should, if implemented, be universal, as is the practice in many health authorities for HBV. Such a programme would require additional or redirected resources. Departments of Virology and Obstetrics and Gynaecology, St Thomas’ Hospital, London SE1 7EH, UK
I. L. CHRYSTIE S. J. PALMER A. KENNEY J. E. BANATVALA
1. Banatvala JE, Chrystie IL, Palmer SJ, et al. HIV screening in pregnancy. Lancet 1991; 337: 1218. 2. Anon. CDR 1991; 1 (no 7): R69-76. 3. Department of Health. Press release H91/313 (July 8, 1991). 4. Voller A. The immunodiagnosis of malaria. In Wemsdorfer WH, McGregor I, eds. Malaria: principles and practice of malariology, vol I. Edinburgh: Churchill Livingstone, 1988. 815-25. 5. Banatvala JE, Chrysne IL, Palmer SJ, Kenney A. Retrospective study of HIV, hepatitis B, and HTLV-I infection at a London antenatal clinic. Lancet 1990; 335: 859-60.
Vertical transmission of HIV SIR,-Dr Sanchez and Dr Casabona (Sept 28, p 829) draw several questionable conclusions about the survival of infected children born to HIV-seropositive mothers. Their assertion of 27% survival by the age of four years is not supported by their graph, which shows a figure of around 80% in children of symptom-free
highly recommended beach on the north shore of Java. If there were signs warning of pollution, they had no effect on the multitude of bathers. My stay in the water was very brief for I was propelled out by the grossest evidence of untreated sewage. My neighbour, a skilled Indonesian physician, was unconcerned ("things have always been so"); his school-age daughter came down with typhoid
HIV SEROPREVALENCE IN 4097 ANTENATAL CLINIC ATTENDERS, ST THOMAS’ HOSPITAL, LONDON, 1990
fever about a week later.
give the impression that all my recollections of Indonesia bowel-related, let me say that the store of memories include the infinite grace of the people of Indonesia and her dancers, gamelan music, shadow plays, and batik. Lest I
are
4911 N E 65th Street, Seattle, Washington 98115, USA
WILLIAM PARSON
HIV seroprevalence among women attending antenatal clinics in London SIR,-Using unlinked anonymous testing we found a nine-fold increase in the prevalence of HIV infection among women attending antenatal clinics at St Thomas’ Hospital between 1988 and 1990.1 Among these patients there was a high proportion of women classified in their notes as being from ethnic minority groups, including women originating from west or central Africa. An increase in HIV prevalence in inner London was also reported by the Public Health Laboratory Service (PHLS).2 This has been interpreted as providing evidence of spread of HI V infection among the heterosexual population in London.3 A Ministerial AIDS Action Group was formed to look at local services and at prevention and educational initiatives and to identify means of reaching women, children, and ethnic minorities. HIV-related resources must be targeted accurately, so we have attempted to identify the risk factors involved. We obtained local ethical approval to re-examine the serum collected from women attending antenatal clinics in 1990, retaining anonymity but linking serum to such factors as ethnic origin, age, and history of injecting drug use (IDU) of patient or partner. In addition we assessed malarial antibodies (Launch Diagnostics, Longfield, Kent) and hepatitis B virus (HBV) core antibodies as surrogate markers of either recent travel to, or of having been raised in, endemic areas. Throughout the analysis we have ensured the impossibility of deductive disclosure of HIV positivity by removing all identifying data (name and hospital number) from serum before testing, and maintaining subgroup sizes of more than 20. This study is complementary to but distinct from the anonymous unlinked study by the PHLS. Records were available for 2931 (72%) of the 4097 patients collected in 1990. Ethnic origins (A African; E = European [Caucasian]; 0 other, including Asian) are given in the table. Of these 2931 patients, 13 (0-4%) were HIV-1 positive, of whom 10 (77%) were in ethnic group A. The remaining 3 (23%) were in group E, 2 being sexual partners of IDU. 10 (2%) of 489 patients in group A but only 3 (0-2%) of 1566 patients in group E were HIV-1 positive (and only 1 of these 3 had no recorded HIV risk factor). No patient in group 0 was HIV positive. Of the 1158 patients for whom no notes were available, 5 (0-4%) were HIV-1 positive. However, the fact that all 5 had malarial antibodies suggested that they had recently visited or been resident in a tropical country. In total, HIV-1 prevalence was 18 (0-4%) of 4097. No HIV-2 was detected. Malarial antibodies were detected in only 1 % of those in group E, infrequently in group 0, but commonly (75%) in group A. Although the serology of malarial infection is complex, antibodies are time dependent and our results suggest that many patients in group A had lately visited or been resident in tropical Africa. That malarial antibodies were detected in 9 of 10 (90%) HIV-positive patients in group A suggests that these patients may have acquired their HIV infection in Africa rather than in the UK. We also tested for antibodies to hepatitis B core antigen. The higher seroprevalence in group A (42%) and in patients from the Far East (45%) compared with group E (2%) suggests that such antibodies may be of some use as a marker of former residence in HBV-endemic areas. Since it may not always be possible to distinguish patients travelling to London for their confinement from patients normally =
=
*Not all sera tested for malarial antibodies. tAntenatal booking at > 20 weeks’ gestation $All HIV-1.
resident in the UK, we have attempted to determine whether late antenatal booking (at more than 20 weeks’ gestation) can be used as a surrogate marker of travel to London. Late booking was more common among patients in group A (25%) (p < 0-05) and Asians (30%) than in group E (14%). We have now completed anonymous unlinked testing of sera collected during 1991, during which time only 7 (0-2%) of 4112 women were HIV positive. The reasons for this decline are unclear but it is not reflected elsewhere in London (PHLS, unpublished). Further extensive and detailed prospective studies should be done in inner London to identify risk categories and to monitor the spread of HIV outside them, if it occurs, so that preventive measures may be targeted accurately. The diagnosis of HIV infection is now thought to be of clinical benefit. For instance, it is only by identifying HIV-positive patients that proper counselling can be given both with regard to the desirability of continuation of pregnancy and diagnosis of HIV infection in and treatment of babies. This, coupled with the high prevalance of infection reported by ourselves and others in parts of London and the rapid spread of HIV infection in other tropical areas from which many of our patients originate, leads us to suggest that consideration be given to initiating testing on a named basis. It would be invidious to target HIV testing at specific ethnic categories. Not only would such a policy fail to identify any spread of infection outside known risk categories but also our experience with HBV infection has demonstrated the inefficiency of selective screening.’ Thus, screening of antenatal clinic patients for HIV infection should, if implemented, be universal, as is the practice in many health authorities for HBV. Such a programme would require additional or redirected resources. Departments of Virology and Obstetrics and Gynaecology, St Thomas’ Hospital, London SE1 7EH, UK
I. L. CHRYSTIE S. J. PALMER A. KENNEY J. E. BANATVALA
1. Banatvala JE, Chrystie IL, Palmer SJ, et al. HIV screening in pregnancy. Lancet 1991; 337: 1218. 2. Anon. CDR 1991; 1 (no 7): R69-76. 3. Department of Health. Press release H91/313 (July 8, 1991). 4. Voller A. The immunodiagnosis of malaria. In Wemsdorfer WH, McGregor I, eds. Malaria: principles and practice of malariology, vol I. Edinburgh: Churchill Livingstone, 1988. 815-25. 5. Banatvala JE, Chrysne IL, Palmer SJ, Kenney A. Retrospective study of HIV, hepatitis B, and HTLV-I infection at a London antenatal clinic. Lancet 1990; 335: 859-60.
Vertical transmission of HIV SIR,-Dr Sanchez and Dr Casabona (Sept 28, p 829) draw several questionable conclusions about the survival of infected children born to HIV-seropositive mothers. Their assertion of 27% survival by the age of four years is not supported by their graph, which shows a figure of around 80% in children of symptom-free
