Vaccine 33 (2015) 4745–4747

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Brief report

Increasing hepatitis A immunity in men who have sex with men in Sydney, 1996–2012 Hammad Ali a,∗ , David G. Regan a , Rebecca J. Guy a , Peter Robertson b , Lucy Watchirs-Smith a , Anna M. McNulty c,d , Basil Donovan a,c a

The Kirby Institute, The University of New South Wales, Sydney, NSW, Australia South Eastern Area Laboratory Services, Prince of Wales Hospital, Sydney, NSW, Australia c Sydney Sexual Health Centre, Sydney Hospital, Sydney, NSW, Australia d School of Public Health and Community Medicine, University of New South Wales, Sydney, NSW, Australia b

a r t i c l e

i n f o

Article history: Available online 23 February 2015 Keywords: Homosexual

a b s t r a c t We examined the hepatitis A virus status of all MSM seen at a large sexual health clinic in inner Sydney between 1996 and 2012. Overall, the proportion of MSM susceptible to hepatitis A decreased from 68.1% in 1996 to 36.2% in 2012; most of this reduction was attributable to vaccination. © 2015 Elsevier Ltd. All rights reserved.

1. Introduction Men who have sex with men (MSM) are at a higher risk of hepatitis A virus (HAV) infection due to anal sexual practices combined with high numbers of sexual partners [1,2]. Hepatitis A is caused by an RNA virus which is highly infectious via the faecaloral route, and is usually acquired from contaminated food or water. Within a few weeks of infection, affected people often experience fever, nausea and vomiting, fatigue, loss of appetite, dark urine, abdominal pain, jaundice, and pale stools [3]. Most infected people recover completely within a few months but on rare occasions the infection may lead to liver failure and death. HAV infection leads to life-long immunity. A prophylactic vaccine against HAV is available and is recommended for people who are considered at high risk of acquiring or transmitting HAV infection including: children in high prevalence areas, travellers to such areas, childcare workers, food handlers, MSM and injecting drug users. The vaccine was first approved in 1994 in Australia [4]. In Australia, MSM are recommended to be vaccinated against HAV [5]; however, HAV vaccination for MSM is not funded by the Australian National Immunisation Program. In inner Sydney, there were two major outbreaks of hepatitis A in the 1990s that were associated with sexual contact in MSM [6,7]. The first was in 1991/1992 with a peak notification rate of 520 per 100,000 in 20–29 year old men and the second was in 1995/1996 with a peak notification rate of 405 per 100,000 in 30–34 year old

∗ Corresponding author. Tel.: +61 02 9385 0912; fax: +61 0 2 9385 0920. E-mail address: [email protected] (H. Ali). http://dx.doi.org/10.1016/j.vaccine.2015.01.090 0264-410X/© 2015 Elsevier Ltd. All rights reserved.

men [6]. Since 1996, there have been no further outbreaks of hepatitis A in MSM in Sydney. We aimed to determine trends in the proportion of MSM who are susceptible to HAV infection and the proportion who had previously received the HAV vaccine in Sydney and compare it to the findings of a modelling study (Submitted as a sister/joint paper) to see if there is a potential for further outbreaks.

2. Methods Sydney Sexual Health Centre (SSHC) is a public sexual health clinic, which offers free and confidential services including HIV and other sexually transmitted infections testing and treatment, hepatitis vaccinations, pap tests, patient counselling, referrals and partner management services [8]. Anonymous data on the HAV status of all MSM seen for the first time at SSHC between 1996 and 2012 were extracted from patient medical and laboratory records. At the first visit, the following dichotomous variables are recorded in the patient proforma: (a) past acute hepatitis A (self-report), (b) past positive test for HAV antibody, (c) past negative test for HAV antibody, (d) no past test for HAV antibody, and (e) past vaccination against HAV (self-report). If the patient is not known to be immune to HAV (i.e. did not report a past hepatitis A infection or vaccination and was never tested positive for HAV antibody), he is routinely offered a test for HAV antibody (total or IgG) with a view to vaccination if the test is negative. Until April 2007, Abbott Axsym assays (sensitivity: 100%) were used and thereafter Abbott Architect assays (sensitivity: 98%) were used to test for HAV antibody. The number of MSM assumed to be not susceptible to HAV included those who are immune to hepatitis A i.e. reported a past

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H. Ali et al. / Vaccine 33 (2015) 4745–4747

Table 1 HAV status of MSM seen for the first time at SSHC, 1996–2012. Year

Number and proportion immune to HAV infection

Number of new MSM Previously vaccinated n (%)

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 p Trend

714 732 713 522 502 691 847 894 908 942 968 991 913 1035 1187 1195 1045

Past hepatitis A illness n (%)

Proportion susceptible n (%)

Past positive antibody test n (%)

Positive antibody test at SSHC n (%)

Total n (%)

70 (9.8%) 108 (14.8%) 133 (18.7%) 130 (24.9%) 147 (29.3%) 214 (31.0%) 287 (33.9%) 339 (37.9%) 359 (39.5%) 385 (40.9%) 378 (39.0%) 425 (42.9%) 398 (43.6%) 404 (39.0%) 508 (42.8%) 511 (42.8%) 472 (45.2%)

62 (8.7%) 43 (5.9%) 40 (5.6%) 38 (7.3%) 35 (7.0%) 34 (4.9%) 47 (5.5%) 28 (3.1%) 29 (3.2%) 24 (2.5%) 28 (2.9%) 25 (2.5%) 15 (1.6%) 17 (1.6%) 17 (1.4%) 9 (0.8%) 15 (1.4%)

19 (2.7%) 24 (3.3%) 21 (2.9%) 23 (4.4%) 13 (2.6%) 27 (3.9%) 22 (2.6%) 30 (3.4%) 30 (3.3%) 23 (2.4%) 21 (2.2%) 15 (1.5%) 12 (1.3%) 19 (1.8%) 19 (1.6%) 16 (1.3%) 10 (1.0%)

77 (10.8%) 87 (11.9%) 87 (12.2%) 46 (8.8%) 67 (13.3%) 95 (13.7%) 99 (11.7%) 110 (12.3%) 135 (14.9%) 144 (15.3%) 160 (16.5%) 167 (16.9%) 130 (14.2%) 173 (16.7%) 220 (18.5%) 214 (17.9%) 170 (16.3%)

228 (31.9%) 262 (35.8%) 281 (39.4%) 237 (45.4%) 262 (52.2%) 370 (53.5%) 455 (53.7%) 507 (56.7%) 553 (60.9%) 576 (61.1%) 587 (60.6%) 632 (63.8%) 555 (60.8%) 613 (59.2%) 764 (64.4%) 750 (62.8%) 667 (63.8%)

486 (68.1%) 470 (64.2%) 432 (60.6%) 285 (54.6%) 240 (47.8%) 321 (46.5%) 392 (46.3%) 387 (43.3%) 355 (39.1%) 366 (38.9%) 381 (39.4%) 359 (36.2%) 358 (39.2%) 422 (40.8%) 423 (35.6%) 445 (37.2%) 378 (36.2%)

Increasing hepatitis A immunity in men who have sex with men in Sydney, 1996-2012.

We examined the hepatitis A virus status of all MSM seen at a large sexual health clinic in inner Sydney between 1996 and 2012. Overall, the proportio...
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