AIDS New Zealand - Issue 61

HIV and AIDS Information
AIDS New Zealand

Issue 61 – February 2008
ISSN 1170-2656 (Print)
ISSN 1178-2692 (Online)

Download Issue 61 (PDF, 352 KB)

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HIV & AIDS In New Zealand – 2007

HIV Infection
A total of 156 people were diagnosed with HIV through antibody testing in New Zealand in 2007.
71 were men infected through sex with other men (MSM), 60 (31 men and 29 women) through heterosexual contact, 1 through injecting drug use, 1 through a blood transfusion overseas, 7 were children infected through perinatal transmission (5 overseas and 2 in New Zealand), and for 16 people the mode of infection remains unknown.

A further 39 people with HIV infection, who had not had an antibody test here, had their first viral load test in New Zealand in this period. These were mostly people who had been previously diagnosed
overseas. 15 were men infected through sex with other men, 13 through heterosexual contact, 1 child was infected through perinatal transmission, and for 10 people the mode of infection was unknown.

AIDS
31 people were notified with AIDS in 2007.
12 were men infected through sex with other men, 17 (12 men and 5 women) were people infected through heterosexual contact, 1 was infected through injecting drug use, and for 1 person the mode of
infection was unknown.

HIV infection

In 2007, 156 people were newly diagnosed with HIV in New Zealand through antibody testing. This is less than the number diagnosed in the previous two years - 177 in 2007 and 183 in 2005, and similar to the overall number diagnosed in 2004 (157). A further 39 people were reported with HIV through viral load testing; mostly people who were previously diagnosed overseas.¹

Figure 1 shows the total annual number, and reported means of infection, of people diagnosed through HIV antibody testing since it first became available in 1985. It must be remembered that these figures relate to people diagnosed in each respective year and that the infection may have occurred many years earlier.

Figure 1 - Number of people diagnosed with HIV in New Zealand through antibody testing by year of diagnosis* and means of infection. (* Infection might have occurred some time before diagnosis.)
¹ Viral load testing has been available in New Zealand since 1996. Only the trends in those diagnosed through antibody testing have been analysed as this has been available for the whole period.

Increase in people receiving care for HIV infection
Since the early 1990s the survival of people with HIV has improved markedly due to advances in antiretroviral therapy. As a result of this, and of more people being diagnosed, there has been a steep increase in the number of people with HIV requiring care.

In 2000, it was estimated that there were 593 people receiving care for HIV in New Zealand (Mills et.al 2002). In 2007, the estimate is 1230, more than doubling in the last seven years. This number is based on information from two sources. Firstly, Pharmac - the agency that advises on and monitors pharmaceutical use in New Zealand – estimates that 985 people received antiretroviral therapy during 2006/7. Secondly, about 80% of HIV-infected people cared for by the Infectious Disease Unit of the Auckland District Health Board are on antiretroviral therapy. If this proportion is representative of the situation nationally, then there were about 1230 infected people receiving medical care at the end of 2007.

This number is considerably less than the 2872 reported as ever being diagnosed with HIV in New Zealand (see Table 1). The main reason for this discrepancy is that 948 people who developed AIDS are known to have died. Other explanations are that some people will have died without developing AIDS (hence these deaths are not known to the AIDS Epidemiology Group), will have gone overseas, or might have opted not to receive medical care.

It is still true that not all people with HIV will have had their infection diagnosed. In the US, Canada and the UK it has been estimated that between 25 and 30% of all infected people are undiagnosed. If the same applies here, there will be about 340 people in New Zealand with undiagnosed HIV. Hence, in total there are probably around 1500 people with HIV in New Zealand.

The combination of improved survival and ongoing new infections means that the prevalence – the proportion of people in the population with HIV - will continue to rise. This in turn could affect the rate of new infections. People who are living with diagnosed HIV must therefore be aware of how they can reduce the risk of infecting others, and encouraged to take such action. As there are also likely to be a considerable number of people with undiagnosed HIV, testing remains very important and everyone should protect themselves from infection in all possible risky situations.

HIV diagnoses among men who had had sex with men (MSM) in 2007
Overall, 71 MSM were diagnosed with HIV through antibody testing in 2007, including three who might have been infected through injecting drug use. This is similar to the numbers diagnosed in 2003 (74), 2004 (75), and 2006 (72), but less than in 2005 (90) which was the highest number of MSM ever diagnosed in one year. Of the 71 MSM diagnosed in 2007, for 53 (75%), the infection was reported to have occurred in New Zealand (Figure 2).

Figure 2 - Place of infection of MSM
diagnosed by antibody test, by year
of diagnosis

Of these 53, at least half (26) were infected in the previous 5 years, and at least 7 in the last 12 months. This information is on the basis of reports of timing of previous negative tests and shows evidence of continuing transmission among men who have sex with men in this country.

The average age of these 53 men was 41 years, with most, 22 (38%), in the 40-49 year age group. Nevertheless, there was a wide range with 15% aged less than 30 years old, and 15% aged 50 years or more. Most of these men (72%) were of European ethnicity, with 19% Māori, 7% Asian and 2% African. The majority (87%) were living in the North Island (mainly in the Auckland region).

The majority (66%) of European men were over the age of 40 compared with 20% of Maori men in this age group.

It is of concern that the number of MSM being diagnosed with HIV in New Zealand has not fallen. HIV remains a threat to this group and risk is not confined to any particular age or ethnic group.

HIV diagnoses among people heterosexually infected in 2007
In 2007 a total of 60 people (31 men and 29 women) were diagnosed with heterosexually acquired infection, This is a reduction in numbers from the previous three years due to a decrease in the number of diagnoses among people heterosexually infected overseas (Figure 3).

There has, however, been a small but steady rise in the number of people infected heterosexually in New Zealand – 16 in 2007 compared with 11 in 2006 and 8 in 2005.

Of these 16 people (5 men and 11 women) infected in New Zealand, almost half were infected by a partner who had been heterosexually infected overseas. The remainder were infected by a partner who had been infected through homosexual contact, injecting drug use or the means of infection of the partner was not reported or unclear.

Figure 3 - Place of infection of those
infected through heterosexual contact,
diagnosed by antibody test,
by year of diagnosis

Children infected through mother to child transmission
Eight children were diagnosed in 2007 with HIV that had been acquired through mother to child transmission, though all but one were born in earlier years (Figure 4). Five were born overseas and three were born in New Zealand to mothers whose HIV was not diagnosed prior to the child’s birth.

Figure 4 -
Number of children
diagnosed with
mother to child
transmission in
New Zealand, by year of birth

AIDS

Trends in AIDS notifications and deaths
Figure 5 shows the annual number of notifications of AIDS by year of diagnosis and the number of deaths of people notified.

A total of 31 people were notified with AIDS in 2007 of whom 13 were diagnosed with HIV in the previous three months. Twelve were men infected through sex with other men, one person was infected through injecting drug use, 17 were people infected through heterosexual contact and for one person the mode of infection was unknown. Fifteen were of European ethnicity, 5 Māori, 1 Pacific person, 6 Africans and 4 Asians. The average age of those notified in 2007 was 41 years.

The effectiveness of treatment for HIV is seen in the decrease in the number of people being diagnosed and dying from AIDS (Figure 5). In 1995, of the 64 people diagnosed with AIDS, 62% died within the following two years compared with 20% of the 25 people diagnosed with AIDS in 2000 and 23% of the 35 people diagnosed with AIDS in 2005.

Figure 5 - Annual number of
diagnoses of AIDS and deaths
among people notified with AIDS.
(The number of notifications and deaths for 2007 might rise due to
delayed reports)

Table 1. Exposure category by time of diagnosis for those found to be infected with HIV by antibody test and first viral load test. (A small number of transsexuals are included with the males).

		HIV Infection*
		1985-1999		2000-2004		2005-2006		2007		Total
Exposure	Sex	No.	%	No.	%	No.	%	No.	%	No.	%
Homosexual contact	Male	907	59.4	346	47.5	199	47.2	83	42.6	1535	53.4
Homosexual & IDU	Male	20	1.3	12	1.6	4	0.9	3	1.5	39	1.3
Heterosexual contact	Male Female	120 128	7.9 8.4	130 141	17.8 19.3	81 90	19.2 21.3	37 36	19.0 18.5	368 395	12.8 13.7
Injecting drug use (IDU)	Male Female	36 10	2.4 0.6	19 1	2.6 0.1	1 0	0.2 0.0	1 0	0.5 0.0	57 11	2.0 0.4
Blood product recipient	Male	34	2.2	0	0.0	0	0.0	0	0.0	34	1.2
Transfusion recipient§	Male Female NS	6 6 5	0.4 0.4 0.3	3 3 0	0.4 0.4 0.0	1 0 0	0.2 0.0 0.0	1 0 0	0.5 0.0 0.0	11 9 5	0.4 0.3 0.2
Perinatal	Male Female	6 4	0.4 0.3	10 10	1.4 1.4	7 1	1.7 0.2	5 3	2.6 1.5	28 18	1.0 0.6
Other	Male Female	3 4	0.2 0.3	1 3	0.1 0.4	2 2	0.4 0.4	1 0	0.5 0.0	7 9	0.2 0.3
Awaiting information/undetermined	Male Female NS	205 19 13	13.4 1.2 0.8	44 6 0	6.0 0.8 0.0	24 10 0	5.7 2.4 0.0	20 5 0	10.2 2.6 0.0	293 40 13	10.2 1.4 0.4
Total		1526	100.0	729	100.0	422	100.0	195	100.0	2872	100.0

* Includes people who have developed AIDS. HIV numbers are recorded by time of diagnosis for those reported through antibody testing and by time of first viral load for those reported through viral load testing. The latter include many who have initially been diagnosed overseas and not had an antibody test here. The date of initial diagnosis may have preceded the viral load date by months or years.
NS = Not stated
§ All people in this category, diagnosed since 1996, acquired overseas

Table 2. Ethnicity‡ by time of diagnosis in New Zealand for those found to be infected with HIV by
antibody test and first viral load test. (A small number of transsexuals are included with the males).

		HIV Infection*
		1996-1999		2000-2004		2005-2006		2007		Total
Ethnicity	Sex	No.	%	No.	%	No.	%	No.	%	No.	%
European/Pakeha	Male Female	257 25	53.5 5.2	337 30	46.4 4.1	170 14	40.3 3.3	76 7	39.0 3.6	840 76	46.0 4.2
Māori `†`	Male Female	29 4	6.0 0.8	41 5	5.6 0.7	24 4	5.7 0.9	21 1	10.8 0.5	115 14	6.3 0.8
Pacific Island	Male Female	4 4	0.8 0.8	19 10	2.6 1.4	13 3	3.1 0.7	3 4	1.5 2.0	39 21	2.1 1.1
African	Male Female	55 33	11.4 6.9	70 85	9.6 11.6	58 57	13.7 13.5	18 24	9.2 12.3	201 199	11.0 10.9
Asian	Male Female	32 16	6.7 3.3	69 32	9.5 4.4	36 15	8.5 3.6	16 4	8.2 2.0	153 67	8.4 3.7
Other	Male Female	7 0	1.4 0.0	16 2	2.2 0.3	10 5	2.4 1.2	6 2	3.1 1.0	39 9	2.1 0.5
Undetermined	Male Female	13 1	2.7 0.2	13 0	1.8 0.0	8 5	1.9 1.2	11 2	5.6 1.0	45 8	2.5 0.4
Total		480	100.0	729	100.0	422	100.0	195	100.0	1826	100.0

* Includes people who have developed AIDS. HIV numbers are recorded by time of diagnosis for those reported through antibody testing and by time of first viral load for those reported through viral load testing. The latter include many who have initially been diagnosed overseas and not had an antibody test here. The date of initial diagnosis may have preceded the viral load date by months or years.
‡ Information on ethnicity of people diagnosed with HIV only collected since 1996
† Includes people who belong to Māori and another ethnic group

The AIDS Epidemiology Group now has a website!

The site contains a variety of information including:

* AIDS-New Zealand newsletters

* Surveillance of HIV and AIDS

* AEG members

* AIDS notification forms

www.otago.ac.nz/aidsepigroup

For further information about the occurrence of HIV/AIDS in New Zealand contact
Sue McAllister, AIDS Epidemiology Group,
Department of Preventive and Social Medicine,
University of Otago Medical School,
PO Box 913, Dunedin, New Zealand.
Website address: www.otago.ac.nz/aidsepigroup
Phone: (03) 479 7220, Fax: (03) 479 7298, or Email aidsepigroup@otago.ac.nz

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