AIDS New ZealandIssue 57 - February 2006
ISSN 1 170-2656

• In 2005, 183 people were diagnosed with HIV through antibody testing in New Zealand, 26 more than in 2004 - a 17% rise.
• 89 men who had had sex with men (MSM) were diagnosed with BIV through antibody testing in 2005, 14more than in 20M-a 19% rise.
• 73 people heterosexually infected were diagnosed with HIV in 2005 - a similar number to 2004.
• In 2005, three quarters of MSM diagnosed were reported to be infected in New Zealand, compared to one in ten of those heterosexually infected.
• There were 6 infants diagnosed with HIV in 2005, acquired through mother to child transmission, 4 of whom were born in New Zealand to women whose HIV was not diagnosed before they gave birth.

HIV infection
In 2005, there were 183 people newIy diagnosed with HIV in New Zealand through antibody testing. This is 26 more than the number diagnosed in 2004, a rise of 17%. A further 35 people were reported with HIV through viral load testing, mostly people who were previously diagnosed overseas. '

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.

HIV diagnoses among men who had hod sex with men (IwSM)
The marked rise in HIV diagnoses among MSM, that has been clearly evident since 2003, continued in 2005.

Overall, 89 MSM were diagnosed with HIV through antibody testing in 2005, including 2 who might have been infected through injecting drug use. This was an increase of 19% from the number diagnosed in 2004.

The increase among MSM is entirely due to an increase in men infected in New Zealand, not overseas (Figure 2 - overleaf).


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 the diagnosis was made.



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

Infection in New Zealand was reported for 66 (74%) of thc MSM diagnosed in 2005.

Of the 66 MSM diagnosed in 2005 and infected in New Zealand, at least 35 were infected in the previous 5 years, and at least 11 of these in the
last 12 months. This information is on the basis of reports of timing of previous negative tests.

The average age of these 66 men was 37 years, with most - 27 (41%) - in the 30-39 year age group. Nevertheless there was a wide range with 23% aged less than 30 years old, and 15% aged 50 years or more.

Most of these men (70%) were of European ethnicity, with 14%, 9% and 5% being of Maori, Asian and Pacific ethicity respectively.

Almost all (94%) were living in the North Island (mainly in the Auckland region).

HIV diagnoses among people heterosexually infected
In 2005, 35 men and 38 women were diagnosed with heterosexually acquired infection. Similar to the numbers in 2004.

As in previous years, in contrast to the data for MSM, the majority - 64 (88%) - of these people were infected overseas, and only 7 (10%) in New Zealand (Figure 3).

In 2005, less than a quarter (21%) of those diagnosed in New Zealand with heterosexually acquired HIV were of European, Maori or Pacific ethnicity.

Over the past 5 years, of the 279 people diagnosed with heterosexually acquired HIV, 40 (14%) - 16 men and 24 women - were reported to have been infected in New Zealand. Of these, 19 (47%) were infected by a parher who had been heterosexually infected overseas, mostly from countries where heterosexual HIV is relatively common. Of the remaining 21, 4 were women infected by partners who had been infected through homosexual contact or injecting drug use. For 17 people 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
Six children were diagnosed in 2005 with HIV that had been acquired through mother to child transmission. Of these, 4 were born in New Zealand, and 2 overseas.

Three of the 4 New Zealand-born children were born in 2005. This already equals the highest number for any one year, even though it is likely to increase due to late diagnosis of infected children.

Figure 4 shows the number of children diagnosed with HIV acquired from an infected mother by place of birth and year of birth (rather than by year of diagnosis).

None of the mothers of the affected children had had their HIV diagnosed prior to giving birth, so they had missed the opportunity to be offered care known to reduce the risk of such transmission. Since 1995, there have been no cases in New Zealand where a mother with HIV diagnosed prior to giving birth has had an infected baby.

These figures reiterate the importance of HIV testing during pregnancy. A policy that all pregnant women be offered - and recommended to have - an HIV test during pregnancy, is currently being implemented by the Ministry of Health.



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

People infected in other ways
While there is no evidence of extensive HIV infection among injecting drug users in New Zealand, over the past 5 years there have been 16 injecting drug users diagnosed. Of these, 6 (37%) were reported to have been infected in New Zealand. This number is still very small compared to the number of people infected with hepatitis C in this population.

In the early years of the epidemic there was a significant number of people infected in New Zealand through the receipt of infected blood products. In recent years, all of the people diagnosed with HIV infection through receipt of blood or blood products had acquired the infection overseas.

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

The levelling of AlDS notifications in the early 1990s was due to a reduction in the incidence of HIV several years earlier. The drop, that has been sustained since 1996, resulted from the effective use of antiretroviral therapy in people with HIV. A similar reduction is seen in many developed countries.

In the early years of the epidemic the rise in numbers of AIDS diagnoses was mirrored by a similar rise in deaths a year or so later, a reflection of the survival of people with AIDS then being around 18 months. In recent years the number of deaths has remained well below the number of AlDS notifications indicating dramatic success in treatment of HIV infection which has allowed prolonged survival in many people with AIDS.

However, frequently infection with HIV is still first recognised at or around the time of AIDS diagnosis - a late stage of HIV infection. While many of these people will still benefit from antiretroviral treatment, earlier diagnosis might have markedly delayed the progress of their infection and reduced their suffering.


Figure 5 Annual number of diagnoses of AlDS and deaths among people notified with AIDS.
(The number of notifications and deaths for 2005 might rise due to delayed reports)

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

		HIV Infection*
		1985-1999		2000-2004		2005		Total
Exposure category	Sex	No.	%	No.	%	No.	%	No.	%
Homosexual contacl	Male	854	55.9	346	47.5	109	50.0	1309	52.9
Homosexual & IDU	Male	19	1.2	12	1.6	2	0.9	33	1.3
Heterosexual contact	Male Female	116 126	7.6 8.2	130 141	17.8 19.3	38 42	17.4 19.3	284 309	11.5 12.5
Injecting drug use (IDU)	Male Female	34 10	2.2 0.6	19 1	2.6 0.1	0 0	0.0 0.0	53 11	2.1 0.4
Blood product recipient	Male	34	2.2	0	0.0	0	0.0	34	1.4
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	0.5 0.0 0.0	10 9 5	0.4 0.4 0.2
Perinatal	Male Female	6 4	0.4 0.3	10 10	1.4 1.4	6 0	2.7 0.0	22 14	0.9 0.6
Other	Male Female	3 4	0.2 0.3	1 3	0.1 0.3	2 2	0.9 0.9	6 9	0.2 0.4
Awaiting information/ undetermined	Male Female NS	266 21 13	17.4 1.4 0.8	44 6 0	6.0 0.8 0.0	12 4 0	5.5 1.8 0.0	322 31 13	13.0 1.2 0.5
TOTAL		1527	100.0	729	100.0	218	100.0	2474	100.0

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. (A small number of transsexuals are included with the males).

		HIV Infection*
		1996-1999		2000-2004		2005		Total
Ethnicity	Sex	No.	%	No.	%	No.	%	No.	%
European/Pakeha	Male Female	257 25	53.4 5.2	337 30	46.4 4.1	92 8	42.2 3.7	686 63	48.0 4.4
Maori**	Male Female	29 4	6.1 0.8	41 5	5.6 0.7	14 1	6.4 0.5	84 10	5.9 0.7
Pacific Island	Male Female	4 4	0.8 0.8	19 10	2.6 1.4	7 1	3.2 0.5	30 15	2.1 1.0
Other	Male Female	94 49	19.6 10.3	155 119	21.1 16.3	52 37	23.8 17.0	301 205	21.1 14.4
Awaiting information/ undetermined	Male Female	13 1	2.7 0.2	13 0	1.8 0.0	5 1	2.3 0.5	31 2	2.2 0.1
TOTAL		480	100.0	729	100.0	218	100.0	1427	100.0

* lncludes people who havc 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 collectcd since 1996
** Includes people who belong to Maori and another ethnic group

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' Viral Ioad 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 wholc period.

For further information about the occurrence of HIVIAIDS in New Zealand contact:

Sue McAllister
AIDS Epidemiology Group
Department of Preventive and Social Medicine
University of Otago Medical School
PO Box 91 3
Dunedin
New Zealand

Phone: (03) 479 7220
Fax: (03) 479 7298
EmaiI sue.mcallister@stonebow.otago.ac.nz

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