The AIDS Epidemiology Group has a primary role in HIV and AIDS case reporting and the measurement of HIV in sub-populations at risk, and is also actively involved in surveys of behaviour.
It also takes an interest in the surveillance of other sexually transmitted infections (STIs) and blood borne viruses as this provides information that will be relevant to the spread of HIV.
HIV and AIDS reporting
(A) People with AIDS
AIDS is notifiable under the Health Act. A person with HIV infection is considered to have AIDS when they first develop one of a number of conditions generally uncommon in people with normal immunity, as outlined in the Ministry of Health Management Guidelines. A CD4 count of less than 200 cells per cubic millimeter of blood, that is used in the US as a criterion for AIDS is not used in New Zealand, nor most other countries.
Attending medical practitioners must initially notify all cases of AIDS to the local Medical Officer of Health, using non-identifiable data, in the initial notification form that can be found on the Public Health Surveillance website administered by ESR (the Institute of Environmental Science and Research).
Entry of this information into EpiSurv by the local public health service will automatically result in the AIDS Epidemiology Group (AEG) receiving access to the information, and in the creation of a web-based detailed notification form. The AEG will send a link to this form to the health provider who notified the case, for the health provider to complete online.
The AEG makes confidential quarterly reports to the Ministry of Health and Medical Officers of Health. It produces the AIDS – New Zealand newsletter annually and disseminates it widely, to stakeholders and the public.
(B) People diagnosed with HIV infection
Since antibody testing for HIV first became available in New Zealand in 1985, information on the number of people newly diagnosed with HIV – and when available their age, sex, and likely means of infection – has been collected by the two laboratories, Auckland Hospital Virus Laboratory and The Institute of Environmental Science and Research Limited, Porirua (ESR), that perform the confirmatory Western Blot HIV antibody test.
Since 1996, the AEG has carried out enhanced surveillance of HIV whereby further information is sought from the clinicians who requested the test. The additional information requested includes the reason for the test, the infected person’s ethnic group, district of usual residence, likely country of infection, and whether – and if so when – they had previously had a negative HIV test. For people heterosexually infected information on the partner’s risk is sought.
Such information is again collected using a code not the patient’s name.
From the beginning of 2002, information has also been received from the four New Zealand laboratories (Auckland, Hamilton, Wellington, and Christchurch) performing viral load tests on the codes of people who are having a viral load test for the first time. If – from the coded information – it appears that a person having a viral load test has not been recorded by the AEG as having a positive HIV antibody test, information is sought from the clinicians who requested the test. This is to gain information on people who are being cared for HIV infection but have not had an HIV test in this country.
Since the beginning of 2017, HIV is classified as a notifiable condition. New laboratory diagnoses are notified to the local Medical Officer of Health via the secure web-based EpiSurv portal, administered by ESR (the Institute of Environmental Science and Research) using non-identifiable data. Acceptance of the incoming e-notification by the local public health service will automatically result in the AIDS Epidemiology Group (AEG) receiving access to the information, and in creation of a web-based notification form. The AEG will send the health provider who ordered the laboratory test a link to this form for the health provider to complete online.
Information is held in conditions of strict confidence. No information on identifiable individuals is ever released. Before any information is published care is taken to ensure that identity of individuals cannot be deduced.
As with AIDS notifications, the AEG provides quarterly reports of people diagnosed with HIV to the Ministry of Health and publishes these data twice a year in AIDS – New Zealand. It is important to appreciate that these data relate to people diagnosed with HIV which will not provide a total measure of people living with HIV as some infected people will remain undiagnosed.
HIV surveillance in sub-populations at risk
(A) Men who have sex with men
Gay Auckland Periodic Sex Surveys (GAPSS)
Behavioural surveillance in New Zealand has been largely carried out through regular Gay Auckland Periodic Sex Surveys (GAPSS) – a joint project between the AIDS Epidemiology Group and the New Zealand AIDS Foundation. GAPSS has been undertaken three times (2002, 2004, and 2006) as part of a regular biannual behavioural programme on HIV risk practices among men who have sex with men.
The project included an online version of the study for the first time in 2006.
Copies of these reports can be found on the New Zealand AIDS Foundation website:
- GAPSS and GOSS 2011 – Basic frequencies report (PDF)
- GAPSS and GOSS 2011 – Condom use research brief (PDF)
- GAPSS and GOSS 2011 – Get it On! recall research brief (PDF)
- GAPSS and GOSS 2011 – Attitudes towards safe sex among men who have sex with men in New Zealand (PDF)
- GAPSS and GOSS 2011 – Characteristics of men who have sex with men surveyed in sex-on-site venues in New Zealand (PDF)
- GAPSS 2008 – Findings from the Gay Auckland Periodic Sex Survey (PDF)
- GAPSS 2006 – Findings from the Gay Auckland Periodic Sex Survey (PDF)
- GAPSS 2004 – Findings from the Gay Auckland Periodic Sex Survey (PDF)
Gay men’s Online Sex Survey (GOSS)
In 2006 and 2008, around the time the GAPSS surveys were being run, equivalent Gay Men’s Online Sex Surveys (GOSS), that recruited men who have sex with men (MSM) using the internet, were undertaken.
Unrecognised HIV infection in a community sample of homosexual men (Get it Wet study)
For the first time in 2011, men who were recruited for the GAPSS survey were invited to provide an oral fluid sample that was tested for HIV antibodies. While the participants remain anonymous, linking this to their responses to the questionnaire, will establish the number of MSM with both diagnosed and undiagnosed HIV.
Behavioural disinhibition and HIV and STI risk at international gay sporting events (SSSS study)
In conjunction with La Trobe University in Melbourne, a survey of the sexual behaviour of MSM attending the Gay Games in Wellington in early 2011 was undertaken to explore behavioural disinhibition at such events.
(B) Antenatal HIV surveillance and evaluation
The Universal Routine Offer HIV Antenatal Screening Programme commenced in the Waikato District Health Board in 2006 and has been progressively rolled-out to other District Health Boards (DHB) throughout the country.
The AIDS Epidemiology Group has been contracted by the National Screening Unit (NSU) to evaluate the impact of non-negative results in women who require repeat sampling for evaluation of their HIV status. This aspect of the evaluation of the Programme is based on a report written by the AEG, in which the potential for false positive tests causing harm to the affected women was recognised.
(C) International Collaborative Indigenous Health Research Partnership
Dr Nigel Dickson, is a member of an international team that was successful in gaining funding for a five year research into the role of resiliency in responding to blood borne viral and sexually transmitted infections in indigenous communities. This is a joint project between Australia, Canada, and New Zealand. The New Zealand arm is being led by Dr Clive Aspin, of Nga Pae o te Maramatanga, of the University of Auckland.