Sexually Transmitted Infections in New Zealand: Annual Surveillance Report 2012

Thursday 24th October 2019


Summary of sexually transmitted infections in New Zealand in 2012

In New Zealand, sexually transmitted infections (STIs) are not notifiable. Surveillance efforts are based on the voluntary provision of data from sexual health clinics (SHCs), family planning clinics (FPCs and laboratories. Population and disease coverage therefore varies with the data source.

This report summarises the surveillance information for STIs in 2012 and examines trends over time. The following STIs are reported: chlamydia, gonorrhoea, genital herpes, genital warts, syphilis, non-specific urethritis (NSU), chancroid, granuloma inguinale (GI) and lymphogranuloma venereum (LGV).

With the increasing participation of diagnostic laboratories around New Zealand, laboratory information has become the best indicator of disease incidence for chlamydia and gonorrhoea in most District Health Boards (DHBs). Laboratories receive specimens from all health providers. In 2012, it was estimated that laboratory surveillance reported approximately five and a half-times the number of chlamydia cases and almost five times the number of gonorrhoea cases reported by clinic surveillance.

SHCs also provide important information about the epidemiology of STIs. This is because many STIs are diagnosed clinically rather than via laboratory testing (either because laboratory testing is not routinely undertaken for that STI or is insufficient by itself to make the diagnosis).  In addition, clinics are currently the only source of information on the distribution of STIs by ethnicity. However, the number of cases reported through the clinic-based surveillance system underestimates the true burden of STI disease because a substantial percentage of STIs are diagnosed by other health care providers, particularly primary health care practitioners.

Since 2009, individual DHB and estimated national rates of chlamydia and gonorrhoea have been calculated from laboratory surveillance data. In 2012, DHB rates were not calculated for a number of DHBs (5 for chlamydia and 3 for gonorrhoea) due to lack of data.

Chlamydia was the most commonly reported STI in 2012, in both laboratory and clinic settings. A national estimated chlamydia rate (based on 15 DHBs) of 744 per 100 000 population was calculated from laboratory surveillance data. Seventy percent of cases reported through laboratory surveillance data in 2012 were aged between 15 and 24 years. There were 94 cases of chlamydia in infants.
In data derived from SHCs, over 50% of cases were from non-European ethnic groups (Māori, Pacific Peoples and Other). Of the 15 DHBs meeting the laboratory selection criteria for analysis in 2012, Tairawhiti, Lakes and Hawke’s Bay DHBs reported the highest chlamydia rates.
Laboratory surveillance data showed the estimated national rate of chlamydia (based on 15 DHBs) was stable between 2009 and 2011 but decreased in 2012.

In 2012, a national gonorrhoea rate (based on 17 DHBs) of 89 per 100 000 population was estimated from laboratory surveillance data. Over 60% of cases reported by laboratories were aged between 15 and 24 years and two cases of gonorrhoea in infants were reported. In SHCs, over 60% of cases were from non-European ethnic groups (Māori, Pacific Peoples and Other ethnic groups). Of the 17 DHBs meeting the laboratory selection criteria for analysis in 2012, Tairawhiti DHB reported the highest gonorrhoea rate – over four times the estimated national rate.

The introduction of testing via nucleic acid amplification tests (NAAT) for gonorrhoea in many regions during 2011 and 2012 impacted on gonorrhoea case numbers. The previously stable estimated national rate increased by about a third in 2012 (based on laboratory data from 17 DHBs).

The number of cases of syphilis reported by SHCs again decreased, from 83 cases in 2011 to 80 cases in 2012. No cases were reported by FPCs. The SHC cases were predominantly male (93.8%) and occurred most commonly in the 40 years and over age group. Seventy two percent of the cases were from the European ethnic group, 13.3% from the Māori ethnic group and 13.3% from the Other ethnic group. Syphilis cases were predominantly reported from clinics in the Auckland region and Canterbury DHB
Other STIs

From 2011 to 2012, SHCs reported a decrease in case counts of genital herpes and genital warts (by 5.4% and 10.5% respectively) and an increase in non-specific urethritis (NSU) case counts (8.1%). The four-year trend showed a decrease across all of these STIs (5.0%, 32.3% and 11.2% respectively).

No cases of chancroid, granuloma inguinale and lymphogranuloma venereum were reported in 2012.

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Report:

STIs in NZ: Annual Surveillance Report 2012

Tables:

SLIDES STIs in NZ: Annual Surveillance 2012

 

DOWNLOADS

STIs in NZ: Annual Surveillance Report 2012

Tables:

SLIDES STIs in NZ: Annual Surveillance 2012

Ph: +64 4 914 0700 Fax: +64 4 914 0770 Email: survqueries@esr.cri.nz