Sexually Transmitted Infections in New Zealand: Annual Surveillance Report 2013

Sunday 20th August 2017


Summary of sexually transmitted infections in New Zealand in 2013

In New Zealand, sexually transmitted infections (STIs) with the exception of AIDs 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 surveillance therefore varies with the data source.

This report summarises the surveillance information for STIs in 2013 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 2013, it was estimated that laboratory surveillance reported approximately three and a half-times the number of chlamydia cases and about three 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). 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 2013, DHB rates were calculated for all DHBs (except Northland for Gonorrhoea) from laboratory surveillance data.

Chlamydia was the most commonly reported STI in 2013, in both laboratory and clinic settings. A national estimated chlamydia rate (based on all DHBs) of 633 per 100 000 population was calculated from laboratory surveillance data. Sixty-eight percent of cases reported through laboratory surveillance data in 2013 were aged between 15 and 24 years. There were 84 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). In data from laboratories, Tairawhiti, Lakes and Hawke’s Bay DHBs reported the highest chlamydia rates.
Laboratory surveillance data showed the estimated national rate of chlamydia (based on all DHBs where data was available) was stable between 2009 and 2011 but has decreased since 2012.

In 2013, a national gonorrhoea rate (based on 19 DHBs) of 78 per 100 000 population was estimated from laboratory surveillance data. Over 50% 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 19 DHBs meeting the laboratory selection criteria for analysis in 2013, Tairawhiti DHB reported the highest gonorrhoea rate, over five times the estimated national rate.
The introduction of testing via nucleic acid amplification tests (NAAT) for gonorrhoea since 2011 may have impacted on gonorrhoea case numbers.

The number of cases of syphilis reported by SHCs remained stable between 2012 and 2013 (80 cases). Three cases were reported by FPCs. The SHC cases were predominantly male (92.5%) and occurred most commonly in the 40 years and over age group. Sixty percent of the cases were from the European ethnic group, 20.5% from the Other ethnic group, 11.0% from the Pacific Peoples ethnic group and 8.2% from the Māori ethnic group. Syphilis cases were predominantly reported from clinics in the Auckland region and Canterbury DHB.

From 2012 to 2013, SHCs reported an increase in case counts of genital herpes and NSU (by 3.0% and 15.2% respectively) and a decrease in case counts of genital warts (16.8%). The five-year trend from 2009 to 2013 showed a decrease in genital herpes and genital warts (2.2% and 43.7% respectively) and an increase in NSU (2.3%).
No cases of chancroid, GI and lymphogranuloma venereum were reported in 2013.

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Report:

STIs in NZ: Annual Surveillance Report 2013

Tables:

SLIDES STIs in NZ: Annual Surveillance 2013

 

DOWNLOADS

STIs in NZ: Annual Surveillance Report 2013

Tables:

SLIDES STIs in NZ: Annual Surveillance 2013

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- Annual Summary of Outbreaks
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- Quarterly STI Clinic Report
- Quarterly STI Lab Report

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