PT  - JOURNAL ARTICLE
AU  - Eline L Korenromp
AU  - Guy Mahiané
AU  - Jane Rowley
AU  - Nico Nagelkerke
AU  - Laith Abu-Raddad
AU  - Francis Ndowa
AU  - Amina El-Kettani
AU  - Houssine El-Rhilani
AU  - Philippe Mayaud
AU  - R Matthew Chico
AU  - Carel Pretorius
AU  - Kendall Hecht
AU  - Teodora Wi
TI  - Estimating prevalence trends in adult gonorrhoea and syphilis in low- and middle-income countries with the Spectrum-STI model: results for Zimbabwe and Morocco from 1995 to 2016
AID  - 10.1136/sextrans-2016-052953
DP  - 2017 Dec 01
TA  - Sexually Transmitted Infections
PG  - 599--606
VI  - 93
IP  - 8
4099  - http://sti.bmj.com/content/93/8/599.short
4100  - http://sti.bmj.com/content/93/8/599.full
SO  - Sex Transm Infect2017 Dec 01; 93
AB  - Objective To develop a tool for estimating national trends in adult prevalence of sexually transmitted infections by low- and middle-income countries, using standardised, routinely collected programme indicator data.Methods The Spectrum-STI model fits time trends in the prevalence of active syphilis through logistic regression on prevalence data from antenatal clinic-based surveys, routine antenatal screening and general population surveys where available, weighting data by their national coverage and representativeness. Gonorrhoea prevalence was fitted as a moving average on population surveys (from the country, neighbouring countries and historic regional estimates), with trends informed additionally by urethral discharge case reports, where these were considered to have reasonably stable completeness. Prevalence data were adjusted for diagnostic test performance, high-risk populations not sampled, urban/rural and male/female prevalence ratios, using WHO's assumptions from latest global and regional-level estimations. Uncertainty intervals were obtained by bootstrap resampling.Results Estimated syphilis prevalence (in men and women) declined from 1.9% (95% CI 1.1% to 3.4%) in 2000 to 1.5% (1.3% to 1.8%) in 2016 in Zimbabwe, and from 1.5% (0.76% to 1.9%) to 0.55% (0.30% to 0.93%) in Morocco. At these time points, gonorrhoea estimates for women aged 15–49 years were 2.5% (95% CI 1.1% to 4.6%) and 3.8% (1.8% to 6.7%) in Zimbabwe; and 0.6% (0.3% to 1.1%) and 0.36% (0.1% to 1.0%) in Morocco, with male gonorrhoea prevalences 14% lower than female prevalence.Conclusions This epidemiological framework facilitates data review, validation and strategic analysis, prioritisation of data collection needs and surveillance strengthening by national experts. We estimated ongoing syphilis declines in both Zimbabwe and Morocco. For gonorrhoea, time trends were less certain, lacking recent population-based surveys.