Reinfection by untreated partners of people treated for Chlamydia trachomatis and Neisseria gonorrhoeae: mathematical modelling study.
OBJECTIVE
Reinfection after treatment for Chlamydia trachomatis or Neisseria gonorrhoeae reduces the effect of control interventions. We explored the impact of delays in treatment of current partners on the expected probability of reinfection of index cases using a mathematical model.


METHODS
We used previously reported parameter distributions to calculate the probability that index cases would be reinfected by their untreated partners. We then assumed different delays between index case and partner treatment to calculate the probabilities of reinfection.


RESULTS
In the absence of partner treatment, the medians of the expected reinfection probabilities are 19.4% (IQR 9.2-31.6%) for C trachomatis and 12.5% (IQR 5.6-22.2%) for N gonorrhoeae. If all current partners receive treatment 3 days after the index case, the expected reinfection probabilities are 4.2% (IQR 2.1-6.9%) for C trachomatis and 5.5% (IQR 2.6-9.5%) for N gonorrhoeae.


CONCLUSIONS
Quicker partner referral and treatment can substantially reduce reinfection rates for C trachomatis and N gonorrhoeae by untreated partners. The formula we used to calculate reinfection rates can be used to inform the design of randomised controlled trials of novel partner notification technologies like accelerated partner therapy.
Institute of Social and Preventive Medicine (ISPM), University of Bern, , Bern, Switzerland.
Nicola
N
Low
Janneke Cornelia Maria
JC
Heijne
Sereina Annik
SA
Herzog
Christian Lorenz
CL
Althaus
D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D016358:Contact Tracing; D005260:Female; D006069:Gonorrhea / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification*; D012017:Referral and Consultation; D012747:Sexual Partners; D013997:Time Factors
CHLAMYDIA TRACHOMATIS; MATHEMATICAL MODEL; NEISSERIA GONORRHOEA; PARTNER NOTIFICATION