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Original research
Prevalence of and risk factors for curable sexually transmitted infections on Bubaque Island, Guinea Bissau
  1. Giovanna Cowley1,
  2. Gregory Milne2,
  3. Eunice Teixeira da Silva3,
  4. Jose Nakutum4,
  5. Amabelia Rodrigues5,
  6. Hristina Vasileva1,
  7. David Mabey6,
  8. Bart Versteeg6,
  9. Anna Last6
  1. 1 London School of Hygiene and Tropical Medicine, London, UK
  2. 2 Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK
  3. 3 Simao Mendes Hospital, Bissau, Guinea-Bissau
  4. 4 Hospital Regional de Bubaque Marcelino Banca, Bubaque, Guinea-Bissau
  5. 5 National Institute of Public Health, Guinea Bissau, Bissau, Guinea-Bissau
  6. 6 Clinical Research, London School of Hygiene and Tropical Medicine, London, UK
  1. Correspondence to Dr Giovanna Cowley, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK; giovanna.cowley{at}


Objectives Complications from sexually transmitted infections (STIs) can result in severe morbidity and mortality. To date, no STI population studies have been conducted on the Bijagos Islands, Guinea Bissau. Our objective was to estimate the prevalence of and identify risk factors for Chlamydia trachomatis (Ct), Neisseria gonorrhoea (Ng), Mycoplasma genitalium (Mg), Trichomonas vaginalis (Tv) and Treponema pallidum (Tp) on Bubaque, the most populated island.

Methods A cross-sectional survey was conducted on the island of Bubaque among people aged 16–49 years. Participants were asked to answer a questionnaire on STI risk factors, to provide urine samples (men and women) and vaginal swabs (women) for PCR testing for Ct, Ng, Mg and Tv, and to provide dry blood spots for Tp particle agglutination assays. Data were analysed to estimate the prevalence of STIs and logistic regression was used to identify risk factors.

Results In total, 14.9% of participants were found to have a curable STI, with the highest prevalence being observed for Tv (5.9%) followed by Ct (3.8%), Ng (3.8%), Mg (1.9%) and Tp (0.8%). Significant risk factors for having any STI included being female, younger age and concurrent partnership. Having had a previous STI that was optimally treated was a protective factor.

Conclusions This study demonstrates that there is a considerable burden of STI on the Bijagos Islands, stressing the need for diagnostic testing to facilitate early detection and treatment of these pathogens to stop ongoing transmission. Moreover, these results indicate the need to conduct further research into the STI burden on the Bijagos Islands to help inform and develop a national STI control strategy.

  • epidemiology (general)
  • risk factors
  • genital tract infection
  • Africa

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  • Handling editor Bea Vuylsteke

  • Twitter @GC_Milne

  • Contributors DM and AL were responsible for funding. AL was responsible for concept of study and design. GC, ETDS and JN conducted the survey. Laboratory work was done by GN, HV and BV. GC and GM performed data analysis and GC prepared the manuscript. AL, DM, BV and AR reviewed the manuscript before submission.

  • Funding This work was supported by a Wellcome Trust Institutional Strategic Support Fund (105609/Z/14/Z) grant awarded to Anna Last and an MRC Global Challenges Research Fund (MR/P023843/1) grant awarded to Professor David Mabey.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request. Deidentified participant data is available from Dr Anna Last ( with information on conditions for re-use available on request.