Recent infections among newly diagnosed cases of HIV infection in Spain, 2015–2016. National estimates using cohort data

Abstract

Background

To estimate the prevalence of recent infection (RI) among people newly diagnosed with HIV in Spain using a representative sample collected by the AIDS Research Network cohort (CoRIS) during 2015–2016.

Methods

Stratified sampling of CoRIS data was used with proportional allocation by mode of transmission of new HIV diagnoses notified to National Surveillance System. Samples used were from patients in the CoRIS cohort with available stored plasma collected within 6 months after diagnosis. Weighted methods were used to estimate the prevalence of RI and multivariate logistic regression models were used to determine associated factors.

Results

Of the 669 individuals included, 55.1% were men who had sex with men (MSM), 24.6% were heterosexual, and 20.3% were non-MSM non-heterosexual. The weighted prevalence of RI was 11.8% (95% Confidence interval [CI] 9.4–14.8%) overall, 15.5% (12.2–19.4%) among MSM, 6.3% (3.9–10.0%) among heterosexual, and 8.6% (3.2–20.9%) in non-MSM non-heterosexual persons. Factors associated with prevalence of RI were: MSM (OR 2.05; 95% CI 1.02–4.14) vs. heterosexual, being Spanish (OR 2.92; 1.36–6.26) or European (OR 3.42; 1.28–9.13) vs. Latin American, having a secondary or higher education level (OR 3.08; 0.95–1.00) vs. primary, and having a CD4 count of 350–499 (OR 3.26; 1.46–7.30) or >500 (OR 6.26; 2.92–13.39) vs. <350 cells/mm³.

Conclusions

In the absence of direct data from surveillance systems, the use of cohort data is a very valuable option for identifying the prevalence of RI at national level. This is the first nationwide study carried out in Spain to determine the prevalence of RI using an avidity assay.

Keywords:

• HIV
• recent infection
• surveillance
• cohort study

Acknowledgements

This study would not have been possible without the collaboration of the patients, medical and nursing staff, and data managers who have taken part in the project. We are particularly grateful to the patients for their participation in the study and the HIV Biobank integrated in the Spanish AIDS Research Network and collaborating centres for the generous gift of clinical samples used in this work.

Disclosure statement

IJ has received teaching fees from ViiV Healthcare. All other authors declare that they have no competing interests.

VH and AD designed the study. MTC and MPO performed the laboratory analysis and interpreted the test results. All authors and CoRIS contributors listed in the Appendix were involved in data and blood sample collection. VH and AD performed the statistical analysis. VH, MTC, MPO, IJ, and AD reviewed the different versions of the manuscript. All the authors were involved in the design of the study, reviewed the manuscript for important intellectual content, and contributed to the final version of the manuscript. All the authors have read and approved the final draft.

Additional information

Funding

This work was supported by the Institute of Health Carlos III through the Spanish AIDS Research Network. The HIV BioBank [Grant nos. RD06/0006/0035, RD12/0017/0037 and RD16/0025/0019] and the CoRIS cohort [RD06/006, RD12/0017/0018 and RD16/0002/0006] are integrated in the Spanish AIDS Research Network, as part of the Plan Nacional I + D + i and cofinanced by ISCIII-Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER).