Related Experiment Video
Updated: Jan 6, 2026

Prediction of HIV-1 Coreceptor Usage Tropism by Sequence Analysis using a Genotypic Approach
Published on: December 1, 2011
Factors associated with the informal use of HIV pre-exposure prophylaxis in Germany: a cross-sectional study
Uwe Koppe1, Ulrich Marcus1, Stefan Albrecht2
1Department of Infectious Disease Epidemiology, Robert Koch-Institute, Berlin, Germany.
Introduction:
Until September 2019, pre-exposure prophylaxis (PrEP) with tenofovir disoproxil/emtricitabine for HIV prevention was not covered by health insurance plans in Germany, and was only available through private prescriptions with self-pay or through informal non-prescription sources. The objective of this study was to investigate the proportion of informal PrEP use among PrEP users and to identify factors of public health relevance that might be associated with informal PrEP use.
Methods:
We conducted a cross-sectional study recruiting PrEP users independent of their PrEP source. Clients from anonymous community testing checkpoints, users of three dating apps for men who have sex with men residing in Germany and users of a PrEP community website, were recruited to complete a short anonymous online survey. Participants were recruited between 24 July and 3 September 2018. The results were analysed using univariable and multivariable logistic regressions.
Results:
We recruited 2005 participants currently using PrEP. The median age was 38 years, and 80.3% of the participants identified themselves as male (missing: 19.1%). Overall, 71.6% obtained PrEP through medical services with a private prescription or a clinical trial, and 17.4% obtained PrEP through informal sources (missing: 11.0%). The most common informal sources were ordering online from another country (8.8%), travel abroad (3.6%), and friends (2.5%). Factors associated with informal PrEP use were on demand/intermittent dosing (adjusted OR: 3.5, 95% CI 2.5 to 5.0) and not receiving medical tests during PrEP use (adjusted OR: 3.2, 95% CI 2.0 to 5.2). In addition, informal PrEP users who did not take PrEP daily had a strongly increased risk of starting PrEP without prior medical tests (adjusted stratum-specific OR = 31.7, 95% CI 4.6 to 219.5).
Conclusions:
Informal PrEP use was associated with a higher risk of not getting tested before and during PrEP use, which could lead to HIV infections resistant to tenofovir and emtricitabine if people with undiagnosed HIV use PrEP. Health insurance plans that cover PrEP and the accompanying routine tests could ensure adequate medical supervision of PrEP users and reduce barriers to PrEP use. Our findings strongly support the implementation of PrEP programmes in countries with similar patterns of informal PrEP use.
Related Concept Videos
Factors Affecting the Risk of Infection
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...
Sexually Transmitted Infections
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health...
Factors Affecting Illness
For instance, risk factors are connected to illness,...
Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
Factors Affecting Protein-Drug Binding: Patient-Related Factors
Age stands as a key determinant in protein-drug binding. Neonates, characterized by low albumin content, experience heightened concentrations of unbound drugs such as phenytoin and...

