Carel Hooykaas

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OBJECTIVE To assess prevalence, incidence and potential risk factors of human papillomavirus (HPV) infection among heterosexual men and women with multiple partners and to identify niches of HPV-infection. DESIGN A prospective study of heterosexual men and women with multiple partners attending an STD clinic as participants in a study on HIV from May 1988(More)
This study investigates the perceived risk of an HIV infection. Cognitive antecedents of biases in risk perception and their effects on behavioral intentions were investigated. The purpose of this study was to determine the relative accuracy of risk assessments for samples that vary in actual risk for AIDS. Subjects were citizens of Amsterdam, heterosexuals(More)
BACKGROUND AND OBJECTIVES The incidence of four STDs that are mainly transmitted during vaginal intercourse, and risk factors for acquisition during follow-up were studied in a cohort of heterosexuals with multiple partners in Amsterdam, the Netherlands. These heterosexuals with > or = 5 different sexual partners in the preceding 6 months were recruited(More)
To study the prevalence of HIV and other sexually transmitted diseases (STDs), sexual behaviour and condom use among heterosexuals, 193 women and 157 men entered a longitudinal study. Participants were recruited through an STD clinic, and had had five or more heterosexual partners in the preceding 6 months but had no other AIDS risk factors. Participants(More)
In the course of a prospective study of the prevalence and incidence of infection with the human immunodeficiency virus (HIV) and risk factors for the acquired immune deficiency syndrome among 961 homosexual men, 97 initially HIV antibody seronegative men reported a febrile period lasting at least three days. In 60 of these men serological evidence for an(More)
To determine the heterosexual spread of human T-cell leukemia virus (HTLV-I) infections, a cohort of 472 individuals with more than 5 heterosexual partners in the 6 months before entry was studied. They were recruited from visitors to the Clinic for Sexually Transmitted Diseases of the Municipal Health Service. Half of the study group was born in the(More)
A study among heterosexual men and women with multiple sexual partners was carried out to assess the seroprevalence of antibody against hepatitis C virus (HCV). The 468 participants were recruited among visitors to the Clinic for Sexually Transmitted Diseases in Amsterdam. Sera were tested by an enzyme-linked immunosorbent assay (ELISA; Ortho), a(More)
To study changes in sexual behaviour, heterosexuals with multiple sexual partners were recruited through an STD-clinic and asked to return every 4 months for follow-up. Between October 1987 and June 1989, 512 heterosexuals entered the study and 140 men and 200 women had at least one follow-up visit. No changes were found between 3 visits in the kind of(More)
The aim of the study was to assess prevalence and incidence of hepatitis B virus (HBV) infection among heterosexual men and women with multiple partners attending a sexually transmitted disease (STD) clinic and to establish risk factors of HBV infection in order to consider immunisation for those subjects. A prospective study of heterosexual men and women(More)