Molecular epidemiology of hepatitis B virus in Amsterdam 1992-1997.

To gain insight into the spread of hepatitis B among various risk groups in Amsterdam a 6-year (1992-1997) retrospective DNA sequencing study was carried out on isolates from stored sera from reported primary cases of acute hepatitis B infection. Cases were classified according to risk behavior, as determined in interviews. Of the available serum, a selected region of hepatitis B-virus-DNA was amplified and sequenced.

Evaluation of the hepatitis B antenatal screening and neonatal immunization program in Amsterdam, 1993-1998.

In the enhanced antenatal hepatitis B screening and neonatal immunization program in Amsterdam, 691 hepatitis B surface antigen (HBsAg) positive expectant mothers were reported in the period 1993-1998. The coverage of the screening was calculated at 97%. HBsAg-prevalence was high in women from Ghana and South-East Asia, and lowest in Dutch women.

A survey of liver pathology in needle biopsies from HBsAg and anti-HBe positive individuals.

Aims: To use laboratory data and liver biopsies, prospectively obtained from hepatitis B surface antigen (HBsAg) and anti hepatitis B e antigen (anti-HBe) positive patients, for the assessment of: (1) the relation between biopsy length/number of portal tracts and sampling error; (2) the relation between the severity of piecemeal necrosis and the new grading terminology (minimal, mild, moderate, and severe chronic hepatitis); and (3) liver pathology, which has not been studied in patients with this specific serological profile.

Methods: The study group (n = 174) included 104 patients with normal aminotransferase concentrations and no cases with clinically apparent cirrhosis. The specimen length and number of portal tracts were measured at light microscopy examination.

[Tinea capitis in primary school age children in southeastern Amsterdam: primarily due to Trichophyton tonsurans].

Objective: To establish prevalence and aetiology of tinea capitis in children attending primary school in Amsterdam South-East.

Design: Prevalence survey.

Methods: The Municipal Health Service Amsterdam, the Netherlands, selected classes of four primary schools in a survey with children clinically suspected of having tinea capitis as well as classes without clinical cases.

[Accidental exposure to blood and the risk of transmission of virus infections for various occupational groups in Amsterdam, 1986-1996].

Since 1986 the number of parenteral exposures to potentially infectious blood reported to the Amsterdam Public Health Service increases every year. The number of needlestick accidents increased significantly from 64 in 1986 to 166 in 1996 whereas the number of other exposures decreased from 59 to 44 in these years. The increase was mainly seen in nonhospital based (para)medics.

[Annual epidemics of hepatitis A in four large cities related to holiday travel among immigrant children].

Objective: Analysis of the transmission pattern of hepatitis A in relation to ethnicity and travel behaviour in Amsterdam. Utrecht, Rotterdam and The Hague.

Design: Descriptive study of notified cases.

Incidence and risk factors of diarrhoea in Dutch travellers: consequences for priorities in pre-travel health advice.

A cohort of 743 Dutch short-term travellers (1-6 weeks) to various (sub)tropical areas was studied to assess incidences of travellers' diarrhoea (TD) and risk factors to guide prevention policies. The occurrence of TD was ascertained retrospectively by questionnaire; independent risk factors were identified by logistic regression analysis. The overall attack rate (AR, 95% CI) of TD was 52% (49-56); 11% (9-14) reported two or more episodes.

An economic evaluation of hepatitis A vaccination in Dutch military personnel.

We analyzed the cost-effectiveness of hepatitis A vaccination regimens using a mathematical simulation model. Passive immunization and two active vaccination strategies (with and without prior screening) were compared with "doing nothing." Hepatitis A antibodies were determined in 2,325 Dutch marines; other input data were retrieved from published and unpublished sources.

Relation between laboratory test results and histological hepatitis activity in individuals positive for hepatitis B surface antigen and antibodies to hepatitis B e antigen.

Background: Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B e antigen (anti-HBe) commonly coexist, and laboratory tests are often requested to assess histological hepatitis activity. An optimum panel of tests has not been found and the usefulness of hepatitis B virus (HBV) DNA assays in this context has not been established. We assessed various blood tests to find which best predicted hepatitis activity.

Testing for anti-circumsporozoite and anti-blood-stage antibodies for epidemiologic assessment of Plasmodium falciparum infection in travelers.

The purpose of this investigation was to assess the role of serology for establishing incidences of Plasmodium falciparum malaria and of exposure to P. falciparum in epidemiologic studies of travelers using chemoprophylaxis. The design was a prospective cohort study involving 548 short-term Dutch travelers to areas endemic for P.

Compliance with malaria chemoprophylaxis and preventative measures against mosquito bites among Dutch travellers.

Self-reported compliance with a malaria chemoprophylaxis regimen of proguanil (PG) plus chloroquine (CQ) was assessed in a cohort of 547 Dutch travellers who visited a single travel clinic when travelling to various areas endemic for falciparum malaria. 503 (92%) had taken PG/CQ prophylaxis, but only 326 (60%) reported regular and uninterrupted use throughout the journey and 4 weeks afterwards. Compliance differed by travel destination and was 45% in South America, 52% in West Africa, 53% in South-east Asia, 60% in the Indian Subcontinent and 78% in East Africa.

Response to a suspected case of diphtheria in Dordrecht, the Netherlands.

About 50 of the refugees in Dordrecht are from the Newly Independent States (NIS) of the former USSR, where diphtheria is rife. Cases have arisen in western Europe through contact with cases from the NIS. No NIS-related cases of diphtheria have been seen

An outbreak of hepatitis A among homosexual men in Amsterdam, 1991-1993.

Background: When in August 1992 it became evident that an outbreak of hepatitis A virus infections (HAV) was taking place in the male homosexual community in Amsterdam a case-control study was conducted to validate the assumption that the outbreak was associated with sexual practices involving oro-anal and digital-anal contact and frequent visits to gay saunas and darkrooms.

Methods: In all, 37 cases reported to the Amsterdam Municipal Health Service (AMHS) in the period December 1991 to March 1993 and 68 anti-HAV negative controls completed an anonymous questionnaire concerning the practice of different sexual techniques and the number of visits to gay saunas and darkrooms in the 2 months preceding the onset of illness or date of interview. Controls were recruited from healthy homosexual men participating in a prospective study on HIV/AIDS conducted by the AMHS.

[Evaluation of the hepatitis B prevention program in newborn infants. II. Amsterdam, 1989-1991].

Objective: To evaluate the efficiency of the hepatitis B surface antigen (HBsAg) screening programme in pregnant women and the hepatitis B prevention programme in neonates of HBsAg-positive mothers from October 1989 to December 1991.

Design: Retrospective.

Setting: Amsterdam Public Health Service, the Netherlands.

Hepatitis A antibody titres after infection and immunization: implications for passive and active immunization.

Titres of antibodies against hepatitis A virus (HAV) were determined in patients, in donors, and in volunteers after active, passive, and combined immunization. Highest titres were found in recently infected persons: in 109 IgM anti-HAV positive persons, the geometric mean titre (GMT) was 15,400 mIU/ml. The GMT in 265 anti-HAV positive blood donors was 10,700 mIU/ml.

Decreasing incidence of PID in Amsterdam.

Objective: To study the incidence of pelvic inflammatory disease (PID) in Amsterdam in the period 1983-1990.

Methods: Patients diagnosed with PID based on a clinical definition were reported weekly by 30 general practices who covered 11% of the Amsterdam population. Annual age specific incidences were calculated using the number of women in the participating practices as the denominator.

Simultaneous passive and active immunization against hepatitis A.

The serum antibody response to simultaneous administration of immune globulin (Ig) and an inactivated hepatitis A vaccine was investigated in healthy volunteers who had been tested and found free of hepatitis A virus. One hundred and forty nine subjects were randomly allocated into three groups. Group 1 received three doses of hepatitis A vaccine at 0, 1 and 6 months, group 2 received 5 ml of Ig and group 3 received a combination of Ig and vaccine.