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Since April 1993 in Finland and March 1994 in Switzerland, polymerase chain reaction (PCR) has been used routinely nationwide for the diagnosis of pertussis. Nasopharyngeal specimens from 3794 patients suspected of having pertussis and 1125 controls were tested. Finnish and Swiss assays found 23% and 36% of clinical specimens positive, respectively. PCR showed a higher incidence of pertussis infection among 1- to 6-year-old children in Switzerland than in Finland (P < .001). This difference may be due to the booster dose of vaccine given at 2 years of age in Finland but not in Switzerland. In Finland, PCR-confirmed asymptomatic cases were more common among children <7 years old than in older children (P < .001), whereas older children tended to have symptomatic infection. The use of PCR markedly improves the diagnosis of pertussis and opens new perspectives for epidemiologic and vaccine efficacy studies.

Two inactivated hepatitis A virus (HAV) candidate vaccine strain were tested, derived from strains CLF and HM175. Neither vaccine increased liver enzymes levels and reactogenicity was similar to that observed with other alum-absorbed products. Antibody responses were dose-dependent and protection against HAV can be presumed to last for at least three years. All persons receiving 720 ELISA units (El.U) of the CLF vaccine seroconverted after one dose. For the HM175 vaccine, anti-HAV persisted until month 12 after injections at months 0 and 1, suggesting that the third dose of vaccine could be given at any time from month 6 to 12. A double dose of HM175 vaccine (1440 El.U) given as a single bolus resulted in 100% seroconversion by day 14 with a geometric mean anti-HAV level of 121 mIU/ml. This implies that rapid protection can be induced using large doses of inactivated HAV vaccine should time constraints dictate such an approach.

The present trials being carried out in Switzerland and Turkey, the reactogenicity and immunogenicity of acellular DTP vaccines containing either 25 micrograms or 8 micrograms of PT and 25 micrograms of FHA were compared with those of a conventional whole-cell DTP vaccine during a primary vaccination course following either a 0-1-2 schedule starting at three months of age (Switzerland) or a 0-2-4 schedule starting at two months of age (Turkey). The whole-cell vaccine was associated with significantly more local reactions than the acellular vaccines; general reactions were also more frequent among whole-cell recipients. The 25 micrograms PT dose vaccine was no more reactogenic than the 8 micrograms PT dose vaccine. There was no evidence of increases in frequencies of local or general reactions from one acellular vaccine dose to the next. The 25 micrograms PT dose acellular DTP vaccine resulted in immune responses to all four antigens (PT, FHA, diphtheria and tetanus toxoids) at least equivalent to those observed with whole-cell vaccination. Significantly lower anti-PT antibody levels were seen with the 8 micrograms PT dose vaccine.

Travel to the developing world by Swiss citizens has been increasing. Vaccine-preventable diseases challenges the physician to provide pre-travel advice. Each traveler's itinerary, duration of stay and medical history, including previous immunization, should be reviewed. Vaccinations are required or recommended according to the requirements and the epidemiology of countries being visited. This article summarizes updated recommendations to individual vaccines and immunoglobulins.

This review discusses the indications for the routine immunizations covered by the Swiss "Immunization Schedule 1981" (diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, rubella, BCG), as well as the indications for special immunizations (hepatitis B, influenza, pneumococci, rabies, tickencephalitis) and for the immunisations for travellers (cholera, yellow fever, meningococci, typhoid fever). Vaccination against measles, mumps and rubella should be given to girls and boys at the age of 18 (to 24) months as a combined injection. In view of the low prevalence of tuberculosis BCG vaccination is justifiable only at school leaving age, if at all. The indications for influenza and pneumococcal vaccines are still limited, the value of a general vaccination of all over 65 year old individuals is not proven for either vaccine. A nationwide vaccination campaign against hepatitis B was started early this year with a newly licensed vaccine for all population groups at risk. Only HDC-vaccines should be used for immunisation against rabies. The newly licensed, highly protective oral attenuated live typhoid vaccine will probably replace the parenteral typhoid vaccine.

A large group of school-children 6-10 years of age were checked for their immunization status and by questionnaire for their parent's attitude to vaccinations. Children of higher socio-economic status have better immunization protection. In spite of pretended high motivation, people from Southern countries have a significantly smaller percentage of immunized children than Swiss people. This is probably caused by insufficient information.

Sera of 47 patients with serious Staphylococcus aureus infections, 55 patients with septicemias caused by other organisms and 147 healthy controls were examined for teichoic acid antibodies by ELISA, counterimmunoelectrophoresis (CIE) and immunodiffusion (ID). The specificity and the predictive value of positive results for metastatic-septic complications were 100% each for ELISA, 93%/88% for CIE and 87%/80% for ID. The low sensitivity with all three test methods of 50-60% relates to single sera. The indication for prolonged antibiotic treatment should therefore be derived only from the analysis of consecutive serum samples. With 12% of the controls above the cut-off, the ID test seems not a very good screening test.

Measles antibody determinations in kindergarten and primary school children in Basle-City showed that today just under 10% of 10-year-olds and roughly 25% of 5-year-olds have no immunity to measles. In the 10-year-old primary school children the effects of measles immunization are not yet markedly apparent, whereas almost half the kindergarten children already owe their measles immunity to immunization. No measles antibodies could be detected in 13,7% of the subjects who, according to their official vaccination certificates, had previously been immunized against measles. Most of these failures are probably due to careless routine immunization techniques.

On the basis of the Federal Health Department's "Swiss Vaccination Scheme" of 1976, some up to data additions and alterations are proposed mainly with regard to combined measles-mumps-rubella vaccination during the second year of life together with the first tetanus, diphtheria and poliomyelitis booster. Oral vaccination against poliomyelitis is not contraindicated during pregnancy. Among the inoculations not considered in the official vaccination scheme, regular influenza vaccination is only indicated for certain chronically ill people. Whether this is also true of the pneumococcal vaccine newly licensed in Switzerland remains uncertain. The (likewise new) meningococcal vaccine is only effective against type A and C and not against the type B meningococci prevalent in Switzerland. In view of its safety, only HDC vaccine produced with human tissue cultures should be used for anti-rabies vaccination. For counselling prior to travel abroad, a simple vaccination scheme is provided and the importance of other prophylactic measures is emphasized.

By means of rubella antibody determinations we attempted to determine the value of routine rubella immunization of adolescent girls. For this purpose we compared the antibody titres of young women and men from Basle City/Basle Country (immunization since 1969) with those of persons of the same age from Uri (no immunization) and Nidwalden (immunization only since 1977). The difference in the infection rate between nonimmunized young men and women of the same age in Basle is significant. In Uri and Nidwalden most young adults have rubella antibodies despite the lack of immunization. The reasons why we nevertheless recommend the introduction of routine immunization in the Canton of Uri are discussed.

In Switzerland 319 of 594 young women seronegative for rubella antibody vaccinated at 15-25 years of age against rubella with the Cendehill vaccine strain were retested 15 years later with three tests (hemagglutination inhibition, enzyme-linked immunosorbent assay, and a neutralization technique) for the presence of rubella antibodies. For 307 women rubella antibodies were still detectable by all three techniques. For nine women rubella antibodies were demonstrable by only one or two tests. Only three vaccinees were seronegative by all three tests. These three women also showed no booster response after challenge with the vaccine strain. The high percentage of women with persistent rubella antibodies 15 years after vaccination might be explained in part by the presence of subclinical reinfections due to a wild rubella virus.

Antibodies against diseases of childhood have been determined in fall 1977 taking bloodsamples of 430 15-year old students. Immunity was widespread for measles (96%), chickenpox (93%), mumps (90%) whereas 27% did not have antibodies against rubella. The level of vaccination (measles, mumps, rubella) is increasing fast in younger children. The possibility of being infected by a wild virus will be low in the future for those who have not been vaccinated. Antibodies against Cytomegalovirus were measured in 120 students of normalschool and 107 "gymnasiasts". The proportion between negative and positive was 1.1 for students in normalschool and 2.7 for those attending a higher education.

In 10,000 cord blood samples from the region of Basel (representing approximately equal to 42% of all live births of 1983 to 1985) anti-Toxoplasma antibodies were determined by agglutination and indirect immunofluorescence (IFA) tests. 47.3% were seronegative. 2.8% (n = 283) exhibited high titers in IFA (greater than 300 IU/ml) suggestive of acute or persistent infection. Questionnaires on potential risk factors were sent to 280 mothers with high antibody titers ("cases"), and to 279 randomised seronegative mothers (controls); 388 questionnaires (75.3%) were returned. Compared to controls, infections in cases were significantly associated with farm work, flower production, or food industry, consumption of lamb meat or improperly heated beefsteak, cat ownership. Risks of infection were significantly reduced when meat was kept in the deep freezer, or by consumption of chicken (probably as a surrogate for lamb and beef meat). Cases had significantly lower average serum concentrations of beta-carotene and tocopherol than controls, while average retinol and cholesterol levels were comparable in both groups. The 283 cord blood samples from the cases were subjected to 4 serological tests for specific IgM and 41 samples were reactive in greater than or equal to 1 test. 35 of the 41 children were reinvestigated greater than or equal to 6 months after delivery. In 8 children specific IgM persisted. Review of delivery charts confirmed that all 8 were asymptomatic at the time of delivery. Also on follow-up clinical examinations were normal. The incidence of congenital, latent toxoplasmosis in the area is thus estimated to nearly 1/1000 live births. These data will be used to promote preventive measures in pregnant women.