Ochratoxin A in corn and wheat: geographical association with endemic nephropathy.

AIM: To determine the presence and concentration of ochratoxin A in wheat and corn from Slavonski Brod surroundings, the area of endemic nephropathy allegedly caused by ochratoxin. METHODS: Thin-layer chromatography was used to determine ochratoxin A concentrations in 92 wheat and 51 corn samples from the surroundings of Slavonski Brod, Osijek, Hrvatsko Zagorje, Istria, and Celje (Slovenia). RESULTS: Ochratoxin A was present in 74 of 92 (75.8%) wheat samples and 17 of 51 (33.3%) corn samples, in a concentration range of 0.02-160.00 mg/kg in wheat and 0.02-40.00 mg/kg in corn. Wheat samples from the Slavonski Brod surroundings contained the highest level of ochratoxin A (38.8 +/- 27.2 mg/kg), followed by Osijek (8.7 +/- 8.3 mg/kg). Ochratoxin A levels in the wheat from Hrvatsko Zagorje, Istria, and Celje were considerably lower (2.1 +/- 1.5, 1.3 +/- 2.6 and 0.2 +/- 0.5 mg/kg, respectively). Wheat samples from Slavonski Brod significantly differed from all other sample groups (p < 0.001), and wheat samples from Osijek differed from those from Hrvatsko Zagorje, Istria, and Celje (p < 0.001, p = 0.003, p < 0.001, respectively). Ochratoxin A level was the highest in the corn samples from the Slavonski Brod surroundings (20.0 +/- 14.8 mg/kg) and considerably lower in samples from Osijek, Celje, Hrvatsko Zagorje, and Istria (0.8 +/- 1.4, 0.7 +/- 1.9, 0.4 +/- 0.4, and 0.4 +/- 0.8 mg/kg, respectively). A statistically significant difference was also observed between the Slavonski Brod samples and all other corn samples (p < 0.001). CONCLUSION: Irrespective of the real association between ochratoxin A and endemic nephropathy, our data clearly demonstrate their geographical overlap.

Rabipur: a reliable vaccine for rabies protection.

Rabipur, a vaccine propagated on chick embryo fibroblasts, is one of the 'second generation' rabies vaccines produced by cell culture techniques. It compares in tolerance, immunogenicity and efficacy with the human diploid cell culture vaccines and is significantly more economical to be produced. It has proven to be an excellent vaccine, particularly when employed by the 2-1-1 schedule vaccination. This approach combines economy of vaccine with increased safety of treatment. Rabipur was investigated in all immunological parameters and can be recommended as a vaccine of choice for postexposure rabies treatment.

Familial epidemic of meningococcal disease.

Two closely related boys from the same house hold (Home 1), aged two and three, were affected with fulminant meningococcal sepsis known as Waterhouse-Friderichsen syndrome. Neisseria meningitidis serogorup B was isolated from their blood and cerebrospinal fluid. The two-year-old boy died one day after the onset of the disease. Epidemiological examination of contacts and pharyngeal swabs were performed in 14 persons from the household, all of them relatives of the affected children, as well as in a number of other contacts. Chemoprophylaxis with cotrimoxazole was simultaneously administered to all contacts. Family histories revealed that two contacts from the household where the patients did not live (Home 2) were inadvertently omitted. Subsequent examinations, following a report of another contagious disease (salmonelosis), revealed that these two persons were Neisseria meningitidis carriers, together with another one in the same household. The carriers most probably caused the infection of a third, five-year-old boy, the deceased boy's brother (Home 1) who also developed fulminant meningococcal sepsis. The failure to take the appropriate prophylaxis led to a prolonged carrier state in the carrier from the second household. Repeated pharyngeal swab sampling revealed two more carriers from both households that had previously been negative. Control of the epidemic was achieved after 5 weeks by repeated and controlled chemoprophylaxis with ciprofloxacin, and by repeated epidemiological examinations, disinfection, and daily health surveillance by the Sanitary Inspectorate. This extremely rare instance of a familial epidemic with three infected persons emphasizes the need for consistent chemoprophylaxis in meningococcal disease contacts.

Persistence of humoral immunity to rabies 1100 days after immunization and effect of a single booster dose of rabies vaccine.

Forty-four vaccinees immunized with rabies vaccine and human rabies immunoglobulin according to the abbreviated intramuscular regimen (the 2-1-1 schedule) were followed-up after 1100 days and had their blood samples taken. The persistence of rabies neutralizing antibody was proven in the sera of all vaccinees. 56% of whom demonstrated titres > or = 0.5 IU ml-1. At the same day the vaccinees were given a single booster dose of vaccine whose effect was measured 2 weeks later. With the RFFI test on day 1114, sera revealed an extraordinarily high booster response in all 44 vaccinees. The study proved the anamnestic response after a full course of rabies vaccination to be a very stable one, and the capability of a single booster dose of vaccine to evoke high-titred rabies antibody response. Of the four vaccines used in the study, under comparable conditions HDCV proved superior to PCECV PDEV and PVRV on all 3 days of serology-35, 1100 and 1114, though this difference was statistically attested only on days 35 and 1114.

Immune Response to Hepatitis A Vaccine Combined or Given Simultaneously with Typhoid Fever Vaccine.

Background: Because both hepatitis A and typhoid vaccination are frequently indicated in the same traveler, a prospective, randomized controlled study was performed to evaluate the feasibility of simultaneous administration of hepatitis A and typhoid fever vaccines in adult volunteers. Methods: Two groups of 25 subjects received either separate injections of hepatitis A (Havrixtrade mark, SmithKline Beecham Biologicals) and typhoid fever (Typhim Vitrade mark, Pasteur-Mérieux) vaccines in opposite arms, or a syringe-mixed combination of both vaccines as a single injection. A booster dose of Havrix was given at 6 months. Results: The immune response to hepatitis A tended to be higher in the mixed-injection group, but this difference was significant (p=.048) only following the booster dose. Adverse reactions were generally mild with no differences between the two groups. Conclusion: A combined formulated vaccine against both typhoid fever and hepatitis A is feasible and offers more convenience without added adverse reactions to travelers who have appropriate indications for both vaccines.

[Protection of adolescents against hepatitis A]. / Zastita adolescenata protiv hepatitisa A.

In Croatia, hepatitis A is still a considerable public health problem which, however, can be efficiently solved by vaccination. The study of vaccine immunogenicity and reactivity was performed in a random sample of 88 high school seniors, mean age 209 +/- 6.4 month (17 years and 5 months), from Ivanic-Grad and surrounding countyside. All the children were immunized by HAV sorbate SSW inactivated vaccine, manufactured by Sächsisches Serumwerk GmbH, Dresden. One 1-ml dose of the vaccine contains at least 720 units of inactivated HAV, MRC 5 strain, grown on human diploid cells and adsorbed on 0.95 mg aluminium hydroxide gel. The vaccine was administered intramuscularly, according to the scheme 0, 30, 60. Postvaccinal reactions were followed for 3 days after each dose and were observed in four (4.6%) children. A month after last dose (day 90), a 100% seroconversion was found. In 84 (95.5%) children, the level of antibodies exceeded 100 IU/L, one (1.1%) child had 80 IU/L, two (2.3%) children had 50 IU/L, one (1.1%) child had only 20 IU/L.

[Immunity against hepatitis A in younger age groups and the basis for an immunization program]. / Imunitet na HAV mladih dobnih skupina osnova za program imunizacije.

The naturally acquired immunity to hepatitis A virus (HAV) in a sample of 305 children, aged up to 15 years, in the municipality of Ivanic-Grad amounted to 18.7%. The study was conducted in September 1989. Of those 305 children, 16.8% of the boys and 20.7% of the girls were positive. No statistically significant difference was observed with regard to sex (p < 0.01) (chi 2 = 1.4). Of the children aged up to two years, 47.4% were exposed to the hepatitis A virus. Seropositive for anti-HAV were 8.3% in the group from 2-3 years of age, 6.4% in those aged from 4-5 years, 15.9% in the group from 6-7 years of age, 6.8% in those aged from 8-9 years, 20.0% in the group from 10-11 years of age, 27.8% in those aged from 12-13 years, and 29.0% in the group from 14-15 years of age. The spread of the infection by contact was predominant, reflecting the socioeconomic standards of the studied community (p < 0.01) (chi 2 = 29.5). A relatively high prevalence of hepatitis A infection compared to that of the developed countries, the first peak immunity rates in first-graders, a low number of cases among infants aged up to 5 years (approximately 6.0%), availability of commercial vaccine, speak in favour of including hepatitis A vaccination into the obligatory community-wide immunization program. It appears that the target age for HAV vaccination would be the age of five.

Preventive medicine in Croatia through time and space.

The Croatian preventive medicine was well-known in the world through history. It was famous from the time of the quarantine in Dubrovnik, through sanitary cordon and contribution in obligatory first immunization against smallpox. Croatia presented Andrija Stampar as the leader in preventive medicine from the World War I till the sixties. We owe him all kinds of public health work both in organization and education as well as the initiating the World Health Organization. Knowledge and capabilities of Croatian preventive medicine workers were demonstrated the most clearly during the Croatian homeland war in 1991/91 when the infectious diseases as permanent war companions did not have effect on the state of health of the people in Croatia.

Comparative study of two human diploid rabies vaccines administered with antirabies globulin.

The association of human rabies immune globulin (HRIG) to the vaccine is recommended for postexposure rabies treatment in cases of severe exposure. In a previous study using an abbreviated postexposure vaccination schedule it was observed that passive immunization could partially inhibit the active immune response, with three cell-culture purified vaccines but not with the concentrated human diploid cell vaccine (HDCV). In order to see if this difference was related to the purification process, the present study was designed comparing two HDCV, one concentrated and the other concentrated and purified, both of them administered in association with HRIG. The neutralizing antibody response in the vaccines was found to be identical with both vaccines, ruling out the role of the purification and confirming the excellent immunogenicity of both human diploid cell vaccines and the absence of inhibition of the active immune response by the association of HRIG to HDCV.

Interaction of rabies vaccine with human rabies immunoglobulin and reliability of a 2-1-1 schedule application for postexposure treatment.

Five commercially available rabies vaccines (HDCV, FBKC vaccine, PCEC vaccine, PVRV and PDEV) applied alone or combined with human rabies immunoglobulin (HRIG) were administered, by random allocation, to 161 volunteer vaccinees, using the abbreviated 2-1-1 postexposure immunization schedule. Protective levels of rabies antibody were demonstrated in all vaccinees by day 14, and in all but one vaccinee from day 21 to day 90. Partial inhibition of the antibody response due to HRIG was observed for three vaccines (PCEC vaccine, PVRV and PDEV). In terms of economy, reliability and rapid antibody induction, the 2-1-1 schedule proves superior to the presently recommended regimen for postexposure rabies prophylaxis.

An evaluation of second generation tissue culture rabies vaccines for use in man: a four-vaccine comparative immunogenicity study using a pre-exposure vaccination schedule and an abbreviated 2-1-1 postexposure schedule.

In a double-blind comparative trial the immunogenicity of three new tissue culture rabies vaccines was evaluated, using a commercial human diploid cell vaccine (HDCV) lot as the reference. Two different vaccination regimens, a pre-exposure schedule, and an abbreviated 2-1-1 postexposure schedule (two doses of the vaccine applied bilaterally on day 0, with subsequent single doses given on days 7 and 21) were employed. In both, two of the new vaccines, purified chick embryo cell vaccine and purified Vero rabies vaccine, induced an antibody response equivalent to that of HDCV, while the geometric mean titres for the fetal bovine kidney cell vaccine were somewhat lower. The 2-1-1 regimen, a candidate regimen for economical rabies postexposure treatment, evoked a rapid and high titre antibody response with all four vaccines, peaking on day 14.

Combined vaccination with live oral polio vaccine and the bovine rotavirus RIT 4237 strain.

A clinical trial was carried out in 3-month-old infants to assess whether concomitant oral administration of live polio and rotavirus RIT 4237 vaccines would reduce their immunogenicities as a result of mutual interference. One hundred and sixty breast-fed male and female infants were randomly allocated to four study groups to receive in a blind fashion the poliovirus vaccine, the RIT 4237 vaccine, a combination of both vaccines or a placebo preparation. Antibody titres were measured in pre- and postvaccination serum samples by the ELISA test and the neutralizing antibody test (NT) for rotavirus and by the NT for polioviruses types 1 and 3. The percentage of subjects with immune responses to rotavirus in the placebo group was low, indicating the absence of wild rotavirus circulation in the population. Antibody responses against polio types 1 and 3 were found in about a quarter of the infants receiving a placebo because the study was performed during a polio vaccination campaign when vaccine viruses are known to circulate. The results showed that 73% of seroconversion was obtained when RIT 4237 was administered alone and that the responses to polioviruses types 1 and 3 were good. However, simultaneous administration of polio and RIT 4237 vaccines caused a significant reduction of the antibody response to rotavirus but not to polioviruses types 1 and 3.

Reactivity and immunogenicity of bivalent (AC) and tetravalent (ACW135Y) meningococcal vaccines containing O-acetyl-negative or O-acetyl-positive group C polysaccharide.

The immunogenicity and the reactivity of two bivalent (AC) and two tetravalent (ACW135Y) meningococcal vaccines containing either the O-acetyl-positive or the O-acetyl-negative group C polysaccharide were compared in healthy adolescent and adult volunteers. The vaccines contained high-molecular-weight, purified capsular meningococcal polysaccharides and were administered subcutaneously at a dose of 50 micrograms for each polysaccharide. Reactivity was low for all vaccines, and the tetravalent vaccines were not significantly more reactive than the bivalent vaccines. Immunogenicity was measured by assay of bactericidal antibodies in pre- and postvaccination sera. More than 90% of the vaccines had at least a fourfold increase in the bactericidal antibody titer against each group of meningococcus represented in the vaccines. Addition of polysaccharide W135 and polysaccharide Y to polysaccharides A and C did not alter the immunogenicity of the latter polysaccharides. Thus, there is no evidence of antigenic competition with the tetravalent vaccine. Comparison of the antibody response to the O-acetyl-positive and the O-acetyl-negative variants of group C polysaccharide in the bivalent vaccines, as measured by both bactericidal and enzyme-linked immunosorbent assays, indicates that in adults, the two types of group C polysaccharide are similarly immunogenic.