Evaluation of a combined tetravalent diphtheria, tetanus, whole-cell pertussis and hepatitis B candidate vaccine administered to healthy infants according to a three-dose vaccination schedule.

A vaccine combining hepatitis B with diphtheria, tetanus and whole-cell Bordetella pertussis (DTPwHBV) would facilitate the attainment of universal vaccination of infants against hepatitis B. A candidate vaccine was administered to 42 infants beginning at 7-15 weeks of age. Antibodies were measured from pre- and postvaccination blood samples. After three doses, at least 94.9% of the infants were protected against hepatitis B, diphtheria and tetanus. Responses to B. pertussis were considered adequate. No serious adverse events were reported. These results indicate that this candidate vaccine is safe and immunogenic when administered to infants according to a three-dose schedule, with doses 2 months apart.

Intrafamilial clustering of hepatitis A.

The intrafamilial clustering of hepatitis A virus infections (HAV) in families with an index case of sporadic hepatitis A was studied. Four hundred and three family members (84.3%) of 113 children with acute hepatitis A admitted to the Paediatric Department of the West Attica Hospital were included in the study. Epidemiological data and serum samples were collected within 1 week after the patient's admittance to the hospital. Enzyme-immunoassays were used to detect recent or past HAV infections. The attack rate of HAV infections in susceptible family members was found to be similar in susceptible fathers (16.6%, 1/6), mothers (23.5%, 4/17) and siblings (18.1%, 37/204). The infected family members belonged to 22 families. The attack rate was found to be higher in families with a lower immunity level, while the social class was not found to play an important role. The administration of ISG prevented further spread of hepatitis A among those susceptible. Our data suggest that immunoglobulin for HAV prevention should be given not only to children but also to parents and other adult family members in areas with a low prevalence of anti-HAV among adults.

Evaluation of the immunogenicity of a recombinant vaccine against hepatitis B containing S and pre-S2 sequences using two different schedules.

The immunogenicities of hepatitis B virus vaccines containing S and pre-S2 regions were compared using two different schedules of immunization (A: 0-1-2-12 months and B: 0-1-6 months). Two hundred males and females aged 17-22 years were vaccinated with 20 micrograms per dose. The follow-up period was extended up to 13 months. One month after the booster dose anti-HBs were detected in 98.9% of those vaccinated with schedule A and 100% of those vaccinated with schedule B. Geometric mean titres (GMT) of anti-HBs were significantly higher with schedule A than schedule B, reaching GMT of 16269.7 mIU ml-1 and 4372.4 mIU ml-1, respectively, one month after the booster dose. Seroconversion rates for the anti-pre-S2 antibodies one month after the booster dose were 89.4% for schedule A and 76.6% for schedule B. GMT were 157.8 mIU ml-1 and 67.5 mIU ml-1, respectively. We conclude that both vaccines elicit high titres of anti-HBs and anti-pre-S2 antibodies. Immunity lasts longer in schedule A than in schedule B.

Brief report: hepatitis A vaccination in Greek military recruits.

Improved standards of sanitation have contributed to a shift in the prevalence of hepatitis A in countries such as Greece. Children are now coming into first contact with the infection at an increasingly later age, leaving more adults susceptible to the disease. In military forces where close living conditions prevail, the likelihood of infection is even more pronounced. An inactivated hepatitis A vaccine has been developed and has been administered successfully to over 24,000 healthy children and adults. This vaccine would be of considerable benefit to military personnel worldwide. The reactogenicity and immunogenicity of a hepatitis A vaccine were evaluated in 200 female military recruits, aged from 17 to 23 years, vaccinated according to a primary vaccination schedule at 0 and 1 months with a booster dose at 6 months. Symptoms reported following vaccination were generally mild and transient. Soreness at the site of injection was the most frequent local symptom and malaise was the most common general symptom. Clinically significant increases in serum liver enzyme levels were not detected. All subjects had seroconverted after the primary vaccination course and maintained anti-HAV titres up to the time of the administration of the booster dose. The booster dose produced more than a tenfold increase in the geometric mean titre (GMT).

Knowledge, attitudes and practices of Greek health professionals, in relation to AIDS.

In order to improve educational programmes directed at health care workers we investigated their knowledge, attitudes and practices in relation to HIV/AIDS. An anonymous self-administered questionnaires was distributed to 609 health care workers. Of these, 59.6% agreed to participate (42.4% of the medical doctors, 74.3% of the nurses and 79.6% of the laboratory technicians, health visitors and other health care workers). All studied groups believed that their knowledge of HIV modes of transmission (84.3%) was sufficient. In contrast, a relatively small percentage reported knowledge of the clinical spectrum of HIV infection (48.8%) and the diagnostic assays (57.6%). Nearly all the study participants believe (92.8%) that there is a risk of acquiring HIV infection during the hospitalization of HIV/AIDS patients. Obligatory screening of all patients was reported by nearly all participants (90.6%) as a chance to minimize their occupational risk. Although health care workers reported satisfactory knowledge of safety measures (87.0%), only 56.7% used gloves and 38.8% accept the hospitalization of HIV/AIDS patients. In spite of the educational programmes for AIDS in Greece, this study demonstrates that health professionals' knowledge and precautionary measures are not sufficient. As a result, a small percentage of them treat AIDS patients without discrimination. There is an urgent need to implement specific educational programmes for health professionals so that they will safely provide high quality care to people affected by HIV/AIDS.

Chronic liver disease rarely follows acute hepatitis B in non-immunocompromised adults.

The risk of developing a chronic carriage state after acute hepatitis B infection in adults was evaluated. Two hundred and eighty-nine HBV-susceptible heterosexual partners of acute hepatitis B patients were used to investigate the effectiveness of post-exposure immunoprophylaxis; 75 of them received hepatitis B vaccine, 72 hepatitis B hyperimmune globulin (HBIG), 71 vaccine plus HBIG and 71 placebo. Participants were interviewed, clinically examined and serum specimens were taken at 1, 3, 6 and 9 months after their first intervention. Serum samples were tested for ALT and HBV markers (HBsAg, anti-HBc and anti-HBs) using radio immunoassays. Forty-six (15.9%) of the heterosexual partners examined were infected; the incidence of HBV infections was higher among placebo (18.3%, 13/71) and HBIG (18.1%, 13/72) recipients compared to vaccine (16.0%, 12/75) and HBIG plus vaccine (11.3%, 8/71) recipients, but the differences were not statistically significant. Infections were significantly more often subclinical after immunoprophylaxis (p = 0.03). HBsAg was detected in all eight clinical and in 13 of the 38 subclinical cases. In the remaining 25 subclinical cases HBV infections were diagnosed by the development of anti-HBc and anti-HBs during the follow-up period. Finally, all 46 cases studied cleared the HBsAg.

HIV infection in Greek intravenous drug users.

In order to investigate the prevalence of HIV infection among Greek intravenous drug users (IVDU), its trend during years recent and possible risk factors, we studied 893 inmates recently admitted to the main prisons of Greece from 1986 to 1989. Screening and counselling was offered to all of them. The acceptance rate was 98%. One thousand one hundred and two IVDUs voluntarily attending the AIDS Reference Centre in Athens for counselling and screening were also included in the study. Anti-HIV were determined by commercially available radioimmunoassays, and positive results were confirmed by Western Blot. Our results showed that the prevalence of HIV infection remained very low in both groups during the study period; it was similar to the prevalence found (2.1%) in stored sera drawn in 1982 from imprisoned IVDU. In the non-prisoner group, the prevalence among those who reported needle/syringe sharing (2.6%) was similar to that among those who denied sharing (2.5%). This lack of difference may be due to the fact that sharing is only an occasional practice and that cleaning of of the injection equipment is common. We conclude that the prevalence of anti-HIV in IVDU in Greece is considerably lower than that in neighbouring countries and that it has remained stable during the last eight years. Further studies are necessary to identify behavioral and other risk factors.

Epidemiological characteristics of hepatitis B virus infection in Cyprus.

The prevalence of hepatitis B virus (HBV) infection in Cyprus was estimated in a sample of 795 blood donors, 388 armed forces recruits, 1872 hospital staff, 135 haemodialysis patients, 559 thalassaemic patients, 722 institutionalised adults, 98 mentally retarded children and 323 family contacts of HBsAg carriers. Commercially available radioimmunoassays were used for screening. Merck Sharpe and Dohme hepatitis B vaccine was used for a vaccination pilot program. Our results showed that the carrier rate of HBsAg in the blood donor and army recruit samples ranged between 0.77% and 1.01% and the prevalence of past infection between 11.1% and 13.6%. Among high risk groups the highest carrier rate was found in family contacts of HBsAg carriers (18.27%), in mentally retarded children (6.12%) and in institutionalized adult patients (5.40%). The frequency of immunes was found 28.5%, 12.2% and 33.2% respectively. The highest frequency of immunes was found in thalassaemic (82.9%) and haemodialysis (43.7%) patients. The carrier rate (2.94%) and the prevalence of immunes (22.5%) in hospital personnel was higher than in general population. Vaccination studies in a limited number of thalassaemic children and hospital personnel showed excellent acceptance of vaccination and excellent immunogenicity. We infer that HBV infection should be consider as a major public health problem in Cyprus. A National Vaccination program has to be implemented for containing its spread.

Education in preventing HIV infection in Greek registered prostitutes.

From March 1984 to November 1985, 350 Greek registered prostitutes were screened for anti-HIV. Twelve of them (3.4%) were found to be positive. To monitor and control the further spread of HIV infection, an intensive educational campaign was established and screening every 3 months was implemented. Until October 1986, two new seroconversions were detected out of 270 examined (seroconversion rate of 0.74% per year). Further HIV infections have not been detected among the 282 prostitutes followed to 1988. This should be attributed to avoidance of clients from Central Africa and mainly to almost universal use of condoms as a result of the intensive educational campaign.

Immune status of Greek patients with beta-thalassemia major negative for anti-HIV.

Patients with thalassemia who receive multiple blood transfusions are at risk for the acquired immunodeficiency syndrome. Peripheral blood lymphocyte subpopulations were studied in 22 multitransfused thalassemic patients; 10 patients were without splenectomy and 12 were studied after splenectomy. Both groups were negative for anti-HIV. Four additional patients who were found positive for anti-HIV and ten healthy controls were also included in this study. Patients without splenectomy compared to controls and to patients after splenectomy showed a significant decrease of both percentage (p less than 0.001) and absolute numbers (p less than 0.001) of Leu-7+ cells without significant abnormalities of T4/T8 ratio (1.56 +/- 0.4). Patients after splenectomy compared to controls and to patients without splenectomy showed a significant increase of the absolute numbers of lymphocytes and lymphocytes subsets T11+, T3+, T4+, T8+ and SmIg+ cells. In the seropositive patients for HIV only a significant increase of the absolute number of T8+ cells was observed while the T4/T8 ratio was 1.24 +/- 0.73. The decrease in the percentage of Leu-7+ cells in patients without splenectomy correlated inversely to the total amount of blood transfused. In conclusion patients with thalassemia had normal T4/T8 ratio and did not show the abnormal immunologic profile that has been reported in haemophiliacs.

High frequency of HLA-DR5 in Greek patients with haemophilia A and haemophilia B.

Sixty unrelated Greek patients with haemophilia (46 with haemophilia A and 14 with haemophilia B) were typed for HLA-A, B and DR antigens. A highly significant increase in the frequency of HLA-DR5 was observed in both groups of patients (58.6% vs 30.0%, chi 2 = 10.47, pc less than 0.03, RR = 3.31 for haemophilia A and 78.5% vs 30.0%, chi 2 = 12.32, pc less than 0.007, RR = 8.5 for haemophilia B). An increased frequency of HLA-B13 was also observed in patients with haemophilia A (15.2% vs 5.7%, chi 2 = 5.74, pc less than 0.4, RR = 2.9). Thirty of the 60 patients (50.0%) were positive for LAV/HTLVIII antibodies. HLA-DR5 was equally distributed in patients with and without these antibodies (63.3% and 63.3%, respectively). The presence of DR5 did not correlate with the severity of haemophilia A or B. These results may suggest an influence of gene(s) on chromosome 6 in haemophilia A and haemophilia B and no effect of HLA antigens in the susceptibility to LAV/ HTLVIII infection among haemophiliac patients.

Epstein-Barr virus infection in polytransfused patients with homozygous beta-thalassaemia.

The frequency of Epstein-Barr virus (EBV) and hepatitis B virus (HBV) infection has been studied in 149 polytransfused thalassaemic patients and in healthy controls. Evidence for EBV infection was based on the detection of antibodies to viral capsid antigen (anti-VCA) and for HBV infection on the detection of either hepatitis B surface antigen (HBsAg) or hepatitis B surface antibody (anti-HBs). The frequency of anti-VCA was not significantly higher in the patients (16.4%) compared to the controls (69.8%) whereas HBV infection was more frequently observed in the patients (91.3%) than in the controls (17.3%). There was also no evidence of repeated infection or recent infection with EBV in the polytransfused patients. These data suggest that transfusion of stored blood does not represent a significant factor of spread for EBV.