Antibody response to heat-inactivated hepatitis B vaccine (CLB-3mg) in hemodialysis patients and occupational risk personnel: a one year follow-up

Immune response against hepatitis B vaccine (CLB 3mg) was evaluated in 59 hemodialysis patients and 20 occupational risk personnel. Seroconversion was induced in 52.5% and 70.0% respectively. Twelve months after the first dose, 37.5% of patients and 60.0% of occupational risk personnel had detectable anti-HBs level. Antibody level was expressed in sample ratio units (SRU). Considering only the responders, in the patients group 38.7% had a low anti-HBs response (2.1-9.9 SRU) 32.3% a medium response (10-99.9 SRU) and 29.0% a high response (>100 SRU) while in occupational risk personnel these values were 14.3%, 64.3% and 21.4% respectively. The authors suggest the use of HBV vaccines with more elevated HBsAg concentration or a reinforced immunization schedule to improve the anti-HBs response not only for patients but also for healthy persons.

Relationship between the prevalence of antibodies to hepatitis B core antigen and arbovirus in fishermen from the Ribeira Valley, Brazil

Sera from 299 fishermen 16 to 80 years old, residents in Cananeia and Iguape counties, southern cost of São Paulo State, Brazil, were studied in order to identify a possible association between the prevalence of specific antibodies to the hepatitis B virus (HBV) and exposure to haematophagus mosquitoes evaluated by the prevalence of arbovirus antibodies. This professional group presented the highest prevalence of arbovirus antibodies (54.1%) in past investigations carried out in this heavily forested region. Detection of antibody to hepatitis B core antigen (anti-HBc) in the sera was done by enzyme immunoassay (Roche). Prevalence of anti-HBc antibodies in this group was 31.4% (94/299) which is very high compared with 7.2% to 15.0% for different groups of healthy adults in State of São Paulo. No significant difference is observed between the prevalences of HBV antibodies in Iguape and Cananeia. Prevalence of anti-HBc and anti-arbovirus antibodies increases with age. There is a concordance in the distribution according to age groups of the frequency of anti-HBc and anti-arbovirus positive sera. Ag HBs was detected in 4% of the studied sera. These results support the hypothesis that the transmission of the hepatitis B virus and the arboviruses may be due to the same factor, one of the possibilities would be by anthropophilic mosquitoes.

Antimicrobial resistance and plasmid detection in strains of the Bacteroides fragilis group

Resistant populations of the Bacteroides fragilis group bacteria (two reference ones and two isolated from human and Callithrix penicillata marmoset) were obtained by the gradient plate technique, to clindamycin, penicillin G, metronidazole and mercuric chloride. All the four tested strains were originaly susceptible to the four antimicrobial drugs at the breakpoint used in this study. MICs determination for the four cultures gave constant values for each antimicrobial, on the several steps by the gradient plate technique. The intestinal human B. fragilis strains showed three DNA bands, that could be representative of only two plasmids in the closed covalently circular (CCC) form with molecular weights of approximately 25 and 2.5 Md. The results do not permit an association between the presence of plasmid in the human strain with the susceptibility to the studied drugs. The four strains were ß-lactamase negative in the two methods used, and no particular chromosomal genetic resistance marker was demonstred. The resistance (MIC) observed, after contact with penicillin G and mercuric chloride, were two-fold in the four tested strains

Detection of hepatitis B virus DNA by the polymerase chain reaction in anti-HBE positive chronic hepatitis B patients

Detection of HBV-DNA by PCR was compared with other serological markers (HBsAg, HBeAg and anti-HBe) in a series of49 Chronic Hepatitis B patients, including 12 with a spontaneous clearance of HBsAg. None of these HBsAg negative cases were PCR positive, but 33/37 (89.2%) HBsAg positive cases were PCR positive (p < 0.0001). Among HBsAg positive samples, nine cases were HBeAg positive and anti-HBe negative, all of them PCR positive. Other 3 patients were HBeAg and anti-HBe positive and these cases were also found PCR positive. A third group included 21 patients anti-HBe positive and HBeAg negative: 19 of them were PCR positive and 2 were PCR negative. The last 4 cases were HBeAg and anti-HBe negative, two of them were PCR positive. The detection of anti-HBe viremic cases in the present series suggest that preC variants could occur in our country. In conclusion, the integrated phase o f chronic hepatitis B seems to be less frequent than it was assumed, when only HBeAg or dot blot hybridization techniques were used. The new term "low replication phase" might favorably replace the former "integrated phase".

Active replication of hepatitis B virus (HBV) in HIV type 1 and in HIV type 2 infected patients

To evaluate the effect of concurrent infection by HIV on HBV infection or immunity, we have studied a group of 66 HIV1+ symptomatic Caucasian patients and another of 38 African HIV2+ asymptomatic individuals, concerning their HBV status: serological markers of infection and presence of HBV-DNA in serum, the last taken as sign of hepatitis B virus active replication, were monitored. HIV+ groups were compared with seronegative controls, adequately matched for age, sex and ethnological background. HBV DNA was found in 7.6% of HIV1+ Caucasian patients and 3.2% of seronegative controls; in African HIV2+ individuals 2.6% were also HBV DNA+, a percentage close to that found in HIV2 seronegative controls (2.9%). No correlation was found between HIV infection and HBV active replication. Immunodepression that follows HIV infection over time may be compatible with a degree of T cell function capable of avoiding reinfection with or reactivation of HBV, even in symptomatic stages of acquired immunodeficiency syndrome. Our findings are relevant to the choice of preventive strategies in populations at risk for HIV and HBV infection.

IMMUNOGENICITY OF LOW-DOSE INTRAMUSCULAR AND INTRADERMAL VACCINATION WITH RECOMBINANT HEPATITIS B VACCINE

The study is a randomized trial using recombinant DNA vaccine to determine whether an intramuscular 10 µg dose or intradermal 2 µg induces satisfactory anti-HBs levels compared to the standard dose of intramuscular 20 µg. participants were 359 healthy medical and nurse students randomly allocated to one of the three groups: Group I - IM 20 µg; Group II - IM 10 µg; Group III - ID 2 µg at 0, 1 and 6 months. Anti-HBs titres were measured after complete vaccine schedule by ELISA/Pasteur. Baseline variables were similar among groups and side effects were mild after any dose. Vaccinees in the IM-10 µg group had seroconversion rate and geometric mean titre (GMT 2344 IU L-1), not significant different from the IM-20 µg group (GMT 4570 IU L-1). On the contrary, 21.4% of the ID - 2 µg recipients mount antibody concentration below 10 IU L1 and GMT of 91 IU L-1, a statiscally significant difference compared with the standard schedule IM-20 µg (p < 0.001). A three dose regimen of half dosse IM could be considered an appropriate schedule to prevent hepatitis B in young health adults which is of relevance to the expansion of hepatitis B vaccine programme

Safety and immunogenicity of hepatitis B vaccine ButaNG in adults

Recombinant yeast-derived hepatitis B vaccine manufactured by Instituto Butantan was administered in two groups of adult volunteers (I, II) following two different schedules of immunization. In the first trial (10 mg doses and 0, 1, 3 months vaccination schedule) 106 individuals completed the full immunization program. The results of seroconversion by age group varied from 70 to 100% and the GMT from 46.5 to 124.9 mIU mL-1. In the second trial with 68 individuals (for dosage comparison and 0, 1, 6 months vaccination schedule) indicated that the vaccine formulated in 20 mg was more effective than in 10 mg. The adverse reactions observed in the vaccinees were less frequent than the ones previously found since the introduction of similar vaccines.

Prevalence of hepatitis B and C in the sera of patients with HIV infection in São Paulo, Brazil

The objective of this study was to evaluate the prevalence of hepatitis B and C viruses in a group of HIV infected patients, followed at a single institution since 1996. 1,693 HIV positive patients (1,162 male, 531 female) were tested for HBV infection. Virological markers for HBV included HBsAg and total anti-HBc by ELISA. 1,457 patients (1,009 male, 448 female) were tested for HCV infection. Detection of HCV antibodies was carried out by ELISA. A sample of HCV antibody positive patients was tested for HCV by PCR to confirm infection. Of 1,693 patients tested for HBV, 654 (38.6%) and 96 (5.7%) were anti-HBc and HBsAg positive, respectively. Of 1,457 patients tested for HCV, 258 (17.7%) were anti-HCV positive. 82 of these patients were also tested by PCR and 81 were positive (98%). Of 1,411 patients tested for HBV and HCV 26 (1.8%) were positive for both viruses.

Susceptibility of clinical isolates of Bacteroides fragilis group strains to cefoxitin, cefoperazone and ticarcillin/clavulanate

A total of 40 strains of the B. fragilis group was isolated from clinical specimens in two hospital centers in Fortaleza from 1993 to 1997. The most frequently isolated species was Bacteroides fragilis (19 strains) and most isolates came from intra-abdominal and wound infections. The susceptibility profile was traced for cefoxitin, cefoperazone and ticarcillin-clavulanate by using the agar dilution reference method. All isolates were susceptible to ticarcillin-clavulanate (128/2mug/ml). Resistance rates of 15 and 70% were detected to cefoxitin (64mug/ml) and cefoperazone (64mug/ml), respectively. Such regional results permit a better orientation in choosing this group of antibiotics for prophylaxis and therapy especially in relation to cefoxitin, which is frequently used in the hospital centers studied.

Hepatitis B and C virus markers among patients with hepatosplenic mansonic schistosomiasis

PURPOSE: To evaluate the frequency and the consequences of the co-infection of hepatitis B and C viruses in patients with hepatosplenic schistosomiasis (HSS). METHODS: B and C serologic markers, exposure to risk factors, biochemical assays, upper gastrointestinal endoscopies, and abdominal ultrasonograms were evaluated in 101 patients with HSS from 1994 to 1997. Whenever possible, PCR was tested and histopathological studies were reviewed. RESULTS: At least one HBV virus marker was found in 15.8%, and anti-HCV was detected in 12.9% of the subjects. The seropositive subjects tended to be older than the seronegative ones. A history of blood transfusion was significantly related to the presence of anti-HCV. Three (18.75%) out of 16 subjects exposed to B virus were HBsAg positive. Eleven (84.6%) out of thirteen patients who were anti-HCV positive demonstrated viral activity. Patients with ongoing viral infection presented a higher average level of liver aminotransferases, a higher frequency of cell decompensation and a higher rate of chronic hepatitis. Portal hypertension parameters were not influenced by viral exposure. CONCLUSIONS: The rate of hepatitis B and C viruses serologic markers observed in the patients with HSS was higher than the control group. The co-infection was responsible for a higher frequency of cell decompensation.

Hepatitis B vaccine in infants: a randomized controlled trial comparing gluteal versus anterolateral thigh muscle administration

A significantly diminished antibody response to hepatitis B vaccine has been demonstrated in adults when the buttock is used as the injection site. However, in Brazil, the buttock continues to be recommended as site of injection for intramuscular administration of vaccines in infants. In this age group, there are no controlled studies evaluating the immunogenicity of the hepatitis B vaccine when administered at this site. In the present study, 258 infants were randomized to receive the hepatitis B vaccine either in the buttock (n = 123) or in the anterolateral thigh muscle (n = 135). The immunization schedule consisted of three doses of hepatitis B vaccine (Engerix Bâ, 10 mug) at 2, 4 and 9 months of age. There were no significant differences in the proportion of seroconversion (99.3% x 99.2%), or in the geometric mean titer of ELISA anti-HBs (1,862.1 x 1,229.0 mIU/mL) between the two groups. This study demonstrates that a satisfactory serological response can be obtained when the hepatitis B vaccine is administered intramuscularly into the buttock.

Human polyclonal anti-hepatitis B surface antigen immunoglobulin reduces the frequency of acute rejection after liver transplantation for chronic hepatitis B

BACKGROUND: Use of polyclonal anti-hepatitis B surface antigen immunoglobulin (HBIg) has been shown to reduce hepatitis B virus (HBV) recurrence after liver transplantation (LT) and to decrease the frequency of acute cellular rejection (ACR). However, the protective role of HBIg against ACR remains controversial, since HBV infection has been also associated with a lower incidence of ACR. AIM: To assess the relationship between HBIg immunoprophylaxis and the incidence of rejection after LT. METHODS: 260 patients (158 males, 43 ± 14 years old) submitted to LT were retrospectively evaluated and divided into three groups, according to the presence of HBsAg and the use of HBIg. Group I was comprised of HBsAg-positive patients (n = 12) that received HBIg for more than 6 months. Group II was comprised of HBsAg-positive patients that historically have not received HBIg or have been treated irregularly for less than 3 months (n = 10). Group III was composed of 238 HBsAg-negative subjects that have not received HBIg. RESULTS: HBIg-treated patients (group I) had significantly less ACR episodes, when compared to group II and III. No differences between groups II and III were observed. CONCLUSIONS: Long-term HBIg administration contributes independently to reduce the number of ACR episodes after LT.

High prevalence of hepatitis B virus among female sex workers in Nigeria

Hepatitis B virus (HBV) infection is endemic in Nigeria and constitutes a public health menace. The prevalence of HBV infection in many professional groups has been described in Nigeria. However, literature on HBV infection among female sex workers (FSW) in Nigeria is scanty. FSW in Nigeria are not subjected to a preventive control of HBV infection. This study assesses the extent of spread of HBV among FSW in Nigeria. Seven hundred and twenty (n = 720) FSW (mean age = 26.7 years) were tested for hepatitis B surface antigen (HBsAg) by a double antibody sandwich ELISA method. The overall HBV prevalence among the FSW was 17.1%. FSWs between the ages of 31-35 year (20.5%) and those with 'age-at-first-sex' below 10 years of age (28%) were most affected. This high prevalence of a vaccine preventable disease is unacceptable, therefore, vaccination of this high risk HBV reservoir group should be considered worthwhile.

Evaluation of glycoprotein B genotypes and load of CMV infecting blood leukocytes on prognosis of AIDS patients

BACKGROUND: Cytomegalovirus (CMV) remains an important pathogen to immunocompromised patients even in the era of HAART. The present study aimed at evaluating the influence of CMV viral load and its gB genotypes on AIDS patients' outcome. METHODS: Blood samples of 101 AIDS patients were collected and tested for HIV load, CD4 - cell count and opportunistic pathogens, including CMV. Semi-nested PCRs were run to detect CMV genome and in the positive samples, gB genotyping and CMV load were established using enzymatic restriction and real time PCR, respectively. All patients were clinically followed for four years. RESULTS: In thirty patients (31%) CMV was detected and all fatal cases (n = 5) occurred in this group of patients (p = 0.007), but only two patients had CMV disease (1.9%). However, viral load was not statistically associated with any analyzed parameter. The most frequently observed CMV genotype was gB2 (45.16%) followed by gB3 (35.48%). gB2 genotype was more frequently found in patients with CD4-cell counts under 200 cells/mm³ (p = 0.0017), and almost all fatal cases (80%) had gB2 genotype. CONCLUSIONS: Our study suggests that CMV and its polymorphisms in biologically relevant genes, such as the gB encoding ORF, may still influence the prognosis and outcome of AIDS patients. The gB2 genotype was associated to patient's bad outcome.

Prevalence of HIV-1/2, HTLV-I/II, hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum and Trypanosoma cruzi among prison inmates at Manhuaçu, Minas Gerais State, Brazil

The purpose of this study was to determine the seroprevalence of human immunodeficiency virus (HIV-1/2), human T-cell lymphotropic virus (HTLV-I/II), hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum and Trypanosoma cruzi among 63 male prisoners in Manhuaçu, Minas Gerais, Brazil and to compare this with data from eligible blood donors. The positive results were as follows: 11/63 (17.5%) for HBV, 5/63 (7.4%) for syphilis, 4/63 (6.3%) for HCV, 3/63 (4.8%) for Chagas' disease, 2/63 (3.2%) for HIV-1/2 and 1/63 (1.6%) for HTLV-I/II. The seroprevalence in prisoners was higher than among blood donors, mainly for antibodies to HIV-1/2, HCV and HBV. This is probably due to low social economic level, illiteracy, higher proportion with a prior history of intravenous drug use and/or unsafe sexual behavior. Therefore, these prisoners constitute a high risk group and routine screening and counseling are recommended.