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Biomedical subjects

S Bassily

Publications and source records attributed to S Bassily.

At least 19 recordsLinked to original sources
PubMed2001

Induction of systemic antifimbria and antitoxin antibody responses in Egyptian children and adults by an oral, killed enterotoxigenic Escherichia coli plus cholera toxin B subunit vaccine.

We assessed serologic responses to an oral, killed whole-cell enterotoxigenic Escherichia coli plus cholera toxin B-subunit (ETEC-rCTB) vaccine in 73 Egyptian adults, 105 schoolchildren, and 93 preschool children. Each subject received two doses of vaccine or placebo 2 weeks apart, giving blood before immunization and 7 days after each dose. Plasma antibodies to rCTB and four vaccine-shared colonization factors (CFs) were measured by enzyme-linked immunosorbent assay. Immunoglobulin A (IgA) antibodies to rCTB and CFA/I were measured in all subjects, and those against CS1, CS2, and CS4 were measured in all children plus a subset of 33 adults. IgG antibodies to these five antigens were measured in a subset of 30 to 33 subjects in each cohort. Seroconversion was defined as a >2-fold increase in titer after vaccination. IgA and IgG seroconversion to rCTB was observed in 94 to 95% of adult vaccinees, with titer increases as robust as those previously reported for these two pediatric cohorts. The proportion showing IgA seroconversion to each CF antigen among vaccinated children (range, 70 to 96%) and adults (31 to 69%), as well as IgG seroconversion in children (44 to 75%) and adults (25 to 81%), was significantly higher than the corresponding proportion in placebo recipients, except for IgA responses to CS2 in adults. IgA anti-CF titers peaked after one dose in children, whereas in all age groups IgG antibodies rose incrementally after each dose. Independently, both preimmunization IgA titer and age were inversely related to the magnitude of IgA responses. In conclusion, serologic responses to the ETEC-rCTB vaccine may serve as practical immune outcome measures in future pediatric trials in areas where ETEC is endemic.

Administration, Oral↗
PubMed1999

Oral, inactivated, whole cell enterotoxigenic Escherichia coli plus cholera toxin B subunit vaccine: results of the initial evaluation in children. PRIDE Study Group.

Two randomized, double-blinded trials assessed the safety and immunogenicity of an oral, killed enterotoxigenic Escherichia coli (ETEC) plus cholera toxin B subunit vaccine in Egyptian children. Two doses of vaccine or E. coli K-12 were given 2 weeks apart to 105 6- to 12-year-olds and 97 2- to 5-year-olds. Safety was monitored for 3 days after each dose. Blood was collected before immunization and 7 days after each dose to measure immune responses. Few children reported postdosing symptoms, with no differences in the frequency of symptoms between treatment groups. Most vaccinees had an IgA antibody-secreting cell response against colonization factor antigen I (100%, 6-12 years; 95%, 2-5 years), coli surface antigen 2 (92%, 6-12 years; 83%, 2-5 years), and coli surface antigen 4 (93%, 6-12 years). Vaccination evoked a >/=4-fold rise in antitoxic IgA and IgG titers in 93% and 81% of children, respectively. In conclusion, the oral ETEC vaccine was safe and immunogenic in 2- to 12-year-old children, justifying further evaluation in infants.

Administration, Oral↗
PubMed1999

Seroprevalence of Helicobacter pylori among Egyptian newborns and their mothers: a preliminary report.

Helicobacter pylori is one of the most common human bacterial infections in the world and children in the developing countries acquire H. pylori infection early in life. We prospectively evaluated the prevalence of serum antibodies to H. pylori in a cohort of pregnant women and their offspring. Mothers' sera were collected during the third trimester of pregnancy and sera from their offspring were collected when they were 7-9 months and 18 months of age. Pylori-Stat, a commercially available ELISA kit, was used to detect antibodies to H. pylori in the serum of the subjects tested. Sera from 169 mothers were available for testing and 88% of these samples were positive for anti-H. pylori IgG. Of the 169 children tested, 13% of the infants 7-9 months of age and 25% of the children 18 months of age had serologic evidence of H. pylori infection. These data indicate that infection with H. pylori is common in Egypt and acquisition of infection occurs at a very young age.

Adolescent↗
PubMed1998

Safety and immunogenicity of an oral, killed enterotoxigenic Escherichia coli-cholera toxin B subunit vaccine in Egyptian adults.

Enterotoxigenic Escherichia coli (ETEC) is the leading cause of bacterial diarrhea in young children in developing countries. The safety and immunogenicity of a killed, oral ETEC vaccine consisting of whole cells plus recombinantly produced cholera toxin B subunit (rCTB) was evaluated in Egypt, which is endemic for ETEC diarrhea. Seventy-four healthy Egyptian adults (21-45 years old) were randomized and received two doses of the ETEC/rCTB vaccine (E003) or placebo 2 weeks apart. The frequency of adverse events after either dose did not differ by treatment group, and no severe adverse events were reported. After vaccination, peripheral blood IgA B cell responses to CTB (100%) and to vaccine colonization factor antigens CFA/I (94%), CS4 (100%), CS2 (81%), and CS1 (69%) were significantly higher than response rates for the placebo group. These favorable results in Egyptian adults indicate that the ETEC/rCTB vaccine is a promising candidate for evaluation in younger age groups in this setting.

Adult↗
PubMed1997

Immunogenicity of recombinant hepatitis B vaccine among infants of mothers with active schistosomiasis.

A study of the immunogenicity of a recombinant hepatitis B vaccine was conducted among 385 Egyptian infants, 191 (49.6%) of whom were born to mothers with moderately active Schistosoma mansoni infection (mean egg count = 224 eggs/g of feces). All mothers were seronegative for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen. Infants were vaccinated with a 2.5-microg dose of this vaccine, given along with diphtheria, tetanus, and pertussis (DTP) vaccine, at the ages of two, four, and six months. Serum samples taken from each infant at nine months of age were tested for HBsAg, antibody to hepatitis B core antigen, and quantitatively for antibody to hepatitis B surface antigen (anti-HBs). There was no significant difference (P = 0.1) between anti-HBs titers in infants of S. mansoni-infected mothers (mean = 539 mIU/ml) and in infants of noninfected mothers (mean = 377 mIU/ml). This study shows that there was no apparent effect of maternal schistosomiasis infection on the immune response of these infants to vaccination.

Adult↗
PubMed1997

Short report: evidence of worldwide transmission of hepatitis G virus.

Hepatitis G virus (HGV) has been recently documented in the Americas, Europe, and Australia. Distinct risk populations from North Africa, South America, and Southeast Asia were screened for HGV, in addition to hepatitis B and C viruses. First time recognition of HGV is described from Egypt and Indonesia. Notable is the high proportion of HGV positive individuals among multiply transfused children, ranging from 24% of those sampled from Egypt to 32% in Indonesia. Also, data from Peru suggest the likely association of HGV infection with progressive liver disease. Hepatitis G virus should be considered a world-wide health concern.

Flaviviridae↗
PubMed1995

A high risk of hepatitis C infection among Egyptian blood donors: the role of parenteral drug abuse.

To determine the prevalence and risk factors of hepatitis C virus (HCV) infection among Egyptian blood donors, 188 consecutive adult blood donors from four hospitals and one temporary donor center located in Cairo, Egypt were evaluated. Sera were tested for HCV antibodies (anti-HCV) using second-generation enzyme-linked immunosorbent assay (ELISA) test kits. Sera that were repeatedly reactive by ELISA were further verified by a second-generation recombinant immunoblot assay (RIBA). Antibodies to HCV were detected by RIBA in 26.6% of the blood donors, which is higher than the 10-19% prevalence of antibody found in other studies of Egyptian blood donors. A history of selling blood (odds ratio [OR] = 12.1) and the use of illicit parenteral drugs (OR = 2.5) were significantly associated with anti-HCV seropositivity after controlling for age and gender. These data indicate that the use of illicit drugs may be one reason for high levels of reported HCV infection among Egyptian blood donors. These findings also indicate that Egyptian blood donors should be screened for anti-HCV and individuals who have a history of drug abuse should be deferred from donating blood.

Adolescent↗
PubMed1995

Comparative study of the immunogenicity and safety of two dosing schedules of hepatitis B vaccine in neonates.

Healthy Egyptian neonates born to hepatitis B surface antigen (HBsAg)-seronegative mothers were randomly enrolled in one of three vaccination schedules. A dose of 2.5 micrograms of recombinant HB vaccine was given at birth, two, and six months of age (group A) or two, four, and nine months of age (group B). These two groups and a third control group (group C) also were given the other routine childhood vaccines (BCG, DPT, polio, and measles). Blood samples were taken one month after the third vaccine dose in groups A (seven months of age) and B (10 months of age), and a second follow-up blood sample was taken at the age of 18 months for all three groups. Sera were tested for HBsAg and antibody to hepatitis B core antigen, and quantitatively for antibody to hepatitis B surface antigen (anti-HBs) using commercial enzyme immunoassay kits. The vaccine was well tolerated and side effects were limited to local soreness, redness, or temporary swelling. Among 590 infants who were followed-up, good (51-300 mIU anti-HBs/ml) or excellent (> 300 mIU/ml) immune responses occurred in 85% of the infants in group A and in 96% in group B. Geometric mean titers of anti-HBs at the first and second follow-up were 306 and 55 mIU/ml in group A, and 1,492 and 147 mIU/ml in group B. The recombinant HB vaccine is safe and immunogenic when given in three doses of 2.5 micrograms in either regimen, but delay of the booster dose of the vaccine until nine months after birth produced a higher immune response.

Female↗
PubMed1994

Monitoring the efficacy of different doses of praziquantel by quantification of circulating antigens in serum and urine of schistosomiasis patients.

We evaluated the quantitation of two schistosome circulating antigens in serum and urine as a tool for the assessment of the efficacy of praziquantel dosage regimens (40 versus 60 mg/kgbw). In addition we compared the efficacy of two different brands of praziquantel (Biltricide and Distocide), given at the same dosage (40 mg/kgbw). Thirty five Egyptian hospitalized schistosomiasis mansoni patients participated in this study. Thirteen patients (Group 1) received 60 mg/kgbw Biltricide, administered in 3 oral doses of 20 mg in one day; 22 individuals (Group 2) were treated with 40 mg/kgbw (12 Biltricide, 10 Distocide), given in one oral dose. Circulating anodic antigen (CAA) and circulating cathodic antigen (CCA) were quantitated by monoclonal antibody-based ELISA's before, and 1, 3 and 6 weeks after chemotherapy. Before treatment, all patients were positive for at least one of the circulating antigen assays. Three to six weeks after treatment significantly more patients were found to be negative in Group 1 compared to Group 2 (X2 = 7.13, P = 0.008, n = 35). Also the levels of CCA and CAA in serum and of CCA in urine were found to be significantly higher in Group 2 (Mann-Whitney U < 85, P < 0.05, n = 35). These results were confirmed by parasitological data. No differences were found between treatment with Biltricide or Distocide.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

Short-course norfloxacin and trimethoprim-sulfamethoxazole treatment of shigellosis and salmonellosis in Egypt.

In a double-blind clinical study, 109 adult Egyptian patients infected with Shigella spp. and 45 infected with Salmonella spp. were randomly assigned to three treatment groups: 1) norfloxacin in a single 800-mg dose, 2) norfloxacin, 400 mg twice a day for three days, and 3) trimethoprim (160 mg)-sulfamethoxazole (800 mg) (TMP-SMX), twice a day for three days. Among Shigella-infected patients, diarrheal symptoms had resolved in 86-97% and bacteriologic failure (repeat positive stool culture) occurred in only two patients five days after the start of the three treatment regimens. Among Salmonella-infected patients, diarrheal symptoms had resolved in 76-82% of patients and bacteriologic failure was common (18-36%) five days after the start of therapy. These data indicate that short-course therapy with either norfloxacin or TMP-SMX can be effectively used to treat shigellosis in adults in developing countries. However, for uncomplicated Salmonella spp. infection, short-course therapy with norfloxacin and TMP-SMX may not lead to a rapid resolution of symptoms or consistently eliminate this enteropathogen.

Adult↗
PubMed1993

Acute sporadic hepatitis E in an Egyptian pediatric population.

A study was conducted to determine the etiology of acute hepatitis among 261 children (age range 1-11 years) living in Cairo, Egypt. A blood sample was obtained from each subject when initially evaluated and a questionnaire was used to collect demographic and risk factor data. Sera were tested by enzyme immunoassay for acute hepatitis A (anti-hepatitis A virus IgM), hepatitis B (anti-hepatitis B core antigen IgM and hepatitis B surface antigen [HBsAg]), hepatitis C (total anti-HCV), delta hepatitis (total anti-delta), and cytomegalovirus infection (anti-CMV IgM). In addition, hepatitis E virus (HEV) infection was diagnosed using a new Western blot technique to test patients with non-A, non-B hepatitis for anti-HEV IgM. Among 261 children, acute hepatitis A was diagnosed in 85 (32.6%) patients, acute hepatitis B in 19 (7.3%), delta hepatitis in 3 (1.1%), mixed hepatitis A and B infection in 2 (0.8%), CMV infection in 1 (0.4%), hepatitis E in 58 (22.2%), and non-A, non-B hepatitis of unknown type in 51 (19.5%). Forty-two (16.1%) subjects had HBsAg without other markers of acute infection. Risk factor analysis indicated that patients living in homes not connected to a municipal source of water were at increased risk of hepatitis E infection. These data provide additional evidence that hepatitis E virus is a common cause of acute sporadic hepatitis in children living in Egypt.

Acute Disease↗
PubMed1992

Efficacy of hepatitis B vaccination in primary school children from a village endemic for Schistosoma mansoni.

To determine whether chronic Schistosoma mansoni infection interferes with hepatitis B virus (HBV) immunization, 308 schoolchildren aged 6-12 years with no evidence of prior HBV infection (156 with active schistosomiasis) were vaccinated with three 5-micrograms injections of recombinant DNA-derived HBV vaccine. The vaccine was given in the deltoid muscle at time 0 and 1 and 7 months later. All vaccinees were examined 1 and 3 years after vaccination for quantitative antibody to hepatitis B surface antigen (anti-HBs). Seroconversion was detected in 284 vaccinated children (92%), of whom 271 had a good (51-300 mIU/mL) or excellent (greater than 300 mIU/mL) anti-HBs response. Sixteen other children (5%) had evidence of natural HBV infection (antibody to hepatitis B core antigen). Of those with good or excellent response, 99% retained high antibody titers for 3 years. Response was not influenced by S. mansoni infection. Hepatomegaly and splenomegaly were associated with reduced vaccine response.

Child↗
PubMed1992

Immunological response to diphtheria/tetanus vaccine in Schistosomiasis mansoni patients.

The cellular and humoral immune responses of patients with S. mansoni infection were evaluated before and one month after each of two intramuscular doses of diphtheria/tetanus toxoid vaccine. Patients were divided into "responder" and "non-responder" groups based on anti-tetanus toxoid (anti-TT) IgG levels after vaccination. The specific anti-TT IgG1 response of the responder group was predominantly in the IgG, subclass. The lymphoproliferative response to PHA was also significantly higher in the responder group; this elevation was detectable before and after each vaccination. The responses to PWM and SPL were comparable in the two groups before vaccination, although the responder group had a higher response to SPL after vaccination. IgG antibodies for schistosome adult worm and egg antigens were significantly lower in the responder group prior to vaccination but not thereafter. Anti-diphtheria IgG antibodies were comparable in the two groups after vaccination at all times. Clinically, the non-responder patients had a higher incidence of splenomegaly (84.6% vs 44.8%) and were significantly older than the responder patients (mean 34.1 yrs vs 18.7 yrs). The cause for the reduced anti-tetanus IgG response in schistosomiasis patients is believed to be multifactorial. T cell or antigen presenting cell dysfunction, high levels of IgG antibodies specific for schistosome antigens, splenomegaly and age are factors that might lead to reduced anti-TT IgG response.

Antibodies, Bacterial↗
PubMed1991

Diagnosis of human schistosomiasis by detection of circulating cathodic antigen with a monoclonal antibody.

Monoclonal antibody (MAb) 5H11 reacted with repeating epitopes on Schistosoma mansoni circulating cathodic antigen (CCA) and detected CCA in sera of Egyptian S. mansoni-infected patients. MAb 5H11 was both capture and biotinylated detection antibody in a sandwich ELISA of trichloroacetic acid-pretreated serum samples. Sera of patients with 7-500 eggs/g of stool were positive by MAb 5H11-CCA sandwich ELISA. Stool egg counts and CCA serum levels correlated (r = .52), and CCA levels decreased by 4 weeks after praziquantel treatment in patients with pretreatment egg counts of greater than or equal to 50/g of stool (P less than .05). Sera of Schistosoma haematobium-infected patients, uninfected individuals, and most patients with other helminths were negative in this assay. The MAb 5H11-CCA sandwich ELISA appears sensitive and specific for immunodetection of active schistosomiasis mansoni and useful for monitoring its chemotherapy.

Adolescent↗
PubMed1991

Assessment of cure in schistosomiasis patients after chemotherapy with praziquantel by quantitation of circulating anodic antigen (CAA) in urine.

The kinetics of circulating anodic antigen (CAA) levels in urine were studied in Egyptian male patients infected with Schistosoma mansoni or with both S. mansoni and S. haematobium, before treatment, and at one, three and six weeks after chemotherapy. A quantitative enzyme-linked immunosorbent assay (ELISA) demonstrated CAA in 82% of the serum and 89% of the urine samples from these 28 patients. To evaluate the possibility of circadian variability in urine CAA levels, samples were examined in 15 patients at four intervals during a 24-hour period. No significant differences in CAA titers were observed. Seventeen patients were subsequently treated with praziquantel and followed for six weeks. CAA titers in serum and urine decreased significantly one week after therapy. Thereafter, the profile of CAA titer in urine continued to show a parallel but delayed decline compared to that in serum. While all serum CAA titers became negative three to six weeks after treatment, urine titers were negative in 47% at three weeks and 69% at six weeks. The remaining positive patients had low titers. A significant quantitative correlation in CAA titer was found between serum and urine before and after treatment. Seventeen Egyptian control subjects with no active schistosome infection were negative for CAA in both serum and urine. Our results confirm that the CAA urine assay could be used as a sensitive and non-invasive method to diagnose the disease, and indicate that the assay can be used to monitor efficacy of schistosome chemotherapy.

Adolescent↗
PubMed1990

Safety and immunogenicity of a recombinant hepatitis B vaccine in patients infected with Schistosoma mansoni.

Thirty Egyptian males, 8-31 years of age, with active Schistosoma mansoni infection and negative serologic tests for hepatitis B markers, were vaccinated with a recombinant hepatitis B vaccine (Merck's Recombivax). The vaccine was given intramuscularly in the deltoid region in three 10 micrograms doses at 0, 1, and 6 months. All patients were treated with praziquantel 2 months after the first vaccination. Sera were collected every 2 months for 12 months and tested for anti-HBs using a quantitative ELISA technique. There were no side reactions except for mild local soreness at the injection site in 3 patients. At 12 months, all subjects seroconverted (antibody levels greater than 10 mIU/mL); 24 patients (80%) developed antibody levels greater than 1,000 mIU/mL. As with a plasma-derived vaccine, antibody levels were negatively correlated with increasing spleen size. A recombinant hepatitis B vaccine was safe and immunogenic when given to patients with schistosomiasis mansoni.

Adolescent↗