Significance of detecting anti-HBc among Egyptian male blood donors negative for HBsAg.

BACKGROUND: Screening for hepatitis B virus surface antigen (HBsAg) reduces the risk of transfusion-transmitted hepatitis B viral (HBV) infection. However, the absence of HBsAg in the blood of apparently healthy individuals may not be sufficient to ensure the lack of circulating HBV. Blood containing anti-hepatitis B core antibody (anti-HBc) without detectable presence of HBsAg might be infectious; therefore, screening for anti-HBc has been implemented in some countries resulting in a decrease in the risk of post-transfusion HBV infection. AIM: To study the seroprevalence of anti-HBc. The relationship between anti-HBc positivity and the presence of circulating HBV among healthy blood donors negative for HBsAg will be helpful to decide whether supplemental testing may bring additional safety to blood products. MATERIAL AND METHODS: A total of 1026 serum samples collected from HBsAg-negative Egyptian healthy male donors were tested for the presence of anti-HBc (both IgM and IgG types) using the competitive enzyme-linked immunosorbent assay technique. Anti-HBc-positive samples were subjected to real-time polymerase chain reaction to confirm the presence of HBV DNA. RESULTS: Of the 1026 samples tested, 80 (7·8%) blood samples were found to be reactive to anti-HBc. Of those, HBV DNA was detected in five of the samples (6·25%). The levels of detected viraemia were variable among the five donors. CONCLUSION: This study shows the insufficient effectiveness of HBsAg screening in protecting blood recipients from HBV infection. Inclusion of anti-HBc testing should be considered in the screening of blood donors.

Prevalence of certain sexually transmitted viruses in Egypt.

The magnitude of Sexually Transmitted Diseases (STD) in the Eastern Mediterranean Region is not exactly known but considered to be not insignificant. A realistic estimate of the problem is necessary, to design an effective control program. This present study aimed to identify the most prevalent sexually transmitted viral agents among patients attending the STD clinic at Cairo Hospital for Skin and Venereal Diseases (El-Haud El-Marsoud). From persons attending this clinic whether complaining or visiting for screening, between October 1993 to April 1995, 95 cases were studied by history taking, clinical examination, bacteriological and serological examination for the detection of the most prevalent sexually transmitted organisms. Certain demographic and socio-economic factors interacting with sexual attitudes and practices were also studied. All the collected data for each patient were recorded. Antibodies (IgG) to cytomegalovirus (CMV) were detected in 86.3%, HBsAg in 10.5%, and antibodies to HBcAg were detected in 45.3%. Antibodies to HCV were detected in 8.4%, and antibodies to HIV in 5.3%.

Nerve growth factor antibody stimulates reactivation of ocular herpes simplex virus type 1 in latently infected rabbits.

Anti-nerve growth factor (anti-NGF) antibody has been shown to induce reactivation of latent herpes simplex virus type 1 (HSV-1) in vitro. We found that systemically administered anti-NGF induces ocular shedding of HSV-1 in vivo in rabbits harboring latent virus. Rabbits in which HSV-1 latency had been established were given intravenous injections of goat anti-NGF serum daily for 10 days beginning 42 days after primary viral infection. Tears were assayed for virus for 12 days beginning on the day of the first injection. All eight rabbits given high titer anti-NGF had infectious virus in their tears at least once during the 12-day period. Fifteen of 16 eyes were positive and the average duration of viral shedding for these eyes was 4.0 days. Latently infected rabbits receiving daily injections of nonimmune goat serum or saline for 10 consecutive days were controls. Only six of the 16 (38%) eyes from rabbits receiving nonimmune goat serum shed virus. Only one of 12 eyes from untreated rabbits shed virus. Sera from control rabbits had no detectable anti-NGF activity; titers in anti-NGF-treated rabbits ranged between 1:1000 and 1:10,000. NGF deprivation may act as a neuronal stressor and may share a common second messenger pathway with heat- or cold-stress induced reactivation of latent HSV-1.

Prevalence of certain sexually transmitted diseases in Egypt.

The prevalence of STD continues to increase throughout the world threatening millions of people. However, the actual incidence of STD is not known in most countries. Little work was done to evaluate the size of this problem in Egypt. This study aimed to identify the most prevalent sexually transmitted organisms among patients attending the STD clinic at Cairo Hospital for Skin and Venereal Diseases (El-Haud El-Marsoud). Among the patients attending this clinic complaining of one or more STD or not complaining, but attending the clinic for screening for fear from STD due to their sex behavior, from October 1993, to April 1995, 95 cases were studied. This was done by history taking, clinical, bacteriological and Certain demographic and interacting with sexual serological examinations. socioeconomic factors attitudes and practices were also studied. Data were recorded in special sheets. The results of this study showed that 68 (71.6%) patients had one or more ST organisms (positive cases) while no ST organisms could be detected in the remaining 27 (28.4%) cases (negative cases). Positive cases were more prevalent n adolescents and young adults (58.8%). A high prevalence of STD was detected in males (73.5%) than females (26.5%); in sinlges (64.7%) than married (30.9%), divorced (2.9%) or widowed (1.5%). The rate of the positive cases was high among those having 5 or more sexual partners and in heterosexuals. All STD positive patients were not condom users except one patient. Most of patients were not drug abusers (66.2%) and were of low socioeconomic class (85.3%). STD were common among those with preparatory school education level (32.4%), or illiterate (26.5%) than those with primary school level (16.2%) or university or institute degree (13.2%) or secondary school degree (11.8%) of education. Among the 68 positive cases, N. gonorrhoeae was isolated from 36.8%, T. pallidum was detected in 30.9%. Using the appropriate serological techniques, HBV and HIV were detected in 14.7% and HCV in 11.8%. G. vaginalis was isolated from 11.8%; each of group B Streptococci and Strept. pneumoniae was isolated from 4.4% and each of T. vaginalis and C. albicans was isolated from 1.5%. Concomitant STD were detected in 18 out of 68 patients. So, STD is a variable state regarding the number of the causative organisms and their relative incidence according to several factors. For that, the state of STD in any location must be checked periodically to plan restrictive managing and controlling programs.

Hemophilus influenzae and Streptococcus pneumoniae as causative agents of pneumonia in Egyptian preschool children: analysis and serotyping of Hemophilus isolates from hospital patients in Cairo, 1991-93.

The Hemophilus influenzae blood culture and nasopharyngeal isolates, collected during a limited Surveillance of Antimicrobial Resistance in 1991-1993 from 1,635 Egyptian children under 5 years of age, presenting with pneumonia to Embaba and Abbassia Fever Hospitals, were serotyped. The 8 blood culture isolates confirmed H. influenzae to be responsible for 0.5% of the cases of pneumonia, versus 50 Streptococcus pneumoniae blood culture isolates from the same population that confirmed it responsible for 3.1% of the cases. The invasive Hemophilus strains were exclusively isolated from infants below 1 year, from one hospital (Embaba), on one winter season (January to March, 1992). On serotyping, 50% of the blood culture isolates were found to be non-b by latex agglutination. Some 297 nasopharyngeal isolates from cases of pneumonia were also serotyped and 45% were found to be non-b, thus confirming the invasive strains findings. Furthermore, the typing results from ARI-free controls nasopharyngeal isolates--though limited--were consistent with the findings and showed a 43% proportion of non-b. These findings put a question mark on the benefit of a large scale use of the available H. influenzae type b polysaccharide and conjugated vaccines in Egypt. But before interpreting out data in terms of vaccine needs, more specifically designed epidemiological studies need to be conducted to assess the role of H. influenzae as a pathogen in Egypt.

Detection of hepatitis B virus DNA by in situ tissues hybridization in corneal of HBsAG positive donors.

HBV is a hepatotropic virus. The highest concentration found in the blood and liver with lower amount in saliva and semen. The virus was also detected in body fluids. Keratoplasty is an essential operation for the treatment of corneal blindness. At Ain Shams University International Eye Bank 10% of the collected corneas were from donors with HBs antigenemia. These corneas were rejected according to the Eye Bank Association of America. In this study 32 corneal tissues of 16 donors positive HBsAg were examined for,the presence of HBV by in situ DNA hybridization technique to detect HBV DNA in the corneal sections. This marker could not be seen in this work. This preliminary study could be an encouraging step for further researches to evaluate the possibility of the avascular cornea to carry HBV.

Bordetella pertussis FHA antibodies in maternal/infants sera and colostrum.

The high incidence of pertussis in the first year of life confirms that susceptibility remains high for children in this age group despite > 90% pertussis vaccine compliance. In this respect, immunoresponse to Bordetella pertussis was investigated. Filamentous hemagglutinin (FHA) antibodies were studied due to their important protective role, in blocking the adherence of the bacteria to respiratory tract ciliated cells. The relative rate of detection and degree of positivity of IgG and IgA antibodies to Bordetella pertussis FHA were studied in maternal and infant sera and in colostrum samples of the respective mothers. The study comprised 143 mothers of child bearing age and 25 newborns. The highest percentages of serum IgG and IgA were present in the younger females group (15-25 yrs). Both IgG and IgA were detected in the same mother in 60% of them. The study showed that 96.9% of colostrum samples who were positive for IgA, were associated with IgA positivity in serum, also an increase in the degree of serum IgA positivity was associated with a higher rate of detection of IgA in colostrum. Maternal serum IgA could therefore be used as a marker for the future presence of IgA in colostrum. This work demonstrated that newborns show little passive immunity to pertussis, evidenced by the low placental transfer of IgG (35.7%) and the low rate of detection of IgA in the colostrum (41%). We concluded that, it would be advantageous to reimmunize pregnant women, without adequate serum antibody to Bordetella pertussis, with appropriate new vaccine which would offer a better passive immunity to their infants.

The effect of HSV multiplication rate on antiviral drug efficacy in vitro.

HSV-1 multiplication rates have been shown to vary in different tissues and the rate of multiplication may correlate with susceptibility to antiviral chemotherapy. Herpetic stromal keratitis is a necrotizing condition refractive to antiviral therapy and this lack of antiviral efficacy in stromal disease may be the result of very low rates of viral replication in the corneal stromal keratocytes. In this study, we investigated the efficacy of antiviral drugs in an in vitro system in which the virus multiplication rate is slow. In this system, the reduced rate of virus multiplication is achieved by a reduction in the incubation temperature. Vero cells were infected at one of several multiplicities of infection with McKrae strain HSV-1 and incubated for 24, 48, or 72 h at 26 or 36.5 degrees C in the presence or absence of trifluridine (50 micrograms/ml) or acyclovir (20 micrograms/ml). Both drugs suppressed viral replication at 36.5 degrees C. However, under some specific sets of conditions, trifluridine was not effective in suppressing viral replication in cells incubated at 26 degrees C. At this temperature, viral replication and cell metabolism are slowed to a pace which may be similar to that which occurs in corneal stromal keratocytes in vivo. Acyclovir significantly reduced HSV-1 replication under all conditions at 26 degrees C, indicating that the antiviral activity of this compound is effective in cells whose metabolic rate is slow and in which viral replication is taking place slowly.

Branhamella catarrhalis and respiratory tract infections.

Branhamella catarrhalis, a Gram negative diplococci, is gaining increasing recognition as a respiratory pathogen. In this study 40 sputum samples were collected from patients with acute or chronic lower respiratory tract infections and 15 samples from healthy controls. Each sample was examined for the isolation and identification of B. catarrhalis and other respiratory pathogens. From the control group 3 strains of B. catarrhalis were encountered: two of these were of low number in the collected sample and the third was found in a sample containing low number of leukocytes and more than 10 BSE cells/HPF which indicate that the sample was just saliva. From the cases of this study B. catarrhalis was isolated from 7 sputum samples. It was of the same frequency of isolation as the other known respiratory pathogens, more in old age, smokers and ex-smokers and all the strains were in mixed infections. B. catarrhalis isolated in this study were susceptible to cephalosporin regardless of the production of Beta-lactamase.

A suggested vaccine formulation for the control of pneumococcal meningitis in Egypt.

Mortality rates of pneumococcal meningitis ranges from 13-60% in different parts of the world. Reports of pneumococci with multiple antibiotic resistance add urgency to the need for developing means of primary prevention. A 14-valent pneumococcal vaccine was licensed in 1977, and a 23-valent pneumococcal vaccine in 1983. In the present work 131 strains of pneumococci isolated from meningitis cases in Egypt were identified and serotyped by Quellung reaction. The most frequently isolated serotype was serotype 1 (32%). Serotypes 6A, 9L, 12A, 19A and 29 were next in prevalence. The age groups 0-18 years were the most frequently affected groups (79%) and over 18 years of age were only 21% of total cases. A vaccine formulation is suggested to have a coverage rate against pneumococcal meningitis cases of 79.3% and 89.3% of a proposed 14-valent vaccine and 23-valent vaccine versus to coverage rate of 48% and 54% of 14-valent and 23-valent International vaccines respectively. According to the age distribution of cases and the isolated serotypes a vaccination could be recommended during the first two years of age in order to protect the most frequently infected groups.

Hepatitis B virus infection among immunocompromised patients in Egypt.

Several workers reported an increased susceptibility to hepatitis B virus (HBV) in immunosuppressed patients. A study was carried out on 4 groups of supposedly immunocompromised patients for hepatitis B surface antigen (HBsAg), and anti-HBs. The 4 groups of patients were suffering from: Leprosy, Bronchial asthma, Diabetes and hepatosplenic Schistosomiasis. Serum specimens were obtained from 137 patients representing the 4 groups and from a control group of 25 healthy individuals. All sera were tested by ELISA technique for HBsAg and anti-HBs. Results indicated that HBsAg carrier rate was 4% for the control healthy group, 7% for Bronchial asthma, 10% for Diabetes, 24% for Leprosy and 28% for hepatosplenic Schistosomiasis. On the other hand, the anti-HBs was 21% for the control group, 29% for Schistosomiasis, 55% and 58% for Diabetes and Bronchial asthma respectively and 74% for Leprosy. This study shows that immunosuppressed patients particularly those suffering from leprosy and hepatosplenic Schistosomiasis experience higher HBsAg carrier rate than the control group for the endemic hepatitis B (6-7 times higher for leprosy and Schistosomiasis). An important observation was the diminished anti-HBs rate in hepatosplenic Schistosomiasis patients, despite the highest HBsAg carrier rate they exhibited. This may be due to an immunological defect, resulting in an unsatisfactory antibody response and chronic hepatitis B antigenemia. In Egypt, where Schistosomiasis is prevalent (40-50%), the problems caused by hepatitis B infection are increased.