Is hepatitis C virus genotype 4 predominant in Saudi Arabia?

Hepatitis C virus (HCV) genotype 4 is believed to be predominant in the Middle East including Saudi Arabia (SA). We attempted to genotype 80 HCV isolates from different parts of SA by direct sequencing of a variable 222bp fragment from the NS5B region. The phylogenetic analysis of the NS5B sequences was complemented by direct sequence analysis of the conserved 5'-NCR region for HCV type-specific polymorphism. All 80 NS5B sequences separated into 3 clades which comprised 6 type 1b variants, 30 type 4 variants (24 of type 4a and 6 of type 4c or d) and 44 type 3 variants. Apart from two definitive type 3b variants the other 42 type 3 NS5B sequences formed 4 clusters with low similarity to type 3a-f HCV sequences from the database. The precise subtyping of these 42 type 3 variants awaits sequencing of longer HCV RNA stretches. Our results indicate that HCV type 4 may not be the only dominant genotype in SA.

Viral aetiology and epidemiology of acute respiratory infections in hospitalized Saudi children.

A total of 1429 Saudi children of either sex and under 5 years of age who were admitted to King Khalid University Hospital, Riyadh during a three year period (April 1993-March 1996) with complaints suggestive of acute respiratory tract infections (ARTI) were investigated for viral aetiology of the infection. Viruses could be detected in 522 (37 per cent) cases with respiratory syncytial virus (RSV) the most commonly detected (79 per cent) followed by parainfluenza type 3 (8 per cent). Detection of influenza A, B and adenoviruses accounted for 6 per cent, 3 per cent and 2 per cent respectively. Except for parainfluenza virus type 3 the peak of activity of the respiratory viruses was during the winter months (October-February). Parainfluenza virus type 3 could be detected all year round but epidemics can occur in the hottest months of the year (June-August) when the temperature can exceed 40 degrees C. Association between clinical manifestation, type of causative agent, and age was evaluated in 137 infected Saudi children in the first year of the study (April 1993-March 1994). The majority of our cases presented with bronchiolitis (58 per cent) while only 26 per cent had bronchopneumonia. There was a significant association between bronchiolitis and lower age groups (0-6 months), with RSV as the major causative agent of bronchiolitis cases (88 per cent).

Infection with hepatitis viruses (B and C) and human retroviruses (HTLV-1 and HIV) in Saudi children receiving cycled cancer chemotherapy.

Serological markers of hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphotropic virus type 1 (HTLV-1), and human immunodeficiency viruses (HIV-1 and HIV-2) were studied in 53 Saudi children (31 males, 22 females; 1-12 years of age) receiving cycled cancer chemotherapy and in 168 healthy Saudi children taken as control. Exposure to HBV in the patients was similar to that in the control (6 per cent HBsAg in patients v. 7 per cent in the control; 19 per cent exposure rate in patients v. 20 per cent in control). None of our patients was vaccinated against HBV prior to chemotherapy. The fact that among the 10 HBV exposed patients five patients were anti-HBs-positive is in favour of vaccinating Saudi oncology patients against HBV prior to chemotherapy. In contrast to the situation with HBV the prevalence of anti-HCV in the patients (11 per cent) was significantly higher than that in the control (1 per cent) (P = 0.003). None of our patients or the control were anti-HTLV-1 or anti-HIV-positive. The results of this study stress the need for an awareness of HCV problem in Saudi oncology patients. Strict measures of screening blood donors for all blood-borne viruses and, in particular, for HCV in addition to the use of disposable equipment in management of cancer patients are items that should be implemented as soon as possible.

Detection of human papillomavirus DNA in skin warts from immunocompromised patients but not in semen from men whose wives have abnormal cervical cytology.

The epidemiology of human papillomaviruses (HPV) was studied in 61 immunocompromised patients (e.g. renal and cardiac transplants; Bowen's disease; genital cancer) undergoing therapy at the University Hospital of Wales at Cardiff U.K. Warts from various sites of these patients were studied for the presence of HPV types 6, 11, 16 and 18 using the dot-blot DNA hybridization technique. Four HPV-16 and one HPV-11 was detected. The presence of HPV-16 in our study is quite significant since it suggests the potential occurrence of genital HPV types in skin warts in immunocompromised patients and hence the need for screening such patients against HPV types. HPV, mainly types 16 and 18 are usually associated with genital cancer, cervical malignancies and cervical intraepithelial neoplasia. The semen of the husband of 30 women with cervical abnormalities and the semen of 30 husbands (control) of wives with normal cervix were tested for HPV-6, 11, 16 and 18. No HPV-DNA could be detected in all of the 60 specimen. This suggests that specimens were either truly negative for any of those types or because virus DNA could present in a small amount less than 5 pg/microliters in some patients. Whether semen plays a role in transmitting HPV is still controversial.

Hepatitis C virus antibodies in high-risk Saudi groups.

The recombinant-based enzyme immunoassay developed by Ortho Diagnostic System for the detection of antibodies of hepatis C virus (HCV) was used to determine the extent of exposure to HCV in healthy Saudi subjects (500 males; 260 females) without liver disease and with no history of percutaneous exposure to blood and in Saudis who are considered at high risk for contracting the disease: hemophiliacs (28), thalassemics (78), hemodialysis patients with renal failure (65) and patients with sexually transmitted diseases (STD) (220). The results show that HCV is endemic in the Saudi population with an overall frequency of 5.3% in healthy Saudi adults which is at least 5 times higher than what has been reported from Western Europe and the United States. Seropositivity rate in the high-risk groups ranges from 15.9% in patients with STD to 78.6% in hemophiliacs. These data underscore the urgent need for routine anti-HCV screening of blood donations in order to reduce the frequency of postransfusion non-A, non-B hepatitis and its sequelae in the Saudi population.

PIP: Non-A, non-B hepatitis, recently renamed as hepatitis C virus (HCV), accounts for over 90% of hepatitis cases worldwide associated with blood transfusions. Application of a recombinant-based enzyme immunoassay for the detection of antibodies to HCV to a sample of 500 male Saudi blood donors and 260 healthy Saudi pregnant women indicated that HVC is endemic in the Saudi population. Anti-HCV was detected in 28 (5.6%) of the blood donors and 12 (4.6%) of the pregnant women, for an overall frequency of 5.3% in healthy Saudi adults who had never received blood transfusions. This rate is at least 5 times higher than that reported for the US and Western Europe. Also assessed was the HCV rate in subsamples of Saudis considered at risk of this infection. Here, anti-HCV was detected in 22 (78.6%) hemophiliacs, 26 (33.3%) patients with thalassemia and sickle cell disease, 17 (26.1%) hemodialysis patients with renal failure, and 35 (15.9%) individuals with a sexually transmitted disease. The prevalence of anti-HBc ranged from 28% in blood donors to 46% in hemophiliacs. The significantly higher prevalence of HCV in patients with sexually transmitted diseases than in blood donors suggests that this disease is transmitted through heterosexual contact as well as blood transfusions. Given the high baseline level of HCV infection in the Saudi population and the possibility of serious sequelae (e.g., chronic active hepatitis, cirrhosis, and hepatocellular carcinoma), routine anti-HCV screening of blood donations is urged.

An outbreak of acute hepatitis A infection in rural Saudi Arabia.

In areas of hyperendemicity of hepatitis A virus (HAV) infection, acquisition of immunity occurs relatively early in life. In such populations epidemic outbreaks are rare. A recent HAV infection outbreak occurred in the Al-Dahnah district in Saudi Arabia. In thirty day period, 23 children and adolescents were diagnosed by clinical examination. 19 of these were positive for IgM anti-HAV. Concomitant acute infections with the Epstein Bar Virus (EBV) was documented in 4 of these patients. A limited epidemiological survey suggested that the source of infection might have been a contamination of one of the tankers which delivered water supplies to the various houses. In a transitional period of development the rapid improvement in socio economic status and standards of living may increase the susceptible pool. Therefore a greater surveillance is needed to identify and contain such possible outbreaks.

Rubella and cytomegalovirus (CMV) infections: laboratory aspects of investigation of antenatal, congenital, persistent, and subclinical infections.

Rubella specific IgM tests carried out on pregnant women with history of rubella contact or rubella-like rash indicated the presence of rubella-IgM by the second week after contact, persistence to 3-4 weeks followed by a decline and non-detectability around 8-9 weeks and at delivery. Laboratory investigation of cases of rubella infection in infants and children, including clinically proven and suspected congenital rubella revealed distinct patterns of combinations of positivity and negativity of IgM and IgG antibodies. Three cases of persistence of rubella specific IgM antibodies with one even up to 3 years in congenital rubella and a case of CMV-IgM persistence in congenital CMV are described. Rubella-IgM and CMV-IgM were detected in the serum of two patients aged 12 years and 24 years with CMV mononucleosis. Utilization of rubella-IgM/CMV-IgM tests enabled the identification of four cases of subclinical rubella and one of subclinical CMV in a pediatric population.

Indirect haemagglutination (IHA) test in the serodiagnosis of amoebiasis.

Among 72 patients clinically suspected of Entamoeba histolytica (E. histolytica) infections, 39 positive cases (54%) were detected serologically by the indirect hemagglutination (IHA) test. Parasitologically, microscopic examination of three consecutive stool specimens from all these patients indicated positivity for E. histolytica cysts and or trophozoites in 10 of the patients with IHA antibody titers greater than or equal to 1:128, which is of clinical significance. Another 2 patients were parasitologically positive but showed low IHA antibody titres (1:32-1:64); follow up indicated response to treatment with metronidazole. The highest serological positivity (100%) were detected in patients with liver abscess, all were clinically proven cases of extra-intestinal amoebiasis. IHA antibody levels of clinical significance were seen in all four patients with chronic dysentery with parasitological evidence of E. histolytica in their stools. In a group of patients with abdominal pain nine positives were detected serologically, four of which were positively diagnosed concurrently by parasitology; the remaining five patient's sera showed high IHA antibody titres with absence of cysts or trophozoites in stools, indicative possibly of persistence of antibodies from past infection. The serologic determination of E. histolytica IHA antibodies in a control group consisting of normal healthy school children and adults of both sexes without any clinical evidence of amoebiasis showed the absence of any positive titres of clinical significance; low titres (1:32-1:64) were detected in 5.2% of 232 sera tested. Parasitological examination of three consecutive stool specimens from all individuals in the control group showed the presence of cysts of E. histolytica in just two among 232 tested (0.9%).

Enzyme immunoassay in the diagnosis of Chlamydia trachomatis infections in diverse patient groups.

An enzyme immunoassay (EIA) in parallel with cell culture was used to investigate the extent of infections due to Chlamydia trachomatis. EIA reactive confirmed in cell culture was taken as positive. C. trachomatis was found in 6 (26.0%) of 23 men with symptomatic non-gonococcal urethritis (NGU), ten (17.2%) of 58 symptom-free males and in three of 4 with postgonococcal urethritis. Among 106 asymptomatic pregnant women studied the incidence of C. trachomatis was 8.5% while a higher incidence (16.7%) was found in those with symptoms. C. trachomatis positivity in asymptomatic and symptomatic post-natal screening were 11.4% and 7.7%. Of 43 symptomatic non-pregnant females investigated, 7 (16.3%) were found to be positive for C. trachomatis. Of 3 women with PID, 2 (66.7%) harboured C. trachomatis in their cervix while in another 29 infertile women, C. trachomatis was positive in 3 (8.1%). Contraceptives appeared to have an effect on the chlamydial positivity. Comparative testing of EIA with the standard cell culture method in this study indicate EIA as a suitable alternative for the definitive diagnosis of chlamydial infection in high prevalence settings and with caution in low prevalence settings.

PIP: In Riyadh, Saudi Arabia, physicians took endocervical swab examples from 325 women and urethral swab samples from 85 men to determine the extent of Chlamydia trachomatis infections and to compare an enzyme immunoassay (EIA) for the detection of C. trachomatis with the standard cell culture. All the men had urethritis. The women included pregnant, postnatal, and nonpregnant women. EIA positive tests were used to indicate C. trachomatis infection. 22.4% of all men had chlamydia infection (17.2% of symptom free men, 26% of men experiencing pain when urinating and/or urethral discharge, and 75% of men with postgonococcal urethritis). 8.6% of all pregnant women had cervical C. trachomatis infection (8.5% of asymptomatic pregnant women and 16.7% of pregnant women with vaginal discharge). 11.4% of all postnatal and nonpregnant women tested positive for C. trachomatis. The rates among these women were 66.7% for those who had pelvic inflammatory disease (PID), 50% for those with a history of abortion. 50% for those with a herpetic lesion, 25% for those using oral contraceptives (OCs), 16.3% for nonpregnant women with pain during urination and/or vaginal discharge, 11.4% for those with no symptoms, 8.1% for those with infertility, 7.7% for postnatal women having pain during urination or vaginal discharge, and 4% for those using IUDs. The EIA's sensitivity rates ranged from 75% for women with infertility to 100% for symptomatic men and those with postgonococcal urethritis, symptomatic pregnant women, symptomatic postpartum women, women with PID, and women using OCs. Specificity rates were higher and ranged 92.9-100%. EIA's high sensitivity and specificity along with its rapid performance make it a valuable diagnostic test in clinics where incidence of C. trachomatis infection tends to be high, e.g., sexually transmitted disease clinics. Clinicians could also use it in low risk settings, but they should be careful when interpreting results.

Lack of evidence for transplacental transmission of HBV infection by HBsAg-carrier mothers.

The possibility of transplacental transmission of HBV infection was investigated in 54 HBsAg-carrier Saudi mothers and their newborns. Controls were 60 Saudi mothers with previous exposure to HBV, and their newborns. Thirteen cord blood samples were HBsAg-positive by ELISA, including three from mothers with previous exposure to HBV, compared with one sample which was HBsAg- and HBeAg-positive and three samples which were only HBeAg-positive. Eight of the 13 cord blood samples which were HBsAg-positive by ELISA were haemolysed sera and were found to be HBsAg-negative by RIA and RPHA. None of the infants' sera, taken within 1-4 days of delivery, was positive for HBsAg or IgM anti-HBc. These results indicate that HBV markers in cord blood are either false-positive or due to contamination by maternal blood rather than an indication of in utero infection.

Comparison of haemagglutination test, enzyme-linked immunosorbent assay and indirect immunofluorescence antibody test for determination of rubella immune status.

Comparative evaluations of immune status for rubella are described for the enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence (IFA) and two standard haemagglutination inhibition tests (HAI kaolin; HAI heparin-MnCl2). In general, a reasonably good correlation was obtained between the level of rubella antibodies measured by the HAI (kaolin) test and by ELISA, but an appreciable proportion (15%) of ELISA positive specimens were encountered among HAI (kaolin) negative sera. All of these HAI negative, ELISA positive sera, except one were found to be positive for rubella antibodies by IFA. Neutralization test performed on this serum positive by ELISA only, confirmed the presence of protective rubella antibodies. Of all the tests evaluated ELISA appeared unequivocally to be the most sensitive test followed closely by IFA. The standard HAI (heparin-MnCl2) was more suitable than the HAI (kaolin), for the determination of immune status. Further, no linear relationship between single rubella virus HAI and ELISA values was observed.

Enzyme immunoassay (EIA) in the rapid diagnosis of gonorrhoea.

The diagnostic value of a new, modified enzyme immunoassay (EIA) (Gonozyme; Abbott Laboratories, North Chicago III) was evaluated for the rapid antigenic detection of Neisseria gonorrhoeae in endocervical and urethral specimens. EIA results were compared with those of Gram stain (GS) and conventional culture tests. EIA sensitivity and specificity for male patients attending dermatovenerological clinic were 100% and 96.8% respectively in comparison to 86.7% and 96.8% obtained by Gram staining. For female Obstetrics-Gynaecology patients EIA sensitivity of 100% was highly significant compared to 50% sensitivity by the Gram stain. In culture, 30 strains of N. gonorrhoeae were isolated from 125 male specimens and 2 from 105 specimens from females; this suggests a prevalence of N. gonorrhoeae of 24% in males and 1.9% in females. In vitro antibiotic sensitivity testing indicated 55% resistance to penicillin and 43% to ampicillin in these isolated strains; all were sensitive to erythromycin/tetracycline. 12% of the strains were beta-lactamase producers.

Routine screening of gynaecological and obstetric patients for Chlamydia trachomatis.

Chlamydia trachomatis infection of the cervix uteri was diagnosed in 9% of 221 gynaecological and obstetric patients. Infection occurred more commonly among obstetric (12.6%) than gynaecological patients (5.5%). In obstetric patients chlamydial infection was commoner in those complaining of excessive vaginal discharge or spontaneous premature rupture of the membranes. Chlamydial infection in gynaecological patients occurred in those with previous pelvic infection, menstrual disorders or excessive vaginal discharge. No cases of chlamydial infection were detected among intrauterine device users. The enzyme immunoassay we used is an easy and relatively quick method of diagnosis for genital chlamydial infection.

A serological survey of the prevalence of Toxoplasma gondii antibodies in dogs and cats in Saudi Arabia.

The prevalence of Antibodies to Toxoplasma gondii in dogs and cats were determined by an indirect haemagglutination (IHA) test. 3% of the dogs' sera and 15.2% of that of the cats showed titres diagnostically significant of toxoplasmosis in humans; their possible role in transmission of toxoplasmosis to humans in Saudi Arabia is discussed.