Isolation of enterovirus 70 (EV70) from patients with acute haemorrhagic conjunctivitis in two areas of Saudi Arabia

This is the first epidemic of acute haemorrhagic conjunctivitis (AHC) reported from Saudi Arabia in which enterovirus 70 (EV70) was implicated as aetiological agent. EV70 was isolated from 5 of 29 conjunctival scrapings from patients with AHC. Two human diploid cell lines, human skin fibroblast (HSF) and human embryonic lung fibroblast (MRC-5), were quite sensitive for the isolation of this virus. The relatively high isolation rate could also be attributed to the timing of collection of specimens and perhaps to the fact that conjunctival scrapings contained more virus particles than did eye swabs.     

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.     

Bacterial, parasitic and viral enteropathogens associated with diarrhoea in Saudi children

In a 2-year study of stools from Saudi children with gastro-enteritis and from controls, rotavirus was the pathogen most frequently detected, either alone (44.3%) or in combination with other enteropathogens (7%). There were two peaks for rotavirus isolates, one during the cold months and the other during the dry, hot season. Salmonella spp. and Campylobacter jejuni were the second and third most frequently isolated enteropathogens. Enteropathogenic Escherichia coli did not contribute significantly to diarrhoea. Detection of enterotoxigenic E. coli was not attempted and its role in diarrhoea remains obscure. Giardia lamblia was detected more frequently in controls than in cases of diarrhoea. Neither Entamoeba histolytica nor Schistosoma mansoni was detected in any of the children studied.     

Decline in hepatitis B infection in sickle cell anaemia and beta thalassaemia major.

Seventy five Saudi children, 55 with sickle cell anaemia and 20 with beta thalassaemia major, who were negative for all hepatitis B virus (HBV) markers five years ago were recently investigated for exposure to HBV and hepatitis C virus (HCV) infection. Of the 55 patients with sickle cell anaemia and 20 with beta thalassaemia major, 20 and five patients respectively had been vaccinated against HBV earlier and all of them still had protective antibody (anti-HBs 42-96 IU) 3-5 years after vaccination and there was no vaccine failure. Among the non-vaccinated children the exposure rates to HBV were 14.3% among those with sickle cell anaemia and 26.7% among those with beta thalassaemia and this was not statistically significant when compared with the exposure rate to HBV among the general paediatric population (20.1%). Anti-HCV positivity among those with beta thalassaemia major and sickle cell anaemia was 70% and 18.2%, respectively, and this was significantly higher than anti-HCV positivity among the control group (0.8%). Anti-HCV positivity was directly related to the amount of blood transfused and to the duration of transfusion. The results of the study show that although the exposure rates to HBV among patients with sickle cell anaemia and beta thalassaemia major were not significantly different than that among the general paediatric population, infection with HBV still takes place among non-vaccinated patients despite strict precautionary measures taken. Hence early vaccination against HBV would probably be the only effective way of controlling HBV infection. For HCV infection, and because a vaccine against HCV is still not available, preventive measures such as blood screening for anti-HCV before transfusion and stringent infection control measures are crucial steps to be implemented for the control of spread of HCV among these groups of patients.     

Hepatitis B virus DNA in serum of 'anti-HBc only'-positive healthy Lebanese blood donors: significance and possible implications

Transmission of HBV infection through transfusion of HBsAg-negative blood has been documented. It is evident that low levels of HBV-DNA remain detectable in serum and liver tissue of some patients who clear HbsAg, and that the detection rate is highest in individuals who are 'anti-HBc positive alone'. This study was designed to assess the frequency and clinical significance of 'anti-HBc alone' in Lebanese blood donors. A total of 5511 blood donor samples from three major hospitals representing most regions of the country were tested for anti-HBc, amongst other screening tests. Samples positive for 'anti-HBc alone' were then tested for HBV-DNA and any positive for HBV-DNA were then genotyped and investigated for hepatitis B viral load. The study showed that 203 (3.7%) of randomly selected Lebanese blood donors were confirmed as 'anti-HBc alone'. Of these, 11 (5.4%) were HBV-DNA positive as detected by nested PCR. All samples had HBV-DNA levels below 400 copies/ml and all were genotype D. It can be concluded that HBV was present, although the circulating amount of virus was below the detectable limit for the assay used. Therefore, routine screening for anti-HBc may be required in Lebanese blood donation centres as an additional preventive measure for controlling transmission of HBV via blood transfusion.     

Genotypes of hepatitis C virus (HCV) among positive Lebanese patients: comparison of data with that from other Middle Eastern countries

Recently we identified hepatitis C virus (HCV) genotype 4 as the principle genotype among Lebanese thalassaemics. In an attempt to confirm the predominance of genotype 4 in Lebanon and perhaps in the Middle East, genotyping was attempted on 142 HCV-infected Lebanese patients from five different hospitals in the country. These included 38 HCV-positive patients with symptomatic liver disease who were referred to gastroenterologists and 104 HCV-positive patients with no symptoms of liver disease: 27 patients with thalassaemia, 30 patients on haemodialysis, 32 multi-transfused and 15 intravenous drug users. HCV genotyping was performed on PCR HCV RNA-positive samples using a commercial line probe assay (LiPA; Innogenetics, Ghent, Belgium). HCV genotype 4 is found to be the predominant genotype among HCV-infected Lebanese patients (ranging from 34.2% to 53.3%) followed by 1a (ranging from 12.5% to 43.3%) and 1b (ranging from 8.0% to 34.4%). In patients with symptomatic liver disease, however, genotype 4 (34.2%) was preceded by genotype 1a (39.5%). The predominance of HCV genotype 4 in our population (45.7%) confirms the predominance of HCV genotype 4 in Lebanon and most of the Arab countries in the Middle East but contrasts with data reported from non-Arab Middle Eastern Countries as can be seen from the literature review. Implications of genotyping for clinical outcome of HCV infection, response to treatment as well as for vaccine development are discussed.