Changing patterns of hepatitis A prevalence within the Saudi population over the last 18 years

AIM: To determine the seroprevalence of Hepatitis A (HAV) amongst Saudi children and compare it with previously reported prevalence data from the same population.

METHODS: A total of 1357 students were randomly selected between the ages of 16 and 18 years (689 males and 668 females) from three different regions of Saudi Arabia (Madinah, Al-Qaseem, and Aseer) and tested for anti-HAV-IgG.

RESULTS: The overall prevalence of anti-HAV-IgG among the study population was 18.6%. There was no difference between males and females but there was a significant difference in the seroprevalence (P = 0.0001) between the three different regions, with Madinah region showing the highest prevalence (27.4%). When classified according to socioeconomic status, lower class students had a prevalence of 36.6%, lower middle class 16.6%, upper middle class 9.6%, and upper class 5.9% (P = 0.0001). Comparing the current study results with those of previous studies in 1989 and 1997 involving the same population, there was a marked reduction in the overall prevalence of HAV from 52% in 1989, to 25% in 1997, to 18.6% in 2008 (P < 0.0001).

CONCLUSION: Over the last 18 years, there has been a marked decline in the prevalence of HAV in Saudi children and adolescents. The current low prevalence rates call for strict adherence to vaccination policies in high-risk patients and raises the question of a universal HAV vaccination program.

Occurrence of inhibitors in previously untreated or minimally treated patients with haemophilia A after exposure to a plasma-derived solvent-detergent factor VIII concentrate

A solvent-detergent virus-inactivated plasma-derived FVIII concentrate (SD-pdFVIII) has been employed for treatment of Italian patients with haemophilia A for 15 years. This product is a non-monoclonally purified, high purity FVIII concentrate, containing large amounts of von Willebrand factor (VWF). A retrospective survey was carried out in Italy in order to evaluate the immunogenicity of SD-pdFVIII in previously untreated patients (PUPs) or in minimally treated patients (MTPs), i.e. previously exposed for up to 5 days only to other plasma-derived concentrates. The survey included 99 patients with ages ranging from 6 to 64 years (median=21.3) of whom 31 PUPs and 68 MTPs, the latter with a median of four exposure days (EDs; range 1-5) to other plasma products. Surveyed patients had been exposed to SD-pdFVIII for a median of 83 EDs (range 21-1580). Seven patients (three PUPs and four MTPs), all with severe haemophilia, had developed inhibitors [7.1%, 95%; confidence interval: 3-14%] after a median of 11 EDs (range 4-22). Of them, two were low responders (<or=5 BU mL-1) and five high responders. Two low responders and one high responder tolerated inhibitors spontaneously; one high responder underwent immunotolerance treatment with complete, long-standing response. These findings show that SD-pdFVIII is at low risk of inhibitor development in PUPs and MTPs with severe and moderate haemophilia, the risk of inhibitor development being similar to that previously reported for other plasma-derived VWF-containing FVIII products.