Epidemiological and clinical analysis of hepatitis virus A infections during three successive outbreaks in Sfax (Tunisia) between 2007 and 2010.

to describe the epidemiological and clinical characteristics of HAV infection during three successive outbreaks occurring between 2007 and 2010 in the governorate of Sfax. epidemiological and clinical characteristics were retrospectively analyzed from the outbreak investigations. The diagnosis of acute hepatitis A was confirmed by ELISA detection of immunoglobulin M serum antibodies to HAV. 443 patients were identified and 159 of them investigated. Their mean age was 12.2 years and the M/F ratio was 0.9. The most affected age groups were 6-10 years (35%) and 11-15 years (33%). The most likely sources of contamination were drinking water from wells or tanks and direct transmission. The most frequent symptoms included asthenia, digestive disorders, and jaundice. Two cases of fulminant hepatitis were reported, one lethal. our results show that HAV endemicity in the governorate of Sfax has dropped from high to intermediate as demonstrated by the increasing age at primary HAV infection. Strengthening health education and improving access to drinking water would reduce the transmission risk of HAV in our regions.

[North African and Southeast Asian nasopharyngeal carcinomas: between the resemblance and the dissemblance]. / Le carcinome nasopharyngé en Afrique du Nord et dans le Sud-Est asiatique: entre similitude et différence.

Nasopharyngeal carcinoma (NPC) is an unusual head and neck cancer because of its unequal geographical distribution and its consistent association with the Epstein-Barr virus (EBV). This malignant tumor poses a serious public health problem in many countries, especially in Southeast Asia and North Africa where the recorded incidence are highest. During the past decade, a growing number of studies were undertaken to define the molecular basis of NPC. However, the analysis of several clinical and biological parameters of North African and Southeast Asian NPCs has shown notable differences, suggesting that they could result from a distinct combination of etiological factors. One intriguing characteristic of North African NPC, concerns its bimodal age distribution with a secondary peak of incidence in the range of 15-25 years, not observed in Asian NPC. In this juvenile form of NPC, immuno-histochemistry assay has shown that the two key proteins controlling the apoptotic-survival balance p53 and Bcl-2 are less frequently expressed whereas the transmembrane tyrosine-kinase receptor c-kit and the main EBV oncoprotein LMP1 were more abundant. In addition, the EBV serological alterations are less informative for the diagnosis of the juvenile compared to the adult form. In addition, most North African NPCs contain EBV strains with genetic polymorphisms distinct from those described in the Southeast Asia series (predominance of F, D, H1-H2, XhoI+ and f, C, H, XhoI- respectively). In contrast, studies relating on tumor chromosomal alterations or aberrant promoter methylation result in data very similar to those obtained from the Southeast Asia series, supporting the concept of a common molecular basis for all NPC regardless of patient geographic origin.

Comparison of hepatitis A seroprevalence in blood donors in South Tunisia between 2000 and 2007.

The aim of the study was to assess hepatitis A virus (HAV) seroprevalence in blood donors from South Tunisia in two periods 2000 and 2007. Serum samples collected from 376 blood donors in each period aged 18 to 30 years from different regions of South Tunisia were analysed for anti-HAV IgG. The global seroprevalence of HAV infection was 85.9% in 2007 as compared with 94.9% in 2000. The seroprevalence in the 18-20 years age group was 91.9% in 2000 vs 80.6% in 2007, and increased to 99% in 2000 and 92% in 2007 in the subjects over 26. Taking account of geographic area, the HAV seroprevalence in Sfax city decreased from 88.9% in 2000 to 62.7% in 2007 (p < 0.001), but it is still approximatively the same in rural areas (98.4% and 96%) and in the governorates of South Tunisia (97.6% and 99.2%). In conclusion, the number of adults in the city of Sfax which are not immunized against HAV is increasing. Thus, adolescents and young adults are at risk to develop symptomatic and potentially severe hepatitis A.

[Significance of "anti HBC alone" serological profile in 284 patients suspicious of being infected with hepatitis B virus]. / Signification du profil sérologique "anticorps anti-HBC isolés" chez 284 patients suspects d'être infectés par le virus de l'hépatite B.

The "anti-HBc alone" serological profile is a frequent finding in hepatitis B virus infections, but little is known about its clinical significance. The aim of this study was to explore the 'anti-HBc alone' serological profile obtained by immunosorbent assay (ELISA) in 284 patients suspicious of being infected with hepatitis B virus. Sera were screened for following serological markers: HBs Ag, anti-HBc and anti-HBs antibodies using immunoradiometric assay (IRMA) and for HBV DNA using polymerase chain reaction. Among 284 studied sera with 'anti-HBc alone' serological profile, 124 were positives for anti-HBs antibodies by IRMA and corresponding to a recovered form of hepatitis B. Nineteen sera were negatives for anti-HBc antibodies, suggesting false positive results by ELISA. Two sera were found positives for HBs Ag by IRMA, which are related to authentic hepatitis B. HBV DNA was positive in 4 sera, suggesting occult hepatitis B. This study indicates that "anti-HBc alone" serological profile is most often correlates with recovered hepatitis B infection, but it can mask an occult hepatitis B.

[Streptococcus pneumoniae of lesser sensitivity to penicillin in the Sfax region, Tunisia (1994-1995)]. / Streptococcus pneumoniae de sensibilité diminuée à la pénicilline dans la région de Sfax, Tunisie (1994-1995).

In the last fifteen years, the frequency of Streptococcus pneumoniae resistance to penicillin has been regularly increasing with various degrees in different geographical zones. In order to determine the epidemiological situation in our region, we studied penicillin G susceptibility of S. pneumoniae strains isolated in our laboratory for 2 years 1994 and 1995. The S. pneumoniae strains with reduced susceptibility to penicillin G (PSDP) were detected by oxacillin screen test (using 1 microgram oxacillin disk) and completed with the determination of penicillin G MIC. We isolated 107 S. pneumoniae strains (41 in 1994 and 66 in 1995); 12 of them had reduced susceptibility to penicillin (11.2%). The study showed a difference in the percentage of penicillin susceptibility between invasive (5.1%) and non invasive strains (28.6%). The rate of strains with reduced susceptibility to penicillin increased from 7.3% in 1994 to 13.6% in 1995 with a higher degree of resistance in 1995. We concluded that our region is not spared from the problem of the decreased susceptibility to penicillin G of S. pneumoniae. These results should prompt us to survey the evolution of such resistance.