[Seroprevalence of human parvovirus B19 in children with fever and rash in the North of Tunisia]. / Prévalence de l'infection par le parvovirus B19 humain au cours des éruptions fébriles de l'enfant dans le Nord tunisien.

The aim of the study is to evaluate the prevalence of specific antibodies anti-human parvovirus B19 (PVB19) immunoglobulin M (IgM) and IgG in children with fever and rash. This study involved 257 children aged from 7 months to 15 years with febrile rash unrelated to measles and rubella (seronegative for IgM). The sera were examined by immunoenzymatic assay. Detection of antibodies of PVB19 was done by enzyme-linked immunosorbent assay (Elisa). In our study, prevalence of immunoglobulin G (IgG) and IgM were 44 and 11.3%, respectively. Clinically, children with positive IgM serology had submitted an erythema infectiosum (13/29 cases), myocarditis (1 case), encephalitis (1 case), severe sickle cell anemia (7 cases), and immunocompromised (7 cases). The incidence rate of viral infection was 11.3%; most of the cases of PVB19 infection occurred between the months of May and August. Incidence was higher in the 10-15 years age group (21%). The prevalence of IgG antibody varied and increased with age, it rises from 38.2% in preschool children (19 months-4 years) to 53.5% in those aged between 4.5 and 15 years, reaching 58% in the 10-15 years age group. The four risk factors of PVB19 infection are: (1) those aged between 4.5 and 9 years, which is the most affected age group (P = 0.0018); (2) female gender in children aged between 19 months and 4 years (P = 0.037); (3) transfusion and (4) immune deficiency (P = 0.022 and P = 0.001, respectively). The study of the prevalence of PVB19 infection shows that viral infection is acquired early in childhood, increases with age; viral transmission is favored by the community life. Because of the widespread vaccination program against measles and rubella, the systematic search of PVB19 in front of eruptive fevers becomes important.

Congenital Thrombotic Thrombocytopenic Purpura: Atypical Presentation and New ADAMTS 13 Mutation in a Tunisian Child.

BACKGROUND: Congenital deficiency of ADAMTS13 is characterized by systemic platelet clumping, hemolytic anemia and multiorgan failure. Although, more than 100 mutations have been reported, atypical clinical presentation may be involved in diagnostic difficulties. CASE REPORT: A 2 year old Tunisian child presented with chronic thrombopenic purpura which failed to respond to corticosteroids. Hemolytic anemia with schistocytes, occurred ten months later, with no previous history of diarrhea or any neurological abnormality. Renal function and coagulation screening tests were normal. The count of platelet improved after fresh frozen infusion (FFP). Extensive investigations revealed a severe deficiency of ADAMTS 13 activity (level< 5%). Gene sequencing identified mutation in exon 18 of ADAMTS 13 gene. Prophylactic regimen with regular infusions of FFP was associated to favorable outcome. CONCLUSION: Early ADAMTS 13 activity testing and gene sequencing associated to precocious plasmatherapy are recommended to reduce morbidity and mortality of congenital TTP.

Glucose-6-phosphate dehydrogenase deficiency in Tunisia: molecular data and phenotype-genotype association.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect. In this study, we aimed to perform a molecular investigation of G6PD deficiency in Tunisia and to associate clinical manifestations and the degree of deficiency with the genotype. A total of 161 Tunisian subjects of both sexes were screened by spectrophotometric assay for enzyme activity. Out of these, 54 unrelated subjects were selected for screening of the most frequent mutations in Tunisia by PCR/RFLP, followed by size-based separation of double-stranded fragments under non-denaturing conditions on a denaturing high performance liquid chromatography system. Of the 56 altered chromosomes examined, 75 % had the GdA(-) mutation, 14.28 % showed the GdB(-) mutation and no mutations were identified in 10.72 % of cases. Hemizygous males with GdA(-) mutation were mostly of class III, while those with GdB(-) mutation were mainly of class II. The principal clinical manifestation encountered was favism. Acute hemolytic crises induced by drugs or infections and neonatal jaundice were also noted. Less severe clinical features such as low back pain were present in heterozygous females and in one homozygous female. Asymptomatic individuals were in majority heterozygote females and strangely one hemizygous male. The spectrum of mutations seems to be homogeneous and similar to that of Mediterranean countries; nevertheless 10.72 % of cases remain with undetermined mutation thus suggesting a potential heterogeneity of the deficiency at the molecular level. On the other hand, we note a better association of the molecular defects with the severity of the deficiency than with clinical manifestations.

[Mortality rates in pediatric septic shock secondary to community-acquired infection: about 70 cases]. / Mortalité au cours du choc septique de l'enfant secondaire à une infection communautaire: à propos de 70 cas.

GOAL: This study had for aim to determine the mortality rate and the factors affecting mortality among 70 children admitted for septic shock secondary to a community acquired infection. PATIENTS AND METHODS: A retrospective analysis was made of patients admitted between January 1998 and August 2005, in a pediatric ICU for septic shock secondary to a community-acquired infection. Neonates under 7 days of age were excluded from the study. RESULTS: Seventy cases were included and 32 (45.7 %) of them died. Their average age was 3.8+/-4.2 years and their PRISM during the first 24 hours was 19.2+/-8.4. Sixty-nine children (98.6 %) presented with multivisceral failure and 60 (85.7 %) with more than two deficient organs. The average time between the observation of first hemodynamic disorders and admission to ICU was 9.4+/-11.3 hours. Three independent mortality risk factors were identified: failure of more than two organs on admission (OR, 4.4; 95 % CI [2.1-9.4]), an infusion volume superior to 20ml/kg on the second day of resuscitation (OR, 3.4; 95 CI % [1.1-10.3]), and the use of more than two vasoactive drugs (OR, 3.3; 95 CI % [1.2-9]).

[Epidemiology of nosocomial bacterial infections in a neonatal and pediatric Tunisian intensive care unit]. / Epidémiologie des infections bactériennes nosocomiales dans une unité de réanimation néonatale et pédiatrique tunisienne.

OBJECTIVE: The authors had for aim to describe the epidemiology of nosocomial bacterial infections in the neonatal and pediatric intensive care unit of the Tunis children's hospital. DESIGN: A prospective surveillance study was made from January 2004 to December 2004. All patients remaining in the intensive care unit for more than 48 h were included. CDC criteria were applied for the diagnosis of nosocomial infections. RESULTS: 340 patients including 249 (73%) neonates were included. 22 patients presented with 22 nosocomial bacterial infections. The incidence and the density incidence rates of nosocomial bacterial infections were 6.5% and 7.8 per 1,000 patient-days, respectively. Two types of infection were found: bloodstream infections (68.2%) and pneumonias (22.7%). Bloodstream infections had an incidence and a density incidence rate of 4.4% and 15.3 per 1,000 catheter-days, respectively. Pneumonia had an incidence and a density incidence rate of 2% and 4.4 per 1,000 mechanical ventilation-days, respectively. The most frequently isolated pathogens were Gram-negative bacteria (68%) with Klebsiella pneumoniae isolates accounting for 22.7%. The most common isolate in bloodstream infections was K. Pneumoniae (26.7%), which was multiple drug-resistant in 85% of the cases, followed by Staphylococcus aureus (20%). Pseudomonas aeruginosa was the most common isolate in pneumonia (28.6%). Associated factors of nosocomial infection were invasive devices and colonization with multiple drug-resistant Gram-negative bacteria. CONCLUSIONS: The major type of nosocomial bacterial infections in our unit was bloodstream infection and the majority of infections resulted from Gram-negative bacteria. Factors associated with nosocomial bacterial infections were identified in our unit.