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Viral infections remain a major complication of allogeneic bone marrow transplantation. A population of children who underwent unrelated allogeneic bone marrow transplantation in a single centre has been followed-up for viral infections and diseases. We describe the detection of cytomegalovirus (CMV) and adenovirus among 75 children transplanted between 1989 and 2000. CMV was detected among 22 patients (29%) and adenovirus among 19 patients (25%); they were associated with clinical diseases in 10 and 8 patients, respectively. Four patients had adenovirus and CMV coinfection. The obvious risk factor for CMV infection is seropositivity of the recipient prior to transplantation. Adenovirus is detected significantly more frequently when conditioning regimen includes anti-thymocyte or anti-lymphocyte globulin. Diseases associated with adenovirus have been correlated with a significantly higher mortality rate, stressing the need for the implementation of a systematic virological survey for this virus and for the evaluation of therapeutic protocols including new molecules., (Copyright 2004 Wiley-Liss, Inc.)

HSV infections are treated efficiently and prevented by acyclovir, although resistant strains have been reported. Resistance to acyclovir involves mainly mutations in the viral gene encoding thymidine kinase; mutations may lead to an altered or, more frequently, deficient TK. These acyclovir-resistant TK deficient strains are not able to reactivate from a latent infection in an experimental model, compared to TK positive strains. A case is reported of a bone marrow transplant child who developed HSV infection at 11 days post-transplantation. Acyclovir-resistant HSV 1 was isolated on day 19 post-transplantation. The patient was cured of his infection. A resistant virus was detected 20 months later that harboured the same TK gene mutation as the first resistant virus. This mutation is an insertion of one guanine in a homopolymer repeat of seven guanines located at codon 146 of TK. It has previously been reported and associated with the expression of a deficient TK activity and the ability to reactivate in mice. These results corroborate the clinical relevance of this mutation, which is associated with acyclovir-resistant recurrent infections in humans., (Copyright 2000 Wiley-Liss, Inc.)

Herpes simplex viruses (HSV) are responsible for neurological disorders that require rapid diagnostic methods and specific antiviral therapy. During 1997, 1431 cerebrospinal fluid samples (CSF) collected from 1339 patients with neurological disorder presentations were processed for HSV detection. Eleven patients were positive for HSV, seven presenting with encephalitis (6/7 due to HSV1) and 4 with aseptic meningitis (4/4 due to HSV2). The incidence of HSV encephalitis was 2.33 cases / 10(6) inhabitants/year. Among encephalitis (HSV encephalitis) cases, 1 patient died due to the late implementation of antiviral therapy, and sequelae were observed in 4 cases. No sequelae were observed in aseptic meningitis cases. Four HSV encephalitis cases were monitored by PCR detection in CSF. Despite acyclovir therapy, PCR remained positive in CSF up to 20 days in 2 cases. This result suggest that the antiviral treatment for HSV encephalitis should be monitored by PCR detection of HSV in CSF., (Copyright 2000 Wiley-Liss, Inc.)

In a prospective comparative study, the use of combined analysis of upper respiratory tract swab samples and cerebrospinal fluid (CSF) samples was assessed to improve the detection rate of enteroviral meningitis in children. An enterovirus was detected in 32% of patients with aseptic meningitis when testing CSF samples alone compared with 71.5% when combining CSF and respiratory tract findings. An enterovirus was detected in 17% of respiratory tract samples in an age- and sex-matched control group without meningitis. Thus, combining the examination of upper respiratory tract with CSF findings may improve the detection rate of enteroviral meningitis. Upper respiratory tract samples should be included in the diagnosis scheme to differentiate benign enteroviral meningitis from other life-threatening infections of the central nervous system.