Monitoring rotavirus environmental contamination in a pediatric unit using polymerase chain reaction

Rotavirus environmental contamination in a pediatric unit was investigated. Surfaces were swabbed, then viruses eluted, ultracentrifuged, and detected by polymerase chain reaction (PCR) amplification. Of 55 samples, 25 (46%) tested positive. Rotavirus RNA was more prevalent on surfaces in direct contact with children (thermometers and play mats) than on other environmental surfaces (washbasins, door handles, etc). PCR has proved useful for monitoring rotavirus environmental contamination.

[Adenocarcinoma of unknown primary site with thoracic localization and HIV: four case reports]

INTRODUCTION

Non AIDS-defining cancer would have increased in HIV-patients as suggested by numerous studies. Four cases of adenocarcinoma of unknown primary site with thoracic localization that occurred in HIV-infected patients are described.

EXEGESIS

To date, there have been no published data about carcinomas of unknown primary site relating to HIV-infected patients; however, immunodepression could promote them. Carcinomas of unknown primary site account for 0.5 to 10% of all cancer in general population. Primary carcinoma is identified in approximately one third of the cases and often corresponds to lung cancer in case of sus-diaphragmatic metastasis, particularly in case of pleural metastasis. Lung cancer in HIV-infected patients affects mostly young men who smoke and are often intravenous drug addicts. Adenocarcinoma is the most common histological type of cancer.

CONCLUSION

Further studies of lung cancer in HIV-infected patients will help evaluate their frequency. In case of increasing frequency, lung cancer should then be included in AIDS-defining cancers.

[Virus resistance in a hospital environment: overview of the virucide activity of disinfectants used in liquid form]

Human pathogenic viruses can be detected in the hospital environment, on contaminated surfaces or medical instruments. Their transmission to patients or staff has already been reported. Lipophilic viruses (HIV, HBV, HCV,...) are susceptible to many liquid chemicals, but they can survive during short time on inadequately disinfected surfaces. Hydrophilic viruses, without envelope, are more resistant, but generally not associated with severe illnesses. Viruses survival in environment depends on many factors and is always improved with viral aggregation and low temperature, whereas organic matters and relative humidity effects are contrasted. The mechanism of virucide disinfectants is not yet well established, and their targets are not known with precision. Different disinfection procedures (disinfectant concentration, contact time, temperature, pH) can provide a similar virucidal activity on a given virus. The virucidal activity of a disinfectant is evaluated with a cell culture assay in Afnor guidelines. But, there are three major problems with this method, concerning need of high viruses titers, residual disinfectant cytotoxicity on cell culture, and non cultivable viruses. Non standardized tests are also described in papers, but their results can generally not be compared. Molecular biology improvements may lead to reproducible and sensitive tests. At present, no general disinfection procedure effective for most of the viruses, without risks for staff or materials, and with an acceptable economic cost can be recommended.

Zidovudine plus didanosine in primary HIV-1 infection

Viraemia levels in the months following primary HIV-1 infection (PHI) predict the subsequent course of the infection. Inhibition of viral replication in PHI patients might improve their clinical prognosis. In this study, we evaluated the antiviral efficacy of the association of two reverse transcriptase inhibitors--zidovudine at 250 mg twice daily and didanosine at 200 mg twice daily--in 12 patients treated for at least 6 months (median 10 months, range 6-15 months). We compared values for viraemia, proviral DNA and CD4:CD8 ratios in these patients with two historical control groups consisting of 16 untreated patients and 15 patients on zidovudine therapy. Significantly lower viraemia was observed between 3 and 12 months in patients on zidovudine-didanosine therapy. Viraemia levels lower than 200 HIV-1 RNA copies/ml were observed in 3/12 patients on zidovudine-didanosine therapy after 3 months, in 8/12 after 6 months and in 3/5 after 12 months. Only one of the 31 historical control patients had undetectable viraemia. For proviral DNA, smaller differences between groups were observed, although with time proviral DNA became undetectable (< 1 copy/7.5 x 10(5) lymphocytes) in four patients from the zidovudine-didanosine group versus one in the control groups. Finally, the CD4:CD8 ratio was significantly higher in the zidovudine-didanosine group and none of the patients in this group developed HIV-1-associated clinical complications. These data suggest a higher efficacy of combined therapy compared with zidovudine monotherapy in PHI patients and indicate that control of viraemia for at least 1 year is achievable in PHI patients.