Infectionwith BKvirus in man is common in England (Gardner, 1973); haemagglutinationinhibiting (HI) and complement-fixing antibodies were found in all age gropps. We investigated 453 healthy people in Italy by the HI test, and also by the fluorescent-antibody (FA) technique to detect antibodies to other structural components of the virion. MATERIALS AND METHODS Virus and cells. BK virus was kindly supplied by Dr S. D. Gardner and was grown inVero cells. Growth and maintenance media were Eagle's minimum essential medium supplemented with 2.5 % foetal bovine serum. One week after infection of the cultures the medium was changed and after a further 7-10 days' incubation, when cytopathic effects were clearly evident, cells and medium were frozen and thawed once, treated for 2 min. in a Branson ultrasonic disintegrator, and centrifuged at 800 g for 10 min. to sediment cellular debris. The supernatant fluid had a titre of 2048 to 40,768 haemagglutinating units (HAU) per ml, and was used as antigen in the haemagglutination (HA) and HI antibody tests. SV40 was grown in Vero cells in the same way as BK virus.Sera. Serum specimens were obtained from healthy donors, ages 19-65 years, in the Blood Centre of the University Hospital, Bologna. Other sera were collected from healthy children and young people, aged 6 months-18 years, in Milan.Haemagglutination. HA and HI antibody tests were performed in disposable plates by the microtitre method (Sever, 1962). Serial two-fold dilutions of BK virus were made in 0.05-ml amounts of phosphate-buffered saline (PBS), pH 7.2. Human type-0 erythrocytes, from healthy donors, were washed three times and suspended to a concentration of 0-5 % in PBS. One volume of PBS and two volumes of 0.5% erythrocytes were added to each virus dilution. Plates were incubated at +4"C and the HA titre was read 4 hours later, when control erythrocytes in PBS only had completely sedimented. The highest dilution of antigen giving complete haemagglutination was considered to contain 1 HAU. Haemagglutination-inhibition. Sera were heated at 56°C for 30 min. and treated with NaI04 to remove non-specific inhibitors. Serial, two-fold dilutions of serum, from 1 in 4 to 1 in 8192, were made in 0.05 ml amounts of PBS. One volume of PBS containing 8 HAU of antigen was added to each serum dilution and the mixtures were kept at room temperature for 1 hour. After this time, two volumes of 05% erythrocytes were added, the plates were incubated at + 4°C for 4 hours, and the HI-antibody titres were read. From the correlation

Primary hamster kidney cells were transformed by BK virus, a new human papovavirus. Transformed (HKBK) cells produced BK virus T antigen and induced tumors in hamsters that developed antibodies to BK virus T antigen. BK virus was rescued from HKBK cells by Sendai virus-assisted fusion with permissive cells. One out of six cell lines derived from HKBK cell-induced tumors showed the same characteristics as HKBK cells.

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The leishmanin skin test was used in four different areas of the Italian Adriatic coast (Emilia Romagna, Marche, San Marino and Abruzzi), old endemic areas for cutaneous leishmaniasis. The test was found to be postitive in 80% of past infections, the 20% negative reactions being found in those who had been infected 20 or more years before. In the old endemic area of Teramo there was increasing positivity with age, with a sharp rise in the over 30 years age group suggesting that there had been a sudden break in transmission 30 years ago, coinciding with the DDT campaign of 1944-45. In San Marino in the past overt infection had occurred in a number of small microfoci, centred on houses surrounded by a larger number of inapparent infection. Control studies on a number of infectious and non-infectious diseases were all negative, and there was no relationship between tuberculin and leishmanin sensitivity.

Given the current lack of a therapeutic vaccine for coronavirus disease 2019 (COVID-19), preventive measures including mask wearing are crucial in slowing the transmission of cases. However, prolonged wearing of protective respirators, medical and fabric masks can easily generate excessive sweating, moisture and friction. Closed and warm environments heighten the skin's permeability and sensitivity to physical or chemical irritants, leading to chronic cumulative irritant contact dermatitis or, rarely, even allergic contact dermatitis. Although not representing a lifethreatening condition, contact dermatitis can have a significant impact on emergency management, as it is potentially able to reduce work performance and create emotional discomfort due to the involvement of evident body areas. To minimize the skin breakdown, adherence to standards on wearing protective and safe equipments and avoidance of overprotection should be performed. At the same time, some measures of skin care are recommended. Here, we offer some tips on how to prevent and manage contact dermatitis due to masks not only in health care workers, but also in the general population during this COVID-19 outbreak.