Severe acute respiratory syndrome coronavirus 2 detection by real time polymerase chain reaction using pooling strategy of nasal samples.

COVID-19 is a life-threatening multisistemic infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Infection control relies on timely identification and isolation of infected people who can alberg the virus for up to 14 days, providing important opportunities for undetected transmission. This note describes the application of rRT-PCR test for simpler, faster and less invasive monitoring of SARS-CoV-2 infection using pooling strategy of samples. Seventeen positive patients were provided with sterile dry swabs and asked to self-collected 2 nasal specimens (#NS1 and #NS2). The #NS1 was individually placed in a single tube and the #NS2 was placed in another tube together with 19 NSs collected from 19 negative patients. Both tubes were then tested with conventional molecular rRT-PCR and the strength of pooling nasal testing was compared with the molecular test performed on the single NS of each positive patient. The pooling strategy detected SARS-CoV-2 RNA to a similar extent to the single test, even when Ct value is on average high (Ct 37-38), confirming that test sensibility is not substantially affected even if the pool contains only one low viral load positive sample. Furthermore, the pooling strategy have benefits for SARS-CoV-2 routinary monitoring of groups in regions with a low SARS-CoV-2 prevalence.

[Assessment of occupational risk of Legionella spp. infection among dental health-care personnel]. / Valutazione del rischio professionale per infezioni da Legionella spp nel personale di assistenza odontoiatrica.

Various authors have reported the presence of Legionella spp. in dental unit waterlines with prevalence rates reaching, in some cases, 69.7% In order to evaluate the association between occupational exposure to Legionella and risk of infection, anti-Legionella spp. antibodies were measured in 88 dental assistants, 44 of which exposed and 44 not exposed to dental environments. Antibody levels > 1:128 were considered positive for infection. Relative risk was found to be 3.5 (p<0.01). These results confirm the hypothesis that workers in dental health-care settings are at occupational risk for Legionella infection. It is essential, therefore, that surveillance of microbiological quality of dental waterlines be implemented and appropriate disinfection procedures performed where necessary.

Clinical-environmental surveillance of legionellosis: an experience in Southern Italy.

In Italy, although the number of cases of legionellosis notified to the health authorities has significantly increased in recent years, the incidence is still believed to be underestimated. To verify the true frequency and identify the sources of infection, an active clinical-environmental surveillance program was instituted in three hospital facilities in Southern Italy. Between January 2001 and March 2005, a total of 1000 patients admitted to the three hospitals with a diagnosis of pneumonia were enrolled. The urinary antigen and anti-Legionella antibody titre were assayed in each subject, and direct searches for the microorganism were made in biological specimens. Legionellosis was found to be present in 5.9% of the patients. For each of the cases of legionellosis, microbiological surveys were made of the water supply in the public and/or private facilities involved. Overall, 197 water samples of hospital origin and 218 of community origin were analysed: Legionella spp was isolated in 44.2 and 36.7% of the cases, respectively. Comparison of our data with those of the routine surveillance system for the same area (only 7 cases during the period 1997-2000), showed that the frequency of legionellosis is grossly underestimated in Southern Italy. It is therefore necessary to set up more rigorous controls in both hospital and community facilities, so that timely preventive measures can be taken to avoid any further spread of the disease.

Legionella contamination in hot water of Italian hotels.

A cross-sectional multicenter survey of Italian hotels was conducted to investigate Legionella spp. contamination of hot water. Chemical parameters (hardness, free chlorine concentration, and trace element concentrations), water systems, and building characteristics were evaluated to study risk factors for colonization. The hot water systems of Italian hotels were strongly colonized by Legionella; 75% of the buildings examined and 60% of the water samples were contaminated, mainly at levels of > or =10(3) CFU liter(-1), and Legionella pneumophila was the most frequently isolated species (87%). L. pneumophila serogroup 1 was isolated from 45.8% of the contaminated sites and from 32.5% of the hotels examined. When a multivariate logistic model was used, only hotel age was associated with contamination, but the risk factors differed depending on the contaminating species and serogroup. Soft water with higher chlorine levels and higher temperatures were associated with L. pneumophila serogroup 1 colonization, whereas the opposite was observed for serogroups 2 to 14. In conclusion, Italian hotels, particularly those located in old buildings, represent a major source of risk for Legionnaires' disease due to the high frequency of Legionella contamination, high germ concentration, and major L. pneumophila serogroup 1 colonization. The possible role of chlorine in favoring the survival of Legionella species is discussed.

[A survey of preventive measures against infection risk in dental surgery]. / Indagine conoscitiva sulla prevenzione del rischio infettivo negli studi odontoiatrici.

In dental healthcare surgeries, both workers and patients are regularly exposed to various infectious agents. It is essential therefore that dental healthcare workers have a good knowledge of disinfection systems and that dentists' surgeries be effectively managed so as to reduce or even eliminate the risk of cross infections. In order to evaluate infectious risk prevention methods and describe the procedures used by dental healthcare workers on a daily basis, a sample of dentists who work in public surgeries were asked to anonymously fill up a questionnaire. The results of this survey show that dental healthcare workers are sufficiently well-informed about the infectious hazards present in the workplace and are aware of the high risk of exposure to infections but seem to be especially concerned about blood-borne infections (hepatitis, AIDS). Only 67.5%, however, are immunised against HBV. Individual safety devices are used correctly while there seems to be a lack of knowledge about the proper use of disinfection and sterilization systems. In addition, some dental healthcare workers still today refuse to treat HIV-positive patients.

[Importance of oral signs in the diagnosis of atypical forms of celiac disease]. / Importanza dei segni orali nella diagnosi di forme atipiche di malattia celiaca.

The dramatic improvement in knowledge concerning celiac disease (CD) has disclosed the pattern of the associated clinical manifestations and the often atypical or silent presentation of this disease, which makes clinical diagnosis difficult. Also oral manifestations, mostly recurrent apthous stomatitis (RAS) and dental enamel hypoplasia, are atypical signs of CD. Our opinion about the possibility of performing mass-screening to reveal atypical or silent CD is in agreement whit who is asserting that a sistematical case-finding is, at present, the most suitable epidemiological approach. So, we think that patients affected by RAS, or dental enamel hypoplasia, should be considered, even in the absence of any gastrointestinal symptom, at-risk subjects, and should therefore undergo diagnostic procedure for CD.

Legionella infection risk from domestic hot water.

We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <100 microg/L and copper levels of >50 microg/L appeared to be protective against Legionella colonization [corrected]. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches.