1,355,534 research outputs found
Can reasoned mass testing impact covid-19 outcomes in wide community contexts?An evidence-based opinion: Mass testing and outcomes of COVID-19 in Lombardy and Veneto
No full textWe describe the early phases of a COVID-19 epidemic in two contiguous Italian regions, Lombardy and Veneto, which were heavily and simultaneously hit by SARS-CoV-2 in Italy but showed markedly different disease outcome in terms of case fatality rate, SARS-CoV-2-attributable mortality and hospitalization. We discuss data limitations together with similarities and differences of the regional context possibly affecting COVID-19 control in the two regions. We conclude that the better COVID-19 outcome in Veneto was due, at least in part, to the adoption of a strategy of active search of asymptomatic SARS-CoV-2 infections (Reasoned Mass Testing), instead of a strategy strictly based on the detection of symptomatic cases
Candida and candidiasis in HIV-infected subjects. Where commensalism, opportunistic behavior and frank pathogenicity lose their borders
No full textIn this era of efficacious antiretroviral therapy and consequent immune-reconstitution, oropharyngeal and oesophageal candidiasis (OPC and OEC) still remain two clinically relevant presentations in the global HIV setting. Both diseases are predominantly caused by Candida albicans, a polymorphic fungus which is a commensal microbe in the healthy subject but can become an aggressive pathogen in a debilitated host. Actually, C.albicans commensalism is not the result of a benign behavior of one of the many components of human microbiota, but rather the result of host's potent innate and adaptive immune responses that restrict the growth of a potentially dangerous microrganism on the epithelia. An important asset guarding against the fungus is the Th17 functional subset of T helper cells. The selective loss of these cells with the progression of HIV infection causes the decay of fungal containment on the oral epithelium and allows C.albicans to express its pathogenic potential. An important part of this potential is represented by mechanisms to evade host immunity and enhance inflammation and immunoactivation. In C.albicans these mechanisms are mostly incorporated into, and expressed by characteristic morphogenic transitions such as the yeast to hyphal growth and the white to opaque switch. In addition, HIV infection generates an 'environment' selecting for overexpression of the virulence potential by the fungus, particularly concerning the secretion of aspartyl proteinases (Sap). These enzymes can degrade critical host defense components such as complement and epithelial defensive proteins such as histatin-5 and E-cadherin. It appears that part of this enhanced Candida virulence could be induced by the binding of the fungus to HIV and/or induced by HIV proteins such as GP160 and tat. Both OPC and OEC can be controlled by old and new antimycotics, but in the absence of host collaboration, anticandidal therapy may become in the long run ineffective. For these reasons, new therapeutics targeting virulence factors such and specific immune interventions are being addressed. Among these new approaches, vaccination is a promising one. Two subunit vaccines based on antigens dominantly expressed by C.albicans in vivo, i.e. the Als3 adhesin and sap2, have recently undergone Phase 1 clinical trials. Overall, studies of Candida and candidiasis in the HIV+ subject, while certainly contributing to a more effective control of the microorganism, and may also provide useful information on HIV-host relationship itself that can assist the fight against the virus
Passive vaccination and antidotes: a novel strategy for generation of wide-spectrum protective antibodies
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