WHO haipendekezi masks ya uso kwa ujumla kwa watu wenye afya. Walakini, CDC sasa imeweka mwongozo mpya na kusema "watu wanapaswa kuvaa vinyago vya kitambaa wanapotoka nje". Ushahidi mpya unaonyesha kuwa utumiaji wa barakoa za uso wa upasuaji unaweza kuzuia kuenea kwa virusi vya korona ya binadamu na virusi vya mafua kutoka kwa watu wenye dalili.
Covid-19 virusi Inapatikana katika pumzi iliyotoka na kikohozi cha watu walioambukizwa na huenea kupitia matone ya hewa kutoka kwa watu wanaokohoa na kupiga chafya.
Kumekuwa na mjadala juu ya ufanisi wa masks ya uso in reducing spread of the virusi. The international body WHO doesn’t recommend them generally to the healthy people. However, CDC has now laid down new guideline and say ”people should wear cloth masks when they go outside”.
In the brief communication published in Nature Medicine on 03 April 2020, the researchers found that the usage of surgical face masks could prevent spread of human coronaviruses and influenza virusi from symptomatic individuals.
kupumua virusi infections spread between human beings through contact, respiratory droplets and fine-particle aerosols. However, there are uncertainties around modes of transmission of COVID-19.
In this study, the researchers quantified the amount of virusi in exhaled breath of participants and determined the potential efficacy of surgical face masks in preventing the transmission. Of 3,363 screened individuals, 246 individuals provided exhaled breath samples The 50% participants were randomized to ‘not wearing a face mask’ during the exhaled breath collection and the rest were randomized to ‘wearing a face mask’. They tested viral shedding in nasal swabs, throat swabs, respiratory droplet samples and aerosol samples and compared the latter two between samples collected with or without a face mask.
They found viral shedding to be higher in nasal swabs than in throat swabs. Further, they detected coronavirus in 30-40% samples collected from participants without face masks but no virusi was detected in droplets and aerosols collected from patients wearing face masks.
This study demonstrated the efficacy of surgical masks in reducing coronavirus detection and viral copies in respiratory droplets and in aerosols suggesting that the surgical face masks could be used by ill people to reduce onward transmission of the virusi.
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Reference:
Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al. Respiratory virusi shedding in exhaled breath and efficacy of face masks. Published on 03 April 2020. Nature Medicine (2020). DOI: https://doi.org/10.1038/s41591-020-0843-2
