tetano
Editor, Senior Moderator
PLoS One. 2016 May 6;11(5):e0154418. doi: 10.1371/journal.pone.0154418. eCollection 2016.
[h=1]Individual Correlates of Infectivity of Influenza A Virus Infections in Households.[/h] Tsang TK[SUP]1[/SUP], Fang VJ[SUP]1[/SUP], Chan KH[SUP]2[/SUP], Ip DK[SUP]1[/SUP], Leung GM[SUP]1[/SUP], Peiris JS[SUP]1,[/SUP][SUP]3[/SUP], Cowling BJ[SUP]1[/SUP], Cauchemez S[SUP]4[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Identifying individual correlates of infectivity of influenza virus is important for disease control and prevention. Viral shedding is used as a proxy measure of infectivity in many studies. However, the evidence for this is limited.
[h=4]METHODS:[/h] In a detailed study of influenza virus transmission within households in 2008-12, we recruited index cases with confirmed influenza infection from outpatient clinics, and followed up their household contacts for 7-10 days to identify secondary infections. We used individual-based hazard models to characterize the relationship between individual viral shedding and individual infectivity.
[h=4]RESULTS:[/h] We analyzed 386 households with 1147 household contacts. Index cases were separated into 3 groups according to their estimated level of viral shedding at symptom onset. We did not find a statistically significant association of virus shedding with transmission. Index cases in medium and higher viral shedding groups were estimated to have 21% (95% CI: -29%, 113%) and 44% (CI: -16%, 167%) higher infectivity, compared with those in the lower viral shedding group.
[h=4]CONCLUSIONS:[/h] Individual viral load measured by RT-PCR in the nose and throat was at most weakly correlated with individual infectivity in households. Other correlates of infectivity should be examined in future studies.
PMID: 27153194 [PubMed - in process] Free full text
[h=1]Individual Correlates of Infectivity of Influenza A Virus Infections in Households.[/h] Tsang TK[SUP]1[/SUP], Fang VJ[SUP]1[/SUP], Chan KH[SUP]2[/SUP], Ip DK[SUP]1[/SUP], Leung GM[SUP]1[/SUP], Peiris JS[SUP]1,[/SUP][SUP]3[/SUP], Cowling BJ[SUP]1[/SUP], Cauchemez S[SUP]4[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Identifying individual correlates of infectivity of influenza virus is important for disease control and prevention. Viral shedding is used as a proxy measure of infectivity in many studies. However, the evidence for this is limited.
[h=4]METHODS:[/h] In a detailed study of influenza virus transmission within households in 2008-12, we recruited index cases with confirmed influenza infection from outpatient clinics, and followed up their household contacts for 7-10 days to identify secondary infections. We used individual-based hazard models to characterize the relationship between individual viral shedding and individual infectivity.
[h=4]RESULTS:[/h] We analyzed 386 households with 1147 household contacts. Index cases were separated into 3 groups according to their estimated level of viral shedding at symptom onset. We did not find a statistically significant association of virus shedding with transmission. Index cases in medium and higher viral shedding groups were estimated to have 21% (95% CI: -29%, 113%) and 44% (CI: -16%, 167%) higher infectivity, compared with those in the lower viral shedding group.
[h=4]CONCLUSIONS:[/h] Individual viral load measured by RT-PCR in the nose and throat was at most weakly correlated with individual infectivity in households. Other correlates of infectivity should be examined in future studies.
PMID: 27153194 [PubMed - in process] Free full text