3.4 Association between co-infection and negative conversion
All patients achieved negative conversion, with the median duration of
negative conversion among all COVID-19 patients was 13 days (IQR:
10-18). Moreover, it was 13 days (IQR: 10-15) in patients with bacterial
co-infection, as well as 10 days (IQR: 7.5-16.5) in patients with viral
co-infection. Results from multivariate Cox regression model revealed
that after controlling independent factors reported in the previous
study, such as age older than 45 years and chest tightness, co-infection
of other respiratory pathogens also significantly associated with
negative conversion of SARS-CoV-2 RNA (Hu et al., 2020). Co-infection of
only bacteria, only viruses and mixed of them were all able to promote
negative conversion of COVID-19, but the promotion was different in
terms of different types of co-infection. As shown in Figure 2 ,
the strongest promotion for negative conversion was detected with
co-infection of only viruses (HR: 4.039; 95%CI: 1.238-13.177), and the
weakest was found for co-infection of only bacteria (HR: 2.909; 95%CI:
1.308-6.471). Interestingly, the promotion in co-infection of mixed
bacteria and viruses was between co-infection of only bacteria and only
viruses, and its HR was 3.242 with 95%CI ranging from 1.171 to 8.977.