1 Introduction
Since a cluster of coronavirus disease 2019 (COVID-19) cases were first
reported in Wuhan, China, in December 2019, it has become a global
threat and spread rapidly across more than 200 countries and regions
(WHO, 2020). A striking aspect of COVID-19 is that the disease became a
pandemic in several months, resulting in over 16 million cases and 600
thousand deaths worldwide as of 30 July (WHO, 2020). Although we learned
more about COVID-19 and severe acute respiratory syndrome coronavirus 2
(SARS-CoV-2) in the past several months depending on the modern advanced
technology, some issues, such as a useful strategy to prevent disease
spread, transmission route, and effective treatments, have been still
severe challenges until now. Additionally, the possibility of
co-infection with other respiratory pathogens remains unclear. This
should be an important concern for clinicians in the management of
COVID-19.
Generally, co-infection has been already detected during the epidemic of
previous emerging infectious diseases, including severe acute
respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
Previous serological evidence revealed that the incidences of acute or
recent Chlamydophila pneumonia (CP) or Mycoplasma pneumonia (MP)
infection in SARS patients were 30% and 9%, respectively (Zahariadis
et al., 2006). In Hong Kong, a major nosocomial outbreak of SARS
revealed co-infection of human metapneumovirus (MPV) (Lee et al., 2007).
Moreover, co-infection of Middle East respiratory syndrome coronavirus
(MERS-CoV) with influenza has been reported, and it demonstrated that
18% critically ill patients with MERS-CoV had bacterial co-infection,
followed by 5% with viral co-infection, in a multicenter retrospective
cohort study (Alfaraj et al., 2017; Arabi et al., 2017). However, there
is limited data regarding co-infection of other respiratory pathogens in
COVID-19 patients, as well as the impact of co-infection on COVID-19
prognosis.
It is considered that the recognition of SARS-CoV-2 infection is
important as it enables the implementation of appropriate infection
control measures and possible promising antiviral therapy, but
clinicians should not neglect the possibility of SARS-CoV-2 co-infection
(Lai et al., 2020).
Therefore,
we aim to expand the knowledge of distribution and associated factors of
co-infection in COVID-19 patients, and assess the impact of co-infection
on COVID-19 prognosis.