INTRODUCTION
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by a
new strain of coronavirus which was initially unknown until its outbreak
in Wuhan, China last December 2019, and it has been declared as a Public
Health Emergency of International Concern by the World Health
Organization.1 In the Philippines, the total number of
positive COVID-19 cases has risen to more than 65,000 Filipino by mid
July 2020, and it continuously rose to more than 4ยท10 million cases by
June 2023.2
As the COVID-19 pandemic spreads worldwide and the number of affected
individuals rises, the healthcare system of the Philippines has been
greatly challenged,3 making the identification of
individuals at greatest risk a key challenge.4Cognizant of the significant mortality and morbidity associated with
COVID-19, scientific interest in identifying the characteristics which
increases susceptibility to the disease and factors which determine its
progression, severity, and prognosis has increased.5-7
One of the characteristics that has recently gained scientific interest
is the association of the ABO blood type with COVID-19 infection
susceptibility. It is hypothesized that the ABO carbohydrate moieties
are genetically inherited, and it is associated with certain conditions
and diseases such as cardiovascular diseases, cancer, and certain
infections, including coronavirus infections.4,7,8With the increasing number of COVID-19 cases and the increasing
scientific interest in the association of ABO blood type and COVID-19
susceptibility and outcomes, it is imperative to determine this
association among Filipino patients. This knowledge can help medical
professionals further determine the relative risk of specific Filipino
subpopulations for COVID-19 and its outcomes. This study determined the
relative risk of COVID-19 infection and disease outcomes (ICU admission,
intubation, and mortality) with ABO blood type among the hospitalized
Filipino patients from select tertiary hospitals in Metro Manila,
Philippines.