The secondary outcome of public health measures amidst the COVID-19 pandemic in the spread of other respiratory infectious diseases in Thailand.

The coronavirus disease 2019 (COVID-19) has promoted stringent public health measures such as hand hygiene, face mask wearing, and physical distancing to contain the spread of the viral infection. In this retrospective study, the secondary outcomes of those public health measures on containing other respiratory infections among the Thai population were investigated. Hospitalization data spanning from 2016 to 2021 of six respiratory infectious diseases, namely influenza, measles, pertussis, pneumonia, scarlet fever, and tuberculosis (TB), were examined. First, the expected respiratory infectious cases where no public health measures are in place are estimated using the seasonal autoregressive integrated moving average (SARIMA) model. Then the expected number of cases and the observed cases were compared. The results showed a significant drop in the incidence of respiratory infectious diseases by an average of 61%. The reduction in hospitalization is significant for influenza, measles, pertussis, pneumonia, and scarlet fever (p < 0.05), while insignificant for TB (p = 0.54). The notable decrease in the incidence of cases is ascribed to the implementation of public health measures that minimized the opportunity for spread of disease. This decline in cases following relaxation of pandemic countermeasure is contingent on its scope and nature, and it is proof that selective physical distancing, hand hygiene, and use of face masks in public places is a viable route for mitigating respiratory morbidities.