Background: One would assume that infection outbreaks such as the COVID-19 pandemic have a deleterious effect upon the physical, mental, and/or social functioning of people with intellectual disabilities (ID). Methods: A systematic search of four databases produced 18 articles. General information pertaining to the topics under consideration, information related to infectious diseases and ID were extracted. Results: All but one of the studies investigated the impact of infection outbreaks on the physical functioning of people with ID. Although in some instances certain studies briefly reflected on the impact of infection outbreaks on mental or social functioning, there was no empirical data available. Conclusions: There is scarce scientific knowledge on the impact of infection outbreaks on the mental and social functioning of people with ID. This underscores the exigency for further psychosocial research to both explore the impact of infection outbreaks and develop strategies to deal with them in the future.