The All-Ireland Infectious Diseases (AIID) Cohort is a multicentre, prospective, longitudinal observational cohort that enrols consecutive adult subjects attending participating institutions for infectious disease services. This is an ongoing prospective observational cohort of unlimited duration.

The All-Ireland Infectious Diseases cohort study (AIID Cohort) is enrolling patients at a number of Irish Hospitals with infectious diseases, including Covid-19. The AIID Cohort is a multicentre, prospective, longitudinal, observational cohort that enrols consecutive adult subjects (>18 years old) attending hospitals services for management of infections.

Subjects provide consent for use of routine clinical and laboratory data for research. All data is collected by a combination of retrospective medical note review and extraction of data from electronic health records. At a minimum, the following data items are to be collected at enrolment and subsequent clinic visits:

1. Demography and basic information (e.g. date of birth, gender, country of origin, ethnicity, anthropometric assessments, and reasons for the attendance, date or year for disease diagnosis and transmission risk.
2. Laboratory data: Relevant routine virological (including genotyping) and immunological data for characterisation of the HIV infection, TB, hepatitis C, COVID-19 and other relevant co-infections will also be collected as well as other relevant clinical routine data on tolerability and safety (i.e., renal, liver, lipids)
3. Medical treatment: All medications, including start-and stop dates and reason for discontinuation, adherence. Concomitant medical treatment related to co-infections and co-morbidities.
4. Clinical events: hospitalisation, diseases specific relevant active and previous diagnosis (e.g., AIDS and non-AIDS events, including comorbidities).

In addition, subjects are asked to provide biological samples for up to five occasions every six months for bio-banking for host profiling and pathogen bio-repository. To provide flexibility for participants around requirements for fasting or scheduling, participants may be asked to attend to provide samples for biobanking outside of routine scheduled clinic visits. These stored samples provide the opportunity for future research studies investigating host factors associated with the response to infection.

The AIID Cohort is approved by local institutional review boards and all participants provide written, informed consent. Data and samples within the AIID Cohort are accessed through standardised Data Access Guidelines and all approved Data Access Requests are approved by the local Ethics Committee.

Inclusion criteria:

• ≥ 18 years of age patients attending clinical services of participating institutions with issues related to infectious diseases.
• Willing and able to provide informed consent or
• Provide deferred assent if an incapacitated or unconscious patient is unable to provide informed consent

Exclusion criteria:

• Patients under 18 years of age
• Patients with learning disabilities, mental illness, or dementia

All adult patients attending Clinical Services relating to infectious diseases at participating hospitals in Ireland who provide written informed consent.