Elizabeth Crock: HIV Nurse Practitioner, Bolton Clarke HIV Program, Melbourne  

Acknowledgement: Jayne Howard: Melbourne Sexual Health Centre, Melbourne (first edition)

Summary 

• Introduction and definitions 
• The importance of early diagnosis and linkage to care 
• Barriers to testing and risk factors for late HIV diagnoses. 
• Nursing implications – severe disease 
• Immune reconstitution inflammatory syndrome 

Introduction and definitions 

Late diagnoses of HIV, delayed presentation to care, and people presenting late with severe disease are ongoing concerns globally (1).  Late presentation of HIV, defined as a diagnosis with a CD4 T-lymphocyte (CD4) count of less than 350 cells/µL, accounted for an estimated 48% of human immunodeficiency virus (HIV) diagnoses in Australia in 2021 (2) This is the highest proportion reported in the last ten years.   Approximately 34% of these were advanced infections, defined as having a CD4 count of less than 200 cells/µL (2). The proportion of people diagnosed late in Australia is higher amongst people born in Central or South America (44%), Sub-Saharan Africa (59%) and Southeast Asia (57%) than amongst those born in Australia.  Late diagnoses are also higher amongst people who report heterosexual sex or injecting drug use as their HIV risk exposure (2) 

People diagnosed late often learn of their HIV status only after being diagnosed with an opportunistic illness (OI) such as Pneumocystis jirovecii pneumonia or Toxoplasmosis gondii infection (3, 4) (see also Clinical Manifestations of HIV disease). These OIs occur with severe immunosuppression.  They are at risk of serious morbidity and mortality, are more likely to require intensive care support if hospitalised and they have an increased risk of acquired immune deficiency syndrome (AIDS) or death, particularly in the first year after diagnosis (5-7) After starting ART, those who have been diagnosed late generally experience a longer time to immune reconstitution, may be at ongoing risk of OIs and experience immune reconstitution inflammatory syndrome (IRIS) (8).