Table 2. Stages in the HIV infection and care continuum.

Infection/care stage of transmitter	Definition
Undiagnosed	Transmission intervals whose midpoint is before diagnosis:
Confirmed recent infection at diagnosis	All transmission intervals of transmitters that were in laboratory confirmed recent infection at time of diagnosis.
Estimated to be in recent infection	Considering transmitters that had no evidence for recent infection at time of diagnosis, all transmission intervals whose midpoint is less than 12 months after the estimated infection date.
Estimated to be in chronic infection	Considering transmitters that had no evidence for recent infection at time of diagnosis, all transmission intervals whose midpoint is more than 12 months after the estimated infection date.
Diagnosed	Transmission intervals whose midpoint is after diagnosis and before ART start (only of transmitters that are in contact with care services):
Diagnosed < 3mo, Recent infection at diagnosis	Considering potential or probable transmitters that were in laboratory confirmed recent infection at time of diagnosis, all transmission intervals whose midpoint is within the first three months after diagnosis.
No CD4 measured	No available CD4 count since diagnosis up to the midpoint of the interval.
CD4 > 500	CD4 counts remained above 500 cells/ml between the first CD4 count up to the midpoint of the interval.
CD4 in [350-500]	CD4 counts decreased to 350-500 cells/ml between the first CD4 count up to the midpoint of the interval.
CD4 < 350	CD4 counts decreased to below 350 cells/ml between the first CD4 count up to the midpoint of the interval.
ART initiated	Transmission intervals whose midpoint is after ART start (only of transmitters that are in contact with care services):
Before first viral suppression	No first viral load measurement below 100 copies/ml in any transmission interval of the transmitter after ART start
After first viral suppression¶
No viral load measured¶	No viral load measurement in any transmission interval of the transmitter after ART start
No viral suppression¶	At least one viral load measurement at or above 100 copies/ml in any transmission interval of the transmitter after ART start
Viral suppression, one observation¶	One viral load measurement in any transmission interval of the transmitter after ART start, which is below 100 copies/ml.
Viral suppression, >1 observations¶	Several viral load measurements in any transmission interval of the transmitter after ART start, all of which are below 100 copies/ml.
Not in contact	No patient record (last contact, clinic visit, CD4 measurement, viral load measurement) in the past and future 9 months from the midpoint of the transmission interval.

^¶While flow through the stages is typically unidirectional, men could move freely between these stages.