Initial results of recent HIV infection surveillance in Cambodia, 2020

BACKGROUND: Recent HIV infection surveillance can help to identify populations and geographies with active transmission. We compared risk factors among recent and long-term infections from the initial ten months of recent HIV infection surveillance in Cambodia to help target prevention interventions and rapid treatment initiation among newly diagnosed individuals of recent HIV infection.
METHODS: We used demographic and risk data collected in the National HIV Voluntary Counselling and Testing (VCT) data from March through December 2020. Clients aged '¥15 years and newly diagnosed as HIV-positive were offered recency testing at 66 facilities in all 25 provinces of Cambodia. Blood specimens from consenting individuals were tested by the Asante HIV-1 Rapid Test for Recent Infection (RTRI). We compared the distribution of clients with RTRI-recent and long-term infection by select characteristics using chi-square tests in STATA16.
RESULTS: Of 2,464 newly diagnosed HIV-positive VCT clients, 2,080 (84%) consented to RTRI testing, and 161 (8%) were classified as RTRI-recent infections. The percentage of clients with recent infection did not vary by sex (men, 76%; women, 24%; p=0.629). Overall, there were statistically significant differences in some age groups, population groups, and provinces. Recent infections were significantly more frequent among clients aged 20-34 years (p<0.001), entertainment workers (p=0.001), and men who have sex with men (MSM) (p<0.001) compared to those with long-term infections. Similarly, recent infections were more frequent identified in Siem Reap (p=0.010) and Phnom Penh (p=0.038) provinces (Table 1).
CONCLUSIONS: Initial recent HIV surveillance data suggest that recent transmission in Cambodia may be driven by several age, population, and geographic groups different from those with long-term infections. Continued surveillance may facilitate improved targeting of HIV prevention and treatment interventions.

Table 1. Comparison of RTRI-long term and RTRI-recent by demographic and risk group characteristics

Demographic Characteristics	Percentage of RTRI-Long-term infection (n=1919)	Percentage of RTRI-recent infection (n=161)	P-value
<20 years	6% (109)	6% (9)	0.962
20-34 years	60% (1145)	76% (123)	<0.001
>=35 years	35% (664)	18% (29)	<0.001
Male	75% (1433)	76% (123)	0.629
Female	25% (486)	24% (38)
Siem Reap province	12% (234)	19% (31)	0.010
Phnom Penh province	42% (815)	51% (82)	0.037
Other provinces	26% (496)	12% (20)	<0.001
Risk group characteristics
Entertainment worker	3% (54)	7% (12)	0.001
Men who have Sex with Men	41% (793)	58% (94)	<0.001
General population	50% (967)	32% (51)	<0.001