Risk Factors for Kaposi’s Sarcoma–Associated Herpesvirus DNA in Blood and in Saliva in Rural Uganda

• Published in: Clinical infectious diseases 2020-08, Vol.71 (4), p.1055-1062
• Main Authors: Nalwoga, Angela, Nakibuule, Marjorie, Marshall, Vickie, Miley, Wendell, Labo, Nazzarena, Cose, Stephen, Whitby, Denise, Newton, Robert
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; and Commentaries; Child; Child, Preschool; Diagnostic Tests, Routine; DNA, Viral - genetics; Female; Herpesvirus 8, Human - genetics; Humans; Male; Middle Aged; Risk Factors; Saliva; Sarcoma, Kaposi; Uganda - epidemiology; Young Adult
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1093/cid/ciz916

Abstract Background Detectable Kaposi’s sarcoma–associated herpesvirus (KSHV) DNA in blood and increased antibody titres may indicate KSHV reactivation, while the transmission of KSHV occurs via viral shedding in saliva. Methods We investigated the risk factors for KSHV DNA detection by real-time polymerase chain reaction in blood and by viral shedding in saliva, in 878 people aged 3 to 89 years of both sexes in a rural Ugandan population cohort. Helminths were detected using microscopy and the presence of malaria parasitaemia was identified using rapid diagnostic tests. Regression modelling was used for a statistical analysis. Results The KSHV viral load in blood did not correlate with the viral load in saliva, suggesting separate immunological controls within each compartment. The proportions of individuals with a detectable virus in blood were 23% among children aged 3–5 years and 22% among those 6–12 years, thereafter reducing with increasing age. The proportions of individuals with a detectable virus in saliva increased from 30% in children aged 3–5 years to 45% in those aged 6–12 years, and decreased subsequently with increasing age. Overall, 29% of males shed in saliva, compared to 19% of females (P = .008). Conclusions Together, these data suggest that young males may be responsible for much of the onward transmission of KSHV. Individuals with a current malaria infection had higher levels of viral DNA in their blood (P = .031), compared to uninfected individuals. This suggests that malaria may lead to KSHV reactivation, thereby increasing the transmission and pathogenicity of the virus. Human herpesvirus type 8 shedding in saliva is associated with viral transmission, while viral detection in blood is associated with disease pathogenesis. Children may be a major transmission source and malaria could play a role in susceptibility to infection.