A population-based study of how children are exposed to saliva in Africa: implications for KSHV transmission
© Butler et al; licensee BioMed Central Ltd. 2009
Published: 17 June 2009
Kaposi's sarcoma-associated herpesvirus (KSHV) is endemic among most sub-Saharan African populations. In those regions with the highest seroprevalences, there is a steady increase in KSHV seropositivity with age among children indicating that horizontal non-sexual transmission in childhood is the primary means of spread. While it is known that saliva is the body fluid that most commonly harbors KSHV and is therefore an important conduit for KSHV transmission, there is scant information on how African children are exposed to saliva and whether this exposure is preventable.
In two settings in or near Durban, South Africa – Cato Manor, an urban community, and KwaXimba, a rural community – we first used qualitative methods to identify the range of acts by which children are exposed to saliva from others. We conducted focus groups and semi-structured interviews with prototypical individuals who have contact with children ≤ 6 years old, including mothers, fathers, grandparents, siblings, and traditional healers. We also performed participant observation, where we lived amongst families with children, observing and participating in their everyday activities. We then created a structured questionnaire to quantitate the prevalence of the various saliva-passing acts we identified in the qualitative work. The questionnaire was administered to a door-to-door population-based sample of mothers, fathers, grandmothers and siblings of children ≤ 6 years old residing in either Cato Manor or KwaXimba.
Percent of caregivers who reported ever practicing acts involving saliva passage to children ≤ 6 years old
N = 258
N = 198
N = 204
N = 236
Shared toothbrush or toothstick
Cleaned eyes or face with tongue
Used mouth/cloth soaked with saliva to soothe insect bite
Premastication of food
Shared sweets or candy
Blown herbs via mouth into nostril
Rubbed premasticated herbs on head or face
Pushed substance into rectum from mouth through pipe
Inserted finger lubricated with saliva into rectum
A variety of acts, practiced by a variety of persons of differing relation to children, expose children to saliva in Africa; there is no single predominant practice. This poses substantial challenges for epidemiologic work seeking to identify specific routes by which KSHV is spread. The saliva-passing acts include ones that expose oral-respiratory mucosa and cutaneous surfaces to saliva as well as acts that expose anal-rectal mucosa to saliva. The latter exposure has similarities to how homosexual men in resource-replete settings (who also have high KSHV seroprevalence) are exposed to saliva, providing speculation regarding a common route of KSHV transmission. While there are many acts that expose African children to saliva, the majority of these practices could be replaced by other actions and are therefore theoretically preventable.
This article is published under license to BioMed Central Ltd.