Implication of Ariaal sexual mixing on gonorrhea.
Recent research on sexual mixing in populations of sub-Saharan Africa raises the question as to whether STDs can persist in these populations without the presence of a core group. A mathematical model is constructed for the spread of gonorrhea among the Ariaal population of Northern Kenya. A formula for the basic reproduction number R(0) (the expected number of secondary infections caused by a single new infective introduced into a susceptible population) is determined for this population in the absence of a core group. Survey data taken in 2003 on sexual behavior from the Ariaal population are used in the model which is formulated for their age-set system including four subpopulations: single and married, female and male. Parameters derived from the data, and other information from sub-Saharan Africa are used to estimate R(0). Results indicate that, even with the elevating effect of the age-set system, the disease should die out since R(0) < 1. Thus, the persistence of gonorrhea in the population must be due to factors not included in the model, for example, a core group of commercial sex workers or concurrent partnerships.
McCluskey
C Connell
CC
Department of Mathematics and Statistics, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
Roth
Eric
E
van den Driessche
P
P
D005260:Female; D006069:Gonorrhea / Q000453:epidemiology* / Q000208:ethnology / Q000635:transmission; D006306:Health Surveys; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D011336:Probability; D012307:Risk Factors; D012309:Risk-Taking; D012423:Rural Health / Q000706:statistics & numerical data; D011477:Sex Work; D012725:Sexual Behavior / Q000208:ethnology*; D012747:Sexual Partners; D012749:Sexually Transmitted Diseases / Q000453:epidemiology / Q000208:ethnology / Q000635:transmission; D018454:Spouses; D011795:Surveys and Questionnaires