Heterogeneities in the transmission of infectious agents: Implications for the design of control programs

Abstract

From an analysis of the distributions of measures of transmission rates among hosts, we identify an empirical relationship suggesting that, typically, 20% of the host population contributes at least 80% of the net transmission potential, as measured by the basic reproduction number, R 0 . This is an example of a statistical pattern known as the 20͞80 rule. The rule applies to a variety of disease systems, including vector-borne parasites and sexually transmitted pathogens. The rule implies that control programs targeted at the ''core'' 20% group are potentially highly effective and, conversely, that programs that fail to reach all of this group will be much less effective than expected in reducing levels of infection in the population as a whole.

Leishmaniose visceral: estudo de flebotomíneos e infecção canina em Montes Claros, Minas Gerais

“…Um importante aspecto de doenças ligadas a vetor, é a existência de uma população de hospedeiros, que é efetivamente responsável pela manutenção e dispersão da doença 28 . Portanto, o conhecimento dos reservatórios é importante para o efetivo controle da LV.…”

Trypanosomes, fleas and field voles: ecological dynamics of a host-vector–parasite interaction

“…This has often been expressed as an 80/20 ' rule ', which suggests that, typically, 20 % of the host population supports 80 % of the parasite population (Woolhouse et al 1997 ;see, for example, Perkins et al 2003). However, while in the present case males in the upper two mass groups comprise 22 % of the population, the number of fleas estimated to have been found on them is only approximately 36 % of the total (where category 1 is taken as 1 .…”

Long-term outcomes of school-based treatment for control of urinary schistosomiasis: a review of experience in Coast Province, Kenya

“…There was a significant clustering effect around the specific sites on Nimbodze pond found to have snails shedding cercariae of Schistosoma haematobium. The influential radius of the clustering effect is between 200 and 1000 m from these transmission sites, but, not shown here, the significant distance factor varies according to subject age group studied, growing larger for older age groups (see Clennon et al 2004). tain local transmission for an indefinite period (Woolhouse et al 1991(Woolhouse et al , 1997(Woolhouse et al , 1998.…”