It is often claimed that urbanization makes pathogen emergence more likely, but the underlying mechanisms are poorly understood. What characteristics of urban environments might predispose to an emergence event, and what is the contribution of livestock keeping to this process?

The 99 Household study is a cross sectional survey of households across socio-economic groups in Nairobi to isolate a diverse population of Escherichia coli (E. coli) bacteria from the city.

The overall objective of the ESEI project(Urban Zoo) is to understand the mechanisms that may lead to the introduction of pathogens into urban environments, and the emergence of those pathogens in the human population. The project is focusing on livestock as sources of these pathogens: emerging diseases are likely to be zoonotic in origin, and livestock pathogens, through the close interactions between livestock, their products and people, are at high of risk crossing the species barrier. ESEI project will study Escherichia coli (E. coli), an exemplar of many potential emerging pathogens, which exists in a diversity of hosts, in the environment, on food, in waste.

With Nairobi as the study area, we will study a diversity of neighborhoods and social groups stratified by poverty status. Poverty status is a function of ability to pay to sustain a basic nutritional requirement and to pay for basic non-food needs. Using this status, Nairobi will be divided into 9 strata, on which a cross sectional sampling of 11 households in each stratum will take place, giving a total of 99 HH. The selection of sub-locations is also purposeful but within each of the 33 selected sub-locations a random procedure will be used to identify three specific households: one with no livestock and the other two representing a diversity of livestock keeping. At each site, detailed investigations on the households will take place including animal sampling if present.

It is important to stress at the outset that the primary objectives of the 99 household survey are:

1. To map Escherichia coli (E. coli) diversity across Nairobi city, and
2. To explore the links between microbial diversity and urban livestock.

Article by Dr. Victoria Kyallo