Quinnell, R.J., Courtenay, O., Garcez, L.M. and Dye, C. (1997) The epidemiology of canine leishmaniasis: transmission rates estimated from a cohort study in Amazonian Brazil. Parasitology, 115 (02). pp. 143-156. ISSN 1469-8161Full text available as:
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We estimate the incidence rate, serological conversion rate and basic case reproduction number (R0) of Leishmania infantum from a cohort study of 126 domestic dogs exposed to natural infection rates over 2 years on Marajó Island, Pará State, Brazil. The analysis includes new methods for (1) determining the number of seropositives in cross-sectional serological data, (2) identifying seroconversions in longitudinal studies, based on both the number of antibody units and their rate of change through time, (3) estimating incidence and serological pre-patent periods and (4) calculating R0 for a potentially fatal, vector-borne disease under seasonal transmission. Longitudinal and cross-sectional serological (ELISA) analyses gave similar estimates of the proportion of dogs positive. However, longitudinal analysis allowed the calculation of pre-patent periods, and hence the more accurate estimation of incidence: an infection–conversion model fitted by maximum likelihood to serological data yielded seasonally varying per capita incidence rates with a mean of 8·66×10[minus sign]3/day (mean time to infection 115 days, 95% C.L. 107–126 days), and a median pre-patent period of 94 (95% C.L. 82–111) days. These results were used in conjunction with theory and dog demographic data to estimate the basic reproduction number, R0, as 5·9 (95% C.L. 4·4–7·4). R0 is a determinant of the scale of the leishmaniasis control problem, and we comment on the options for control.
|Copyright, Publisher and Additional Information:||© 1997 Cambridge University Press|
|Keywords:||canine leishmaniasis, Leishmania infantum, serology, domestic dog, incidence rate; basic reproduction number|
|Academic Units:||The University of Leeds > Faculty of Biological Sciences (Leeds) > Institute of Integrative and Comparative Biology (Leeds)|
|Depositing User:||Repository Officer|
|Date Deposited:||07 Jun 2006|
|Last Modified:||08 Feb 2013 17:06|
|Publisher:||Cambridge University Press|
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