Studies that have measured the direct effect of ill health on agricultural production have mostly dwelt on the impact of one or two selected diseases on a single crop, and relied on incidence of the disease in an area without taking into cognizance the hours or days of agricultural activities lost due to health problems; see Audibert  and Audiber and Etard  for instance.
A study of technical efficiency in Mali by Audibert and Etard  revealed that treatment for schistosomiasis increased technical efficiency.
Bocca ML, Le Doze F, Etard
O, Pottier M, L'Hoste J, Denise P.
Address for correspondence: Jean-Francois Etard, Institut de Recherche pour le Developpement, BP 1386, Dakar, Senegal; fax: +221 832 43 07; email: etard@ird.
Jean-Francois Etard, * Pierre Colbachini, [dagger] Jacques-Albert Dromigny, [double dagger] and Jean-David Perrier- Gros-Claude [double dagger]
JF, Ndiaye I, Thierry-Mieg M, Gueye NF, Gueye PM, Laniece I, Dieng AB, Diouf A, Laurent C, Mboup S, Sow PS and E Delaporte Mortality and causes of death in adults receiving highly active antiretroviral therapy in Senegal: a 7-year cohort study.
Woolhouse MEC, Dye C, Etard
JF, Smith T, Charlwood JD, Garnett GP, et al.
9 Zimbabwe Taylor et al, 49 Mauritania Etard