High efficacy of integrated preventive measures against zoonotic cutaneous leishmaniasis in northern Afghanistan, as revealed by Quantified Infection Rates

Following an outbreak of more than 200 cases of zoonotic cutaneous leishmaniasis (ZCL) during 2004 and 2005 among International Security Assistance Force (ISAF) troops stationed in the Mazar-e Sharif (MeS) airport area, epidemiological investigations indicated the presence of a local high-density ZCL focus. Based on ZCL's specific transmission modes, density and seasonality, integrated preventive measures were continuously implemented from February 2006 at a German military camp constructed at MeS. Preventive techniques included such synergistic measures as skin repellents and insecticide-impregnated clothing, bednets and curtains, sand fly and rodent monitoring and control, extended habitat sanitation, and health education, all designed to achieve maximum protection against ZCL. Habitat alteration included: (a) erection of a 3.0 m high stone wall around the entire camp area; (b) removal of ≥30 cm of the upper earth layer throughout the site; (c) soil compaction and stone paving to a depth of ≥30 cm plus compaction of the surrounding area to a distance of 100 m outside the camp wall; and (d) regular eradication of vegetation. Aggressive implementation of these measures led to a 166-fold and 546-fold reduction in sand fly numbers and complete eradication of the local rodent reservoir, Rhombomys opimus, inside the camp during 2006 and 2007, respectively. ZCL attack rates decreased significantly (p < 0.0001), from 17.5% (14 cases/80 persons) for the 2005 German assessment teams to 0.087% (1 case/1150 persons) for the 2006 contingent, and 0% (0 cases) (p < 0.0001) for the 2007 contingent, with Quantified Infection Rates (QIRs) of 0.058, 0.0000055, and 0.0, respectively. Using QIR values, the protective factor of the integrated preventive measures was shown to be ≥10,545 times higher in the 2006 and 2007 contingents, compared with the 2005 assessment teams. Results show that the continuously implemented, integrated preventive techniques used in this study gave excellent and long-lasting protection against zoonotic cutaneous leishmaniasis under field conditions.