Field evaluations of topical arthropod repellents in North, Central, and South America.

Recently, vector-borne diseases have been resurging in endemic areas and expanding their geographic range into nonendemic areas. Such changes have refocused attention to the potential for major public health events, as naive populations are exposed to these pathogens. Personal topical repellents, recommended by the United States Centers for Disease Control and Prevention and World Health Organization, remain a first line of protection against infection. The current study evaluated the repellent efficacy of four new U.S. Environmental Protection Agency-registered topical repellent products, two with picaridin as the active ingredient and two with IR3535, against a standard DEET (N,N-diethyl-3-methylbenzamide)-based product. All products were evaluated against a wide range of vector species under field conditions across the Americas. Human volunteers were used to evaluate product efficacy as compared with a well-known DEET-based formulation and determine suitability for use by the U.S. military. Findings demonstrated the new formulations performed as well as the standard U.S. military repellent and could be recommended for use.

Natural Leishmania infection of Lutzomyia auraensis in Madre de Dios, Peru, detected by a fluorescence resonance energy transfer-based real-time polymerase chain reaction.

Leishmania species of the Viannia subgenus are responsible for most cases of New World tegumentary leishmaniasis. However, little is known about the vectors involved in disease transmission in the Amazon regions of Peru. We used a novel real-time polymerase chain reaction (PCR) to assess Leishmania infections in phlebotomines collected in rural areas of Madre de Dios, Peru. A total of 1,299 non-blood fed female sand flies from 33 species were captured by using miniature CDC light traps. Lutzomyia auraensis was the most abundant species (63%) in this area. Seven of 164 pools were positive by PCR for Leishmania by kinetoplast DNA. The real-time PCR identified four Lu. auraensis pools as positive for L. (Viannia) lainsoni and L. (V.) braziliensis. The minimum infection prevalence for Lu. auraensis was estimated to be 0.6% (95% confidence interval = 0.20-1.42%). Further studies are needed to assess the importance of Lu. auraensis in the transmission of New World tegumentary leishmaniasis in hyperendemic areas of Peru.

Operational vector-borne disease surveillance and control: closing the capabilities gap through research at overseas military laboratories.

Malaria, dengue fever, chikungunya virus, leishmaniasis, and a myriad of other vector-borne diseases pose significant threats to the warfighter and to the overall combat effectiveness of units. Military preventive medicine (PM) assets must accurately evaluate the vector-borne disease threat and then implement and/or advise the commander on countermeasures to reduce a particular threat. The success of these measures is contingent upon the biology of the disease vector and on the tools or methods used to conduct vector/pathogen surveillance and vector control. There is a significant gap between the tools available and those required for operational PM assets to provide real-time, effective surveillance and control. A network of US Army and US Navy overseas laboratories is focused on closing the current capabilities gap. Their mission is to develop and field test tools and methods to enhance the combatant commander's ability to identify and mitigate the threat posed by these vector-borne diseases.

Using banded sunflower moth (Lepidoptera: Tortricidae) egg density to estimate damage and economic distance in oilseed sunflower.

The banded sunflower moth, Cochylis hospes Walsingham (Lepidoptera: Tortricidae), is an important economic pest of sunflower in the Upper Great Plains of North America. Economic losses due to reductions in seed number, weight, and quality can be significant. Previously, the potential for economic losses were estimated by sampling for adult moths. However, sampling for moths can be difficult and inaccurate. An alternative is to sample for banded sunflower moth eggs, which can be accurately counted in the field by using a binocular 3.5 headband magnifier. The egg counts are used to calculate the economic injury level (EIL) (EIL = C/VWPK), where C is the cost of treatment per unit area, V is the crop market value per unit of weight, W is the slope of the regression between banded sunflower moth egg densities and weight loss per plant, P is a term for plant population per unit area, and K is the control treatment efficacy. Estimates of populations of banded sunflower moth eggs are taken from the center of 400-m spans along all field sides. From these samples and the calculated EIL, a map of the extent of the economically damaging banded sunflower moth population throughout the field is made using economic distance; ED = e ( ( (EIL/E)-1.458)/-0.262). Economic distance estimates the distance an economic population extends into the field interior along a transect from the sampling site. By using egg samples to calculate the EIL and mapping the distribution of economic populations throughout a field, producers can then make more effective pest management decisions.