Phlebotominae

Methods for investigating suspected breeding sites of phlebotomine sand flies include the direct examination of soil and litter, extraction by Berlese funnel, wet sieving or flotation, and emergence trapping. Surveillance and collection methods for adult sand flies include trapping and aspiration from resting sites, humans, and bait animals. Effective trap designs include light traps, bait traps, sticky traps, and flight traps. Smoke, insect repellent spray, or a twig or stick can be used to flush sand flies from inaccessible resting sites for collection.

Insect repellents and protective clothing are effective personal protectants. Sand flies do not bite through clothing; however,L. verrucarum is reported to crawl beneath clothing and bed sheets to reach the skin. Long sleeves, trousers, and socks should be worn in areas where sand flies are active. Head nets, gloves, repellent-treated net jackets and hoods, and repellent lotions and sprays provide effective protection for the face, hands, arms, and other exposed areas of the body.

Outdoor sleeping areas should be high, open, breezy, dry, and as far from potential breeding sites as possible. Bed nets should be used when sleeping in areas where sand flies are present. Standard 16- and 18-mesh bed nets, head nets, window screens, and screen doors do not exclude sand flies, but both standard and large-mesh screens and nets are effective when treated with contact insecticides or repellents. Fine-mesh nets and screens are little used because they impede circulation of the air. Sand flies will bite through untreated nets in contact with the skin.

Ultraviolet electrocutor traps have been recommended for control of Phlebotomus papatasi. Indoor flight activity can be reduced by use of electric fans. Sand flies do not usually fly into the upper stories of buildings.

The use of insecticides can be helpful in reducing sand fly numbers. Natural and synthetic pyrethroid and thiocyanate aerosols provide effective control indoors when applied twice daily, at night and in the early morning. Smoke from "mosquito coils" containing pyrethroids is also effective. Organochlorine, organophosphate, carbamate, and pyrethroid insecticides are effective for residual control of adult sand flies; however, resistance to organochlorine insecticides has been reported in P. papatasi. Insecticides should be applied to inside walls and ceilings, to the inside and outside of screens and doors, and to 1—2 feet of the outer wall around window and door casements and along foundations. Wall hangings impregnated with pyrethroids have been used for sand fly control in homes in Kenya. Area treatments may be needed out-of-doors. Area treatments should be directed toward potential breeding and resting sites, such as outcroppings, fences, walls, buildings, caves, burrows, and tree trunks.

Another approach for effective control is the elimination of breeding sites and resting sites of sand flies. Breeding and resting sites of P. papatasi in and around homes can be destroyed by filling cracks and crevices of walls, ceilings, and floors and by clearing and rolling, tamping, or paving outdoor areas. In Italy, transmission of leishmanial agents by P. perjiliewi has been reduced by locating piles of farm manure where the sand flies breed at safe distances from homes. In Kenya, the transmission of leishmanial agents by P. martini has been reduced by destroying all termite mounds, in which this species breeds, within 20 m of homes. In Panama and French Guiana, leishmaniasis has been reduced by eliminating breeding and resting sites of sand flies by deforestation.

Control of animals that serve as reservoirs for leishmanial organisms may be feasible in some areas. Elimination of dogs is an effective preventive measure where dogs have been implicated as reservoirs. Reduction of feral dog and jackal populations by disposal of offal from slaughter houses and poultry farms has significantly reduced the incidence of visceral leishmaniasis in Iraq. P. papatasi has been controlled in Jordan and Russia by digging, plowing, or flooding gerbil burrows.

The use of parasites and predators in sand fly control has not been demonstrated. The bacteria Bacillus sphae-ricusznA B. thuringiensis var. israelensis (Bti, or serotype H12), and certain gregarine protozoa and tylenchid nematodes, are potential agents.

The immunization of humans by inoculation of living Leishmania tropica, called leishmanization, has been employed for control of cutaneous leishmaniasis in Iran, Israel, and Russia.

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