Natural and experimental studies on domestic animal infections with visceral and cutaneous leishmaniases in Kenya

The control of visceral and cutaneous leishmaniases in Kenya has been difficult due to poor knowledge of animal reservoirs of these diseases. Little is known about the feeding preferences of phlebotomine sand flies that transmit some of the leishmaniases that are endemic in some areas in Kenya, which makes it difficult to control the diseases by targeting the animal reservoirs. This article reviews the efforts that have been made to identify reservoirs of known Leishmania parasites that cause leishmaniases in Kenya. The account includes studies that have been carried out on Kenyan canids, felines, ungulates and murines

Nocturnal activities of phlebotomine sand flies (Diptera: Psychodidae) in Baringo County, Kenya

Leishmaniasis is a disease of both humans and animals. It is transmitted by the bite of sand flies of the genus Phlebotomus in the Old World and Lutzomyia in the New World. Nocturnal activities of phlebotomine sand flies were monitored by trapping flies exiting and entering termite mounds and animal burrows in Baringo County. Exit/entrance traps were set from dusk to midnight and from midnight to dawn in the termite mound and animal burrow openings. The study which lasted seven months (November 1993/May 1994), was designed to reveal sand fly behavior in their natural habitats. A total of 11,787 sand flies was trapped and their nocturnal activities studied. Significantly more sand flies(85.6%) were caught exiting than entering animal burrows and termite mounds in the 1st half of the night p<0.05. This trend was reversed by sand flies (61.4%) caught entering the burrows termite mounds during the 2nd half of the night p<0.05. Most sugar/positive sand flies were collected after midnight in both animal burrows and termite mounds while more blood/fed sand flies were caught in the 1st than in the 2nd half of the night p<0.05. At Perkerra, 87.8% of the blood/fed female sand flies were trapped in the 1st half of the night compared with 12.2% caught in the 2nd half. At Rabai, 72.6% of the total number of those caught blood fed were in the 1st half and 27.4% in the 2nd half of the night. P. martini which is the vector of L. donovani which causes visceral leishmaniasis, was predominantly trapped in termite mounds whereas P duboscqi (vector of L. major) that causes cutaneous leishmaniasis, was trapped in large numbers in animal burrows. These habitats pre/dispose themselves as ideal targets for control measures of the vectors. Keywords: Sugar, blood feeding, sand flies, animal burrows, termite mounds, Keny

Helminth parasites in the intestinal tract of indigenous poultry in parts of Kenya : short communication

A study was carried out on 456 indigenous poultry intestinal specimens from various towns in Kenya to determine the occurrence and distribution of helminth parasites in the intestinal tract of the birds. Of the specimens examined, 414 had parasites whereas the remaining 42 had none, which is an infection rate of 90.78 %. The main species of helminths found in the intestines were Raillietina sp. (47.53 %), Heterakis gallinarum (21.33 %), Ascaridia galli (10.03 %), Strongyloides avium (9.96 %), Choanotaenia infundibulum (4.61 %), Cotugnia digonopora (3.6 %), Capillaria sp. (1.5 %), Trichostrongylus tenius (1.04 %) and Syngamus trachea (0.40 %). Most helminths were present in both the mid- and hindguts. Syngamus trachea and C. digonopora were only found in the foregut and midgut, respectively. Although chickens from which the specimens were collected appeard healthy, the high prevalence of helminthiasis observed shows the poor level of helminth infection control practiced by the indigenous poultry keepers in the country, which might affect the health status of the birds and their growth rates. Poultry keepers should be encouraged to prevent, control and treat such cases

Comparative field evaluation of the Mbita trap, the Centers for Disease Control light trap, and the human landing catch for sampling of malaria vectors in western Kenya

The mosquito sampling efficiency of a new bed net trap (the Mbita trap) was compared with that of the Centers for Disease Control miniature light trap (hung adjacent to an occupied bed net) and the human landing catch in western Kenya. Overall, the Mbita trap caught 48.7 +/- 4.8% (mean SEM) the number of Anopheles gambiae Giles sensu lato caught in the human landing catch and 27.4 +/- 8.2% of the number caught by the light trap. The corresponding figures for Anopheles funestus Giles were 74.6 +/- 1.3% and 39.2 +/- 1.9%, respectively. Despite the clear differences in the numbers of mosquitoes caught by each method, both the Mbita trap and light trap catches were directly proportional to human landing catches regardless of mosquito density. No significant differences in parity or sporozoite incidence were observed between mosquitoes caught by the three methods for either An. gambiae s.l. or An. funestus. Identification of the sibling species of the An. gambiae complex by a polymerase chain reaction indicated that the ratio of An. gambiae Giles sensu stricto to An. arabiensis Patton did not vary according to the sampling method used. It is concluded that the Mbita trap is a promising tool for sampling malaria vector populations since its catch can be readily converted into equivalent human biting catch, it can be applied more intensively, it requires neither expensive equipment nor skilled personnel, and it samples mosquitoes in an exposure-free manner. Such intensive sampling capability will allow cost-effective surveillance of malaria transmission at much finer spatial and temporal resolution than has been previously possible