Publications

molecular evidence of the camel strain (g6 genotype) of echinococcus granulosus in humans from turkana, kenya.	cystic echinococcosis (ce) is a zoonotic helminthic disease, which is widely distributed throughout the world. although g1 is the echinococcus granulosus genotype most commonly involved in ce in humans, the prevalence of infection with other genotypes, such as g6, may be higher than previously thought. we performed molecular analysis to identify which e. granulosus genotypes are the causative agents of ce in humans in kenya's turkana district. during a hydatid control programme in 1993-1994, 71 ...	2010	19786289
rift valley fever outbreak in livestock in kenya, 2006-2007.	we analyzed the extent of livestock involvement in the latest rift valley fever (rvf) outbreak in kenya that started in december 2006 and continued until june 2007. when compared with previous rvf outbreaks in the country, the 2006-07 outbreak was the most extensive in cattle, sheep, goats, and camels affecting thousands of animals in 29 of 69 administrative districts across six of the eight provinces. this contrasted with the distribution of approximately 700 human rvf cases in the country, whe ...	2010	20682907
epidemiological assessment of the rift valley fever outbreak in kenya and tanzania in 2006 and 2007.	to capture lessons from the 2007 rift valley fever (rvf) outbreak, epidemiological studies were carried out in kenya and tanzania. somali pastoralists proved to be adept at recognizing symptoms of rvf and risk factors such as heavy rainfall and mosquito swarms. sandik, which means "bloody nose," was used by somalis to denote disease consistent with rvf. somalis reported that sandik was previously seen in 1997/98, the period of the last rvf epidemic. pastoralists communicated valuable epidemiolog ...	2010	20682908
using participatory epidemiological techniques to estimate the relative incidence and impact on livelihoods of livestock diseases amongst nomadic pastoralists in turkana south district, kenya.	a participatory epidemiological (pe) study was carried out with turkana pastoralists in turkana south district, kenya, to determine the relative incidence of livestock diseases and their impact on livelihoods. a sub-location was used as the sampling unit. a sub-location is the smallest administrative unit and is occupied by clusters of families (called adakars) that share common grazing patterns. a total of 32 sub-locations were randomly selected for the study. at least one focus group discussio ...	2009	19487039
multiple virus lineages sharing recent common ancestry were associated with a large rift valley fever outbreak among livestock in kenya during 2006-2007.	rift valley fever (rvf) virus historically has caused widespread and extensive outbreaks of severe human and livestock disease throughout africa, madagascar, and the arabian peninsula. following unusually heavy rainfall during the late autumn of 2006, reports of human and animal illness consistent with rvf virus infection emerged across semiarid regions of the garissa district of northeastern kenya and southern somalia. following initial rvf virus laboratory confirmation, a high-throughput rvf d ...	2008	18786992
[el niño and its consequences: outbreak of rift valley fever in kenya].		2007	17385249
the effect of weather on the occurrence and magnitude of periparturient rise in trichostronglyid nematode egg output in dorper ewes in a semi-arid area of kajiado district of kenya.	an investigation was carried out to assess the effects of weather on the occurrence and magnitude of the periparturient rise (ppr) in trichostrongylid nematode egg output in breeding dorper ewes. the study was conducted over three breeding seasons on a ranch in the semi-arid area of kajiado district in kenya between june 1999 and december 2001. during each breeding season 20 ewes randomly selected from the breeding stock and 20 others selected from the unmated yearlings were monitored for faecal ...	2006	17165610
epidemiology of gastrointestinal helminths infections in dorper sheep in a semi-arid area of kenya.	a survey on the prevalence and intensity of infection with gastrointestinal helminths of dorper sheep in relation to age and weather factors was carried out on a ranch in kajiado district, a semi-arid area of kenya for a period of 13 months (may 1999 to may 2000). faecal samples from lambs (3 months to 1 year), yearlings (1-2 years) and adult breeding ewes (2-4 years) were examined for helminth egg output and helminth genus composition at 3-week intervals. the results indicated that the prevalen ...	2004	15580771
occurrence of peri-parturient rise in trichostrongylid nematode egg output in dorper ewes in a semi-arid area of kajiado district of kenya.	an investigation on the occurrence of peri-parturient rise in trichostrongylid nematode egg output in breeding ewes was carried out on a ranch in the semi-arid area of kajiado district in kenya during the period may 1999-april 2000. during the study, 20 ewes randomly selected from the breeding stock and 20 un-mated female yearlings were monitored for faecal strongyle egg output every 3 weeks. a significant peri-parturient rise in faecal egg output occurred at around the time of lambing and throu ...	2004	15533289
development, survival and availability of gastrointestinal nematodes of sheep on pastures in a semi-arid area of kajiado district of kenya.	a study was carried out on a ranch in the semi-arid area of kajiado district in kenya during the period july 2000 to june 2001 to determine the seasonal patterns of development and survival of gastrointestinal nematodes of sheep on pastures. a series of plots were contaminated with sheep faeces every month and pasture samples were collected weekly for the recovery and identification of larvae. the availability of infective larvae on naturally contaminated pastures was also monitored on the paddo ...	2004	15509023
efficacy of myrsine africana, albizia anthelmintica and hilderbrantia sepalosa herbal remedies against mixed natural sheep helminthosis in samburu district, kenya.	traditional livestock healers from samburu and turkana communities in samburu district of kenya were identified and recruited for participation in this study. sheep with mixed gastrointestinal helminthosis were purchased from nomadic livestock owners in the area. three herbal anthelmintic remedies, viz. myrsine africana, albizia anthelmintica and hilderbrantia sepalosa were administered in the traditional way by the healers and their efficacy determined using percent fecal egg count reduction (p ...	2004	15036460
an outbreak of rift valley fever in northeastern kenya, 1997-98.	in december 1997, 170 hemorrhagic fever-associated deaths were reported in garissa district, kenya. laboratory testing identified evidence of acute rift valley fever virus (rvfv). of the 171 persons enrolled in a cross-sectional study, 31(18%) were anti-rvfv immunoglobulin (ig) m positive. an age-adjusted igm antibody prevalence of 14% was estimated for the district. we estimate approximately 27,500 infections occurred in garissa district, making this the largest recorded outbreak of rvfv in eas ...	2002	11897064
a study of cystic echinococcosis in slaughter animals in three selected areas of northern turkana, kenya.	in an attempt to establish the prevalence of cystic echinococcosis, a study was conducted in slaughter animals in three divisions of northern turkana, kenya. a total of 5752 goats, 588 sheep, 381 cattle and 70 camels were examined at slaughter. echinococcus granulosus metacestodes were found in 19.4% of the cattle, 3.6% of sheep, 4.5% of goats and 61.4% of camels. the prevalence of cystic echinococcosis in cattle, sheep and goats was higher in lokichogio than in either kakuma or central division ...	2002	11779657
climate-disease connections: rift valley fever in kenya.	all known rift valley fever(rvf) outbreaks in kenya from 1950 to 1998 followed periods of abnormally high rainfall. on an interannual scale, periods of above normal rainfall in east africa are associated with the warm phase of the el niño/southern oscillation (enso) phenomenon. anomalous rainfall floods mosquito-breeding habitats called dambos, which contain transovarially infected mosquito eggs. the eggs hatch aedes mosquitoes that transmit the rvf virus preferentially to livestock and to human ...	2001	11426274
prevalence of besnoitiosis in domestic ruminants in kenya: a preliminary survey.	a preliminary survey on the prevalence of besnoitiosis in domestic ruminants in kenya based on field and farm visits, clinical and post mortem examinations and histopathological examination of tissues and biopsies, showed that goats are the most affected, followed by cattle, while sheep were unaffected. caprine besnoitiosis occurred in a continuous belt in 5 of the 8 provinces in kenya stretching from the coast, eastern, north eastern, nairobi and the rift valley provinces. mandera, in the north ...	1999	10855837
an investigation of camelpox outbreaks in two principal camel (camelus dromedarius) rearing areas of kenya.	in 1992, during an investigation into camelpox in two principal camel-rearing areas of kenya, the disease was found in 1,100 camels at a prevalence of 6% in turkana and 27% in samburu. in turkana, outbreaks were detected in two herds of young animals, while in samburu, outbreaks were found in two herds of adult animals, as well as in two herds of young camels. in all cases, there was 100% morbidity in the affected herds. when young camels were involved, the main lesions were confined to the mout ...	1997	9567310
the use of ultrasound to study the prevalence of hydatid cysts in the right lung and liver of sheep and goats in turkana, kenya.	ultrasound examination of the liver and right lung was performed in 260 sheep and 320 goats from the turkana district of kenya. hydatid cysts were visualized in 9.2% of the sheep and 2.5% of the goats. of the animals positive on ultrasound, 87.5% received post-mortem examinations. eighteen (6.9%) sheep and 5 (1.5%) goats were positive for hydatid cysts on ultrasound and post-mortem examination. false-positives were a result of taenia hydatigena cysticerci present in the liver in all but 1 case. ...	1996	9024882
host feeding preference of phlebotomus guggisbergi, a vector of leishmania tropica in kenya.	recently the sandfly phlebotomus guggisbergi was found to be a vector of leishmania tropica causing cutaneous leishmaniasis in the laikipia focus, kenya, but extensive searches have shed no light on the identity of the rural reservoir host(s). in order to discover more about the biology of the vector, a host feeding preference study was conducted on wild sandflies in their natural cave environment over a 6-month period. solid state army miniature (ssam) traps, without light bulb, were suspended ...	1993	8369555
molecular examination of the sympatry and distribution of sheep and camel strains of echinococcus granulosus in kenya.	previous studies have shown that camel and sheep strains of the cystic hydatid parasite echinococcus granulosus occur in kenya. we examined 208 larval isolates and 40 worm samples of e. granulosus from various hosts in kenya using restriction fragment length polymorphism analysis of a segment of ribosomal dna amplified by the polymerase chain reaction. this was in an effort to determine whether additional strains of e. granulosus occur in kenya, to examine the level of genetic heterogeneity with ...	1993	8097619
observations on rinderpest in kenya, 1986-1989.	rinderpest was confirmed in kenya in 1986, 1987, 1988 and 1989. three epidemiologically distinct events appear to have occurred: repeated outbreaks in west pokot district related to cross-border movement of stock, an outbreak in marsabit district in 1987 (thought to have been caused by illegal movement of cattle, possibly in vehicles, from countries further north) and a series of related outbreaks in and near nairobi between 1988 and 1989 due to the unauthorized movement from abattoirs and holdi ...	1992	1472724
dermatophilosis in camels (camelus dromedarius linnaeus, 1758) in kenya.	natural dermatophilosis (caused by dermatophilus congolensis van saceghem, 1915) has only recently been described in camels (camelus dromedarius). further work has shown that the disease is actually widespread. at the ol maisor farm where it was first diagnosed (in the laikipia district of northern kenya), detailed investigations have revealed that thirty camels (ten calves and twenty adult animals) were infected. the signs varied from mild to more than 50% skin involvement. patches of wool on t ...	1992	1305855
serological evidence of arboviral infections among humans of coastal kenya.	a serosurvey was conducted during september 1987 for evidence of human arboviral infections in the coast province of kenya. sera were collected from 1624 outpatients at three hospitals and tested for antibody to eight arboviruses by the indirect immunofluorescent antibody technique. antibody prevalence rates were: rift valley fever, 2.8%; sindbis, 2.6%; dugbe, 2.1%; dengue-2, 1.0%; west nile, 0.9%; chikungunya, 0.7% and nairobi sheep disease, 0.3%. evidence of crimean-congo haemorrhagic fever vi ...	1991	2051522
influence of regular tick and helminth control on productivity of small ruminants in the lolgorien area, narok district, kenya.	forty-five indigenous goats (one to two years old) and 45 indigenous sheep (six to eight months old) were exposed to natural tick and gastro-intestinal parasite challenge. all animals were born and reared in a pastoral husbandry system. throughout the study they were housed at night under improved hygienic conditions and grazed during daytime with the flock from which they originated. improvement of hygienic conditions reduced mortality. control of intestinal parasites increased liveweight gain ...	1989	2515642
hydatid disease: research and control in turkana, kenya. 1. epidemiological observations.	a brief account is given of the geographical features of the turkana area and of the events which led to the discovery that this part of kenya had the highest incidence of clinically recognized hydatid disease in man anywhere in the world. observations were made on the distribution of the disease following an aerial survey designed to determine the distribution of the people. it was found that the highest incidence of 198 surgical cases per 100,000 people per annum was in the north-western area ...	1986	3787676
rift valley fever in kenya: the presence of antibody to the virus in camels (camelus dromedarius).	five hundred and seventy-one camel sera collected after an epizootic of rift valley fever were examined for antibody to the virus. clinical disease had not been observed in cattle and sheep in the ecosystems shared with the camels. positive sera with high titres of serum neutralizing antibody were found in 22% of camels at one of the seven sampling sites.	1985	3989285
rainfall and epizootic rift valley fever.	epizootic rift valley fever (rvf) has occurred in kenya four times over the last 30 years. widespread, frequent, and persistent rainfall has been a feature of these epizootic periods. a composite statistic, based upon measurements of these rainfall characteristics, is positive during periods of epizootic rift valley fever. the heavy rainfall raises the level of the water table in certain areas, flooding the grassland depressions (dambos) that are the habitat of the immature forms of certain grou ...	1985	3879206
hydatid disease in the turkana district of kenya, iv. the prevalence of echinococcus granulosus infections in dogs, and observations on the role of the dog in the lifestyle of the turkana.	the prevalence of echinococcus granulosus in dogs in the turkana district of kenya was 39.4% of 695 examined. of these, 98 (35.8%) had heavy echinococcus worm burdens (10(3)-5 x 10(4) ), while 54 (19.7%) and 122 (44.5%) had medium (201-1000) and light (1-200) burdens. the possible sources of these infections are discussed. the prevalence rate differed in various parts of the district, ranging from 63.5% in the northwest, where the highest incidence of human hydatidosis also occurs, to nil along ...	1985	3985706
an active intermediate host role for man in the life cycle of echinococcus granulosus in turkana, kenya.	hydatid material removed at operation from 97 turkana was compared for fertility and viability with hydatid material removed from camels, cattle, sheep, and goats. the results showed that the human material was extremely fertile and viable, as was material from the camels, goats, and sheep. cattle cysts were invariably sterile, and the protoscoleces, when present, were comparatively less viable. the high incidence and fertility of hydatid cysts in the turkana, together with the lack of burial cu ...	1983	6837848
an ecological interdependence of diet and disease? a study of infection in one tribe consuming two different diets.	the nature and incidence of infections were studied in two groups of turkana living in the same area but eating different diets; one consumed milk only and the other a combination of fish and milk. the only apparent and significant nutritional difference between the two groups was mild iron deficiency in the milk drinkers. episodes of fever, symptomatic infection with malaria and brucellosis, molluscum contagiosum and common warts, episodes of diarrhea, and serological evidence of infection with ...	1980	7355850
observations on the epidemiology of rift valley fever in kenya.	the epizootic range of rift valley fever in kenya is defined from the results of virus isolations during epizootics, and form an extensive serological survey of cattle which were exposed during an epizootic. a study of the sera from a wide range of wild bovidae sampled immediately after the epizootic, showed that they did not act as reservoir or amplifying hosts for rvf. virus isolation attempts from a variety of rodents proved negative. rift valley fever did not persist between epizootics by pr ...	1975	1058243