Cryptosporidium parasites are leading causes of enteric disease, especially in children. A prospective survey on the prevalence of cryptosporidiosis in children less than five years of age was undertaken at six microbiology laboratories in Kenya on fecal samples submitted for routine parasite and ova investigations. Analysis of 4,899 samples over a two-year study period showed an overall prevalence of cryptosporidiosis of 4% that was highest between November to February. Investigations on the nature of enteric diseases prompting ova and cyst examination requests showed 66.4% had acute diarrhea, 9% had persistent diarrhea, and 21% had recurrent diarrhea. The main symptoms were abdominal pain (51.1%), vomiting (51.6%), and abdominal swelling (11%). The prevalence of cryptosporidiosis was highest among children 13-24 months of age (5.2%) and least among those 48-60 months of age (2%). No significant differences were observed by sex but vomiting was slightly higher in males than in females (65% males and 52% females; P = 0.07). Cryptosporidiosis was significantly associated with persistent diarrhea (P = 0.0001, odds ratio [OR] = 2.193, 95% confidence interval [CI] = 1.463-3.29), vomiting (P = 0.0273, OR = 1.401, 95% CI = 1.04-1.893), and abdominal swelling (P = 0.0311, OR = 1.56, 95% CI = 1.04-2.34). Genotype analysis based on polymerase chain reaction-restriction fragment length polymorphism of the 18S rRNA gene fragment showed that 87% (153 of 175) of the Cryptosporidium isolates were C. hominis, 9% (15 of 175) were C. parvum, and remaining 4% were C. canis, C. felis, C. meleagridis, and C. muris. The most common protozoa in coinfected patients were Entamoeba histolytica/E. dispar, E. coli, and Giardia intestinalis (6%, 5%, and 2%, respectively). Our results show that Cryptosporidium is among the most common protozoan parasites in children with enteric diseases and that anthroponotic species are the leading cause of human cryptosporidiosis in Kenya, which suggests that human-to-human transmission is the main mode of spread.

BackgroundThe distribution of and factors associated with intestinal parasitic infections are poorly defined in high risk vulnerable populations such as urban slums in tropical sub-Saharan Africa.MethodsIn a cross sectional study, children aged 5 years and below who presented with diarrhoea were recruited from selected outpatient clinics in Mukuru informal settlement, and from Mbagathi District hospital, Nairobi, over a period of two years (2010–2011). Stool samples were examined for the presence of parasites using direct, formal-ether concentration method and the Modified Ziehl Neelsen staining technique.ResultsOverall, 541/2112 (25.6%) were positive for at least one intestinal parasite, with the common parasites being; Entamoeba histolytica, 225 (36.7%),Cryptosporidium spp. 187, (30.5%), Giardia lamblia, 98 (16%).The prevalence of intestinal parasites infection was higher among children from outpatient clinics 432/1577(27.4%) than among those admitted in hospital 109/535 (20.1%) p < 0.001. Infections with E. histolytica, and G. lamblia were higher among outpatients than inpatients (13.8% vs 1.3% p < 0.001 and 5.8% vs 1.3% p < 0.049) respectively, while infection with Cryptosporidium spp. was higher among inpatients than outpatients (15.3% vs 6.7%) respectively p < 0.001. Other parasites isolated among outpatients included Isospora belli, 19 (1.2%), Ascaris lumbricoides, 26 (1.6%), and Hymenolepis nana 12 (0.8%), with the remainder detected in less than ten samples each. HIV-infected participants were more likely to be infected with any parasite than uninfected participants, Adjusted Odds Ratio (AOR), 2.04, 95% CI, 1.55-2.67, p < 0.001), and with Cryptosporidium spp. (AOR, 2.96, 95% CI 2.07-4.21, p < 0.001).The inpatients were less likely to be infected with E. histolytica than outpatients (AOR, 0.11, 95% CI, 0.51- 0.24, p < 0.001), but more likely for inpatients to be infected with Cryptosporidium spp. than outpatients (AOR, 1.91, 95% CI, 1.33-2.73, p < 0.001). Mixed parasitic infections were seen in 65 (12.0%) of the 541 infected stool samples.ConclusionIntestinal parasitic infections are common in urban informal settlements’ environment. Routine examinations of stool samples and treatment could benefit both the HIV infected and uninfected children in outpatient and inpatient settings.

Cystic echinococcosis (CE) is a zoonotic disease caused by several members of the Echinococcus granulosus species complex. In East Africa, several species/strains are known to occur in livestock and humans, but host preferences, relative frequencies and spatial distribution of these taxa are poorly known. Here, we contribute livestock data for Maasailand of southern Kenya. Total CE prevalence was 25.8 % in cattle (151/587), 16.5 % in sheep (71/430) and 10.8 % in goats (21/194), which is a significant increase compared to surveys done about three decades ago. The majority of cysts occurred in the liver (56 % in cattle, 70 % in sheep and 65 % in goats). Molecular characterization by PCR-RFLP and sequencing of parts of the mitochondrial nad-1 gene was done for a subsample of 285 cysts. E. granulosus G1 was dominant in all host species (200 of 201 cysts from cattle, 68 of 69 from sheep and 11 of 15 from goats); the remaining taxa were Echinococcus canadensis G6 (one cyst from sheep, four from goats) and Echinococcus ortleppi (one cyst from cattle). Considering cyst fertility, sheep appear to be the most important hosts for E. granulosus G1, while goats were found to be suitable hosts for E. canadensis G6 (three of four cysts were fertile). For the first time, E. ortleppi was found in cattle from southern Kenya. Our data show an intense and possibly increasing level of CE transmission in southern Kenya, and the predominance of E. granulosus G1, which appears to be particularly pathogenic to humans, calls for urgent control measures.

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Research on cystic echinococcosis (CE) has a long history in Kenya, but has mainly concentrated on two discrete areas, Turkana and Maasailand, which are known to be foci of human CE in Africa. Here, we report on a survey for CE in livestock from central to northeastern Kenya, from where no previous data are available. A total of 7,831 livestock carcasses were surveyed. CE prevalence was 1.92% in cattle (n = 4,595), 6.94% in camels (n = 216), 0.37% in goats (n = 2,955) and 4.62% in sheep (n = 65). Identification of the parasite was done using an RFLP-PCR of the mitochondrial nad1 gene, which had been validated before against the various Echinococcus taxa currently recognized as distinct species. From a total of 284 recovered cysts, 258 could be identified as Echinococcus granulosus sensu stricto (n = 160), E. ortleppi (n = 51) and E. canadensis (n = 47) by RFLP-PCR of nad1. In cattle, fertile cysts occurred mostly in the lungs and belonged to E. ortleppi (31 of 54), while the vast majority were sterile or calcified cysts of E. granulosus s.s.. Most fertile cysts in camels belonged to E. canadensis (33 of 37); sterile or calcified cysts were rare. Goats harboured fertile cysts of E. ortleppi (n = 3)--which is the first record in that host species--and E. canadensis (n = 1), while all cysts of E. granulosus were sterile. Only sterile cysts were found in the three examined sheep. Typically, all cysts in animals with multiple infections belonged to the same species, while mixed infections were rare. Our data indicate that the epidemiological situation in central to northeastern Kenya is clearly different from the well-studied pastoral regions of Turkana and Maasailand, and the apparently low number of human CE cases correlates with the infrequent occurrence of E. granulosus s.s.

IntroductionGlobally Cryptosporidium and Giardia species are the most common non-bacterial causes of diarrhoea in children and HIV infected individuals, yet data on their role in paediatric diarrhoea in Kenya remains scant. This study investigated the occurrence of Cryptosporidium species, genotypes and subtypes in children, both hospitalized and living in an informal settlement in Nairobi.MethodsThis was a prospective cross-sectional study in which faecal specimen positive for Cryptosporidium spp. by microscopy from HIV infected and uninfected children aged five years and below presenting with diarrhoea at selected outpatient clinics in Mukuru informal settlements, or admitted to the paediatric ward at the Mbagathi District Hospital were characterized. The analysis was done by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) of the 18srRNA gene for species identification and PCR-sequencing of the 60 kDa glycoprotein (GP60) gene for subtyping.Results C. hominis was the most common species of Cryptosporidium identified in125/151(82.8%) of the children. Other species identified were C. parvum 18/151(11.9%), while C. felis and C. meleagridis were identified in 4 and 2 children, respectively. Wide genetic variation was observed within C. hominis, with identification of 5 subtype families; Ia, Ib, Id, Ie and If and 21 subtypes. Only subtype family IIc was identified within C. parvum. There was no association between species and HIV status or patient type.Conclusion C. hominis is the most common species associated with diarrhoea in the study population. There was high genetic variability in the C. hominis isolates with 22 different subtypes identified, whereas genetic diversity was low within C. parvum with only one subtype family IIc identified.

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BackgroundGiardia duodenalis is an important intestinal protozoan in humans worldwide with high infection rates occurring in densely populated and low resource settings. The parasite has been recorded to cause diarrhea in children. This study was carried out to identify G. duodenalis assemblages and sub-assemblages in children presenting with diarrhea in Kenya.MethodsA total of 2112 faecal samples were collected from children aged ≤5 years and screened for the presence of Giardia cysts using microscopy. A total of 96 (4.5 %) samples were identified as Giardia positive samples and were genotyped using glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi) and β-giardin loci.ResultsThe three markers successfully genotyped 72 isolates and grouped 2 (1.4) isolates as Assemblage A, 64 (88.9) as Assemblage B and 7 (9.7 %) consisted of mixed infections with assemblage A and B. A further analysis of 50 isolates using GDH Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) categorized 2 assemblage A isolates as sub-assemblage AII while 6 and 14 assemblage B isolates were categorized into sub-assemblage BIII and BIV respectively. A mixed infection with sub-assemblage BIII and BIV was recorded in 28 isolates. Over half (55.6 %) of Giardia infections were recorded among the children between 13 to 48 months old.ConclusionThis paper reports the first data on the assemblages and sub-assemblages of Giardia duodenalis in children representing with diarrhea in Kenya.