Seroprevalence of Taenia saginata Cysts in Cattle, Human Hospital Cases, and Risk Factors for Human Taeniasis in Kajiado County, Kenya.

Taenia saginata is a zoonotic tapeworm that causes diseases in cattle and humans. A cross-sectional survey was conducted between June and July 2021 in Kajiado County, Kenya, to estimate the seroprevalence of Taenia saginata cysts in cattle presented for slaughter in Kitengela, Kiserian, and Keekonyokie slaughterhouses; determine the annual hospital reported cases of T. saginata in humans that visited all level 4 hospitals in Kajiado County between 2015 and 2021; and assess the risk factors for Taenia saginata in humans. Analyzed data in this study revealed that the seroprevalence of Taenia saginata cysts in cattle in the selected slaughterhouses was 2.67% (4/150). The meat inspectors recorded no cysts during the study period, confirming that antibody ELISA is three times as sensitive as meat inspection. Data from hospital records showed that a total of 1,487,687 patients visited different facilities in Kajiado County between 2015 and 2021. During the same period, 29 patients were diagnosed with human taeniasis. From the risk factors assessed, uninspected home slaughter (75%), consumption of raw/improperly cooked beef (100%), and open defecation by herders (11%) still pose a risk to humans getting infected by Taenia saginata, while the presence and use of latrines (89%) and availability, accessibility, and use of taenicides (89%) seem to have significantly contributed to the reduction of Taenia saginata prevalence in this region. It is recommended that control of the infection should be centered towards continuous focused education coupled with regular deworming of the herders and school going children. This will gradually result in behavior and culture change that will ultimately reduce the prevalence and lead to the elimination of the disease.

Epidemiological study on foot-and-mouth disease in small ruminants: Sero-prevalence and risk factor assessment in Kenya.

Foot-and-mouth disease (FMD) is endemic in Kenya affecting cloven-hoofed ruminants. The epidemiology of the disease in small ruminants (SR) in Kenya is not documented. We carried out a cross-sectional study, the first in Kenya, to estimate the sero-prevalence of FMD in SR and the associated risk factors nationally. Selection of animals to be sampled used a multistage cluster sampling approach. Serum samples totaling 7564 were screened for FMD antibodies of non-structural-proteins using ID Screen® NSP Competition ELISA kit. To identify the risk factors, generalized linear mixed effects (GLMM) logistic regression analysis with county and villages as random effect variables was used. The country animal level sero-prevalence was 22.5% (95% CI: 22.3%-24.3%) while herd level sero-prevalence was 77.6% (95% CI: 73.9%-80.9%). The risk factor that was significantly positively associated with FMD sero-positivity in SR was multipurpose production type (OR = 1.307; p = 0.042). The risk factors that were significantly negatively associated with FMD sero-positivity were male sex (OR = 0.796; p = 0.007), young age (OR = 0.470; p = 0.010), and sedentary production zone (OR = 0.324; p<0.001). There were no statistically significant intra class correlations among the random effect variables but interactions between age and sex variables among the studied animals were statistically significant (p = 0.019). This study showed that there may be widespread undetected virus circulation in SR indicated by the near ubiquitous spatial distribution of significant FMD sero-positivity in the country. Strengthening of risk-based FMD surveillance in small ruminants is recommended. Adjustment of husbandry practices to control FMD in SR and in-contact species is suggested. Cross-transmission of FMD and more risk factors need to be researched.

Seroprevalence and Risk Factors for Hepatitis B Virus Infection in Adolescent Blood Donors within Selected Counties of Western Kenya.

Hepatitis B virus is a widespread public health menace approximated to have infected 257 million people chronically by 2015. Data on the prevalence of HBV is important in formulating public health policies on HBV control like safe blood transfusion. Adolescents aged 15 to 24 years, known to engage in risky activities associated with HBV spread, constitute major blood donors in Kenya. Notwithstanding current blood donation safety measures, HBV still remain hazardous transfusion-transmissible infections in donated blood. This study therefore was to determine the prevalence of HBsAg and related risk factors among this donor group. A cross-sectional study was conducted from April 2019 to August 2019 in Siaya, Kisumu, and Homa Bay counties. One thousand (1000) voluntary blood donors 18 to 25 years old were recruited. A predonation questionnaire was used to record their sociodemographic features and prior risk exposures. Blood samples were initially tested for HBsAg using Murex HBsAg Version 3 (DiaSorin, UK) and positives confirmed using ARCHITECT HBsAg Qualitative Confirmatory assay (Abbott Ireland) as per the manufacturer's instructions. A result was considered positive if the first and confirmatory tests were all reactive. Generally, the prevalence of HBV was 3.4%, with no significant association between various sociodemographic variables and HBsAg positivity. Nevertheless, scarification and risky sexual behavior were significantly linked to HBV infections (odds ratio (OR) = 8.533, 95%confidence interval (CI) = 3.128-23.275, p value of 0.001 and OR = 5.471, 95%CI = 1.925-15.547, p value of 0.002, respectively). This study revealed a prevalence of 3.4% HBsAg among adolescent blood donors, with perilous sexual behaviors being the most significant risk factor, evidence that sexual contact still plays a major role in transmission of HBV among this donor group despite blood transfusion safety measures put in place. These study findings should therefore be put into consideration while framing health policies to mitigate effects of HBV infection on safe blood transfusion.

Hematologic Values of Healthy and Sick Free-ranging Lesser Flamingos ( Phoeniconaias minor) in Kenya.

We determined hematologic parameters of five healthy and nine sick free-ranging Lesser Flamingos ( Phoeniconaias minor) from Lake Nakuru, Kenya. Heterophilia and lymphopenia were evident in sick birds, with up to 7.5-fold higher heterophil-to-lymphocyte ratio in sick birds compared to healthy birds. Leucopenia was present in a few sick birds. A higher than normal packed cell volume was observed in birds that had evidence of acute disease, whereas a lower than normal packed cell volume was seen in birds with evidence of prolonged sickness. Healthy birds had higher total white blood cell counts and lymphocyte counts and lower heterophil counts than zoo flamingos. Most sick birds were diagnosed with septicemia, occasionally with fibrinous exudation into the coelomic cavities. One bird had mycobacterial granulomas, one had a corynebacterium-associated wing abscess, and one had a wing fracture. We provide hematologic data for free-ranging Lesser Flamingos and compare the parameters of sick and healthy birds.

Seroepidemiological Survey of Rift Valley Fever Virus in Ruminants in Garissa, Kenya.

INTRODUCTION: Rift Valley fever (RVF) is a vector-borne zoonotic disease caused by phlebovirus in the family Bunyaviridae. In Kenya, major outbreaks occurred in 1997-1998 and 2006-2007 leading to human deaths, huge economic losses because of livestock morbidity, mortality, and restrictions on livestock trade. AIM: This study was conducted to determine RVF seroprevalence in cattle, sheep, and goats during an interepidemic period in Garissa County in Kenya. METHODS: In July 2013, we performed a cross-sectional survey and sampled 370 ruminants from eight RVF-prone areas of Garissa County. Rift Valley fever virus (RVFV) antibodies were detected using a multispecies competitive enzyme-linked immunosorbent assay. Mixed effect logistic regression models were used to determine the association between RVF seropositivity and species, sex, age, and location of the animals. RESULTS: A total of 271 goats, 87 sheep, and 12 cattle were sampled and the overall immunoglobulin G seroprevalence was 27.6% (95% CI [23-32.1]). Sheep, cattle, and goats had seroprevalences of 32.2% (95% CI [20.6-31]), 33.3% (95% CI [6.7-60]), and 25.8% (95% CI [22.4-42]), respectively. Seropositivity in males was 31.8% (95% CI [22.2-31.8]), whereas that of females was 27% (95% CI [18.1-45.6]). CONCLUSIONS: The high seroprevalence suggests RVFV circulation in domestic ruminants in Garissa and may be indicative of a subclinal infection. These findings provide evidence of RVF disease status that will assist decision-makers to flag areas of high risk of RVF outbreaks and prioritize the implementation of timely and cost-effective vaccination programs.

A systematic review of Rift Valley Fever epidemiology 1931-2014.

BACKGROUND: Rift Valley Fever (RVF) is a mosquito-borne viral zoonosis that was first isolated and characterized in 1931 in Kenya. RVF outbreaks have resulted in significant losses through human illness and deaths, high livestock abortions and deaths. This report provides an overview on epidemiology of RVF including ecology, molecular diversity spatiotemporal analysis, and predictive risk modeling. METHODOLOGY: Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched for relevant RVF publications in repositories of the World Health Organization Library and Information Networks for Knowledge (WHOLIS), U.S Centers for Disease Control and Prevention (CDC), and Food and Agricultural Organization (FAO). Detailed searches were performed in Google Scholar, SpringerLink, and PubMed databases and included conference proceedings and books published from 1931 up to 31st January 2015. RESULTS AND DISCUSSION: A total of 84 studies were included in this review; majority (50%) reported on common human and animal risk factors that included consumption of animal products, contact with infected animals and residing in low altitude areas associated with favorable climatic and ecological conditions for vector emergence. A total of 14 (16%) of the publications described RVF progressive spatial and temporal distribution and the use of risk modeling for timely prediction of imminent outbreaks. Using distribution maps, we illustrated the gradual spread and geographical extent of disease; we also estimated the disease burden using aggregate human mortalities and cumulative outbreak periods for endemic regions. CONCLUSION: This review outlines common risk factors for RVF infections over wider geographical areas; it also emphasizes the role of spatial models in predicting RVF enzootics. It, therefore, explains RVF epidemiological status that may be used for design of targeted surveillance and control programs in endemic countries.

Origin and diversification of the human parasite Schistosoma mansoni.

Schistosoma mansoni is the most widespread of the human-infecting schistosomes, present in 54 countries, predominantly in Africa, but also in Madagascar, the Arabian Peninsula, and the Neotropics. Adult-stage parasites that infect humans are also occasionally recovered from baboons, rodents, and other mammals. Larval stages of the parasite are dependent upon certain species of freshwater snails in the genus Biomphalaria, which largely determine the parasite's geographical range. How S. mansoni genetic diversity is distributed geographically and among isolates using different hosts has never been examined with DNA sequence data. Here we describe the global phylogeography of S. mansoni using more than 2500 bp of mitochondrial DNA (mtDNA) from 143 parasites collected in 53 geographically widespread localities. Considerable within-species mtDNA diversity was found, with 85 unique haplotypes grouping into five distinct lineages. Geographical separation, and not host use, appears to be the most important factor in the diversification of the parasite. East African specimens showed a remarkable amount of variation, comprising three clades and basal members of a fourth, strongly suggesting an East African origin for the parasite 0.30-0.43 million years ago, a time frame that follows the arrival of its snail host. Less but still substantial variation was found in the rest of Africa. A recent colonization of the New World is supported by finding only seven closely related New World haplotypes which have West African affinities. All Brazilian isolates have nearly identical mtDNA haplotypes, suggesting a founder effect from the establishment and spread of the parasite in this large country.