Social Mobilization and Compliance with Mass Treatment for Lymphatic Filariasis Elimination in Kenya

This study aimed to establish the role of social mobilization in mass drug administration (MDA) uptake during the National Programme to Eliminate Lymphatic Filariasis (LF) in Kenya. MDA for LF based on diethylcarbamazine (DEC) and albendazole using community-based treatment approach has been conducted for three years (2003, 2005 and 2008) in Kwale and Malindi districts. In each district, one high and one low, compliance locations were selected based on 2008 MDA data. From the four locations, nine villages were systematically sampled and a total of 965 randomly selected household heads interviewed. Sixteen focus group discussions with adult and youth male and female groups and separate in-depth interviews with eighty opinion leaders and eighty LF patients with clinical manifestations, purposively selected were conducted. Semi-structured interviews were held separately with fifteen community drug distributors, five health personnel and four LF coordinators also purposively selected. The results showed that knowledge about MDA for LF was not significantly associated with compliance (P>0.05). Seventy three percent in low and 78% in high compliance villages knew about MDA. The most common source of MDA information given by 49% of respondents in high and 40% in low compliance villages were the community drug distributors (CDDs). The content of MDA information received influenced compliance (P< 0.001), 71% in high compared to 61% in low compliance villages received correct information. The frequency of receiving MDA information also influenced compliance (P< 0.001), 65.5% in high compared to 50% in low compliance villages received the correct information at least once before treatment. Opinion towards the source of MDA information was also associated with compliance, 46% in high compared to 43% in low compliance villages considered the source as adequate (P< 0.001). The study results show that for MDA to be successful, information dissemination should be done by all stakeholders with the health personnel taking the lead role so that more adequate and factual content is relayed. Community sensitization and mobilization should be done repeatedly for all to get the information in good time to comply with treatment. Keywords: Compliance; Lymphatic Filariasis; Mass Drug Administration; Social Mobilizatio

Analysis of small ruminants’ pastoral management practices as risk factors of peste des petits ruminants (PPR) spread in Turkana District, Kenya

Peste des petits ruminants (PPR) is an emerging viral disease spreading throughout Kenya and East Africa causing major losses in the small stock. This study is an attempt to evaluate small stock management practices in Turkana pastoral system, Kenya as predictors of PPR outbreaks. Information on the social practices and the occurrence of PPR outbreaks was obtained by participatory techniques. The small stock management practices, evaluated as factors, in a previous study were simultaneously analyzed with seasons and administrative divisions as the independent risk factors for the presence or absence of PPR outbreaks in 142 Adakars (villages) as the dependent variable. Analyses were carried out for the years 2009 and 2010 combined as one data set and considered as longitudinal repeated data. In the analyses, the presence or absence of PPR outbreaks was the dependent variable. Data were further analyzed separately disaggregated by season where the presence or absence of PPR outbreaks in a season was considered as the dependent variable. All analyses utilized multivariable logistical regression analyses. In the longitudinal analysis, season was the only significant factor associated with PPR outbreak. Disaggregating the data by season revealed that certain seasonal-specific livestock management activities increased the risk of reporting PPR outbreaks: (1) sharing water sources leading to social aggregation of young stock in one point (Factor 3) (odds ratio (OR) = 2.0) in season 2 (wet season) of 2009; (2) sick dams left to nurse their young kids/lambs (Factor 7) (OR=1.62) in the same season in 2010. The finding of diverse risk factors in the same seasons across years suggests temporal heterogeneity in the distribution and occurrence of the determinants of PPR in the Turkana ecosystem. The study discusses the implications of these findings on disease control

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Evaluation of ICT Filariasis Card Test Using Whole Capillary Blood: Comparison with Knott's Concentration and Counting Chamber Methods

Article JournalAn immunochromatographic card test (ICT) that uses fingerprick whole blood instead of serum for diagnosis of bancroftian filariasis has recently been developed. The card test was validated in the field in Kenya by comparing its sensitivity to the combined sensitivity of Knott’s concentration and counting chamber methods. A total of 102 (14.6%) and 117 (16.7%) persons was found to be microfilaremic by Knott’s concentration and counting chamber methods, respectively. The geometric mean intensities (GMI) were 74.6 microfilariae (mf)/ml and 256.5 mf/ml by Knott’s concentration and counting chamber methods, respectively. All infected individuals detected by both Knott’s concentration and counting chamber methods were also antigen positive by the ICT filariasis card test (100% sensitivity). Further, of 97 parasitologically amicrofilaremic persons, 24 (24.7%) were antigen positive by the ICT. The overall prevalence of antigenemia was 37.3%. Of 100 nonendemic area control persons, none was found to be filarial antigen positive (100% specificity). The results show that the new version of the ICT filariasis card test is a simple, sensitive, specific, and rapid test that is convenient in field settings

Evaluation of Effectiveness of Diethylcarbamazine/Albendazole Combination in Reduction of Wuchereria Bancrofti Infection using Multiple Infection Parameters

Article JournalTo evaluate the effect of multiple rounds of annual single dose of DEC (6 mg/kg) or albendazole (400 mg) given alone or in combination on Wuchereria bancrofti microfilaraemia, anti-filarial IgG1 and IgG4 and antigenaemia. A total of 170 participants were randomly assigned to albendazole (n = 62), DEC (n = 54), and DEC plus albendazole (DEC/ALB) combination (n = 54). Blood samples were collected at pre-treatment in 1998, at 1 week and 6 months after the first treatment and thereafter before subsequent treatments in 1999 and 2000. Effects of treatment on W. bancrofti infection were determined by changes in levels of microfilaraemia, antifilarial antibodies and circulating filarial antigen. Comparison of geometric mean microfilariae intensities between DEC/ALB combination and DEC or albendazole single therapy groups after two rounds of annual treatment and 24 months follow-up showed that combination therapy resulted in a greater reduction of microfilaraemia than single therapy with either albendazole (p < 0.001) or DEC alone (p = 0.146). The overall levels of anti-filarial antibodies decreased significantly (p = 0.028 for IgG1 and p < 0.043 for IgG4) in all treatment groups at 24 months follow-up. Additionally, overall reduction in geometric mean circulating filarial antigen levels at 24 months was 44%, 60% and 85% for albendazole, DEC and DEC/ALB groups, respectively.These study findings suggest that albendazole improved efficacy of DEC and mass administration of a combination of the two drugs would therefore enhance the interruption of transmission of W. bancrofti in endemic areas. This information has important implications for the ongoing Global Program for Elimination of Lymphatic Filariasis

Chronic Clinical Manifestations Related to Wuchereria Bancrofti Infection in A Highly Endemic Area in Kenya

Journal ArticleClinical examinations were conducted in an effort to provide baseline data for a pilot filariasis elimination programme implemented in a Wuchereria bancrofti-endemic focus in Malindi district, Kenya. Of 186 males aged 15 years and above examined, 64 individuals (34.4%) had hydrocele, and the prevalence of the manifestation in those above 40 years old was 55.3%. The prevalence of leg lymphoedema in persons aged 15 years and above was 8.5%, with a higher rate in males (12.6%) than in females (5.7%). The overall prevalence of inguinal adenopathy was 8.6%, and males had a significantly higher (12.9%) prevalence of adenopathy than females (5.1%) (P < 0.001). The data in the present study provided support for consideration of filarial infection as a possible cause of inguinal lymphadenopathy in bancroftian filariasis-endemic areas. The results of this study also indicate that lymphatic filariasis is a serious public health problem in the northern coastal areas and morbidity control programmes should be implemented to alleviate the suffering of those affected

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

Sero-epidemiology of Peste des petits ruminants virus infection in Turkana County, Kenya

Background Peste des petits ruminants (PPR) is a contagious viral disease of small ruminants. Serum samples from sheep (n = 431) and goats (n = 538) of all ages were collected in a cross-sectional study in Turkana County, Kenya. The objective was to estimate the sero-prevalence of PPR virus (PPRV) infection and associated risk factors in both species. PPRV competitive enzyme-linked immuno-sorbent assay (c-ELISA) analysed the presence of antibodies in the samples. All analyses were conducted for each species separately. Multivariable logistic regression models were fitted to the data to assess the relationship between the risk factors and PPRV sero-positivity. Mixed-effect models using an administrative sub-location as a random effect were also fitted to adjust for possible clustering of PPRV sero-positivity. Intra-cluster correlation coefficients (ρ) that described the degree of similarity among sero-positive responses for each species in each of the six administrative divisions were estimated. Results Goats had a significantly higher sero-prevalence of 40% [95% confidence interval (CI): 36%, 44%] compared to sheep with 32% [95% CI: 27%, 36%] (P = 0.008). Combined sero-prevalence estimates were heterogeneous across administrative divisions (n = 6) (range 22% to 65%) and even more across sub-locations (n = 46) (range 0% to 78%). Assuming that PPRV antibodies are protective of infection, a large pool of PPRV susceptible middle age group (>6 months and < 24 months) in both species was estimated. This was based on the low sero-prevalence in this group in goats (14% [95% CI: 10%, 20%]) and in sheep (18% [95% CI: 13%, 25%]). Regression analysis returned significant risk factors across species: in sheep - vaccination status, age and administrative division; in goats - sex, age, administrative division and sex*age interaction. The intra-sub-location correlation coefficients varied widely across divisions (range <0.001 to 0.42) and across species within divisions. Conclusions Biological, spatial and socio-ecological factors are hypothesized as possible explanations for variation in PPRV sero-positivity in the Turkana pastoral ecosystem