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BACKGROUND: Kenya introduced a monovalent rotavirus vaccine administered orally at 6 and 10 weeks of age into her National Immunization Program in July 2014. The study evaluated the long-term impact of the vaccine on hospitalization for all-cause and rotavirus-specific acute gastroenteritis (AGE) and strain epidemiology in Kenya. METHODS: Data on all-cause and rotavirus-specific AGE and strain distribution were derived from an eleven-year hospital-based surveillance of AGE among children aged <5 years at Kiambu County Teaching and Referral Hospital (KCTRH) in Central Kenya between 2009 and 2020. Fecal samples were screened for group A rotavirus using ELISA and genotyped using multiplex semi-nested RT-PCR. Trends in all-cause and rotavirus-related AGE and strain distribution were compared between the pre-vaccine (July 2009-June 2014), early post-vaccine (July 2014-June 2016) and late post-vaccine (February 2019-October 2020) periods. RESULTS: Rotavirus-specific AGE was detected at 27.5% (429/1546, 95% CI: 25.5-30.1%) in the pre-vaccine period; 13.8% (91/658, 95% CI: 11.3-16.6%) in the early post-vaccine period (July 2014-June 2016); and 12.0% (229/1916, 95% CI: 10.6-13.5%) in the late post-vaccine period (February 2019-October 2020). This amounted to a decline of 49.8% (95% CI: 34.6%-63.7%) in rotavirus-specific AGE in the early post-vaccine period and 53.4% (95% CI: 41.5-70.3%) in the late post-vaccine period when compared to the pre-vaccine period. All-cause AGE hospitalizations declined by 40.2% (95% CI: 30.8%-50.2%) and 75.3% (95% CI: 65.9-83.1%) in the early post-vaccine and late post-vaccine periods, respectively, when compared to the pre-vaccine period. G3P [8] was the predominant strain in the late post-vaccine period, replacing G1P[8] which had predominated in the pre-vaccine and early post-vaccine periods. Additionally, we detected considerable proportions of uncommon strains G3P[6] (4.8%) and G12P[6] (3.5%) in the post-vaccine era. CONCLUSION: Rotavirus vaccination has resulted in a significant decline in all-cause and rotavirus-specific AGE, and thus, provides strong evidence for public health policy makers in Kenya to support the sustained use of the rotavirus vaccine in routine immunization. However, the shift in strain dominance and age distribution of rotavirus AGE in the post-vaccine era underscores the need for continued surveillance to assess any possible vaccine-induced selective pressure that could diminish the vaccine effectiveness over time.
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AIM: This study aimed to develop a multiplex PCR assay for simultaneous detection of major Gram-negative etiologies of septicemia and evaluate its performance. METHODS: Multiplex PCR (mPCR) assays were developed targeting 11 bacterial strains. Species-specific primers were confirmed using known clinical isolates and standard strains. Gradient PCR was performed on each primer against its target bacterial gene to determine its optimal amplification condition. The minimum detectable DNA concentration of the two assays was evaluated by adjusting bacterial DNA concentration to 100 ng/µL and, tenfold serially diluting it up to 10 pg/µL with DNAse-free water. The diagnostic accuracy of mPCR assays was established by subjecting the assays to 60 clinical blood samples. RESULTS: Two mPCR assays were developed. Optimal primer annealing temperature of 55 °C was established and utilized in the final amplification conditions. The assays detected all targeted bacteria, with a 100 pg minimum detectable DNA concentration. Pathogens were not detected directly from whole blood, but after 4 h and 8 h of incubation, 41% (5/12) and 100% (12/12) of the bacteria were detected in culture fluids, respectively. The assays also identified Salmonella spp. and Klebsiella pneumoniae co-infections and extra pathogens (1 E. coli and 2 K. pneumoniae) compared with culture. The sensitivity and specificity of the mPCR were 100.0% (71.7-100.0) and 98.0% (90.7-99.0), respectively. The area under the ROC curve was 1.00 (1.00-1.00). CONCLUSIONS: The mPCR assays demonstrated substantial potential as a rapid tool for septicemia diagnosis alongside the traditional blood culture method. Notably, it was able to identify additional isolates, detect co-infections, and efficiently detect low bacterial DNA loads with high sensitivity, implying its value in enhancing efficiency of diagnosis of septicemia.
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BACKGROUND: Influenza viruses are an important cause of respiratory infections across all age groups. Information on occurrence and magnitude of influenza virus infections in different populations in Kenya however remains scanty, compromising estimation of influenza disease burden. This study examined influenza infection in an urban high-income setting in Nairobi to establish its prevalence and activity of influenza viruses, and evaluated diagnostic performance of a rapid influenza diagnostic test. METHODOLOGY: A cross-sectional hospital-based study was conducted in six private health facilities located within high-income residential areas in Nairobi from January 2019 to July 2020. Patients of all ages presenting with influenza-like illness (ILI) were recruited into the study. Detection of influenza virus was conducted using rapid diagnosis and reverse transcription-polymerase chain reaction (RT-PCR). Data were summarized using descriptive statistics and tests of association. Sensitivity, specificity and area under receiver operating characteristics curve was calculated to establish diagnostic accuracy of the rapid diagnosis test. RESULTS: The study recruited 125 participants with signs and symptoms of ILI, of whom 21 (16.8%) were positive for influenza viruses. Of all the influenza-positive cases, 17 (81.0%) were influenza type A of which 70.6% were pandemic H1N1 (A/H1N1 2009). Highest detection was observed among children aged 5-10 years. Influenza virus mostly circulated during the second half of the year, and fever, general fatigue and muscular and joint pain were significantly observed among participants with influenza virus. Sensitivity and specificity of the diagnostic test was 95% (95% confidence interval 75.1-99.9) and 100% (95% confidence interval 96.5-100.0), respectively. CONCLUSIONS: Findings of this study shows continuous but variable activity of influenza virus throughout the year in this population, with substantial disease burden. The findings highlight the need for continuous epidemiologic surveillance including genetic surveillance to monitor activity and generate data to inform vaccine introduction or development, and other interventions.
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OBJECTIVES: We assessed the impact of water, hygiene and sanitation (WASH), maternal, new-born and child health (MNCH), nutrition and early childhood development (ECD) on diarrhoea and microbial quality of water in a resource-constrained rural setting in Kenya. METHODS: Through a controlled intervention study, we tested faecal and water samples collected from both the intervention and control sites before and after the interventions using microbiological, immunological and molecular assays to determine the prevalence of diarrhoeagenic agents and microbial quality of water. Data from the hospital registers were used to estimate all-cause diarrhoea prevalence. RESULTS: After the interventions, we observed a 58.2% (95% CI: 39.4-75.3) decline in all-cause diarrhoea in the intervention site versus a 22.2% (95% CI: 5.9-49.4) reduction of the same in the control site. Besides rotavirus and pathogenic Escherichia coli, the rate of isolation of other diarrhoea-causing bacteria declined substantially in the intervention site. The microbial quality of community and household water improved considerably in both the intervention (81.9%; 95% CI: 74.5%-87.8%) and control (72.5%; 95% CI: 64.2%-80.5%) sites with the relative improvements in the intervention site being slightly larger. CONCLUSIONS: The integrated WASH, MNCH, nutrition and ECD interventions resulted in notable decline in all-cause diarrhoea and improvements in water quality in the rural resource-limited population in Kenya. This indicates a direct public health impact of the interventions and provides early evidence for public health policy makers to support the sustained implementation of these interventions.
Subject(s)
Hygiene , Sanitation , Child , Child, Preschool , Diarrhea/epidemiology , Diarrhea/prevention & control , Humans , Infant , Kenya/epidemiology , Sanitation/methods , Water QualityABSTRACT
The NUITM-KEMRI biosafety training program was developed for capacity building of new biosafety level three (BSL-3) laboratory users. The training program comprehensively covers biosafety and biosecurity theory and practice. Its training curriculum is based on the WHO biosafety guidelines, local biosafety standards, and ongoing biosafety level three research activities in the facility, also taking into consideration the emerging public health issues. The program's training approach enhances the participant's biosafety and biosecurity knowledge and builds their skills through the hands-on practice sessions and mentorship training. Subsequently, the trainees are able to integrate acquired knowledge and good practices into their routine laboratory procedures. This article describes implementation of the NUITM-KEMRI biosafety training program.
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Pathogens handled in a Biosafety Level 3 (BSL-3) containment laboratory pose significant risks to laboratory staff and the environment. It is therefore necessary to develop competency and proficiency among laboratory workers and to promote appropriate behavior and practices that enhance safety through biosafety training. Following the installation of our BSL-3 laboratory at the Center for Microbiology Research-Kenya Medical Research Institute in 2006, a biosafety training program was developed to provide training on BSL-3 safety practices and procedures. The training program was developed based on World Health Organization specifications, with adjustments to fit our research activities and biosafety needs. The program is composed of three phases, namely initial assessment, a training phase including theory and a practicum, and a final assessment. This article reports the content of our training program.