Browsing by Author "Velu RM"

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Development of a diarrhoea severity scoring scale in a passive health facility-based surveillance system.
(2022) St Jean DT; Chilyabanyama ON; Bosomprah S; Asombang M; Velu RM; Chibuye M; Mureithi F; Sukwa N; Chirwa M; Mokha P; Chilengi R; Simuyandi M; Department of Biostatistics, School of Public Health, University of Ghana, Ghana, Accra.; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.; Centre for Infectious Diseases Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Diarrhoeal disease remains a leading cause of death among children mostly in low and middle-income countries. Factors contributing to disease severity are complex and there is currently no consensus on a scoring tool for use in community-based studies. METHODS: Data were collected during a passive surveillance system in an outpatient health facility in Lusaka, Zambia from March 2019 to July 2019. Diarrhea episodes were assessed for severity using an in-house severity scoring tool (CIDRZ) and previously published scores (Vesikari, Clark, CODA, and DHAKA). The CIDRZ score was constructed using fieldworker-reported clinical signs and exploratory factor analysis. We used precision-recall curves measuring severe diarrhoea (i.e., requiring intravenous rehydration or referred for hospital admission) to determine the best performing scores. Then, we used Cronbach's alpha to assess the scale's internal consistency. Finally, we used Cohen's kappa to assess agreement between the scores. RESULTS: Of 110 diarrhea episodes, 3 (3%) required intravenous rehydration or were referred for hospital admission. The precision-recall area under the curve of each score as a predictor of severe diarrhoea requiring intravenous rehydration or hospital admission was 0.26 for Vesikari, 0.18 for CODA, 0.24 for Clark, 0.59 for DHAKA, and 0.59 for CIDRZ. The CIDRZ scale had substantial reliability and performed similarly to the DHAKA score. CONCLUSIONS: Diarrhoea severity scores focused on characteristics specific to dehydration status may better predict severe diarrhea among children in Lusaka. Aetiology-specific scoring tools may not be appropriate for use in community healthcare settings. Validation studies for the CIDRZ score in diverse settings and with larger sample sizes are warranted.
Ecological Niche Modeling of
(2023-Sep-08) Velu RM; Kwenda G; Bosomprah S; Chisola MN; Simunyandi M; Chisenga CC; Bumbangi FN; Sande NC; Simubali L; Mburu MM; Tembo J; Bates M; Simuunza MC; Chilengi R; Orba Y; Sawa H; Simulundu E; Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia.; Macha Research Trust, Choma P.O. Box 630166, Zambia.; Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, N 20 W10, Kita-Ku, Sapporo 001-0020, Japan.; Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka P.O. Box 32379, Zambia.; International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Hokkaido 060-0808, Japan.; Zambia National Public Health Institute, Ministry of Health, Lusaka P.O. Box 51925, Zambia.; One Health Research Center, Hokkaido University, Sapporo 001-0020, Japan.; Department of Geography and Environmental Studies, School of Natural Sciences, University of Zambia, Lusaka P.O. Box 32379, Zambia.; Department of Biostatistics, School of Public Health, University of Ghana, Accra P.O. Box LG13, Ghana.; National Malaria Elimination Centre, Chainama Hills Hospital Grounds, Lusaka P.O. Box 32509, Zambia.; Joseph Banks Laboratories, School of Life and Environmental Sciences, University of Lincoln, Lincolnshire LN6 7TS, UK.; Institute for Vaccine Research and Development, Hokkaido University, Sapporo 001-0021, Japan.; Africa Centre of Excellence for Infectious Diseases of Humans and Animals, University of Zambia, Lusaka P.O. Box 32379, Zambia.; Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka P.O. Box 50110, Zambia.; International Collaboration Unit, Global Virus Network, Baltimore, MD 21201, USA.; Department of Medicine and Clinical Sciences, School of Medicine, Eden University, Lusaka P.O. Box 37727, Zambia.; HerpeZ, University Teaching Hospital, Lusaka 10101, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
The circulation of both West Nile Virus (WNV) and Chikungunya Virus (CHIKV) in humans and animals, coupled with a favorable tropical climate for mosquito proliferation in Zambia, call for the need for a better understanding of the ecological and epidemiological factors that govern their transmission dynamics in this region. This study aimed to examine the contribution of climatic variables to the distribution of
Immunogenicity and safety of two monovalent rotavirus vaccines, ROTAVAC® and ROTAVAC 5D® in Zambian infants.
(2021-Jun-16) Chilengi R; Mwila-Kazimbaya K; Chirwa M; Sukwa N; Chipeta C; Velu RM; Katanekwa N; Babji S; Kang G; McNeal MM; Meyer N; Gompana G; Hazra S; Tang Y; Flores J; Bhat N; Rathi N; PATH, India. Electronic address: nrathi@path.org.; Centre for Infectious Disease Research in Zambia, Zambia.; Department of Pediatrics, University of Cincinnati College of Medicine, Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.; The Wellcome Trust Research Laboratory, Vellore, India.; PATH, India.; PATH, USA.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND AND AIMS: ROTAVAC® (frozen formulation stored at -20 °C) and ROTAVAC 5D® (liquid formulation stable at 2-8 °C) are rotavirus vaccines derived from the 116E human neonatal rotavirus strain, developed and licensed in India. This study evaluated and compared the safety and immunogenicity of these vaccines in an infant population in Zambia. METHODS: We conducted a phase 2b, open-label, randomized, controlled trial wherein 450 infants 6 to 8 weeks of age were randomized equally to receive three doses of ROTAVAC or ROTAVAC 5D, or two doses of ROTARIX®. Study vaccines were administered concomitantly with routine immunizations. Blood samples were collected pre-vaccination and 28 days after the last dose. Serum anti-rotavirus IgA antibodies were measured by ELISA, with WC3 and 89-12 rotavirus strains as viral lysates in the assays. The primary analysis was to assess non-inferiority of ROTAVAC 5D to ROTAVAC in terms of the geometric mean concentration (GMC) of serum IgA (WC3) antibodies. Seroresponse and seropositivity were also determined. Safety was evaluated as occurrence of immediate, solicited, unsolicited, and serious adverse events after each dose. RESULTS: The study evaluated 388 infants in the per-protocol population. All three vaccines were well tolerated and immunogenic. The post-vaccination GMCs were 14.0 U/mL (95% CI: 10.4, 18.8) and 18.1 U/mL (95% CI: 13.7, 24.0) for the ROTAVAC and ROTAVAC 5D groups, respectively, yielding a ratio of 1.3 (95% CI: 0.9, 1.9), thus meeting the pre-set non-inferiority criteria. Solicited and unsolicited adverse events were similar across all study arms. No death or intussusception case was reported during study period. CONCLUSIONS: Among Zambian infants, both ROTAVAC and ROTAVAC 5D were well tolerated and the immunogenicity of ROTAVAC 5D was non-inferior to that of ROTAVAC. These results are consistent with those observed in licensure trials in India and support use of these vaccines across wider geographical areas.
Mosquito-Borne Viral Pathogens Detected in Zambia: A Systematic Review.
(2021-Aug-10) Velu RM; Kwenda G; Libonda L; Chisenga CC; Flavien BN; Chilyabanyama ON; Simunyandi M; Bosomprah S; Sande NC; Changula K; Muleya W; Mburu MM; Mubemba B; Chitanga S; Tembo J; Bates M; Kapata N; Orba Y; Kajihara M; Takada A; Sawa H; Chilengi R; Simulundu E; HerpeZ Infection Research and Training, University Teaching Hospital, Lusaka Private Bag RW1X Ridgeway, Lusaka P.O. Box 10101, Zambia.; Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia.; School of Life Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa.; School of Life Sciences, University of Lincoln, Brayford Pool, Lincoln LN6 7TS, UK.; Department of Paraclinical Studies, School of Veterinary Medicine, University of Zambia, Lusaka P.O. Box 32379, Zambia.; Macha Research Trust, Choma P.O. Box 630166, Zambia.; Division of Molecular Pathobiology, International Institute for Zoonosis Control, Hokkaido University, N 20 W10, Kita-ku, Sapporo 001-0020, Japan.; Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka P.O. Box 32379, Zambia.; Department of Disease Control, School of Veterinary Medicine, University of Zambia, Lusaka P.O. Box 32379, Zambia.; Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido University, N 20 W10, Kita-ku, Sapporo 001-0020, Japan.; School of Veterinary Medicine, University of Namibia, Windhoek Private Bag 13301, Namibia.; Department of Biostatistics, School of Public Health, University of Ghana, Accra P.O. Box LG13, Ghana.; Africa Center of Excellence for Infectious Diseases of Humans and Animals, University of Zambia, Lusaka P.O. Box 32379, Zambia.; Department of Zoology and Aquatic Sciences, School of Natural Resources, Copperbelt University, Kitwe P.O. Box 21692, Zambia.; Global Virus Network, 725 W Lombard St., Baltimore, MD 21201, USA.; Zambia National Public Health Institute, Ministry of Health, Lusaka P.O. Box 30205, Zambia.; Department of Disease Control and Prevention, School of Medicine and Health Sciences, Eden University, Lusaka P.O. Box 37727, Zambia.; Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka P.O. Box 50110, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Emerging and re-emerging mosquito-borne viral diseases are a threat to global health. This systematic review aimed to investigate the available evidence of mosquito-borne viral pathogens reported in Zambia. A search of literature was conducted in PubMed and Google Scholar for articles published from 1 January 1930 to 30 June 2020 using a combination of keywords. Eight mosquito-borne viruses belonging to three families,
Prevalence and predictors of virological failure in pediatric patients on HAART in sub-Saharan Africa: a systematic review and meta-analysis.
(2023) Machila N; Libonda L; Habineza P; Velu RM; Kamboyi HK; Ndhlovu J; Wamunyima I; Sinadambwe MM; Mudenda S; Zyambo C; Bumbangi FN; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.; Division of Infection and Immunity, International Institute for Zoonosis Control, Hokkaido University, Hokkaido, Japan.; Department of Community and Family Health, School of Public Health, University of Zambia, Lusaka, Zambia.; Department of Disease Control and Prevention, School of Medicine, Eden University, Lusaka, Zambia.; Department of Women and Newborn, University Teaching Hospital, Lusaka, Zambia.; Department of Pharmacy, School of Medicine, University of Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Antiretroviral treatment failure has emerged as a challenge in the management of pediatric human immunodeficiency virus (HIV) patients, especially in resource-limited countries despite accessibility to Highly Active Antiretroviral Therapy (HAART). A systematic review and meta-analysis was conducted to synthesize virological failure (VF) prevalence and ascertain its predictors in children in sub-Saharan Africa. An electronic database search strategy was conducted from January to September 2021 on PubMed, EMBASE, SCOPUS, HINARI, and CINAHL. Further, manual searching was conducted on non-indexed journals. Utilizing the JASP© version 0.17.2 (2023) statistical software, a meta-analysis of pooled prevalence of VF was estimated using the standardized mean differences. Further, selection models were used to assess the risk of bias and heterogeneity. The pooled odds ratios were estimated for the respective studies reporting on predictors of VF. The overall pooled estimate of the prevalence of VF in sub-Saharan Africa among the sampled population was 29% (95% CI: 27.0-32.0; p<0.001). Predictors of VF were drug resistance (OR: 1.68; 95% CI: 0.88-2.49; p < 0.001), poor adherence (OR: 5.35; 95% CI: 5.26-5.45; p < 0.001), nevirapine (NVP)-based regimen (OR: 5.11; 95% CI: 4.66-5.56; p < 0.001), non-usage of cotrimoxazole prophylaxis (OR: 4.30; 95% CI: 4.13-4.47; p < 0.001), higher viral load at the initiation of antiretroviral therapy (ART) (OR: 244.32; 95% CI: 244.2-244.47; p <0.001), exposure to the prevention of mother to child transmission (PMTCT) (OR: 8.02; 95%CI: 7.58-8.46; p < 0.001), increased age/older age (OR: 3.37; 95% CI: 2.70-4.04; p < 0.001), advanced World Health Organization (WHO) stage (OR: 6.57; 95% CI: 6.17-6.98; p < 0.001), not having both parents as primary caregivers (OR: 3.01; 95% CI: 2.50-3.53; p < 0.001), and tuberclosis (TB) treatment (OR: 4.22; 95% CI: 3.68-4.76; p <0.001). The mean VF prevalence documented is at variance with studies in other developing countries outside the sub-Saharan region. The high prevalence of HIV cases contrasting with the limited expertise in the management of pediatric ART patients could explain this variance.
Sero-prevalence of arthropod-borne viral infections among Lukanga swamp residents in Zambia.
(2020) Chisenga CC; Bosomprah S; Musukuma K; Mubanga C; Chilyabanyama ON; Velu RM; Kim YC; Reyes-Sandoval A; Chilengi R; Department of Biostatistics, School of Public Health, University of Ghana, Accra.; The Jenner Institute, University of Oxford, The Henry Wellcome Building for Molecular Physiology, Oxford, England, United Kingdom.; Centre for Infectious Diseases Research in Zambia, Lusaka, Zambia.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
INTRODUCTION: The re-emergence of vector borne diseases affecting millions of people in recent years has drawn attention to arboviruses globally. Here, we report on the sero-prevalence of chikungunya virus (CHIKV), dengue virus (DENV), mayaro virus (MAYV) and zika virus (ZIKV) in a swamp community in Zambia. METHODS: We collected blood and saliva samples from residents of Lukanga swamps in 2016 during a mass-cholera vaccination campaign. Over 10,000 residents were vaccinated with two doses of Shanchol™ during this period. The biological samples were collected prior to vaccination (baseline) and at specified time points after vaccination. We tested a total of 214 baseline stored serum samples for IgG antibodies against NS1 of DENV and ZIKV and E2 of CHIKV and MAYV on ELISA. We defined sero-prevalence as the proportion of participants with optical density (OD) values above a defined cut-off value, determined using a finite mixture model. RESULTS: Of the 214 participants, 79 (36.9%; 95% CI 30.5-43.8) were sero-positive for Chikungunya; 23 (10.8%; 95% CI 6.9-15.7) for Zika, 36 (16.8%; 95% CI 12.1-22.5) for Dengue and 42 (19.6%; 95% CI 14.5-25.6) for Mayaro. Older participants were more likely to have Zika virus whilst those involved with fishing activities were at greater risk of contracting Chikungunya virus. Among all the antigens tested, we also found that Chikungunya saliva antibody titres correlated with baseline serum titres (Spearman's correlation coefficient = 0.222; p = 0.03). CONCLUSION: Arbovirus transmission is occurring in Zambia. This requires proper screening tools as well as surveillance data to accurately report on disease burden in Zambia.