1
|
Nyathi S, Rezende IM, Walter KS, Thongsripong P, Mutuku F, Ndenga B, Mbakaya JO, Aswani P, Musunzaji PS, Chebii PK, Maina PW, Mutuku PS, Ng'ang'a CM, Malumbo SL, Jembe Z, Vu DM, Mordecai EA, Bennett S, Andrews JR, LaBeaud AD. Molecular epidemiology and evolutionary characteristics of dengue virus 2 in East Africa. Nat Commun 2024; 15:7832. [PMID: 39244569 PMCID: PMC11380673 DOI: 10.1038/s41467-024-51018-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/25/2024] [Indexed: 09/09/2024] Open
Abstract
Despite the increasing burden of dengue, the regional emergence of the virus in Kenya has not been examined. This study investigates the genetic structure and regional spread of dengue virus-2 in Kenya. Viral RNA from acutely ill patients in Kenya was enriched and sequenced. Six new dengue-2 genomes were combined with 349 publicly available genomes and phylogenies used to infer gene flow between Kenya and other countries. Analyses indicate two dengue-2 Cosmopolitan genotype lineages circulating in Kenya, linked to recent outbreaks in coastal Kenya and Burkina Faso. Lineages circulating in Western, Southern, and Eastern Africa exhibiting similar evolutionary features are also reported. Phylogeography suggests importation of dengue-2 into Kenya from East and Southeast Asia and bidirectional geneflow. Additional lineages circulating in Africa are also imported from East and Southeast Asia. These findings underscore how intermittent importations from East and Southeast Asia drive dengue-2 circulation in Kenya and Africa more broadly.
Collapse
Affiliation(s)
- Sindiso Nyathi
- Department of Epidemiology and Population Health, Stanford University School of Medicine, Stanford, CA, 94305, USA.
| | - Izabela M Rezende
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Katharine S Walter
- Division of Epidemiology, Department of Internal Medicine, University of Utah School of Medicine, University of Utah, Salt Lake City, UT, 84132, USA
| | - Panpim Thongsripong
- Florida Medical Entomology Laboratory, University of Florida, Vero Beach, FL, 32962, USA
| | - Francis Mutuku
- Department of Environment and Health Sciences, Technical University of Mombasa, Mombasa, Kenya
| | - Bryson Ndenga
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Joel O Mbakaya
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Peter Aswani
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | | | - Philip K Chebii
- Vector-borne Disease Unit, Msambweni Hospital, Msambweni, Kenya
| | | | - Paul S Mutuku
- Vector-borne Disease Unit, Msambweni Hospital, Msambweni, Kenya
| | | | - Said L Malumbo
- Vector-borne Disease Unit, Msambweni Hospital, Msambweni, Kenya
| | | | - David M Vu
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford University, Stanford, CA, 94305, USA
| | - Erin A Mordecai
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Shannon Bennett
- Department of Microbiology, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA, 94118, USA
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - A Desiree LaBeaud
- Department of Pediatrics, Division of Infectious Diseases, Stanford University School of Medicine, Stanford University, Stanford, CA, 94305, USA
| |
Collapse
|
2
|
Barbirou M, Miller AA, Mezlini A, Bouhaouala-Zahar B, Tonellato PJ. Variant Characterization of a Representative Large Pedigree Suggests "Variant Risk Clusters" Convey Varying Predisposition of Risk to Lynch Syndrome. Cancers (Basel) 2023; 15:4074. [PMID: 37627102 PMCID: PMC10452890 DOI: 10.3390/cancers15164074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
Recently, worldwide incidences of young adult aggressive colorectal cancer (CRC) have rapidly increased. Of these incidences diagnosed as familial Lynch syndrome (LS) CRC, outcomes are extremely poor. In this study, we seek novel familial germline variants from a large pedigree Tunisian family with 12 LS-affected individuals to identify putative germline variants associated with varying risk of LS. Whole-genome sequencing analysis was performed to identify known and novel germline variants shared between affected and non-affected pedigree members. SNPs, indels, and structural variants (SVs) were computationally identified, and their oncological influence was predicted using the Genetic Association of Complex Diseases and Disorders, OncoKB, and My Cancer Genome databases. Of 94 germline familial variants identified with predicted functional impact, 37 SNPs/indels were detected in 28 genes, 2 of which (MLH1 and PRH1-TAS2R14) have known association with CRC and 4 others (PPP1R13B, LAMA5, FTO, and NLRP14) have known association with non-CRC cancers. In addition, 48 of 57 identified SVs overlap with 43 genes. Three of these genes (RELN, IRS2, and FOXP1) have a known association with non-CRC digestive cancers and one (RRAS2) has a known association with non-CRC cancer. Our study identified 83 novel, predicted functionally impactful germline variants grouped in three "variant risk clusters" shared in three familiarly associated LS groups (high, intermediate and low risk). This variant characterization study demonstrates that large pedigree investigations provide important evidence supporting the hypothesis that different "variant risk clusters" can convey different mechanisms of risk and oncogenesis of LS-CRC even within the same pedigree.
Collapse
Affiliation(s)
- Mouadh Barbirou
- Circulating Tumor Cell Core Laboratory, Population Science Division, Medical Oncology Department, Medical College, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA;
- Center for Biomedical Informatics, Department of Health Management and Informatics, School of Medicine, University of Missouri, Columbia, MI 65211, USA;
- Medical School, University of Tunis El Manar, Tunis 1068, Tunisia;
| | - Amanda A. Miller
- Circulating Tumor Cell Core Laboratory, Population Science Division, Medical Oncology Department, Medical College, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA;
- Center for Biomedical Informatics, Department of Health Management and Informatics, School of Medicine, University of Missouri, Columbia, MI 65211, USA;
| | - Amel Mezlini
- Medical Oncology Division, Salah Azeiz Oncology Institute, University of Tunis El Manar, Tunis 1068, Tunisia;
| | - Balkiss Bouhaouala-Zahar
- Medical School, University of Tunis El Manar, Tunis 1068, Tunisia;
- Laboratory of Venoms and Therapeutic Biomolecules, LR16IPT08 Institute Pasteur of Tunis, University of Tunis El Manar, Tunis 1068, Tunisia
| | - Peter J. Tonellato
- Center for Biomedical Informatics, Department of Health Management and Informatics, School of Medicine, University of Missouri, Columbia, MI 65211, USA;
| |
Collapse
|
3
|
Kimathi D, Juan-Giner A, Orindi B, Grantz KH, Bob NS, Cheruiyot S, Hamaluba M, Kamau N, Fall G, Dia M, Mosobo M, Moki F, Kiogora K, Chirro O, Thiong'o A, Mwendwa J, Guantai A, Karanja HK, Gitonga J, Mugo D, Ramko K, Faye O, Sanders EJ, Grais RF, Bejon P, Warimwe GM. Immunogenicity and safety of fractional doses of 17D-213 yellow fever vaccine in HIV-infected people in Kenya (YEFE): a randomised, double-blind, non-inferiority substudy of a phase 4 trial. THE LANCET. INFECTIOUS DISEASES 2023; 23:974-982. [PMID: 37127045 PMCID: PMC10371873 DOI: 10.1016/s1473-3099(23)00114-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND Evidence indicates that fractional doses of yellow fever vaccine are safe and sufficiently immunogenic for use during yellow fever outbreaks. However, there are no data on the generalisability of this observation to populations living with HIV. Therefore, we aimed to evaluate the immunogenicity of fractional and standard doses of yellow fever vaccine in HIV-positive adults. METHODS We conducted a randomised, double-blind, non-inferiority substudy in Kilifi, coastal Kenya to compare the immunogenicity and safety of a fractional dose (one-fifth of the standard dose) versus the standard dose of 17D-213 yellow fever vaccine among HIV-positive volunteers. HIV-positive participants aged 18-59 years, with baseline CD4+ T-cell count of at least 200 cells per mL, and who were not pregnant, had no previous history of yellow fever vaccination or infection, and had no contraindication for yellow fever vaccination were recruited from the community. Participants were randomly assigned 1:1 in blocks (variable block sizes) to either a fractional dose or a standard dose of the 17D-213 yellow fever vaccine. Vaccines were administered subcutaneously by an unblinded nurse and pharmacist; all other study personnel were blinded to the vaccine allocation. The primary outcome of the study was the proportion of participants who seroconverted by the plaque reduction neutralisation test (PRNT50) 28 days after vaccination for the fractional dose versus the standard dose in the per-protocol population. Secondary outcomes were assessment of adverse events and immunogenicity during the 1-year follow-up period. Participants were considered to have seroconverted if the post-vaccination antibody titre was at least 4 times greater than the pre-vaccination titre. We set a non-inferiority margin of not less than a 17% decrease in seroconversion in the fractional dose compared with the standard dose. This study is registered with ClinicalTrials.gov, NCT02991495. FINDINGS Between Jan 29, 2019, and May 17, 2019, 303 participants were screened, and 250 participants were included and vaccinated; 126 participants were assigned to the fractional dose and 124 to the standard dose. 28 days after vaccination, 112 (96%, 95% CI 90-99) of 117 participants in the fractional dose group and 115 (98%, 94-100) of 117 in the standard dose group seroconverted by PRNT50. The difference in seroconversion between the fractional dose and the standard dose was -3% (95% CI -7 to 2). Fractional dosing therefore met the non-inferiority criterion, and non-inferiority was maintained for 1 year. The most common adverse events were headache (n=31 [12%]), fatigue (n=23 [9%]), myalgia (n=23 [9%]), and cough (n=14 [6%]). Reported adverse events were either mild (182 [97%] of 187 adverse events) or moderate (5 [3%]) and were self-limiting. INTERPRETATION Fractional doses of the 17D-213 yellow fever vaccine were sufficiently immunogenic and safe demonstrating non-inferiority to the standard vaccine dose in HIV-infected individuals with CD4+ T cell counts of at least 200 cells per mL. These results provide confidence that fractional dose recommendations are applicable to populations with high HIV prevalence. FUNDING Wellcome Trust, Médecins Sans Frontières Foundation, and the UK Department for International Development.
Collapse
Affiliation(s)
- Derick Kimathi
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | | | - Benedict Orindi
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kyra H Grantz
- Department of Biology and Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Stanley Cheruiyot
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Mainga Hamaluba
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - Naomi Kamau
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | | | - Moses Mosobo
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Felix Moki
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kenneth Kiogora
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Oscar Chirro
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Alexander Thiong'o
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Jane Mwendwa
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Andrew Guantai
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Henry K Karanja
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - John Gitonga
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Daisy Mugo
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Kelly Ramko
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Eduard J Sanders
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | | | - Philip Bejon
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - George M Warimwe
- Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya; Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK.
| |
Collapse
|
4
|
Changing Ecotypes of Dengue Virus 2 Serotype in Nigeria and the Emergence of Cosmopolitan and Asian I Lineages, 1966–2019. Vaccines (Basel) 2023; 11:vaccines11030547. [PMID: 36992135 DOI: 10.3390/vaccines11030547] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/13/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023] Open
Abstract
Dengue virus (DENV) is a leading mosquito-borne virus with a wide geographical spread and a major public health concern. DENV serotype 1 (DENV-1) and serotype 2 (DENV-2) were first reported in Africa in 1964 in Ibadan, Nigeria. Although the burden of dengue is unknown in many African countries, DENV-2 is responsible for major epidemics. In this study, we investigated the activities of DENV-2 to determine the circulating strains and to appraise the changing dynamics in the epidemiology of the virus in Nigeria. Nineteen DENV-2 sequences from 1966–2019 in Nigeria were retrieved from the GenBank of the National Center of Biotechnology Information (NCBI). A DENV genotyping tool was used to identify the specific genotypes. The evolutionary history procedure was performed on 54 DENV-2 sequences using MEGA 7. There is a deviation from Sylvatic DENV-2 to other genotypes in Nigeria. In 2019, the Asian I genotype of DENV-2 was predominant in southern Edo State, located in the tropical rainforest region, with the first report of the DENV-2 Cosmopolitan strain. We confirmed the circulation of other non-assigned genotypes of DENV-2 in Nigeria. Collectively, this shows that DENV-2 dynamics have changed from Sylvatic transmission reported in the 1960s with the identification of the Cosmopolitan strain and Asian lineages. Sustained surveillance, including vectorial studies, is required to fully establish the trend and determine the role of these vectors.
Collapse
|
5
|
Sun YT, Varani G. Structure of the dengue virus RNA promoter. RNA (NEW YORK, N.Y.) 2022; 28:1210-1223. [PMID: 35750488 PMCID: PMC9380747 DOI: 10.1261/rna.079197.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Dengue virus, a single-stranded positive sense RNA virus, is the most prevalent mosquito-borne pathogen in the world. Like all RNA viruses, it uses conserved structural elements within its genome to control essential replicative steps. A 70 nt stem-loop RNA structure (called SLA), found at the 5'-end of the genome of all flaviviruses, functions as the promoter for viral replication. This highly conserved structure interacts with the viral polymerase NS5 to initiate RNA synthesis. Here, we report the NMR structure of a monomeric SLA from dengue virus serotype 1, assembled to high-resolution from independently folded structural elements. The DENV1 SLA has an L-shaped structure, where the top and side helices are coaxially stacked, and the bottom helix is roughly perpendicular to them. Because the sequence is highly conserved among different flavivirus genomes, it is very likely that the three-dimensional fold and local structure of SLA are also conserved among flaviviruses and required for efficient replication. This work provides structural insight into the dengue promoter and provides the foundation for the discovery of new antiviral drugs that target this essential replicative step.
Collapse
Affiliation(s)
- Yi-Ting Sun
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
| | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA
| |
Collapse
|
6
|
Langat SK, Eyase FL, Berry IM, Nyunja A, Bulimo W, Owaka S, Ofula V, Limbaso S, Lutomiah J, Jarman R, Distelhorst J, Sang RC. Origin and evolution of dengue virus type 2 causing outbreaks in Kenya: Evidence of circulation of two cosmopolitan genotype lineages. Virus Evol 2020; 6:veaa026. [PMID: 32523778 PMCID: PMC7266482 DOI: 10.1093/ve/veaa026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Dengue fever (DF) is an arboviral disease caused by dengue virus serotypes 1-4 (DENV 1-4). Globally, DF incidence and disease burden have increased in the recent past. Initially implicated in a 1982 outbreak, DENV-2 recently reemerged in Kenya causing outbreaks between 2011 and 2014 and more recently 2017–8. The origin and the evolutionary patterns that may explain the epidemiological expansion and increasing impact of DENV-2 in Kenya remain poorly understood. Using whole-genome sequencing, samples collected during the 2011–4 and 2017–8 dengue outbreaks were analyzed. Additional DENV-2 genomes were downloaded and pooled together with the fourteen genomes generated in this study. Bioinformatic methods were used to analyze phylogenetic relationships and evolutionary patterns of DENV-2 causing outbreaks in Kenya. The findings from this study have shown the first evidence of circulation of two different Cosmopolitan genotype lineages of DENV-2; Cosmopolitan-I (C-I) and Cosmopolitan-II (C-II), in Kenya. Our results put the origin location of C-I lineage in India in 2011, and C-II lineage in Burkina Faso between 1979 and 2013. C-I lineage was the most isolated during recent outbreaks, thus showing the contribution of this newly emerged strain to the increased DENV epidemics in the region. Our findings, backed by evidence of recent local epidemics that have been associated with C-I in Kenya and C-II in Burkina Faso, add to the growing evidence of expanding circulation and the impact of multiple strains of DENV in the region as well as globally. Thus, continued surveillance efforts on DENV activity and its evolutionary trends in the region, would contribute toward effective control and the current vaccine development efforts.
Collapse
Affiliation(s)
- Solomon K Langat
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Fredrick Lunyagi Eyase
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology
| | | | - Albert Nyunja
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Wallace Bulimo
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Department of Biochemistry, University of Nairobi
| | - Samuel Owaka
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Victor Ofula
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Samson Limbaso
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Center for Virus Research, Kenya Medical Research Institute
| | - Joel Lutomiah
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Center for Virus Research, Kenya Medical Research Institute
| | - Richard Jarman
- Viral Diseases Branch, Walter Reed Army Institute of Research
| | - John Distelhorst
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya
| | - Rosemary C Sang
- Department of Emerging Infectious Diseases, United States Army Medical Research Directorate-Africa, Nairobi, Kenya.,Center for Virus Research, Kenya Medical Research Institute
| |
Collapse
|
7
|
Barsosio HC, Gitonga JN, Karanja HK, Nyamwaya DK, Omuoyo DO, Kamau E, Hamaluba MM, Nyiro JU, Kitsao BS, Nyaguara A, Mwakio S, Newton CR, Sang R, Wright D, Sanders EJ, Seale AC, Agoti CN, Berkley JA, Bejon P, Warimwe GM. Congenital microcephaly unrelated to flavivirus exposure in coastal Kenya. Wellcome Open Res 2020; 4:179. [PMID: 32175480 PMCID: PMC7059837 DOI: 10.12688/wellcomeopenres.15568.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Zika virus (ZIKV) was first discovered in East Africa in 1947. ZIKV has caused microcephaly in the Americas, but it is not known whether ZIKV is a cause of microcephaly in East Africa. Methods: We used surveillance data from 11,061 live births at Kilifi County Hospital in coastal Kenya between January 2012 and October 2016 to identify microcephaly cases and conducted a nested case-control study to determine risk factors for microcephaly. Gestational age at birth was estimated based on antenatal ultrasound scanning ('Scanned cohort') or last menstrual period ('LMP cohort', including births ≥37 weeks' gestation only). Controls were newborns with head circumference Z scores between >-2 and ≤2 SD that were compared to microcephaly cases in relation to ZIKV exposure and other maternal and newborn factors. Results: Of the 11,061 newborns, 214 (1.9%, 95%CI 1.69, 2.21) had microcephaly. Microcephaly prevalence was 1.0% (95%CI 0.64, 1.70, n=1529) and 2.1% (95%CI 1.81, 2.38, n=9532) in the scanned and LMP cohorts, respectively. After excluding babies <2500 g (n=1199) in the LMP cohort the prevalence was 1.1% (95%CI 0.93, 1.39). Microcephaly showed an association with being born small for gestational age (p<0.001) but not with ZIKV neutralising antibodies (p=0.6) or anti-ZIKV NS1 IgM response (p=0.9). No samples had a ZIKV neutralising antibody titre that was at least fourfold higher than the corresponding dengue virus (DENV) titre. No ZIKV or other flavivirus RNA was detected in cord blood from cases or controls. Conclusions: Microcephaly was prevalent in coastal Kenya, but does not appear to be related to ZIKV exposure; the ZIKV response observed in our study population was largely due to cross-reactive responses to DENV or other related flaviviruses. Further research into potential causes and the clinical consequences of microcephaly in this population is urgently needed.
Collapse
Affiliation(s)
- Hellen C Barsosio
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Liverpool School of Tropical Medicine, Liverpool, UK
| | | | | | | | | | - Everlyn Kamau
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Joyce U Nyiro
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Amek Nyaguara
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Stella Mwakio
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | - Charles R Newton
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Daniel Wright
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,The Jenner Institute, University of Oxford, Oxford, UK
| | | | - Anna C Seale
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,London School of Hygiene & Tropical Medicine, London, UK
| | | | - James A Berkley
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| | - George M Warimwe
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.,Centre for Tropical Medicine & Global Health, University of Oxford, Oxford, UK
| |
Collapse
|
8
|
Masika MM, Korhonen EM, Smura T, Uusitalo R, Vapalahti K, Mwaengo D, Jääskeläinen AJ, Anzala O, Vapalahti O, Huhtamo E. Detection of dengue virus type 2 of Indian origin in acute febrile patients in rural Kenya. PLoS Negl Trop Dis 2020; 14:e0008099. [PMID: 32126086 PMCID: PMC7069648 DOI: 10.1371/journal.pntd.0008099] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 03/13/2020] [Accepted: 01/29/2020] [Indexed: 01/25/2023] Open
Abstract
Dengue virus (DENV) has caused recent outbreaks in coastal cities of Kenya, but the epidemiological situation in other areas of Kenya is largely unknown. We investigated the role of DENV infection as a cause of acute febrile disease in non-epidemic settings in rural and urban study areas in Kenya. Altogether, 560 patients were sampled in 2016–2017 in rural Taita–Taveta County (n = 327) and urban slums of Kibera, Nairobi (n = 233). The samples were studied for DENV IgM, IgG, NS1 antigen and flaviviral RNA. IgG seroprevalence was found to be higher in Taita–Taveta (14%) than in Nairobi (3%). Five Taita–Taveta patients were positive for flaviviral RNA, all identified as DENV-2, cosmopolitan genotype. Local transmission in Taita–Taveta was suspected in a patient without travel history. The sequence analysis suggested that DENV-2 strains circulating in coastal and southern Kenya likely arose from a single introduction from India. The molecular clock analyses dated the most recent ancestor to the Kenyan strains a year before the large 2013 outbreak in Mombasa. After this, the virus has been detected in Kilifi in 2014, from our patients in Taita–Taveta in 2016, and in an outbreak in Malindi in 2017. The results highlight that silent transmission occurs between epidemics and also affects rural areas. More information is needed to understand the local epidemiological characteristics and future risks of dengue in Kenya. Dengue virus (DENV) is an emerging mosquito-borne global health threat in the tropics and subtropics. The majority of the world’s population live in areas at risk of dengue that can cause a wide variety of symptoms from febrile illness to haemorrhagic fever. Information of DENV in Africa is limited and fragmented. In Kenya, dengue is a recognized disease in coastal cities that have experienced recent outbreaks. We investigated the role of DENV infection as a cause of acute febrile disease in non-epidemic settings in rural and urban study areas in Kenya. We found DENV-2 in five febrile patients from rural Taita–Taveta, where no dengue has been reported before. Genetic analysis of the virus suggests it to be most likely of Indian origin. This Indian origin DENV-2 was detected in the Mombasa outbreak in 2013, in Kilifi in 2014, in Taita–Taveta in 2016 (our study samples) and again in the Malindi outbreak in 2017. The results suggest that dengue is unrecognized in rural Kenya and more studies are needed for local risk assessment. Our findings of virus transmission between epidemics contribute to better understanding of the epidemiological situation and origins of DENV in Kenya.
Collapse
Affiliation(s)
- Moses Muia Masika
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- KAVI Institute of Clinical Research, University of Nairobi, Nairobi, Kenya
| | - Essi M. Korhonen
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- * E-mail:
| | - Teemu Smura
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
| | - Ruut Uusitalo
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
| | - Katariina Vapalahti
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Dufton Mwaengo
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- Institute of Tropical and Infectious Diseases, University of Nairobi, Nairobi, Kenya
| | - Anne J. Jääskeläinen
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Omu Anzala
- Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya
- KAVI Institute of Clinical Research, University of Nairobi, Nairobi, Kenya
| | - Olli Vapalahti
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
- Department of Virology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Eili Huhtamo
- Department of Virology, Medicum, University of Helsinki, Helsinki, Finland
- Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| |
Collapse
|
9
|
Kamau E, Oketch JW, de Laurent ZR, Phan MVT, Agoti CN, Nokes DJ, Cotten M. Whole genome sequencing and phylogenetic analysis of human metapneumovirus strains from Kenya and Zambia. BMC Genomics 2020; 21:5. [PMID: 31898474 PMCID: PMC6941262 DOI: 10.1186/s12864-019-6400-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 12/15/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Human metapneumovirus (HMPV) is an important cause of acute respiratory illness in young children. Whole genome sequencing enables better identification of transmission events and outbreaks, which is not always possible with sub-genomic sequences. RESULTS We report a 2-reaction amplicon-based next generation sequencing method to determine the complete genome sequences of five HMPV strains, representing three subgroups (A2, B1 and B2), directly from clinical samples. In addition to reporting five novel HMPV genomes from Africa we examined genetic diversity and sequence patterns of publicly available HMPV genomes. We found that the overall nucleotide sequence identity was 71.3 and 80% for HMPV group A and B, respectively, the diversity between HMPV groups was greater at amino acid level for SH and G surface protein genes, and multiple subgroups co-circulated in various countries. Comparison of sequences between HMPV groups revealed variability in G protein length (219 to 241 amino acids) due to changes in the stop codon position. Genome-wide phylogenetic analysis showed congruence with the individual gene sequence sets except for F and M2 genes. CONCLUSION This is the first genomic characterization of HMPV genomes from African patients.
Collapse
Affiliation(s)
- Everlyn Kamau
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya.
| | - John W Oketch
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - My V T Phan
- Department of Viroscience, Erasmus MC, Rotterdam, The Netherlands
| | | | - D James Nokes
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- School of Life Sciences and Zeeman Institute, University of Warwick, Coventry, UK
| | - Matthew Cotten
- MRC/UVRI & LSHTM Uganda Research Unit, Entebbe, Uganda
- MRC-University of Glasgow Centre for Virus Research, Glasgow, UK
| |
Collapse
|
10
|
Kimathi D, Juan A, Bejon P, Grais RF, Warimwe GM. Randomized, double-blinded, controlled non-inferiority trials evaluating the immunogenicity and safety of fractional doses of Yellow Fever vaccines in Kenya and Uganda. Wellcome Open Res 2019; 4:182. [PMID: 31984244 PMCID: PMC6971842 DOI: 10.12688/wellcomeopenres.15579.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2019] [Indexed: 01/22/2023] Open
Abstract
Introduction: Yellow fever is endemic in specific regions of sub-Saharan Africa and the Americas, with recent epidemics occurring on both continents. The yellow fever vaccine is effective, affordable and safe, providing life-long immunity following a single dose vaccination. However, the vaccine production process is slow and cannot be readily scaled up during epidemics. This has led the World Health Organization (WHO) to recommend the use of fractional doses as a dose-sparing strategy during epidemics, but there are no randomized controlled trials of fractional yellow fever vaccine doses in Africa. Methods and analysis: We will recruit healthy adult volunteers, adults living with HIV, and children to a series of randomized controlled trials aiming to determine the immunogenicity and safety of fractional vaccine doses in comparison to the standard vaccine dose. The trials will be conducted across two sites; Kilifi, Kenya and Mbarara, Uganda. Recruited participants will be randomized to receive fractional or standard doses of yellow fever vaccine. Scheduled visits will include blood collection for serum and peripheral blood mononuclear cells (PBMCs) before vaccination and on various days - up to 2 years - post-vaccination. The primary outcome is the rate of seroconversion as measured by the plaque reduction neutralization test (PRNT 50) at 28 days post-vaccination. Secondary outcomes include antibody titre changes, longevity of the immune response, safety assessment using clinical data, the nature and magnitude of the cellular immune response and post-vaccination control of viremia by vaccine dose. Ethics and dissemination: The clinical trial protocols have received approval from the relevant institutional ethics and regulatory review committees in Kenya and Uganda, and the WHO Ethics Review Committee. The research findings will be disseminated through open-access publications and presented at relevant conferences and workshops. Registration: ClinicalTrials.gov NCT02991495 (registered on 13 December 2016) and NCT04059471 (registered on 15 August 2019).
Collapse
Affiliation(s)
- Derick Kimathi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Philip Bejon
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - George M Warimwe
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| |
Collapse
|
11
|
Genome Sequences of Human Coronavirus OC43 and NL63, Associated with Respiratory Infections in Kilifi, Kenya. Microbiol Resour Announc 2019; 8:8/46/e00730-19. [PMID: 31727697 PMCID: PMC6856263 DOI: 10.1128/mra.00730-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Coding-complete genomes of two human coronavirus OC43 strains and one NL63 strain were obtained by metagenomic sequencing of clinical samples collected in 2017 and 2018 in Kilifi, Kenya. Maximum likelihood phylogenies showed that the OC43 strains were genetically dissimilar and that the NL63 strain was closely related to NL63 genotype B viruses. Coding-complete genomes of two human coronavirus OC43 strains and one NL63 strain were obtained by metagenomic sequencing of clinical samples collected in 2017 and 2018 in Kilifi, Kenya. Maximum likelihood phylogenies showed that the OC43 strains were genetically dissimilar and that the NL63 strain was closely related to NL63 genotype B viruses.
Collapse
|
12
|
Ayolabi CI, Olusola BA, Ibemgbo SA, Okonkwo GO. Detection of Dengue viruses among febrile patients in Lagos, Nigeria and phylogenetics of circulating Dengue serotypes in Africa. INFECTION GENETICS AND EVOLUTION 2019; 75:103947. [PMID: 31276800 DOI: 10.1016/j.meegid.2019.103947] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 11/16/2022]
Abstract
Dengue fever, a mosquito borne viral disease, is caused by Dengue virus. This virus and its vector is endemic in most tropical countries including Nigeria. Dengue presents with febrile symptoms and is a major cause of morbidity and mortality in affected countries. The infection presently has no licensed drugs and vaccine is only available for previously exposed individuals. Despite the endemicity of Dengue in Nigeria, very few studies have identified circulating Dengue genotypes in the country. There is also sparse information on the occurrence, distribution and temporal patterns of circulating dengue virus serotypes as well as genotypes in Africa. This situation creates barriers to effective control of the infection in the continent. This study identified Dengue serotypes and genotypes among febrile patients in two health centers in Lagos, Nigeria. Phylogenetic analysis of Dengue sequences previously collected from African countries and submitted to GenBank database from 1944 till date was also performed. One hundred and thirty febrile persons were recruited for the study between April and August 2018. Eleven (8.5%) persons were Dengue virus positive. Dengue virus serotypes 1 (genotype I) and 3 (genotype I) were identified as actively circulating in Lagos, Nigeria. DENV 1 genotype V, DENV 2 cosmopolitan genotype and DENV 3 genotype III has over the years been the predominant circulating Dengue strains in Africa. Relative genotypic stability of circulating Dengue serotypes in Africa occurred over the past five decades. This may be due to limited investigations on circulating Dengue serotypes among asymptomatic individuals in the region as most studies focused on disease outbreaks and imported cases. There is the need to describe circulating Dengue genotypes in northern Africa, southern Africa as well as among asymptomatic individuals in other parts of Africa as this will provide further information on the diversity of Dengue genotypes circulating in the region.
Collapse
Affiliation(s)
| | | | - Sylvester Agha Ibemgbo
- Department of Microbiology, University of Lagos, Lagos, Nigeria; Department of Biological Sciences, Mountain Top University, Ogun State, Nigeria.
| | | |
Collapse
|