Comparative Analysis of Spatial-temporal Patterns of Human Metapneumovirus and Respiratory Syncytial Virus in Africa Using Genetic Data, 2011-2014
Background: Human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are leading causes of viral severe acute respiratory illnesses in childhood. Both the two viruses belong to the Pneumoviridae family and show overlapping clinical, epidemiological and transmission features. However, it is unknown whether these two viruses have similar geographic spread patterns which may provide insight into designing and evaluating their epidemic control measures.
Methods: We conducted comparative phylogenetic and phylogeographic analyses to explore the spatial-temporal patterns of HMPV and RSV across Africa using 232 HMPV and 842 RSV attachment (G) glycoprotein gene sequences obtained from 5 countries (The Gambia, Zambia, Mali, South Africa, and Kenya) between August 2011 and January 2014.
Results: Phylogeographic analyses found frequently similar patterns of spread of RSV and HMPV. Viral sequences commonly clustered by region, i.e., West Africa (Mali, Gambia), East Africa (Kenya) and Southern Africa (Zambia, South Africa), and similar genotype dominance patterns were observed between neighbouring countries. Both HMPV and RSV country epidemics were characterized by co-circulation of multiple genotypes. Sequences from different African sub-regions (East, West and Southern Africa) fell into separate clusters interspersed with sequences from other countries globally.
Conclusion: The spatial clustering patterns of viral sequences and genotype dominance patterns observed in our analysis suggests strong regional links and predominant local transmission. The geographical clustering further suggests independent introduction of HMPV and RSV variants in Africa from the global pool, and local regional diversification.
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This is a list of supplementary files associated with this preprint. Click to download.
Additional file 1: The GenBank accession numbers of HMPV and RSV attachment (G) glycoprotein gene sequences generated in this study and the contemporaneous sequences retrieved from GenBank. Sheet1: RSV accession numbers grouped by African country of sampling and global sequences. Sheet2: HMPV accession numbers grouped by African country and global sequences.
Additional file 2: ML phylogenies of G gene sequences collected from Kenya, Mali, Gambia, South Africa and Zambia. Sequences were subtyped using subgroup reference sequences retrieved from GenBank. Panel a: HMPV G gene sequences constructed using 231G gene sequences. Reference sequences are coloured in red. The numbers next to branches indicate the bootstrap values. Subgroups were confirmed if sequences clustered with the reference sequences within a major branch with > 70% bootstrap support. Panel b: RSV G ML phylogeny constructed using 627 unique gene sequences.
Additional file 3: ML phylogenies of subgroup B1 sequences showing within country sequence diversity for Kenya, Gambia, Mali and South Africa sequences. Clustering patterns were determined by within country sampling location and or case/control status. For Gambia, only case/control clustering patterns were determined.
Additional file 4: Panel A; Temporal scaled maximum clade credibility (MCC) tree constructed using HMPV B2 G gene sequences obtained from Africa and GenBank collected between 2000 to 2018. Branches are coloured according to the most probable location as inferred using symmetric discrete phylogeographic diffusion model. Geographic locations considered are shown in the figure key. Sequences from Kenya, Mali, Gambia, South Africa and Zambia collected beyond the study period are indicated with a suffix GB. Posterior probabilities are shown next to nodes. Clades containing African sequences falling in monophyletic clades are highlighted in grey boxes. For each clade, the mean estimated time of the most recent common ancestor (tMRCA) and respective 95% Bayesian credible intervals are shown in a black box alongside the most probable location leading to each clade. Panel B; MCC tree of B2 sequences collected from Africa.
Additional file 5: Panel A; Temporal scaled maximum clade credibility (MCC) tree constructed using HMPV A2c G gene sequences obtained from Africa and GenBank collected between 2000 to 2018. Branches are coloured according to the most probable location as inferred using symmetric discrete phylogeographic diffusion model. Geographic locations considered are shown in the figure key. Sequences from Kenya, Mali, Gambia, South Africa and Zambia collected beyond the study period are indicated with a suffix GB. Posterior probabilities are shown next to nodes. Clades containing African sequences falling in monophyletic clades are highlighted in grey boxes. For each clade, the mean estimated time of the most recent common ancestor (tMRCA) and respective 95% Bayesian credible intervals are shown in a black box alongside the most probable location leading to each clade. Panel B; MCC tree of A2c sequences collected from Africa.
Additional file 6: Panel A; Temporal scaled maximum clade credibility (MCC) tree constructed using HMPV A2a G gene sequences obtained from Africa and GenBank collected between 2000 to 2018. Branches are coloured according to the most probable location as inferred using symmetric discrete phylogeographic diffusion model. Geographic locations considered are shown in the figure key. Posterior probabilities are shown next to nodes. Clades containing African sequences falling in monophyletic clades are highlighted in blue and red. For each clade, the mean estimated time of the most recent common ancestor (tMRCA) and respective 95% Bayesian credible intervals are shown in a black box alongside the most probable location leading to each clade. Panel B; MCC tree of B2 sequences collected from Africa.
Additional file 7: Statistically supported state transitions indicating viral migration events between locations globally. Bayes factor >100 and Posterior probability ≥95% was considered significant.
Additional file 8: ML phylogenies of RSV genotype BA sequences showing within country sequence diversity for Mali and South Africa sequences. Clustering patterns were determined by within country sampling location and or case/control status.
Additional file 9: Statistically supported state transitions indicating viral migration events between African countries. Bayes factor >100 and Posterior probability ≥95% was considered significant.
Posted 29 Dec, 2020
Received 04 Jan, 2021
Received 03 Jan, 2021
On 21 Dec, 2020
Invitations sent on 20 Dec, 2020
On 20 Dec, 2020
On 19 Dec, 2020
On 19 Dec, 2020
On 19 Dec, 2020
On 16 Dec, 2020
Comparative Analysis of Spatial-temporal Patterns of Human Metapneumovirus and Respiratory Syncytial Virus in Africa Using Genetic Data, 2011-2014
Posted 29 Dec, 2020
Received 04 Jan, 2021
Received 03 Jan, 2021
On 21 Dec, 2020
Invitations sent on 20 Dec, 2020
On 20 Dec, 2020
On 19 Dec, 2020
On 19 Dec, 2020
On 19 Dec, 2020
On 16 Dec, 2020
Background: Human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are leading causes of viral severe acute respiratory illnesses in childhood. Both the two viruses belong to the Pneumoviridae family and show overlapping clinical, epidemiological and transmission features. However, it is unknown whether these two viruses have similar geographic spread patterns which may provide insight into designing and evaluating their epidemic control measures.
Methods: We conducted comparative phylogenetic and phylogeographic analyses to explore the spatial-temporal patterns of HMPV and RSV across Africa using 232 HMPV and 842 RSV attachment (G) glycoprotein gene sequences obtained from 5 countries (The Gambia, Zambia, Mali, South Africa, and Kenya) between August 2011 and January 2014.
Results: Phylogeographic analyses found frequently similar patterns of spread of RSV and HMPV. Viral sequences commonly clustered by region, i.e., West Africa (Mali, Gambia), East Africa (Kenya) and Southern Africa (Zambia, South Africa), and similar genotype dominance patterns were observed between neighbouring countries. Both HMPV and RSV country epidemics were characterized by co-circulation of multiple genotypes. Sequences from different African sub-regions (East, West and Southern Africa) fell into separate clusters interspersed with sequences from other countries globally.
Conclusion: The spatial clustering patterns of viral sequences and genotype dominance patterns observed in our analysis suggests strong regional links and predominant local transmission. The geographical clustering further suggests independent introduction of HMPV and RSV variants in Africa from the global pool, and local regional diversification.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6