Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya.
Human movement impacts the spread and transmission of infectious diseases. Recently, a large reservoir of Plasmodium falciparum malaria was identified in a semi-arid region of northwestern Kenya historically considered unsuitable for malaria transmission. Understanding the sources and patterns of tr...
| Main Authors: | , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2022-01-01
|
| Series: | PLOS Global Public Health |
| Online Access: | https://doi.org/10.1371/journal.pgph.0000807 |
| _version_ | 1797694032345825280 |
|---|---|
| author | Christine F Markwalter Diana Menya Amy Wesolowski Daniel Esimit Gilchrist Lokoel Joseph Kipkoech Elizabeth Freedman Kelsey M Sumner Lucy Abel George Ambani Hannah R Meredith Steve M Taylor Andrew A Obala Wendy P O'Meara |
| author_facet | Christine F Markwalter Diana Menya Amy Wesolowski Daniel Esimit Gilchrist Lokoel Joseph Kipkoech Elizabeth Freedman Kelsey M Sumner Lucy Abel George Ambani Hannah R Meredith Steve M Taylor Andrew A Obala Wendy P O'Meara |
| author_sort | Christine F Markwalter |
| collection | DOAJ |
| description | Human movement impacts the spread and transmission of infectious diseases. Recently, a large reservoir of Plasmodium falciparum malaria was identified in a semi-arid region of northwestern Kenya historically considered unsuitable for malaria transmission. Understanding the sources and patterns of transmission attributable to human movement would aid in designing and targeting interventions to decrease the unexpectedly high malaria burden in the region. Toward this goal, polymorphic parasite genes (ama1, csp) in residents and passengers traveling to Central Turkana were genotyped by amplicon deep sequencing. Genotyping and epidemiological data were combined to assess parasite importation. The contribution of travel to malaria transmission was estimated by modelling case reproductive numbers inclusive and exclusive of travelers. P. falciparum was detected in 6.7% (127/1891) of inbound passengers, including new haplotypes which were later detected in locally-transmitted infections. Case reproductive numbers approximated 1 and did not change when travelers were removed from transmission networks, suggesting that transmission is not fueled by travel to the region but locally endemic. Thus, malaria is not only prevalent in Central Turkana but also sustained by local transmission. As such, interrupting importation is unlikely to be an effective malaria control strategy on its own, but targeting interventions locally has the potential to drive down transmission. |
| first_indexed | 2024-03-12T02:52:07Z |
| format | Article |
| id | doaj.art-56019db6d0714b33ac6b10cf1ddbf9d3 |
| institution | Directory Open Access Journal |
| issn | 2767-3375 |
| language | English |
| last_indexed | 2024-03-12T02:52:07Z |
| publishDate | 2022-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLOS Global Public Health |
| spelling | doaj.art-56019db6d0714b33ac6b10cf1ddbf9d32023-09-03T15:31:12ZengPublic Library of Science (PLoS)PLOS Global Public Health2767-33752022-01-0128e000080710.1371/journal.pgph.0000807Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya.Christine F MarkwalterDiana MenyaAmy WesolowskiDaniel EsimitGilchrist LokoelJoseph KipkoechElizabeth FreedmanKelsey M SumnerLucy AbelGeorge AmbaniHannah R MeredithSteve M TaylorAndrew A ObalaWendy P O'MearaHuman movement impacts the spread and transmission of infectious diseases. Recently, a large reservoir of Plasmodium falciparum malaria was identified in a semi-arid region of northwestern Kenya historically considered unsuitable for malaria transmission. Understanding the sources and patterns of transmission attributable to human movement would aid in designing and targeting interventions to decrease the unexpectedly high malaria burden in the region. Toward this goal, polymorphic parasite genes (ama1, csp) in residents and passengers traveling to Central Turkana were genotyped by amplicon deep sequencing. Genotyping and epidemiological data were combined to assess parasite importation. The contribution of travel to malaria transmission was estimated by modelling case reproductive numbers inclusive and exclusive of travelers. P. falciparum was detected in 6.7% (127/1891) of inbound passengers, including new haplotypes which were later detected in locally-transmitted infections. Case reproductive numbers approximated 1 and did not change when travelers were removed from transmission networks, suggesting that transmission is not fueled by travel to the region but locally endemic. Thus, malaria is not only prevalent in Central Turkana but also sustained by local transmission. As such, interrupting importation is unlikely to be an effective malaria control strategy on its own, but targeting interventions locally has the potential to drive down transmission.https://doi.org/10.1371/journal.pgph.0000807 |
| spellingShingle | Christine F Markwalter Diana Menya Amy Wesolowski Daniel Esimit Gilchrist Lokoel Joseph Kipkoech Elizabeth Freedman Kelsey M Sumner Lucy Abel George Ambani Hannah R Meredith Steve M Taylor Andrew A Obala Wendy P O'Meara Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. PLOS Global Public Health |
| title | Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. |
| title_full | Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. |
| title_fullStr | Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. |
| title_full_unstemmed | Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. |
| title_short | Plasmodium falciparum importation does not sustain malaria transmission in a semi-arid region of Kenya. |
| title_sort | plasmodium falciparum importation does not sustain malaria transmission in a semi arid region of kenya |
| url | https://doi.org/10.1371/journal.pgph.0000807 |
| work_keys_str_mv | AT christinefmarkwalter plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT dianamenya plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT amywesolowski plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT danielesimit plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT gilchristlokoel plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT josephkipkoech plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT elizabethfreedman plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT kelseymsumner plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT lucyabel plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT georgeambani plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT hannahrmeredith plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT stevemtaylor plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT andrewaobala plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya AT wendypomeara plasmodiumfalciparumimportationdoesnotsustainmalariatransmissioninasemiaridregionofkenya |