Tracing and tracking the emergence, epidemiology and dispersal of dengue virus to Africa during the 20th century

Abstract

The four mosquito-borne dengue virus serotypes (DENV1–DENV4) cause a high burden of disease throughout the tropical and sub-tropical regions of the world. Nevertheless, their precise epidemiological history in Africa, including when and where they originated and were distributed during the 20th century, remains unclear stressing the need for One Health focused research. Accordingly, we conducted a time-scaled molecular epidemiological reconstruction using publicly available and newly sequenced dengue virus genomes of African origin representing all four serotypes to deduce the most likely temporal and spatial transmission routes of each DENV serotype from their ancestral regions to, within and from Africa. Our analyses suggest that during the 20th century, serotypes DENV1–DENV3 were introduced to Africa from South East Asia on multiple occasions. The earliest evidence recorded indicates introduction of DENV2 during the early-1940s and of DENV1 during the mid-1940s to Western Africa from South East Asia. The analysis also implies an early introduction of DENV4 during the mid-1940s to Western Africa, alongside DENV1, probably originating in South East Asia. Establishment of DENV3 in Africa appears to have occurred later in the 1960s, apparently originating from South East Asia. However, with the re-establishment of DENV in the Americas, following the cessation of the PAHO mosquito control programme during the mid-20th century, evidence of introductions of DENV1 and DENV2 from the Americas to Western Africa was also observed. The data also identify intra-regional circulation of DENV, but also inter-regional dispersal of all four serotypes within Africa, which has led to a high degree of geographical overlap among serotypes. It is also noteworthy that DENV from both Eastern and Western Africa, have been introduced into Central Africa but there is no support for the converse relationship. For serotypes DENV1–DENV3, we observed probable exports from within established African DENV clusters (≥2 sequences) primarily to Eastern and Southern Asia. Collectively, our findings support the view that all DENV serotypes, apart from DENV4, have been introduced on multiple occasions to Africa, primarily originating from South East Asia, and subsequently to neighbouring regions within Africa.

Arboviruses as an unappreciated cause of non-malarial acute febrile illness in the Dschang Health District of western Cameroon

“…The two DENV2 genomes belonged to the Cosmopolitan genotype, and fell within a sub-lineage with sequences that have been circulating in West Africa for 20–35 years. [ 40 , 41 ] Interestingly, these sequences were distinct from and ancestral to sequences obtained from Burkina Faso, Cote d’Ivoire, and Senegal between 2016 and 2019 ( Fig 1A ). The Cameroon sequences, which were from samples collected in 2020, shared a common ancestor in approximately 2017 and diverged from other West African sequences in approximately 2013 ( Fig 1B ).…”

“…The two DENV2 genomes belonged to the Cosmopolitan genotype, and fell within a sub-lineage with sequences that have been circulating in West Africa for 20-35 years. [40,41] Interestingly, these sequences were distinct from and ancestral to sequences obtained from Burkina Faso, Cote To better understand the extent of ARBV transmission in the region, we tested for IgG antibodies to DENV and CHIKV, which revealed a seroprevalence of 24.8% (96/387) for DENV and 15.7% (67/427) for CHIKV (Fig 2A -2D). The ELISA testing approach was validated by testing a small random subset of samples for neutralizing antibodies (Fig 2E and 2F).…”

Molecular characterization of dengue virus serotype 1 infections in French travelers from Africa between 2013 and 2019

“…The infection occurred in March during the 8-month-long dry season (i.e., the period of no rainfall from October to April), suggesting the presence of competent vectors outside the rainy season. Among other Sahelian countries, DENV-1 had previously been found in travelers returning from Eritrea (7,15), Chad (35), and Sudan (39), and it caused an outbreak in Bamako, the capital city of Mali, in 2006 (32) (Figure 3). The DENV-1 infection of case number 30078 also places this serotype in Mauritania, 1 year after the description of the establishment of Ae.…”

“…However, recent observations from Gabon in 2012 and Angola in 2013 indicate that the GV African lineage is also present in Central Africa (11,12). In addition to these DENV-1 lineages endemic in Africa, strains phylogenetically related to the Asian lineage of GV have recently been detected in travel-acquired infections from East and West Africa (13)(14)(15)(16) and in outbreaks in West Africa (17,18).…”

Ultrasensitive Aptasensors for the Detection of Viruses Based on Opto-Electrochemical Readout Systems

“…One such example is the aptamer-dependent detection of dengue virus belonging to the Flavi virus family causing dengue fever. This is one of the endemic diseases in tropical and subtropical regions, affecting around 40% of the world population [ 95 ]. The existing diagnostic methods of dengue fever are considered as expensive, time-consuming, and too complex to be used in remote areas, especially in places where infrastructure is not well established.…”