Prevalence of SARS-CoV-2 antibodies in the Republic of Congo in mid-2021.

Objectives: To estimate the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies in the general population in the Republic of Congo. Methods: In this cross-sectional study, conducted from June to July 2021, participants were recruited from the general population in three districts in the Republic of Congo. Eligible participants were tested for anti-SARS-CoV-2 antibodies using a rapid diagnostic assay. Results: Overall, 31.8% [95% confidence interval (CI) 29.5-34.0] of the 1669 participants tested positive for anti-SARS-CoV-2 antibodies. Higher prevalence was observed in the rural region (37.3%, 95% CI 31.0-44.1%) than the urban region (30.9%, 95% CI 28.5-33.3); however, the difference was not significant. The risk of testing positive for anti-SARS-CoV-2 antibodies increased significantly with age, ranging from 22.5% (95% CI 18.1-27.5) in 15-24 year olds to 47.9% (95% CI 39.3-56.5) in 55-64 year olds. Conclusions: The antibody levels observed in this survey correlate with a moderate rate of virus circulation, which correlates with the low number of confirmed cases of coronavirus disease 2019 in the Republic of Congo.

Early Circulation of SARS-CoV-2, Congo, 2020.

To determine when severe acute respiratory syndrome coronavirus 2 arrived in Congo, we retrospectively antibody tested 937 blood samples collected during September 2019-February 2020. Seropositivity significantly increased from 1% in December 2019 to 5.3% in February 2020, before the first officially reported case in March 2020, suggesting unexpected early virus circulation.

Orbivirus RNA in a Banana Serotine (Afronycteris nanus) Bat in the Republic of the Congo.

Orbiviruses are arthropod borne viruses of vertebrates, with some of them being important pathogens of veterinary, conservation and economic importance, while others are occasionally associated with human disease. Some apparently bat specific orbiviruses have been detected, but little is known about their distribution and diversity. We thus sampled and screened 52 bats living in the Congo Basin, and detected RNA indicative of a novel orbivirus in a single banana serotine (Afronycteris nanus) by PCR. The detected RNA clusters with epizootic haemorrhagic disease virus, bluetongue virus, and others. The findings highlight the need for more studies into arbovirus presence and diversity in bat species.

Coronavirus surveillance in wildlife from two Congo basin countries detects RNA of multiple species circulating in bats and rodents.

Coronaviruses play an important role as pathogens of humans and animals, and the emergence of epidemics like SARS, MERS and COVID-19 is closely linked to zoonotic transmission events primarily from wild animals. Bats have been found to be an important source of coronaviruses with some of them having the potential to infect humans, with other animals serving as intermediate or alternate hosts or reservoirs. Host diversity may be an important contributor to viral diversity and thus the potential for zoonotic events. To date, limited research has been done in Africa on this topic, in particular in the Congo Basin despite frequent contact between humans and wildlife in this region. We sampled and, using consensus coronavirus PCR-primers, tested 3,561 wild animals for coronavirus RNA. The focus was on bats (38%), rodents (38%), and primates (23%) that posed an elevated risk for contact with people, and we found coronavirus RNA in 121 animals, of which all but two were bats. Depending on the taxonomic family, bats were significantly more likely to be coronavirus RNA-positive when sampled either in the wet (Pteropodidae and Rhinolophidae) or dry season (Hipposideridae, Miniopteridae, Molossidae, and Vespertilionidae). The detected RNA sequences correspond to 15 alpha- and 6 betacoronaviruses, with some of them being very similar (>95% nucleotide identities) to known coronaviruses and others being more unique and potentially representing novel viruses. In seven of the bats, we detected RNA most closely related to sequences of the human common cold coronaviruses 229E or NL63 (>80% nucleotide identities). The findings highlight the potential for coronavirus spillover, especially in regions with a high diversity of bats and close human contact, and reinforces the need for ongoing surveillance.

Sequences of Previously Unknown Rhabdoviruses Detected in Bat Samples from the Republic of the Congo.

The family Rhabdoviridae contains diverse viruses, including vector-borne and nonvector-borne viruses, some that are human pathogens, including rabies virus and also nonpathogenic viruses. Bats, which are a known reservoir of viruses with zoonotic potential including coronaviruses, also carry multiple rhabdoviruses such as but not limited to lyssaviruses. We collected samples from 193 insectivorous and frugivorous bats in the Republic of the Congo and tested them for rhabdovirus RNA. Four samples were found positive for viral RNA representing sequences of four different, not previously described rhabdoviruses. Although phylogenetic and taxonomic placement of the novel sequences is uncertain, similarities with previously detected rhabdovirus sequences in bats suggest that these could represent vertebrate viruses. Considering the pathogenic risks some rhabdoviruses pose for humans, these results highlight the need for more research and surveillance regarding rhabdoviruses and bats.

First evidence of a new simian adenovirus clustering with Human mastadenovirus F viruses.

BACKGROUND: Adenoviruses play an important role as human pathogens, though most infections are believed to be asymptomatic. The over 100 human adenovirus types are classified into seven species (A-G), some of which include simian adenoviruses. Recent findings have highlighted that simian adenoviruses have a zoonotic potential and that some human adenoviruses are likely the result of relatively recent spillover events. METHODS: In order to evaluate the risks associated with primates hunted and sold as bushmeat, multiple samples from 24 freshly killed monkeys were collected in the Republic of the Congo and tested for adenovirus DNA by PCRs targeting the conserved DNA polymerase and hexon genes. RESULTS: The DNA of a novel simian adenovirus was detected in a moustached monkey (Cercopithecus cephus) by the DNA polymerase PCR, but not by the hexon PCR. The 275 nucleotide amplicon was most closely related to members of the Human mastadenovirus F species (93% HAdV-40 and 89% HAdV-41 amino acid identity), rather than to other known simian adenoviruses. CONCLUSIONS: The phylogenetic clustering with Human mastadenovirus F sequences suggests a common ancestor, more recent than the last common ancestor of humans and moustached monkeys. The findings increase concerns about the zoonotic potential of simian adenoviruses and highlight the need for more research and surveillance on the issue.

Diverse RNA viruses of arthropod origin in the blood of fruit bats suggest a link between bat and arthropod viromes.

Bats host diverse viruses due to their unique ecology, behavior, and immunology. However, the role of other organisms with which bats interact in nature is understudied as a contributor to bat viral diversity. We discovered five viruses in the blood of fruit bats (Hypsignathus monstrosus) from the Republic of Congo. Of these five viruses, four have phylogenetic and genomic features suggesting an arthropod origin (a dicistrovirus, a nodavirus, and two tombus-like viruses), while the fifth (a hepadnavirus) is clearly of mammalian origin. We also report the parallel discovery of related tombus-like viruses in fig wasps and primitive crane flies from bat habitats, as well as high infection rates of bats with haemosporidian parasites (Hepatocystis sp.). These findings suggest transmission between arthropods and bats, perhaps through ingestion or hyperparasitism (viral infection of bat parasites). Some "bat-associated" viruses may be epidemiologically linked to bats through their ecological associations with invertebrates.

CRF45_AKU, a circulating recombinant from Central Africa, is probably the common ancestor of HIV type 1 MAL and HIV type 1 NOGIL.

Abstract In this study, we characterized four HIV-1 strains from Cameroon, Gabon, and the Democratic Republic of Congo (DRC), collected during independent serosurveys, and previously found to cluster in the pol gene with HIV-1 MAL and HIV-1 NOGIL3, two complex recombinant viruses reported in the early HIV epidemic, and with the recombinant strain 04FR.AUK recently described in France. The four newly sequenced viruses shared the same structure as 04FR.AUK, involving alternating fragments of subtype A, K, and unclassified (U) fragments, representing a new CRF called CRF45_AKU. Some of the unclassified fragments were related to unclassified regions described in either CRF04 or CRF09 strains. Careful reanalysis of HIV-1 MAL and HIV-1 NOGIL3 demonstrated that these strains were related exclusively to CRF45_AKU and either two subtype D fragments for HIV-1 MAL or one subtype H segment for HIV-1 NOGIL3. Following extensive blast searches, related gag, pol, and env sequences were observed in Central and West Africa (Senegal, Mali), as well as in Europe (France, Spain, Italy, Cyprus), Argentina, and China.