Concurrent Chikungunya and Dengue Virus Infections during Simultaneous Outbreaks, Gabon, 2007

An outbreak of febrile illness occurred in Gabon in 2007, with 20,000 suspected cases. Chikungunya or dengue-2 virus infections were identified in 321 patients; 8 patients had documented co-infections. Aedes albopictus was identified as the principal vector for the transmission of both viruses

Marburg Virus Infection Detected in a Common African Bat

Marburg and Ebola viruses can cause large hemorrhagic fever (HF) outbreaks with high case fatality (80–90%) in human and great apes. Identification of the natural reservoir of these viruses is one of the most important topics in this field and a fundamental key to understanding their natural history. Despite the discovery of this virus family almost 40 years ago, the search for the natural reservoir of these lethal pathogens remains an enigma despite numerous ecological studies. Here, we report the discovery of Marburg virus in a common species of fruit bat (Rousettus aegyptiacus) in Gabon as shown by finding virus-specific RNA and IgG antibody in individual bats. These Marburg virus positive bats represent the first naturally infected non-primate animals identified. Furthermore, this is the first report of Marburg virus being present in this area of Africa, thus extending the known range of the virus. These data imply that more areas are at risk for MHF outbreaks than previously realized and correspond well with a recently published report in which three species of fruit bats were demonstrated to be likely reservoirs for Ebola virus

Identification of novel orthonairoviruses from rodents and shrews in Gabon, Central Africa

In Africa, several emerging zoonotic viruses have been transmitted from small mammals such as rodents and shrews to humans. Although no clinical cases of small mammal-borne viral diseases have been reported in Central Africa, potential zoonotic viruses have been identified in rodents in the region. Therefore, we hypothesized that there may be unrecognized zoonotic viruses circulating in small mammals in Central Africa. Here, we investigated viruses that have been maintained among wild small mammals in Gabon to understand their potential risks to humans. We identified novel orthonairoviruses in 24.6 % of captured rodents and shrews from their kidney total RNA samples. Phylogenetic analysis revealed that the novel viruses, Lamusara virus (LMSV) and Lamgora virus, were closely related to Erve virus, which was previously identified in shrews of the genus Crocidura and has been suspected to cause neuropathogenic diseases in humans. Moreover, we show that the LMSV ovarian tumour domain protease, one of the virulence determination factors of orthonairoviruses, suppressed interferon signalling in human cells, suggesting the possible human pathogenicity of this virus. Taken together, our study demonstrates the presence of novel orthonairoviruses that may pose unrecognized risks of viral disease transmission in Gabon

Marburg antibody testing in bats collected at locations where PCR positive bats were found.

<p>A.) Corrected OD values from bat sera diluted 1∶100 that are greater than the threshold value of 0.13 (solid horizontal bar) which was calculated as the average corrected OD of the negative control group (<i>E. franqueti</i>, N = 47) plus 3 standard deviations. The numbers of sera specimens used to calculate the values are shown to the right of the corresponding symbol. OD values from nested-PCR positive bats 1448, 2296 (§§) and 1631 (§) are also noted. B.) Antibody titers of sera specimens with corrected OD values greater than 0.13. The numbers of serum specimens used to calculate the values are shown to the right of the corresponding symbol.</p

Phylogenetic analyses and nucleotide sequence alignments of NP and VP35 sequences derived from bat tissues.

<p>A) Maximum likelihood analysis of the concatenated NP (464 nt) and VP35 (302 nt) sequence fragments obtained from each bat specimen and 18 MBG virus isolates. Bootstrap support values are indicated at the nodes. Abbreviations of historical isolates are Rav = Ravn, Ozo = Ozolin, Pop = Popp and Mus = Musoke. B-C) Nucleotide alignment of the sequences in (A) in which the lineages from the Angola 2005 outbreak are singly represented by Ang1379c.</p

Animal collection sites in Gabon and Republic of Congo.

<p>Animal trap locations in Gabon and Republic of Congo (expansion) are indicated by yellow circles. Also indicated are the locations of the four PCR positive bats (by arrows) and the dates and locations of all known origins of previous Marburg virus outbreaks (red circles).</p

Geographic distribution (green shade) of <i>Rousettus aegyptiacus</i> in Africa.

<p>Red dots indicate the locations of all previous known Marburg virus outbreaks, as indicated in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000764#pone-0000764-g001" target="_blank">Figure 1</a>, in addition to the locations of the Marburg-positive bats.</p

Summary of bat species tested for Marburg virus specific RNA and/or antibody.

<p>Description of bat species and their respective numbers analyzed by either PCR or serology followed by the number of bats of each respective species that tested positive by real-time RT-PCR, nested RT-PCR or had corrected OD values greater than 0.13 at serum dilutions of 1∶100. (*) denotes unspeciated bats of the suborder Microchiroptera. (‡) denotes bat species previously identified to show evidence of Ebola infection <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000764#pone.0000764-Leroy1" target="_blank">[4]</a>.</p