Mammarenaviruses have been a growing concern for public health in Africa since the 1970s when Lassa virus cases in humans were first described in west Africa. In southern Africa, a single outbreak of Lujo virus was reported to date in South Africa in 2008 with a case fatality rate of 80%. The natural reservoir of Lassa virus is Mastomys natalensis while for the Lujo virus the natural host has yet to be identified. Mopeia virus was described for the first time in M. natalensis in the central Mozambique in 1977 but few studies have been conducted in the region. In this study, rodents were trapped between March and November 2019in villages, croplands fields and mopane woodland forest. The aim was to assess the potential circulation and to evaluate the genetic diversity of mammarenaviruses in M. natalensis trapped in the Limpopo National Park and its buffer zone in Massingir district, Mozambique. A total of 534 M. natalensis were screened by RT-PCR and the overall proportion of positive individuals was 16.9%. No significant differences were detected between the sampled habitats (χ2 = 0.018; DF = 1; p = 0.893). The Mopeia virus (bootstrap value 91%) was the Mammarenavirus circulating in the study area sites, forming a specific sub-clade with eight different sub-clusters. We concluded that Mopeia virus circulates in all habitats investigated and it forms a different sub-clade to the one reported in central Mozambique in 1977.
- Klíčová slova
- Mammarenavirus, Mastomys natalensis, Mozambique, Phylogeny,
- MeSH
- Arenaviridae izolace a purifikace MeSH
- ekosystém MeSH
- infekce viry z čeledi Arenaviridae epidemiologie veterinární MeSH
- Murinae * MeSH
- veřejné parky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Mosambik epidemiologie MeSH
Rodents are a speciose group of mammals with strong zoonotic potential. Some parts of Africa are still underexplored for the occurrence of rodent-borne pathogens, despite this high potential. Angola is at the convergence of three major biogeographical regions of sub-Saharan Africa, each harbouring a specific rodent community. This rodent-rich area is, therefore, strategic for studying the diversity and evolution of rodent-borne viruses. In this study we examined 290 small mammals, almost all rodents, for the presence of mammarenavirus and hantavirus RNA. While no hantavirus was detected, we found three rodent species positive for distinct mammarenaviruses with a particularly high prevalence in Namaqua rock rats (Micaelamys namaquensis). We characterised four complete virus genomes, which showed typical mammarenavirus organisation. Phylogenetic and genetic distance analyses revealed: (i) the presence of a significantly divergent strain of Luna virus in Angolan representatives of the ubiquitous Natal multimammate mouse (Mastomys natalensis), (ii) a novel Okahandja-related virus associated with the Angolan lineage of Micaelamys namaquensis for which we propose the name Bitu virus (BITV) and (iii) the occurrence of a novel Mobala-like mammarenavirus in the grey-bellied pygmy mouse (Mus triton) for which we propose the name Kwanza virus (KWAV). This high virus diversity in a limited host sample size and in a relatively small geographical area supports the idea that Angola is a hotspot for mammarenavirus diversity.
- Klíčová slova
- Angola, Mastomys natalensis, Micaelamys namaquensis, Mus triton, hantaviruses, mammarenaviruses, phylogeny,
- MeSH
- Arenaviridae klasifikace genetika MeSH
- fylogeneze MeSH
- genom virový MeSH
- infekce viry z čeledi Arenaviridae veterinární MeSH
- lékařská geografie MeSH
- prevalence MeSH
- RNA virová MeSH
- sekvenování celého genomu MeSH
- zdroje nemoci virologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- RNA virová MeSH
BACKGROUND: Parasite evolution is hypothesized to select for levels of parasite virulence that maximise transmission success. When host population densities fluctuate, low levels of virulence with limited impact on the host are expected, as this should increase the likelihood of surviving periods of low host density. We examined the effects of Morogoro arenavirus on the survival and recapture probability of multimammate mice (Mastomys natalensis) using a seven-year capture-mark-recapture time series. Mastomys natalensis is the natural host of Morogoro virus and is known for its strong seasonal density fluctuations. RESULTS: Antibody presence was negatively correlated with survival probability (effect size: 5-8% per month depending on season) but positively with recapture probability (effect size: 8%). CONCLUSIONS: The small negative correlation between host survival probability and antibody presence suggests that either the virus has a negative effect on host condition, or that hosts with lower survival probability are more likely to obtain Morogoro virus infection, for example due to particular behavioural or immunological traits. The latter hypothesis is supported by the positive correlation between antibody status and recapture probability which suggests that risky behaviour might increase the probability of becoming infected.
- Klíčová slova
- Arenavirus, Capture-mark-recapture, Host-parasite interaction, Morogoro virus, Survival analysis,
- MeSH
- analýza přežití MeSH
- Arenavirus imunologie izolace a purifikace MeSH
- chování zvířat MeSH
- infekce viry z čeledi Arenaviridae mortalita veterinární MeSH
- Murinae * MeSH
- nemoci hlodavců mortalita virologie MeSH
- protilátky virové krev MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- protilátky virové MeSH
BACKGROUND: In order to optimize net transmission success, parasites are hypothesized to evolve towards causing minimal damage to their reservoir host while obtaining high shedding rates. For many parasite species however this paradigm has not been tested, and conflicting results have been found regarding the effect of arenaviruses on their rodent host species. The rodent Mastomys natalensis is the natural reservoir host of several arenaviruses, including Lassa virus that is known to cause Lassa haemorrhagic fever in humans. Here, we examined the effect of three arenaviruses (Gairo, Morogoro and Lassa virus) on four parameters of wild-caught Mastomys natalensis: body mass, head-body length, sexual maturity and fertility. After correcting for the effect of age, we compared these parameters between arenavirus-positive (arenavirus RNA or antibody) and negative animals using data from different field studies in Guinea (Lassa virus) and Tanzania (Morogoro and Gairo viruses). RESULTS: Although the sample sizes of our studies (1297, 749 and 259 animals respectively) were large enough to statistically detect small differences in body conditions, we did not observe any adverse effects of these viruses on Mastomys natalensis. We did find that sexual maturity was significantly positively related with Lassa virus antibody presence until a certain age, and with Gairo virus antibody presence in general. Gairo virus antibody-positive animals were also significantly heavier and larger than antibody-free animals. CONCLUSION: Together, these results suggest that the pathogenicity of arenaviruses is not severe in M. natalensis, which is likely to be an adaptation of these viruses to optimize transmission success. They also suggest that sexual behaviour might increase the probability of M. natalensis to become infected with arenaviruses.
- Klíčová slova
- Arenavirus, Gairo virus, Host-pathogen interaction, Lassa virus, Mastomys natalensis, Morogoro virus, Reservoir host, Rodent-borne disease,
- MeSH
- Arenavirus izolace a purifikace MeSH
- infekce přenášené vektorem * MeSH
- infekce viry z čeledi Arenaviridae patologie veterinární virologie MeSH
- Murinae fyziologie virologie MeSH
- přenašečství patologie veterinární virologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Guinea MeSH
- Tanzanie MeSH
Despite its near pan-African range, the Natal multimammate mouse, Mastomys natalensis, carries the human pathogen Lassa virus only in West Africa, while the seemingly non-pathogenic arenaviruses Mopeia, Morogoro, and Luna have been detected in this semi-commensal rodent in Mozambique/Zimbabwe, Tanzania and Zambia, respectively. Here, we describe a novel arenavirus in M. natalensis from Gairo district of central Tanzania, for which we propose the name "Gairo virus". Surprisingly, the virus is not closely related with Morogoro virus that infects M. natalensis only 90km south of Gairo, but clusters phylogenetically with Mobala-like viruses that infect non-M. natalensis host species in Central African Republic and Ethiopia. Despite the evolutionary distance, Gairo virus shares basic ecological features with the other M. natalensis-borne viruses Lassa and Morogoro. Our data show that M. natalensis, carrying distantly related viruses even in the same geographical area, is a potent reservoir host for a variety of arenaviruses.
- Klíčová slova
- Arenavirus, Ecology, Hemorrhagic fevers, Mastomys natalensis, Phylogeny, Tanzania, Virology, Zoonotic infections,
- MeSH
- Arenavirus klasifikace genetika izolace a purifikace MeSH
- fylogeneze MeSH
- genetická variace * MeSH
- infekce viry z čeledi Arenaviridae imunologie veterinární virologie MeSH
- molekulární sekvence - údaje MeSH
- Murinae imunologie virologie MeSH
- nemoci hlodavců imunologie virologie MeSH
- protilátky virové imunologie MeSH
- virus Lassa klasifikace genetika izolace a purifikace MeSH
- zdroje nemoci virologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Tanzanie MeSH
- Názvy látek
- protilátky virové MeSH
