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Tanapox is a rarely diagnosed zoonosis known to be endemic to equatorial Africa. All previously reported human cases were acquired within 10° north or south of the Equator, most recently 19 years ago. We describe a human case of tanapox in South Africa (24° south of the Equator). Expanded surveillance for this pathogen is warranted.
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Infecciones por Poxviridae , Yatapoxvirus , Animales , Humanos , Sudáfrica/epidemiología , Zoonosis , Infecciones por Poxviridae/diagnósticoRESUMEN
We detected Rift Valley fever virus (RVFV) IgM and IgG in human serum samples collected during 2018-2019 in northern KwaZulu-Natal Province, South Africa. Our results show recent RVFV circulation and likely RVFV endemicity in this tropical coastal plain region of South Africa in the absence of apparent clinical disease.
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Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Animales , Anticuerpos Antivirales , Humanos , Fiebre del Valle del Rift/epidemiología , Estudios Seroepidemiológicos , Sudáfrica/epidemiologíaRESUMEN
We conducted a survey for group-specific indirect immunofluorescence antibody to mammarenaviruses by using Lassa fever and Mopeia virus antigens on serum specimens of 5,363 rodents of 33 species collected in South Africa and Zimbabwe during 1964-1994. Rodents were collected for unrelated purposes or for this study and stored at -70°C. We found antibody to be widely distributed in the 2 countries; antibody was detected in serum specimens of 1.2%-31.8% of 14 species of myomorph rodents, whereas 19 mammarenavirus isolates were obtained from serum specimens and viscera of 4 seropositive species. Phylogenetic analysis on the basis of partial nucleoprotein sequences indicates that 14 isolates from Mastomys natalensis, the Natal multimammate mouse, were Mopeia virus, whereas Merino Walk virus was characterized as a novel virus in a separate study. The remaining 4 isolates from 3 rodent species potentially constitute novel viruses pending full characterization.
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Arenaviridae , Enfermedades de los Roedores , Animales , Reservorios de Enfermedades , Virus Lassa , Murinae , Filogenia , Sudáfrica/epidemiología , Zimbabwe/epidemiologíaRESUMEN
ABSTRACT: We present a case of fatal Rickettsiosis from South Africa.
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Infecciones por Rickettsia/diagnóstico , Comorbilidad , Resultado Fatal , Humanos , Masculino , Persona de Mediana Edad , Necrosis , Piel/patología , Sudáfrica , Mordeduras de Garrapatas/patologíaRESUMEN
BACKGROUND: Ebolavirus and Marburgvirus are genera of the virus family Filoviridae. Filoviruses cause rare but fatal viral hemorrhagic fevers (VHFs) in remote villages of equatorial Africa with potential for regional and international spread. Point-of-care (POC) rapid diagnostic tests (RDTs) are critical for early epidemic detection, reponse and control. There are 2 RDTs for Zaire ebolavirus (EBOV), but not other Ebolavirus spp. or Marburg marburgvirus (MARV). We validate 3 conserved B cell epitopes of filovirus glycoprotein (GP) using ebola virus diseases (EVD) survivor samples, towards devising pan-filovirus RDTs. METHODS: In-silico Immuno-informatics:- (a) multiple and basic local alignments of amino-acid sequences of filovirus (4 Ebolavirus spp. & MARV) Gp1, 2 and epitope prediction and conservation analyses within context of ClusterW, BLAST-P and the immune epitope database analysis resource (IEDB-AR); alongside (b) in-vitro enzyme immuno-assays (EIAs) for SUDV Gp1, 2 antigen and host-specific antibodies (IgM and IgG) among 94 gamma irradiated EVD survivor serum and 9 negative controls. RESULTS: Linear B cell epitopes were present across the entire length of all Gp1, 2, most lying in the region between amino acids positioned 350 and 500. Three seperate epitopes 97/80_GAFFLYDRLAST, 39_YEAGEWAENCY and 500_CGLRQLANETTQALQLFLRATTELR (designated UG-Filo-Peptide- 1, 2 and 3 respectively) were conserved within all studied filovirus species Gp1, 2. Gp1, 2 host specific IgM levels were comparably low (av. ODs < 0.04 [95% CI: 0.02837 to 0.04033]) among the 9 negative controls and 57 survivor samples analyzed. Host specific IgG levels, on the other hand, were elevated (av. ODs > 1.7525 [95% CI: 0.3010 to 3.1352]) among the 92 survivor samples relative to the 9 negative controls (av. ODs < 0.2.321 [95% CI: -0.7596 to 0.5372]). Filovirus Gp1, 2 antigen was not detected [av. ODs < 0.20] within EVD survivor serum relative to recombinant protein positive controls [av. ODs = 0.50]. CONCLUSIONS: These conserved B cell epitopes of filovirus Gp1, 2 and their derivative antibodies are promising for research and development of RDTs for EVD, with potential for extension to detect MVD.
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Ebolavirus/inmunología , Epítopos de Linfocito B/inmunología , Glicoproteínas/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Antivirales/inmunología , Secuencia Conservada , Fiebre Hemorrágica Ebola/diagnóstico , Fiebre Hemorrágica Ebola/virología , Humanos , Inmunoglobulina G , Inmunoglobulina M , Enfermedad del Virus de Marburg/diagnóstico , Enfermedad del Virus de Marburg/virología , Marburgvirus/inmunología , Juego de Reactivos para Diagnóstico , Proteínas Virales/genética , Proteínas Virales/inmunologíaRESUMEN
The recently identified arenavirus Lujo virus (LUJV) causes fatal hemorrhagic fever in humans. We analyzed its mechanism of viral release driven by matrix protein Z and the cell surface glycoprotein precursor GPC. The L domains in Z are required for efficient virus-like particle release, but Tsg101, ALIX/AIP1, and Vps4A/B are unnecessary for budding. LUJV GPC is cleaved by site 1 protease (S1P) at the RKLM motif, and treatment with the S1P inhibitor PF-429242 reduced LUJV production.
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Lujo virus/fisiología , Ensamble de Virus , Liberación del Virus , Animales , Línea Celular , Humanos , Lujo virus/crecimiento & desarrollo , Proteínas Virales/metabolismoRESUMEN
BACKGROUND: Rift Valley fever virus (RVFV) remains heavily neglected in humans in Mozambique, even though recent outbreaks were reported in neighboring countries in humans and several cases of RVFV in cattle were reported in several districts in Mozambique. FINDINGS: We conducted a cross sectional study during and after severe flooding that occurred in 2013 in Mozambique. Paired acute and convalescent serum samples were tested from febrile patients attending a primary health care unit in a suburban area of Maputo city for the presence of IgG and IgM antibodies against Rift Valley fever virus (RVFV) using enzyme-linked immunosorbent assay (ELISA). Seroconversion of IgG anti-RVFV was observed in 5 % (10/200) of convalescent patients and specific IgM anti-RVFV was detected in one acute patient (0.5 %; 1/200). All sera from acute patient tested negative by real time PCR. CONCLUSION: In conclusion, our results suggest that RVF represent an important but neglected cause of febrile illness following periods of flooding in southern Mozambique.
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Anticuerpos Antivirales/sangre , Fiebre/epidemiología , Fiebre/etiología , Fiebre del Valle del Rift/diagnóstico , Fiebre del Valle del Rift/epidemiología , Virus de la Fiebre del Valle del Rift/inmunología , Pruebas Serológicas , Adulto , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Femenino , Inundaciones , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Masculino , Mozambique/epidemiología , ARN Viral/sangre , Lluvia , Reacción en Cadena en Tiempo Real de la Polimerasa , Virus de la Fiebre del Valle del Rift/genética , Adulto JovenRESUMEN
Egyptian fruit bats (Rousettus aegyptiacus) were inoculated subcutaneously (n = 22) with Marburg virus (MARV). No deaths, overt signs of morbidity, or gross lesions was identified, but microscopic pathological changes were seen in the liver of infected bats. The virus was detected in 15 different tissues and plasma but only sporadically in mucosal swab samples, urine, and fecal samples. Neither seroconversion nor viremia could be demonstrated in any of the in-contact susceptible bats (n = 14) up to 42 days after exposure to infected bats. In bats rechallenged (n = 4) on day 48 after infection, there was no viremia, and the virus could not be isolated from any of the tissues tested. This study confirmed that infection profiles are consistent with MARV replication in a reservoir host but failed to demonstrate MARV transmission through direct physical contact or indirectly via air. Bats develop strong protective immunity after infection with MARV.
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Quirópteros/virología , Susceptibilidad a Enfermedades/virología , Enfermedad del Virus de Marburg/transmisión , Marburgvirus/patogenicidad , Animales , Brotes de Enfermedades , Susceptibilidad a Enfermedades/sangre , Susceptibilidad a Enfermedades/inmunología , Femenino , Humanos , Masculino , Enfermedad del Virus de Marburg/inmunología , Enfermedad del Virus de Marburg/virología , Marburgvirus/genética , Marburgvirus/inmunología , Replicación Viral/genéticaRESUMEN
As part of a larger survey for detection of pathogens among wildlife in sub-Saharan Africa conducted during 2007-2012, multiple diverse paramyxovirus sequences were detected in renal tissues of bats. Phylogenetic analysis supports the presence of at least 2 major viral lineages and suggests that paramyxoviruses are strongly associated with several bat genera.
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Quirópteros/virología , Henipavirus/patogenicidad , Infecciones por Paramyxoviridae/epidemiología , Paramyxovirinae/clasificación , Prevalencia , África del Sur del Sahara/epidemiología , Animales , Infecciones por Paramyxoviridae/virología , Filogenia , Vigilancia de la Población/métodos , ARN Viral/clasificación , ARN Viral/genéticaRESUMEN
BACKGROUND: Rift Valley fever virus (RVFV) is a zoonotic mosquito-borne virus with serious implications for livestock health, human health, and the economy in Africa, and is suspected to be endemic in north-eastern KwaZulu-Natal (KZN), South Africa. The vectors of RVFV in this area are poorly known, although several species, such as Aedes (Neomelaniconion) mcintoshi, Aedes (Neomelaniconion) circumluteolus, Aedes (Aedimorphus) durbanensis, and Culex (Lasioconops) poicilipes may be involved. The aim of the study was to determine the vertebrate blood meal sources of potential RVFV mosquito vectors in north-eastern KZN and to characterize the host-biting network. METHODS: Blood-fed mosquitoes were collected monthly from November 2019 to February 2023 using a backpack aspirator, CO2-baited Centers for Disease Control and Prevention (CDC) miniature light traps and tent traps, in the vicinity of water bodies and livestock farming households. The mosquitoes were morphologically identified. DNA was extracted from individual mosquitoes and used as templates to amplify the vertebrate cytochrome c oxidase I (COI) and cytochrome b (cytb) genes using conventional polymerase chain reaction (PCR). Amplicons were sequenced and queried in GenBank and the Barcode of Life Data systems to identify the vertebrate blood meal sources and confirm mosquito identifications. All mosquitoes were screened for RVFV using real time reverse transcription (RT)-PCR. RESULTS: We identified the mammalian (88.8%) and avian (11.3%) blood meal sources from 409 blood-fed mosquitoes. Aedes circumluteolus (n = 128) made up the largest proportion of collected mosquitoes. Cattle (n = 195) and nyala (n = 61) were the most frequent domestic and wild hosts, respectively. Bipartite network analysis showed that the rural network consisted of more host-biting interactions than the reserve network. All mosquitoes tested negative for RVFV. CONCLUSIONS: Several mosquito species, including Ae. circumluteolus, and vertebrate host species, including cattle and nyala, could play a central role in RVFV transmission. Future research in this region should focus on these species to better understand RVFV amplification.
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Aedes , Mosquitos Vectores , Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Animales , Sudáfrica , Mosquitos Vectores/virología , Mosquitos Vectores/fisiología , Virus de la Fiebre del Valle del Rift/genética , Virus de la Fiebre del Valle del Rift/aislamiento & purificación , Virus de la Fiebre del Valle del Rift/fisiología , Fiebre del Valle del Rift/transmisión , Fiebre del Valle del Rift/virología , Fiebre del Valle del Rift/epidemiología , Aedes/virología , Aedes/fisiología , Aedes/genética , Aedes/clasificación , Humanos , Conducta Alimentaria , Culex/virología , Culex/fisiología , Mordeduras y Picaduras de Insectos , Femenino , Culicidae/virología , Culicidae/fisiología , Culicidae/clasificaciónRESUMEN
Rift Valley fever (RVF) is an emerging zoonosis posing a public health threat to humans in Africa. During sporadic RVF outbreaks in 2008-2009 and widespread epidemics in 2010-2011, 302 laboratory-confirmed human infections, including 25 deaths (case-fatality rate, 8%) were identified. Incidence peaked in late summer to early autumn each year, which coincided with incidence rate patterns in livestock. Most case-patients were adults (median age 43 years), men (262; 87%), who worked in farming, animal health or meat-related industries (83%). Most case-patients reported direct contact with animal tissues, blood, or other body fluids before onset of illness (89%); mosquitoes likely played a limited role in transmission of disease to humans. Close partnership with animal health and agriculture sectors allowed early recognition of human cases and appropriate preventive health messaging.
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We report the coding-complete genome sequence of human alphaherpesvirus 1 (HHV1) isolated from a previously healthy 64-year-old male with fulminant hepatitis, a rare presentation of a common viral agent. The sequence is highly similar to previously described HHV1 sequences. Additional sequence data for fulminant hepatitis cases are required.
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We report the genetic characterization of two potentially novel rabies-related lyssaviruses identified from bats in Limpopo province, South Africa. Matlo bat lyssavirus (MBLV) was identified in two Miniopterus natalensis (Natal long-fingered) bats in 2015 and 2016, and Phala bat lyssavirus (PBLV) was identified in a Nycticeinops schlieffeni (Schlieffen's) bat in 2021. The distribution of both of these bat species is largely confined to parts of Africa, with limited reports from the Arabian Peninsula. MBLV and PBLV were demonstrated to group with the unassigned and phylogroup I lyssaviruses, respectively. MBLV was most closely related to Lyssavirus caucasicus (WCBV), whereas PBLV was most closely related to Lyssavirus formosa (TWBLV-1) and Taiwan bat lyssavirus 2 (TWBLV-2), based on analysis of the N and G genes, the concatenated N + P + M + G + L coding sequence, and the complete genome sequence. Based on our analysis, MBLV and WCBV appeared to constitute a phylogroup separate from Lyssavirus lleida (LLEBV) and Lyssavirus ikoma (IKOV). Analysis of the antigenic sites suggests that PBLV will likely be serologically distinguishable from established lyssaviruses in virus-neutralization tests, whereas MBLV appeared to be antigenically highly similar to WCBV. Taken together, the findings suggested that, while PBLV is likely a new lyssavirus species, MBLV is likely related to WCBV.
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Quirópteros , Lyssavirus , Virus de la Rabia , Rabia , Infecciones por Rhabdoviridae , Animales , Sudáfrica , Virus de la Rabia/genética , Lyssavirus/genética , Infecciones por Rhabdoviridae/veterinariaRESUMEN
We report the coding-complete sequence of a lyssavirus, provisionally designated Phala bat lyssavirus (PBLV), characterized using a metagenomics approach. PBLV was identified in a Nycticeinops schlieffeni bat that exhibited neurological signs and died within 24 hours of admission to a wildlife rehabilitation center in Phalaborwa, South Africa.
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Novel lyssaviruses, the causative agents of rabies, continue to be described mostly due to increased surveillance in bat hosts. Biologicals for the prevention of rabies in humans have, however, remained largely unchanged for decades. This study aimed to determine if commercial rabies immunoglobulin (RIG) could neutralize diverse lyssaviruses. Two commercial preparations, of human or equine origin, were evaluated against a panel consisting of 13 lyssavirus species. Reduced neutralization was observed for the majority of lyssaviruses compared to rabies virus and was more evident for lyssaviruses outside of phylogroup I. Neutralization of more diverse lyssaviruses only occurred at very high doses, except for Ikoma lyssavirus, which could not be neutralized by the RIG evaluated in this study. The use of RIG is a crucial component of rabies post-exposure prophylaxis and the data generated here indicate that RIG, in its current form, will not protect against all lyssaviruses. In addition, higher doses of RIG may be required for neutralization as the genetic distance from vaccine strains increases. Given the limitations of current RIG preparations, alternative passive immunization options should be investigated.
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Recent studies have indicated that bats are hosts to diverse filoviruses. Currently, no pan-filovirus molecular assays are available that have been evaluated for the detection of all mammalian filoviruses. In this study, a two-step pan-filovirus SYBR Green real-time PCR assay targeting the nucleoprotein gene was developed for filovirus surveillance in bats. Synthetic constructs were designed as representatives of nine filovirus species and used to evaluate the assay. This assay detected all synthetic constructs included with an analytical sensitivity of 3-31.7 copies/reaction and was evaluated against the field collected samples. The assay's performance was similar to a previously published probe based assay for detecting Ebola- and Marburgvirus. The developed pan-filovirus SYBR Green assay will allow for more affordable and sensitive detection of mammalian filoviruses in bat samples.
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Biovigilancia , Quirópteros , Ebolavirus , Filoviridae , Fiebre Hemorrágica Ebola , Animales , Filoviridae/genética , Ebolavirus/genética , MamíferosRESUMEN
Rift Valley fever (RVF) is a re-emerging zoonotic disease of domestic ruminants and humans. While neighbouring countries have reported outbreaks of RVF, Ghana has not yet identified any cases. The aim of this study was to determine whether RVF virus (RVFV) was circulating in livestock and herders in the southern part of Ghana, to estimate its seroprevalence, and to identify associated risk factors. The study surveyed 165 livestock farms randomly selected from two districts in southern Ghana. Serum samples of 253 goats, 246 sheep, 220 cattle, and 157 herdsmen were tested to detect IgG and IgM antibodies against RVFV. The overall seroprevalence of anti-RVF antibodies in livestock was 13.1% and 30.9% of farms had RVFV seropositive animals. The species-specific prevalence was 24.1% in cattle, 8.5% in sheep, and 7.9% in goats. A RVFV IgG seroprevalence of 17.8% was found among the ruminant herders, with 8.3% of all herders being IgM positive. RVFV was shown, for the first time, to have been circulating in southern Ghana, with evidence of a recent outbreak in Kwahu East; however, it was clinically undetected despite significant recent human exposure. A One Health approach is recommended to better understand RVF epidemiology and socio-economic impact in Ghana.
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Enfermedades de los Bovinos , Fiebre del Valle del Rift , Virus de la Fiebre del Valle del Rift , Enfermedades de las Ovejas , Animales , Bovinos , Ovinos , Humanos , Ganado , Estudios Seroepidemiológicos , Ghana/epidemiología , Anticuerpos Antivirales , Enfermedades de las Ovejas/epidemiología , Rumiantes , Cabras , Inmunoglobulina M , Inmunoglobulina GRESUMEN
Novel coronavirus species of public health and veterinary importance have emerged in the first two decades of the twenty-first century, with bats identified as natural hosts for progenitors of many coronaviruses. Targeted wildlife surveillance is needed to identify the factors involved in viral perpetuation within natural host populations, and drivers of interspecies transmission. We monitored a natural colony of Egyptian rousette bats at monthly intervals across two years to identify circulating coronaviruses, and to investigate shedding dynamics and viral maintenance within the colony. Three distinct lineages were detected, with different seasonal temporal excretion dynamics. For two lineages, the highest periods of coronavirus shedding were at the start of the year, when large numbers of bats were found in the colony. Highest peaks for a third lineage were observed towards the middle of the year. Among individual bat-level factors (age, sex, reproductive status, and forearm mass index), only reproductive status showed significant effects on excretion probability, with reproductive adults having lower rates of detection, though factors were highly interdependent. Analysis of recaptured bats suggests that viral clearance may occur within one month. These findings may be implemented in the development of risk reduction strategies for potential zoonotic coronavirus transmission.
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Líquidos Corporales , COVID-19 , Quirópteros , Animales , Animales SalvajesRESUMEN
Mammarenaviruses are hosted by several rodent species, a small number of which have been known to be zoonotic. Host surveillance among small mammals has identified a large diversity of previously undescribed mammarenaviruses. Intensified biosurveillance is warranted to better understand the diversity of these agents. Longitudinal host surveillance involving non-volant small mammals at a site in the Limpopo province, South Africa, was conducted. The study reports on the screening results of 563 samples for the presence of mammarenavirus RNA. PCR-positive samples were subjected to sequencing using Miseq amplicon sequencing. Sequences with close similarity to Mariental and Lunk viruses were identified from two rodent species, Micaelamys namaquensis and Mus minutoides. This represents the first description of these viruses from South Africa. The genomic sequences reported here partially satisfied the requirements put forward by the International Committee on the Taxonomy of Viruses' criteria for species delineation, suggesting that these may be new strains of existing species. The known distribution of these mammarenaviruses is thus expanded further south in Africa.
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Arenaviridae , Animales , Arenaviridae/genética , Filogenia , África Austral , Mamíferos , MurinaeRESUMEN
Background: The National Institute for Communicable Diseases (NICDs) of South Africa (SA) provides technical support to healthcare workers (HCWs) with regard to infectious diseases through the NICD clinician hotline. Queries to the hotline are often about rabies prophylaxis. An analysis of these queries may help to identify knowledge gaps amongst HCWs regarding prevention of rabies in humans in SA. Methods: A retrospective descriptive review was conducted to analyse rabies post-exposure prophylaxis (PEP) queries received by the NICD from 01 January 2016 to 31 December 2019. Results: A total of 4655 queries were received by the NICD clinician hotline for the study period, of which 2461 pertained to rabies PEP (52.87%). The largest number of calls were placed by HCWs (n = 2313/2437; 94.9%). Queries originated mainly from Gauteng (n = 912/2443; 37.3%) and KwaZulu-Natal (n = 875/2443; 35.8%) provinces. A total of 50 different types of animals were related to exposures involving humans. Dogs (67.7%) and cats (11.8%) were the animals most frequently reported and exposure category III was most common (88.6%). Approximately equal numbers of callers were advised active management of administering rabies PEP and conservative management of withholding PEP. This did not seem to be affected by the exposure category related to the call. Conclusion: This analysis shows the ongoing demand by HCWs for technical support regarding patient management following potential exposure to rabies. Gaps in HCWs rabies knowledge provide unique learning points on guiding training to achieve the goal of eliminating dog-mediated human rabies deaths by 2030.