#Hantavirus #seroprevalence and associated factors for exposure in south-central #Uganda

 

ABSTRACT

Orthohantaviruses are largely rodent-borne pathogens that can cause haemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome. In Uganda, the risk of human exposure is heightened by known rodent hosts, close human-rodent interaction in rural areas, and poor housing conditions. Despite this risk, data on human exposure remain scarce. This study sought to ascertain the seroprevalence of orthohantavirus exposure and identify associated factors with exposure among residents of the greater Masaka-Rakai region in Uganda. Seropositivity was assessed for orthohantavirus-specific IgG antibodies using commercial enzyme-linked immunosorbent assays. Logistic regression models were used to identify factors associated with seropositivity. Among 1,199 sera samples, orthohantavirus population-weighted seroprevalence was 7.4% (95% CI: 3.91–10.80). Males had a higher seroprevalence, while higher socioeconomic status was associated with a reduced burden of exposure to orthohantavirus. This study reports evidence of orthohantavirus exposure in Uganda, highlighting a previously underrecognized zoonotic risk in the region likely driven by close contact with rodent reservoirs and poor living conditions. The higher burden among males and lower-burden association with higher socioeconomic status, highlights the need for improved housing, rodent control, and integration of orthohantavirus surveillance into national public health programmes.

Source: 

Link: https://www.tandfonline.com/doi/full/10.1080/22221751.2026.2665002

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Identification and #genetic characterization of a distinct #genotype of #Puumala #orthohantavirus in #Hebei Province, #China

 

Abstract

Orthohantavirus infections pose a significant threat to human health, while numerous orthohantaviruses have been identified, suspected viral infections remain undiagnosed in the world, which highlights the need for further identification and characterization of viruses circulating in humans and host animals. In this study, viral metagenomics was utilized to investigate orthohantaviruses present in tissue samples collected from rodents trapped at the Bashang Grassland of Hebei Province, China. A total of 145 wild rodents belonging to six species were captured in the study area, and 725 tissue samples (lung, liver, kidney, spleen, gut) were collected in 2024. A Puumala orthohantavirus (PUUV), named Guyuan strain, was identified in Myodes rufocanus, with a positive rate of 0.69%. The complete genomic sequences of the L, M, and S segments were obtained and confirmed by Sanger sequencing. Phylogenetic analysis of these genomic sequences with those of other orthohantavirus species showed that the L, M, and S segments clustered with PUUV genomic sequences, while sharing a nucleotide sequence similarity of 81.2%, 80.2%, and 84.3% with previously characterized reference viral strains Kitahiyama128L, Tobetsu_04, and Baltic/205 Cg, respectively. Amino acid homology analysis demonstrated that the sequences exhibited the highest identity to PUUV Hokkaido strain at a level of 95.4%, 94.6%, and 97.0% respectively. Viral particles were observed in lung and kidney tissues using transmission electron microscopy, and viral protein antigen was detected in viral RNA-positive lung, liver, and kidney tissues through immunofluorescence assay with antibodies against the PUUV nucleocapsid protein, thereby confirming the virus’s multiorgan tropism. The results demonstrated that a distinct genotype of PUUV was circulating in rodents in the study areas, which may have implications for zoonotic transmission surveillance and public health management in Hebei Province.

Source: 

Link: https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0014250

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Virological characterization of a new isolated strain of #Andes virus involved in recent person-to-person #transmission #outbreak reported in #Argentina

Abstract

On November 2, 2018, a person-to-person transmission outbreak of Andes virus (Orthohantavirus andesense) began in the small town of Epuyén, Argentina. The strain demonstrated a high capacity for sustained transmission among the human population requiring the implementation of quarantine measures, rigorous contact tracing, isolation of close contacts, and active clinical monitoring to prevent further spread. In this study, we report the isolation of this strain, which we name the ARG-Epuyén strain, directly from a clinical sample after just three passages in cell culture. Complete sequencing revealed only a single amino acid change post-isolation, suggesting that this strain can be considered a non-adapted wild-type Andes virus, marking a critical step toward the development of medical countermeasures against this emerging pathogen. The pathogenicity and transmissibility potential of ARG-Epuyén were evaluated in hamsters, the only animal model for Hantavirus Pulmonary Syndrome. Additionally, this strain was compared with Andes/ARG, an ANDV strain previously isolated from the same geographical area in the Argentinian Patagonia, from a rodent specimen. Our findings revealed high infectiousness and efficient hamster-to-hamster transmission through direct contact experiments, although ARG-Epuyén appeared to be less pathogenic than Andes/ARG.

Source: PLoS Neglected Tropical Diseases, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013205

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#Lanka virus, a #Mus booduga-borne #orthohantavirus #infection-associated febrile illness in #SriLanka

Abstract

Background

In Sri Lanka, a high seroprevalence of antibodies against hantaviruses was reported in communities affected by chronic kidney disease of unknown etiology (CKDu). Recently, two rodent-borne hantaviruses, Lanka virus and Anjozorobe virus, were identified in these areas. However, it is unclear which virus is the source of infection in humans, and its pathogenicity is unknown.

Methodology/principal findings

A total of 181 sera from febrile patients from two CKDu-endemic regions, Girandurukotte and Polonnaruwa, were examined and Lanka virus genome was detected in two IgM-positive febrile patients. Of 76 serum samples from patients with fever of unknown etiology collected during 2016 examined to identify hantavirus genomes, antibodies, and serotypes, 10 were IgG-positive with five of them having IgM also. They were all without clinical features of hemorrhagic fever with renal syndrome, but three patients required treatment in the intensive care unit. A serotyping strategy was established based on the antigenic difference of the glycoprotein Gn of Lanka and Anjozorobe viruses. Using this method, febrile patients were found to be infected with the Lanka virus and none of the patient sera showed Anjozorobe virus infection pattern. Additionally, a total of 373 previously diagnosed seropositive serum samples from CKDu patients and healthy residents were serotyped to categorize 87% of seropositives as Lanka virus infection.

Conclusions/significance

Lanka virus carried by little Indian field mouse (Mus booduga) is transmitted to humans, likely causing febrile illness occasionally while leading to severe disease in some of the febrile patients.

Author summary

Hantaviruses are known to be transmitted by rodents and cause severe diseases such as hemorrhagic fever with renal syndrome (HFRS) in humans. Although there have been few reports of typical HFRS in Sri Lanka, there are many antibody-positive individuals. The antibody positivity rate is particularly high in patients with chronic kidney disease by unknown etiology (CKDu), and the relationship between hantavirus infection and CKDu is being discussed. Meanwhile, rodent surveys have identified Lanka virus in little Indian field mouse (Mus booduga) and Anjozorobe virus in black rat (Rattus rattus) in Sri Lanka. However, it was unclear which virus was infecting the humans and its pathogenicity. This study showed that hantavirus infections in Sri Lanka could be asymptomatic or cause common fever-like symptoms and rarely require treatment in an ICU. It was also shown that the main source of infection is Lanka virus. This study leads us to the starting line of clarifying the Lanka virus-related health risks, such as its association with CKDu.

Source: PLoS Neglected Tropical Diseases, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013169

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Novel #Orthohantavirus Associated with #Hantavirus Pulmonary Syndrome in Northern #Argentina

Abstract

In this work, we performed the genetic characterization of a new variant of orthohantavirus associated with a fatal case of hantavirus pulmonary syndrome, outside the known endemic region, in northwestern Argentina. We first confirmed an orthohantavirus infection by ELISA, testing for the detection of IgM and IgG antibodies. Then, we extracted RNA from 100 microliters of serum, the only sample available, followed by RT-PCR. The amplicons were sequenced using Sanger and next-generation sequencing technology. We obtained partial sequences of 1253 bp, 799 bp and 1675 bp from the S-, M- and L-segments, respectively, showing low sequence identities with all the previously characterized hantaviruses (10.9%, 13.5% and 15.1% of the divergence, respectively). The phylogenetic analysis showed that this virus belongs to the Orthohantavirus andesense species (ANDV), and among the ANDV-like variants, it is more closely related to the Lechiguanas clade. Similar percentages of divergence were considered sufficient to distinguish AND-like variants in previous works. As the patient had no travel history before the onset of disease was reported, we conducted rodent surveys to confirm the presence of reservoirs. The rodent assemblage was compatible with the transitional zone among different ecoregions (Yungas, Chaco and Monte). Moreover, one of the species captured, Oligoryzomys flavescens, was previously described as a reservoir of hantavirus. This species may either host several variants across its range or encompass a species complex, as proposed by some authors.

Source: Viruses, https://www.mdpi.com/1999-4915/17/5/717

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