Explore the vast range of titles available.

Research on morbillivirus infections has led to exciting developments in recent years. Global measles vaccination coverage has increased, resulting in a significant reduction in measles mortality. In 2011 rinderpest virus was declared globally eradicated – only the second virus to be eradicated by targeted vaccination. Identification of new cellular receptors and implementation of recombinant viruses expressing fluorescent proteins in a range of model systems have provided fundamental new insights into the pathogenesis of morbilliviruses, and their interactions with the host immune system. Nevertheless, both new and well-studied morbilliviruses are associated with significant disease in wildlife and domestic animals. This illustrates the need for robust surveillance and a strategic focus on barriers that restrict cross-species transmission. Recent and ongoing measles outbreaks also demonstrate that maintenance of high vaccination coverage for these highly infectious agents is critical. This introduction briefly summarizes the most important current research topics in this field.

Cetacean morbillivirus is an etiologic agent associated with strandings of live and dead cetacean species occurring sporadically or as epizootics worldwide. We report 2 cases of cetacean morbillivirus in humpback whales (Megaptera novaeangliae) in Brazil and describe the anatomopathological, immunohistochemical, and molecular characterization findings in the specimens.

Feline morbillivirus (FeMV) was first isolated in 2012 from stray cats in Hong Kong. It has been found in association with tubulointerstitial nephritis (TIN), the most common cause of feline chronic kidney disease (CKD). However, viral host spectrum and virus tropism go beyond the domestic cat and kidney tissues. The viral genetic diversity of FeMV is extensive, but it is not known if this is clinically relevant. Urine and kidney tissues have been widely tested in attempts to confirm associations between FeMV infection and renal disease, but samples from both healthy and sick cats can test positive and some cross-sectional studies have not found associations between FeMV infection and CKD. There is also evidence for acute kidney injury following infection with FeMV. The results of prevalence studies differ greatly depending on the population tested and methodologies used for detection, but worldwide distribution of FeMV has been shown. Experimental studies have confirmed previous field observations that higher viral loads are present in the urine compared to other tissues, and renal TIN lesions associated with FeMV antigen have been demonstrated, alongside virus lymphotropism and viraemia-associated lymphopenia. Longitudinal field studies have revealed persistent viral shedding in urine, although infection can be cleared spontaneously.

Feline morbillivirus was first identified in healthy and diseased stray cats captured in Hong Kong. Recently, it was demonstrated that the virus circulates within cat populations in Japan, Italy, Germany, and the USA. Importantly, an association between feline morbillivirus infection and chronic kidney disease was suggested by histological analysis of kidney tissue of infected cats. The aim of this study was to verify the presence and examine the genetic diversity of feline morbilliviruses associated with infections of domestic cats in Brazil. Seventeen cats without clinical manifestations of urinary tract diseases from a multi-cat household and 35 random client-owned cats admitted to the Teaching Veterinary Hospital for a variety of reasons were evaluated for paramyxoviral infection and the presence of uropathy. A fragment of the paramyxoviral L gene was amplified from urine samples using a reverse transcription semi-nested PCR assay. For the first time, we detected a feline morbillivirus strain that was genetically related to viral strains previously characterized in Japan in urine samples from cats in South America, in Brazil. This together with the recent description of feline morbillivirus identification within cat populations in the USA, suggests a possible widespread distribution of this viral agent on the American continent. Our data demonstrated feline morbillivirus RNA shedding mostly in the urine of cats without clinical, laboratorial, or ultrasonographic signs of urinary tract diseases. In contrast to previously published findings that associated feline morbillivirus infection with chronic kidney disease, we did not observe a clear relationship between feline morbillivirus RNA shedding in urine and kidney disease in the cats evaluated.

Since 2010, Guiana dolphin morbillivirus (GDMV; family Paramyxoviridae , genus Morbillivirus , species Morbillivirus ceti , syn. Cetacean morbillivirus ) is recognized as the cause of death of multiple cetacean species along the Brazilian coast, including an unusual mortality event in Rio de Janeiro state. Coronaviruses of the genus Gammacoronavirus (family Coronaviridae ) have been previously detected in cetaceans in the northern hemisphere. After the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the COVID-19 pandemic and with the potential to affect several mammal species, there is an increased concern about the risk of infection in aquatic mammals. The goal of this study was to molecularly screen the presence of morbillivirus and coronavirus infections in cetaceans stranded in several regions of the Brazilian coast in order to determine their occurrence rates, pathogenicity, and range of potentially susceptible cetacean species. We molecularly tested tissue samples of 118 cetaceans, belonging to 20 species, found stranded in Brazil, between 2015 and 2022. Overall, 2.5% (3/118) of the analyzed cetaceans were positive for GDMV infection: a Guiana dolphin ( Sotalia guianensis ), an Atlantic spotted dolphin ( Stenella frontalis ), and a humpback whale ( Megaptera novaeangliae ). None of the animals were positive for coronavirus. Our findings indicate that the morbillivirus sequence type identified in Indo-Pacific bottlenose dolphins ( Tursiops aduncus ) of Australia and our GDMV sequences from Brazil belong to the same strain. The systematic monitoring of cetacean morbilliviruses is recommended to properly estimate the occurrence rate, pathogenicity and evolution of these viruses, which may help anticipate novel epizooties and reduce their impact on endangered cetacean populations.

Herpesvirus (HV) is widely distributed among cetacean populations, with the highest prevalence reported in the Mediterranean Sea. In this study, a comprehensive analysis was conducted, including epidemiological, phylogenetic, and pathological aspects, with particular emphasis on neuropathology, to better understand the impact of HV in these animals. Our results show a higher presence of HV in males compared to females, with males exhibiting a greater number of positive tissues. Additionally, adults were more frequently affected by HV infection than juveniles, with no infections detected in calves or neonates. The affected species were striped ( Stenella coeruleoalba ) and bottlenose dolphins ( Tursiops truncatus ). The highest positivity rates were observed in the genital system, cerebrum, and skin tissues. Phylogenetic analysis indicated a higher occurrence of Gammaherpesvirus (GHV) sequences but increased genetic diversity within Alphaherpesvirus (AHV). Key neuropathological features included astro-microgliosis (n = 4) and meningitis with minimal to mild perivascular cuffing (n = 2). The presence of concurrent infections with other pathogens, particularly cetacean morbillivirus (CeMV), underscores the complex nature of infectious diseases in cetaceans. However, the presence of lesions at the Central Nervous System (CNS) with molecular positivity for GHV, excluding the involvement of other potential neurotropic agents, would confirm the potential of this HV subfamily to induce neurological damage. Pathological examination identified lesions in other organs that could potentially be associated with HV, characterized by lymphoid depletion and tissue inflammation. These findings enhance our understanding of HV in odontocetes and highlight the need for ongoing research into the factors driving these infections and their broader implications.

Cetacean morbillivirus (CeMV) drives recurrent unusual‐mortality events, yet surveillance is uneven where laboratory capacity is limited. We developed a portable reverse transcription‐insulated isothermal PCR (RT‐iiPCR) assay targeting a conserved phosphoprotein (P)‐gene segment and evaluated analytical performance, tissue‐level clinical sensitivity, and concordance with reverse transcription‐quantitative PCR (RT‐qPCR) under low‐copy conditions that resemble challenging strandings. Using synthetic RNA, RT‐iiPCR achieved 100% detection from 62,560 to 513 copies µL −1 , and probit analysis estimated a 95% limit of detection (LOD 95 ) of 139 copies µL −1 . Clinical sensitivity was assessed with two spiking regimes (RNA added after or before extraction) in cerebrum and lung. Singleplex RT‐iiPCR maintained 100% positivity to approximately cycle threshold (Ct) 33 irrespective of spiking order, indicating that near‐limit failures are governed by template scarcity rather than extraction loss. Duplex RT‐iiPCR co‐amplifying β2‐microglobulin (B2M) provided process control with a slight sensitivity cost, sustaining perfect detection to ~Ct 30–31. Across low‐copy panels, agreement with RT‐qPCR was substantial (overall κ = 0.68–0.76) and very good in cerebrum (singleplex κ = 0.85; duplex κ = 0.87), while duplex lung showed lower concordance ( κ = 0.55) driven solely by Ct >33 false‐negative calls, with no false positives. The assay detected five lineages (dolphin morbillivirus [DMV], pilot whale morbillivirus [PWMV], beaked whale morbillivirus [BWMV], Guiana DMV [GDMV], and Fraser’s DMV [FDMV]) in formalin‐fixed, paraffin‐embedded tissues archived up to 28 years, and sequence alignments indicate expected coverage of additional lineages. Lyophilized reagents, compact hardware, and a quick, simple workflow support deployment in hot, humid, resource‐limited settings. A strain‐agnostic, field‐ready RT‐iiPCR can underpin transboundary CeMV surveillance, enable rapid carcass triage and sequencing, and provide early warning where diagnostic gaps currently exist.

Morbilliviruses, including measles virus (MV), canine distemper virus (CDV), peste des petits ruminants virus, and cetacean morbillivirus pose a significant threat to humans and animals. While the host range of morbilliviruses is generally well-defined, cross-species transmission events with significant mortality have also been reported. Their entry into immune cells, the primary targets of morbilliviruses, relies on the signaling lymphocytic activation molecule (SLAM), also known as SLAMF1 or CD150. In this study, we hypothesize that the ability of morbilliviruses to utilize heterologous SLAM receptors stems from evolutionarily conserved structural determinants within the SLAM protein and that minimal genetic changes in the viral receptor-binding H protein can enable adaptation to novel hosts. To test this, we systematically assessed SLAM utilization and adaptation by diverse morbilliviruses. We found that most morbilliviruses efficiently utilize SLAM from multiple host species, including Myotis bat SLAM, but not human SLAM. Only MV could efficiently utilize human SLAM. Additionally, unlike other morbilliviruses, MV utilized Myotis bat SLAM inefficiently. As an example of morbillivirus adaptation to non-host animal SLAM, we conducted an MV adaptation experiment with Myotis bat SLAM. We demonstrated that MV readily adapted to utilize Myotis bat SLAM by acquiring a single N187Y mutation in its hemagglutinin protein. Notably, hypothetical ancestral SLAMs acted as universal receptors for all morbilliviruses. These results reinforced that morbillivirus receptor usage is primarily supported by evolutionarily conserved structural features of SLAM, highlighting a molecular basis that enables morbilliviruses to rapidly adapt to diverse animal SLAMs.

Background Cetacean morbillivirus, herpesvirus, avian influenza virus (AIV) and Brucella spp. have been linked to numerous cetacean strandings in the Northeast (NE) Atlantic. Yet, their prevalence in free-living cetaceans remains insufficiently investigated, particularly in northern regions. Methods Between 2016 and 2025, humpback whales ( Megaptera novaeangliae ), sperm whales ( Physeter macrocephalus ) and, opportunistically, fin whales ( Balaenoptera physalus ) and a long-finned pilot whale ( Globicephala melas ), were sampled in two foraging grounds in northern Norway (Skjervøy and Andenes), in Iceland and in Cape Verde. Blow samples ( n  = 76), skin biopsies ( n  = 45), and organ samples from one stranded pilot whale were collected and screened for cetacean morbillivirus, herpesvirus, AIV and Brucella spp, via polymerase chain reaction (PCR). Results In northern Norway, cetacean morbillivirus, identified as the dolphin morbillivirus (DMV) strain, was detected in the blows of two asymptomatic groups of humpback whales, in the blow of one sperm whale in poor health and in the kidney of a stranded pilot whale. An alphaherpesvirus was detected in the blows of five humpback whale groups sampled in Norway, Iceland, and Cape Verde, while a gammaherpesvirus was detected in one humpback whale skin biopsy, sampled in Norway. No other samples tested positive to any of the pathogens, including AIV or Brucella spp. Conclusion Our results demonstrate that minimally invasive sampling, particularly blow sampling, can be used for pathogen surveillance in free-ranging cetaceans. They also provide new insights into the circulation of cetacean morbillivirus and herpesviruses in cetaceans from the NE Atlantic. Continuous monitoring of pathogen exposure, alongside other stressors, will be crucial to assess the cumulative health implications for these cetaceans.

Bats are important reservoirs of paramyxoviruses, yet their role in the evolutionary origins of viruses pertaining to the paramyxoviral genus Morbillivirus , such as measles virus, remains unclear. Here, combining field surveys and data mining, we identified six divergent morbilliviruses by investigating wild bats (38/1,629 RT–PCR-positive) and non-human primates (NHP, 13/1,370 RT–PCR-positive) in Brazil and Costa Rica over 14 years. High morbillivirus concentrations of up to 10 9 RNA copies per g and RNA staining in different organs suggested systemic infection. Of 117 vampire bats, 35.9% had neutralizing antibodies against a primary vampire bat morbillivirus isolate, suggesting frequent non-fatal infections. In vitro assays using bat CD150 for cell entry and partial cross-neutralization of bat-associated morbillivirus by heterologous sera suggested conserved entry and antigenicity. NHP-associated, but not bat-associated morbilliviruses, used human CD150 and nectin-4 cellular receptors, suggesting differential zoonotic potential. Macroevolutionary reconstructions revealed predominance of Neotropical bat hosts during morbilliviral diversification, including bat-associated host shifts into Mexican pigs and Brazilian NHPs. These data argue for increased surveillance, experimental risk assessments and intervention strategies to mitigate risks of reservoir-bound morbilliviruses shifting hosts. Investigations in wild bats and non-human primates in Brazil and Costa Rica inform about diverse Morbillivirus ecology in neotropical bats and host jumps, and about zoonotic potential of morbilliviruses in Latin America.