Human metapneumovirus infection in chimpanzees, United States

Zoonotic Origins of Human Metapneumovirus: A Journey from Birds to Humans

Metapneumoviruses, members of the family Pneumoviridae, have been identified in birds (avian metapneumoviruses; AMPV’s) and humans (human metapneumoviruses; HMPV’s). AMPV and HMPV are closely related viruses with a similar genomic organization and cause respiratory tract illnesses in birds and humans, respectively. AMPV can be classified into four subgroups, A–D, and is the etiological agent of turkey rhinotracheitis and swollen head syndrome in chickens. Epidemiological studies have indicated that AMPV also circulates in wild bird species which may act as reservoir hosts for novel subtypes. HMPV was first discovered in 2001, but retrospective studies have shown that HMPV has been circulating in humans for at least 50 years. AMPV subgroup C is more closely related to HMPV than to any other AMPV subgroup, suggesting that HMPV has evolved from AMPV-C following zoonotic transfer. In this review, we present a historical perspective on the discovery of metapneumoviruses and discuss the host tropism, pathogenicity, and molecular characteristics of the different AMPV and HMPV subgroups to provide increased focus on the necessity to better understand the evolutionary pathways through which HMPV emerged as a seasonal endemic human respiratory virus.

EVALUATING THE EFFICACY OF HUMAN BRONCHIECTASISBASED ANTIBIOTIC THERAPY IN THE TREATMENT OF ORANGUTAN RESPIRATORY DISEASE SYNDROME

Unique among apes, orangutans (Pongo spp.) develop a chronic respiratory disease called orangutan respiratory disease syndrome (ORDS). The authors define ORDS as intermittent bacterial infection and chronic inflammation of any region or combination of regions of the respiratory tract, including the sinuses, air sacs, cranial bones, airways, and lung parenchyma. Infection in any of these areas can present acutely but then becomes recurrent, chronic, progressive, and ultimately fatal. The closest model to this disease is cystic fibrosis (CF) in people. We hypothesized that use of a 4-8-wk course of combined oral antibiotics used in the treatment of bronchiectasis in CF patients would lead to prolonged symptomatic and computed tomography (CT) scan improvement in orangutans experiencing early signs of ORDS. Nine adult Bornean orangutans (Pongo pygmaeus, eight males, one female, 18-29 yr of age) diagnosed with early ORDS-like respiratory disease underwent CT scan before initiation of treatment. Each animal received a combined course of azithromycin (400 mg 3/wk, mean 7 mg/kg) and levofloxacin (500 mg PO q24h, mean 8.75 mg/kg) for a period of 4-8 wk. CT scan was repeated 6-14 mon after completion of antibiotic treatment. Pretreatment CT showed that six of nine animals had lower respiratory pathology (airway disease, pneumonia, or both). All six orangutans had concurrent sinusitis, mastoiditis, airsacculitis, or a combination of these conditions. Upper respiratory disease alone was observed in three animals. CT showed improvement or resolution in four of five sinusitis cases, improvement in one of two instances of mastoiditis, resolution in five of six instances of airsacculitis, improvement or resolution in six of six instance of lower airway disease (P = 0.03, 95% CI 0.54-1.0], and resolution in five of five cases of pneumonia. Resolution of pretreatment clinical signs was observed in all nine animals. Two developed signs not present at pretreatment. These results show that combination antibiotic therapy with azithromycin and levofloxacin provides improvement in clinical signs and CT evidence of ORDS-related pathology, resulting in symptom-free status in some animals for up to 33 mon.

Respiratory Disease Risk of Zoo-Housed Bonobos Is Associated with Sex and Betweenness Centrality in the Proximity Network

Infectious diseases can be considered a threat to animal welfare and are commonly spread through both direct and indirect social interactions with conspecifics. This is especially true for species with complex social lives, like primates. While several studies have investigated the impact of sociality on disease risk in primates, only a handful have focused on respiratory disease, despite it being a major cause of morbidity and mortality in both wild and captive populations and thus an important threat to primate welfare. Therefore, we examined the role of social-network position on the occurrence of respiratory disease symptoms during one winter season in a relatively large group of 20 zoo-housed bonobos with managed fission-fusion dynamics. We found that within the proximity network, symptoms were more likely to occur in individuals with higher betweenness centrality, which are individuals that form bridges between different parts of the network. Symptoms were also more likely to occur in males than in females, independent of their social-network position. Taken together, these results highlight a combined role of close proximity and sex in increased risk of attracting respiratory disease, two factors that can be taken into account for further welfare management of the species.

Endangered mountain gorillas and COVID-19: One health lessons for prevention and preparedness during a global pandemic

The world's 1063 mountain gorillas (Gorilla beringei beringei) live in two subpopulations at the borders of the Democratic Republic of Congo, Rwanda, and Uganda. The majority of mountain gorillas are human-habituated to facilitate tourism and research, which brings mountain gorillas into close proximity of people daily. Wild great apes are proven to be susceptible to human pathogens, including viruses that have caused fatal respiratory disease in mountain gorillas (e.g., human metapneumovirus¹ ). This is the result of the close genetic relatedness of humans and gorillas as species, and the structural and genetic similarity in molecular receptors that allow viruses to infect cells² . At the time of writing, there is no evidence that severe acute respiratory syndrome coronavirus 2, the coronavirus that causes coronavirus disease 19 (COVID-19), has infected a mountain gorilla. However, due to the significant potential for human-to-gorilla transmission, mountain gorilla range States took immediate steps to minimize the COVID-19 threat. These actions included a combination of preventive practice around gorillas and other great apes (e.g., mandatory face mask use, increased "social" minimum distancing from gorillas) as well as human public health measures (e.g., daily health/fever screenings, COVID-19 screening, and quarantines). Minimization of the COVID-19 threat also required socioeconomic decision-making and political will, as all gorilla tourism was suspended by late March 2020 and guidelines developed for tourism reopening. A consortium that collaborates and coordinates on mountain gorilla management and conservation, working within an intergovernmental institutional framework, took a multifaceted One Health approach to address the COVID-19 threat to mountain gorillas by developing a phased contingency plan for prevention and response. The aim of this paper is to describe how range States and partners achieved this collaborative planning effort, with intent that this real-world experience will inform similar actions at other great ape sites.

Human Metapneumovirus Infection and Genotyping of Infants in Rural Nepal

BACKGROUND

Acute respiratory tract infections are a serious clinical burden in infants; human metapneumovirus (HMPV) is an important etiological agent. We investigated genotypic variation and molecular epidemiological patterns among infants infected with HMPV in Sarlahi, Nepal, to better characterize infection in a rural, low-resource setting.

METHODS

Between May 2011 and April 2014, mid-nasal swabs were collected from 3528 infants who developed respiratory symptoms during a longitudinal maternal influenza vaccine study. Sequencing glycoprotein genes permitted genotyping and analyses among subtypes.

RESULTS

HMPV was detected by reverse-transcriptase polymerase chain reaction (RT-PCR) in 187 (5%) infants, with seasonality observed during fall and winter months. Phylogenetic investigation of complete and partial coding sequences for the F and G genes, respectively, revealed that 3 genotypes were circulating: A2, B1, and B2. HMPV-B was most frequently detected with a single type predominating each season. Both HMPV genotypes exhibited comparable median viral loads. Clinically significant differences between genotypes were limited to increased cough duration and general respiratory symptoms for type B.

CONCLUSIONS

In rural Nepal, multiple HMPV genotypes circulate simultaneously with an alternating predominance of a single genotype and definitive seasonality. No difference in viral load was detected by genotype and symptom severity was not correlated with RT-PCR cycle threshold or genotype.

While We Endure This Pandemic, What New Respiratory Virus Threats Are We Missing?

In this paper, we review recent human respiratory virus epidemics, their zoonotic nature, and our current inability to identify future prepandemic threats. We propose a cost-efficient, One Health surveillance strategy that will be more efficient and more sustainable than previous efforts.

Human Respiratory Syncytial Virus Detected in Mountain Gorilla Respiratory Outbreaks

Respiratory illness (RI) accounts for a large proportion of mortalities in mountain gorillas (Gorilla beringei beringei), and fatal outbreaks, including disease caused by human metapneumovirus (HMPV) infections, have heightened concern about the risk of human pathogen transmission to this endangered species, which is not only critically important to the biodiversity of its ecosystem but also to the economies of the surrounding human communities. Our goal was to conduct a molecular epidemiologic study to detect the presence of HRSV and HMPV in fecal samples from wild human-habituated free-ranging mountain gorillas in Rwanda and to evaluate the role of these viruses in RI outbreaks. Fecal samples were collected from gorillas with clinical signs of RI between June 2012 and February 2013 and tested by real-time and conventional polymerase chain reaction (PCR) assays; comparison fecal samples were obtained from gorillas without clinical signs of RI sampled during the 2010 Virunga gorilla population census. PCR assays detected HMPV and HRSV first in spiked samples; subsequently, HRSV-A, the worldwide-circulating ON1 genotype, was detected in 12 of 20 mountain gorilla fecal samples collected from gorillas with RI during outbreaks, but not in samples from animals without respiratory illness. Our findings confirmed that pathogenic human respiratory viruses are transmitted to gorillas and that they are repeatedly introduced into mountain gorilla populations from people, attesting to the need for stringent biosecurity measures for the protection of gorilla health.

Pathogen Transmission from Humans to Great Apes is a Growing Threat to Primate Conservation

All six great ape species are listed as endangered or critically endangered by the IUCN and experiencing decreasing population trends. One of the threats to these non-human primates is the transmission of pathogens from humans. We conducted a literature review on occurrences of pathogen transmission from humans to great apes to highlight this often underappreciated issue. In total, we found 33 individual occurrences of probable or confirmed pathogen transmission from humans to great apes: 23 involved both pathogen and disease transmission, 7 pathogen transmission only, 2 positive antibody titers to zoonotic pathogens, and 1 pathogen transmission with probable disease. Great ape populations were categorized into captive, semi-free-living, and free-living conditions. The majority of occurrences involved chimpanzees (Pan troglodytes) (n = 23) or mountain gorillas (Gorilla beringei beringei) (n = 8). These findings have implications for conservation efforts and management of endangered great ape populations. Future efforts should focus on monitoring and addressing zoonotic pathogen and disease transmission between humans, great ape species, and other taxa to ensure the health of humans, wild and domestic animals, and the ecosystems we share.

Evidence for Human Streptococcus pneumoniae in wild and captive chimpanzees: A potential threat to wild populations

Habituation of wild great apes for tourism and research has had a significant positive effect on the conservation of these species. However, risks associated with such activities have been identified, specifically the transmission of human respiratory viruses to wild great apes, causing high morbidity and, occasionally, mortality. Here, we investigate the source of bacterial-viral co-infections in wild and captive chimpanzee communities in the course of several respiratory disease outbreaks. Molecular analyses showed that human respiratory syncytial viruses (HRSV) and human metapneumoviruses (HMPV) were involved in the etiology of the disease. In addition our analysis provide evidence for coinfection with Streptococcus (S.) pneumoniae. Characterisation of isolates from wild chimpanzees point towards a human origin of these bacteria. Transmission of these bacteria is of concern because - in contrast to HRSV and HMPV - S. pneumoniae can become part of the nasopharyngeal flora, contributing to the severity of respiratory disease progression. Furthermore these bacteria have the potential to spread to other individuals in the community and ultimately into the population. Targeted vaccination programs could be used to vaccinate habituated great apes but also human populations around great ape habitats, bringing health benefits to both humans and wild great apes.

Codetection of Respiratory Syncytial Virus in Habituated Wild Western Lowland Gorillas and Humans During a Respiratory Disease Outbreak

Pneumoviruses have been identified as causative agents in several respiratory disease outbreaks in habituated wild great apes. Based on phylogenetic evidence, transmission from humans is likely. However, the pathogens have never been detected in the local human population prior to or at the same time as an outbreak. Here, we report the first simultaneous detection of a human respiratory syncytial virus (HRSV) infection in western lowland gorillas (Gorilla gorilla gorilla) and in the local human population at a field program in the Central African Republic. A total of 15 gorilla and 15 human fecal samples and 80 human throat swabs were tested for HRSV, human metapneumovirus, and other respiratory viruses. We were able to obtain identical sequences for HRSV A from four gorillas and four humans. In contrast, we did not detect HRSV or any other classic human respiratory virus in gorilla fecal samples in two other outbreaks in the same field program. Enterovirus sequences were detected but the implication of these viruses in the etiology of these outbreaks remains speculative. Our findings of HRSV in wild but human-habituated gorillas underline, once again, the risk of interspecies transmission from humans to endangered great apes.

[Metapneumovirus infection in an adult]

The paper briefly characterizes human metapneumovirus, a newly discovered pathogen of acute respiratory infections, and gives brief clinical, virological, and pathological data concerning a fatal outcome of a 51-year-old obese woman without severe background pathology. Metapneumovirus infection has been verified by real-time PCR. Morphological examination revealed the signs of subtotal diffuse alveolar damage, ciliary epithelial cell overgrowths, and binucleated macrophages. The changes revealed in the lungs are similar to those as previously described in paramyxovirus infections, but are accompanied by severe nonspecific changes that have been recently observed in swine influenza. Those in the brain meninges, kidneys, pancreas, and intestine may be suggestive of the generalization of the infection. It has been proposed that the properties of the virus may vary.

Genome-Wide Analysis of Human Metapneumovirus Evolution

Human metapneumovirus (HMPV) has been described as an important etiologic agent of upper and lower respiratory tract infections, especially in young children and the elderly. Most of school-aged children might be introduced to HMPVs, and exacerbation with other viral or bacterial super-infection is common. However, our understanding of the molecular evolution of HMPVs remains limited. To address the comprehensive evolutionary dynamics of HMPVs, we report a genome-wide analysis of the eight genes (N, P, M, F, M2, SH, G, and L) using 103 complete genome sequences. Phylogenetic reconstruction revealed that the eight genes from one HMPV strain grouped into the same genetic group among the five distinct lineages (A1, A2a, A2b, B1, and B2). A few exceptions of phylogenetic incongruence might suggest past recombination events, and we detected possible recombination breakpoints in the F, SH, and G coding regions. The five genetic lineages of HMPVs shared quite remote common ancestors ranging more than 220 to 470 years of age with the most recent origins for the A2b sublineage. Purifying selection was common, but most protein genes except the F and M2-2 coding regions also appeared to experience episodic diversifying selection. Taken together, these suggest that the five lineages of HMPVs maintain their individual evolutionary dynamics and that recombination and selection forces might work on shaping the genetic diversity of HMPVs.