Despite great progress in decoding disease mechanisms, rabies remains one of the leading causes of human death worldwide. Towards the elimination of human rabies deaths by 2030, feasible and ...affordable post (PEP) and pre-exposure prophylaxis (PrEP) must be available with expansion to rural areas in rabies endemic countries. Vaccination and population control of dogs, principal reservoirs and transmitters, must be done in concert.
Advances in the understanding of rabies neuropathogenesis and pathophysiology are reviewed, including recent experimental findings on host- and virus-specific mechanisms mediating neuronal survival and explaining clinical differences in furious and paralytic rabies. The forthcoming World Health Organization guide on rabies based on pathogenesis and immunization mechanisms data with support by clinical evidence provide new accelerated 1 week intradermal PrEP and PEP schedules. Rabies immunoglobulin injected into the wound only is endorsed at amounts not exceeding the dose interfering with active immunization. Potential therapeutics as designed in accord with rabies neuro-pathophysiology are plausible.
Clinical practice and rabies awareness can be leveraged by transboundary collaboration among different areas. Advancement in prophylaxis and perspectives on animal control offer a new path to conquer rabies by 2030.
Recent ecological theories propose that species reach their highest abundance and genetic diversity in the center of their ecological niche and decline toward the edges. We assessed whether Lyle's ...flying fox, Pteropus lylei, abundance and genetic diversity were correlated with niche centroid distance using an ecological niche model as a proxy for fundamental niche (NF). Alternatively, we assessed whether P. lylei abundance and genetic diversity were correlated with fine‐scale environmental factors as a proxy of the species’ realized niche (NR). We examined relationships between abundance and environmental factors at coarse and fine scales as proxies of NF and NR, respectively. For coarse scale, ecological niche of P. lylei was modeled using all available occurrence records in Thailand, Cambodia, and Vietnam, coupled with climatic data. We conducted field measurements of P. lylei abundance and used genetic structure data across a large portion of the species’ range. We measured Euclidean distances between abundance and genetic data and the niche centroid in environmental dimensions. Spearman’s correlation was estimated between abundance and genetic diversity vs. distance to the niche centroid. Complementarily, for the fine‐scale test, we measured multiple regression models between abundance and genetic diversity versus the normalized difference vegetation index (NDVI), local temperature, percent area of waterbodies, human density, and number of Buddhist temples. We failed to detect relationships between abundance and genetic diversity with the distance to the niche centroid in the coarse‐scale model. When using the fine‐scale, landscape‐level data, we found negative correlation between genetic diversity and number of temples. The data available were unable to support niche centroid hypothesis for the current distribution and abundances of P. lylei. We note that our failure to find an association does not support nor reject the niche centroid hypothesis. Instead, our capacity to test the niche centroid hypothesis may be limited by our ability to use empirical data to accurately reconstruct NF from field observations only. Future research may require physiology‐based experimental approaches to explore relationships between species abundances and the niche structure.
The association between patch metrics and roosting site (n = 31) suitability of Lyle’s flying fox (
) in 26 Central Eastern and Western provinces of Thailand was quantified. Land use classes with ...90-m resolution were identified based on various vegetation and land cover types to calculate patch metrics using FRAGSTATS. Then, Maximum Entropy Modeling (MaxEnt) was performed using patch metrics covariates to produce a predictive potential distribution map. The results indicated that patch contiguity (contiguity index, 63.7%), patch area (29.3%), and patch shape complexity (shape index, 5.7%) are the most influential patch metrics, all of which have negative effects on roosting site suitability. In total, 13,222 small patches were considered highly suitable patches, with a mean area of 0.921 ± 0.698 (SD) ha, which accounted for 122,090 ha (2.04%) of the study area. Roosting sites predicted from the model were consistently associated with occurrences of roosting sites observed in temples; such habitats likely provide shelter from external threats for colonies roosting in a human-dominated landscape.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
Background
Nipah virus (NiV) infection causes encephalitis and has > 75% mortality rate, making it a WHO priority pathogen due to its pandemic potential. There have been NiV outbreak(s) in ...Malaysia, India, Bangladesh, and southern Philippines. NiV naturally circulates among fruit bats of the genus
Pteropus
and has been detected widely across Southeast and South Asia. Both Malaysian and Bangladeshi NiV strains have been found in fruit bats in Thailand. This study summarizes 20 years of pre-emptive One Health surveillance of NiV in Thailand, including triangulated surveillance of bats, and humans and pigs in the vicinity of roosts inhabited by NiV-infected bats.
Methods
Samples were collected periodically and tested for NiV from bats, pigs and healthy human volunteers from Wat Luang village, Chonburi province, home to the biggest
P. lylei
roosts in Thailand, and other provinces since 2001. Archived cerebrospinal fluid specimens from encephalitis patients between 2001 and 2012 were also tested for NiV. NiV RNA was detected using nested reverse transcription polymerase chain reaction (RT-PCR). NiV antibodies were detected using enzyme-linked immunosorbent assay or multiplex microsphere immunoassay.
Results
NiV RNA (mainly Bangladesh strain) was detected every year in fruit bats by RT-PCR from 2002 to 2020. The whole genome sequence of NiV directly sequenced from bat urine in 2017 shared 99.17% identity to NiV from a Bangladeshi patient in 2004. No NiV-specific IgG antibodies or RNA have been found in healthy volunteers, encephalitis patients, or pigs to date. During the sample collection trips, 100 community members were trained on how to live safely with bats.
Conclusions
High identity shared between the NiV genome from Thai bats and the Bangladeshi patient highlights the outbreak potential of NiV in Thailand. Results from NiV cross-sectoral surveillance were conveyed to national authorities and villagers which led to preventive control measures, increased surveillance of pigs and humans in vicinity of known NiV-infected roosts, and increased vigilance and reduced risk behaviors at the community level. This proactive One Health approach to NiV surveillance is a success story; that increased collaboration between the human, animal, and wildlife sectors is imperative to staying ahead of a zoonotic disease outbreak.
Abstract Epidemiological studies in Thailand have reported that inflammatory demyelinating diseases (IDDs) commonly affect the optic nerve and spinal cord. We investigated the diagnostic utility of ...aquaporin (AQP)-4-IgG testing in 31 consecutive patients evaluated for CNS IDDs in 3 academic Thai hospital neurology clinics between February 2008 and January 2009. Patients were classified into 3 clinical diagnostic groups: Neuromyelitis optica (NMO, n = 10) multiple sclerosis (MS, n = 5) and unclassified IDD (n = 16). All sera were tested blindly by cell binding (Euroimmun) assay (CBA). Sera were also tested by indirect immunofluorescence assay (IFA) and ELISA (RSR/Kronus). After initial screening by CBA, AQP4-IgG was detected in 6 NMO patients (60%); 3 of the 4 seronegative cases were receiving immunosuppressants. AQP4-IgG was detected in 13 unclassified IDD cases (81%), but in no MS cases. Cell binding assay and ELISA were more sensitive than IFA (p = 0.0004). The 81% seropositivity rate in “unclassified” patients suggests that AQP4 autoimmunity accounts for a significant proportion of Thai CNS inflammatory demyelinating disease, especially those with optic neuritis or transverse myelitis, with or without abnormal brain MRI, in whom a specific diagnosis or clear-cut treatment approach is unclear.
In resource-limited countries, early detection of novel pathogens is often challenging, due to financial and technical constraints. This study reports the efficacy of family-wide polymerase chain ...reaction (PCR) in screening, detecting, and identifying initial cases of the novel SARS-CoV-2 in Thailand. Respiratory secretions were collected from suspected individuals traveling from Wuhan, China to Thailand at the beginning of January 2020. Family-wide PCR assays yielded positive results for coronavirus in one traveler within 12 h on January 8, 2020. Nucleotide sequences (290 bp) showed 100% similarity to SARS-CoV-2. The whole genome sequence was further characterized by Next Generation Sequencing (NGS) for confirmation. Combining family-wide PCR, as a rapid screening tool, with NGS, for full genome characterization, could facilitate early detection and confirmation of a novel pathogen and enable early containment of a disease outbreak.
Whereas paralysis is the hallmark for paralytic rabies, the precise pathological basis of paralysis is not known. It is unclear whether weakness results from involvement of anterior horn cells or of ...motor nerve fibers. There is also no conclusive data on the cause of the neuropathic pain which occurs at the bitten region, although it has been presumed to be related to sensory ganglionopathy. In this study, six laboratory-proven rabies patients (three paralytic and three furious) were assessed clinically and electrophysiologically. Our data suggests that peripheral nerve dysfunction, most likely demyelination, contributes to the weakness in paralytic rabies. In furious rabies, progressive focal denervation, starting at the bitten segment, was evident even in the absence of demonstrable weakness and the electrophysiologic study suggested anterior horn cell dysfunction. In two paralytic and one furious rabies patients who had severe paresthesias as a prodrome, electrophysiologic studies suggested dorsal root ganglionopathy. Postmortem studies in two paralytic and one furious rabies patients, who had local neuropathic pain, showed severe dorsal root ganglionitis. Intense inflammation of the spinal nerve roots was observed more in paralytic rabies patients. Inflammation was mainly noted in the spinal cord segment corresponding to the bite in all cases; however, central chromatolysis of the anterior horn cells could be demonstrated only in furious rabies patient. We conclude that differential sites of neural involvement and possibly different neuropathogenetic mechanisms may explain the clinical diversity in human rabies.
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