Epidemiology, Haemato-biochemical and Pathological Changes Related to Field Outbreaks of PPR in Small Ruminants in Odisha

Background: Odisha experiencing sporadic outbreaks of Peste des petits ruminants (PPR) throughout the year. There is a scarcity of available literature on PPR in Odisha till today. This is the first ever detail investigative approach in the state undertaken with an objective to corelate the epidemiological risk factors, haemato-biochemical and pathological changes in natural field outbreaks occurring in eight different districts. Methods: Fourteen field outbreaks of PPR were evaluated clinically as well as epidemiologically and confirmed through polymerase chain reaction (PCR). Blood, serum, faecal and tissue samples were collected to observe haemato-biochemical and pathomorphological changes to asses disease severity. Result: Present study concluded an overall mortality rate of 46.81%. Chi-square analysis revealed significant highest prevalence among 7-12 months (46.13%) age, Ganjam breed (45.51%) and females (80.49%). Frequent migration among the border areas along with poor management and helminthic infection was major precipitating factor. There was polycythemia along with neutrophilia and lymphopenia. Significant increase in alanine transaminase (ALT), aspartate aminotransferase (AST), K+ and Ca+2 along with creatinine, urea and blood urea nitrogen (BUN) BUN was observed in affected flocks. Antero-ventral consolidation of lungs, syncytia and presence of both eosinophilic intranuclear and intracytoplasmic inclusion bodies were major pathological changes.

The Investigation of Canine Distemper Virus in Different Diagnosis Materials of Dogs using Molecular and Pathological Methods, Northeastern Turkey

Background: Canine distemper virus (CDV) is highly contagious disease that affects dogs despite several control measures. This study was aimed at investigating the presence of CDV nucleic acid in different clinical and tissue materials, from naturally infected dogs, by reverse transcriptase-polymerase chain reaction (RT-PCR) and to molecularly characterize distemper strains according to the partial Nucleoprotein (NP) gene sequence. Furthermore, tissue samples under went histopathological examination for distemper infection. Methods: A total of 202 different diagnosis materials were collected from dogs (n=60) in the Kars region in northeastern Turkey. The samples were tested for CDV using RT-PCR with primers designed for the CDV NP gene. Samples determined as positive for CDV (n=7) were sequenced. Tissue samples underwent histopathological examination. Result: Most of the cases were in animals aged 0-6 months. The most common clinical finding was severe respiratory system infection. This finding was accompanied by gastrointestinal and nervous system infections. CDV nucleic acid was detected in 112 of 202 materials by RT-PCR. According to RT-PCR results, positivity rates of 88.2% (30/34), 72.2% (13/18), 60% (3/5), 55.5% (10/18), 55.5% (10/18), 51.6% (16/31), 45.5% (5/11), 37.8% (14/37) and 36.7% (11/30) were detected in nasal swab, lung, footpad, kidney, spleen, rectal swab, cerebrospinal fluids (CSF), leuokocyte and cerebellum samples, respectively. Viral nucleic acids were detected at higher rates in nasal swabs. The phylogenetic assessment of the amplicon sequences revealed a 97.7%-100% similarity among the Turkish CDV strains, which are independent from vaccine strains, were found to be more closely related to the European lineage. Intranuclear and intracytoplasmic inclusion bodies were detected by histopathology. This is the first study to investigate CDV in naturally infected dogs from northeastern Turkey and to provide novel and updated epidemiological information.

Infection of Tilapia tilapinevirus in Mozambique Tilapia (Oreochromis mossambicus), a Globally Vulnerable Fish Species

Tilapia tilapinevirus, or tilapia lake virus (TiLV), is a highly contagious virus found in tilapia and its hybrid species that has been reported worldwide, including in Asia, the Americas, and Africa. In this study, we experimentally challenged Mozambique tilapia (Oreochromis mossambicus) with a virulent TiLV strain, VETKU-TV01, at both low (1 × 103 TCID50/mL) and high (1 × 105 TCID50/mL) concentration. After the challenge, the Mozambique tilapia showed pale skin with some hemorrhage and erosion, lethargy, abdominal swelling, congestion around the eye, and exophthalmos; there was a cumulative mortality rate at 48.89% and 77.78% in the groups that received the low and high concentration, respectively. Quantitative PCR and in situ hybridization confirmed the presence of TiLV in the internal organs of moribund fish. Notably, severe histopathological changes, including glycogen depletion, syncytial hepatic cells containing multiple nuclei and intracytoplasmic inclusion bodies, and infiltration of melanomacrophage into the spleen, were frequently found in the Mozambique tilapia challenged with high TiLV concentration. Comparatively, the infectivity and pathology of the TiLV infection in Mozambique tilapia and red hybrid tilapia (Oreochromis spp.) were found to be similar. Our results confirmed the susceptibility of Mozambique tilapia, which has recently been determined to be a vulnerable species, to TiLV infection, expanding knowledge that the virus can cause disease in this fish species.

Investigation of Lethal Concurrent Outbreak of Chlamydiosis and Pigeon Circovirus in a Zoo

During the spring, an outbreak of sudden death involving 58 birds occurred in a zoo. Histopathological examinations revealed variable numbers of intracytoplasmic basophilic microorganisms in the macrophages, hepatocytes, and renal epithelium of most birds, along with occasional botryoid intracytoplasmic inclusion bodies within histiocytes in the bursa of Fabricius. Based on the results of histopathological examinations, immunohistochemical staining, transmission electron microscopy, and polymerase chain reactions, genotype B Chlamydia psittaci infection concurrent with pigeon circovirus (PiCV) was diagnosed. A retrospective survey, including two years before the outbreak and the outbreak year, of C. psittaci and PiCV infections of dead birds in the aviaries, revealed that the outbreak was an independent episode. The findings of this study indicate that concurrent infection with C. psittaci and PiCV might lead to lethal outbreaks of chlamydiosis, particularly Streptopelia orientalis. In addition, persistently monitoring both pathogens and identifying potential PiCV carriers or transmitters might also help prevent lethal disease outbreaks.

Co-Infections of Tilapia Lake Virus, Aeromonas hydrophila and Streptococcus agalactiae in Farmed Red Hybrid Tilapia

A high death rate among red hybrid tilapias was observed in a farm in Selangor, Malaysia, in January 2020. The affected fish appeared lethargic, isolated from schooling group, showed loss of appetite, red and haemorrhagic skin, exophthalmia and enlarged gall bladders. Histopathological assessment revealed deformation of kidney tubules, and severe congestion with infiltrations of inflammatory cells in the brains and kidneys. Syncytial cells and intracytoplasmic inclusion bodies were occasionally observed in the liver and brain sections. Tilapia Lake Virus (TiLV), Aeromonas hydrophila and Streptococcus agalactiae were identified in the affected fish, either through isolation or through PCR and sequencing analysis. The phylogenetic tree analysis revealed that the TiLV strain in this study was closely related to the previously reported Malaysian strain that was isolated in 2019. On the other hand, A. hydrophila and S. agalactiae were closer to Algerian and Brazilian strains, respectively. The multiple antibiotic resistance index for A. hydrophila and S. agalactiae was 0.50 and 0.25, respectively. Co-infections of virus and bacteria in cultured tilapia is a new threat for the tilapia industry.

Lumpy Skin Disease Is Characterized by Severe Multifocal Dermatitis With Necrotizing Fibrinoid Vasculitis Following Experimental Infection

Lumpy skin disease is a high-consequence disease in cattle caused by infection with the poxvirus lumpy skin disease virus (LSDV). The virus is endemic in most countries in Africa and an emerging threat to cattle populations in Europe and Asia. As LSDV spreads into new regions, it is important that signs of disease are recognized promptly by animal caregivers. This study describes the gross, microscopic, and ultrastructural changes that occur over time in cattle experimentally challenged with LSDV. Four calves were inoculated with wildtype LSDV and monitored for 19 to 21 days. At 7 days after inoculation, 2 of the 4 cattle developed multifocal cutaneous nodules characteristic of LSD. Some lesions displayed a targetoid appearance. Histologically, intercellular and intracellular edema was present in the epidermis of some nodules. Occasional intracytoplasmic inclusion bodies were identified in keratinocytes. More severe and consistent changes were present in the dermis, with marked histiocytic inflammation and necrotizing fibrinoid vasculitis of dermal vessels, particularly the deep dermal plexus. Chronic lesions consisted of full-thickness necrosis of the dermis and epidermis. Lesions in other body organs were not a major feature of LSD in this study, highlighting the strong cutaneous tropism of this virus. Immunohistochemistry and electron microscopy identified LSDV-infected histiocytes and fibroblasts in the skin nodules of affected cattle. This study highlights the noteworthy lesions of LSDV and how they develop over time.

A Protein Epitope Targeted by the Antibody Response to Kawasaki Disease

Background Kawasaki disease (KD) is the leading cause of childhood acquired heart disease in developed nations and can result in coronary artery aneurysms and death. Clinical and epidemiologic features implicate an infectious cause but specific antigenic targets of the disease are unknown. Peripheral blood plasmablasts are normally highly clonally diverse but the antibodies they encode are approximately 70% antigen-specific 1–2 weeks after infection. Methods We isolated single peripheral blood plasmablasts from children with KD 1–3 weeks after onset and prepared 60 monoclonal antibodies (mAbs). We used the mAbs to identify their target antigens and assessed serologic response among KD patients and controls to specific antigen. Results Thirty-two mAbs from 9 of 11 patients recognize antigen within intracytoplasmic inclusion bodies in ciliated bronchial epithelial cells of fatal cases. Five of these mAbs, from 3 patients with coronary aneurysms, recognize a specific peptide, which blocks binding to inclusion bodies. Sera from 5/8 KD patients day ≥ 8 after illness onset, compared with 0/17 infant controls (P < .01), recognized the KD peptide antigen. Conclusions These results identify a protein epitope targeted by the antibody response to KD and provide a means to elucidate the pathogenesis of this important worldwide pediatric problem.

1876. A Hepacivirus-Like Protein Is Targeted by the Antibody Response to Kawasaki Disease (KD)

Background Clinical and epidemiologic data support a viral cause of KD, but the etiology has eluded 50 years of study. We previously identified virus-like intracytoplasmic inclusion bodies (ICI) in ciliated bronchial epithelium of KD children but not infant controls, but the antigens within the ICI were unknown. At 1–2 weeks following infection, 75% of peripheral blood plasmablasts (PB) specifically target the infectious agent. We cloned the PB response to KD to identify KD-specific antibodies and their target antigens. Methods We isolated single PB from children with KD 1–3 weeks after fever onset by flow cytometry, and amplified immunoglobulin VDJ and VJ genes from each PB by RT-PCR. We sequenced the products and made monoclonal antibodies (Mab) from clonally expanded PB in individual patients. Mab were tested for binding to KD tissues and to a viral peptide array containing 29,939 peptides from known B cell epitopes of animal viruses (www.iedb.org). Results We sequenced 1156 PB from 11 KD patients, and identified 44 clonally expanded sets of PB. We prepared 61 Mab from clonally expanded and highly mutated IgA PB, and found that 33/61 bind to KD ICI, 10 strongly and 23 weakly. Of 10 Mab that strongly bind, 2 were VH3-33 (single patient), 2 VH3-23 (single patient), 1 VH3-15, 1 VH3-74, 3 VH1-46 (2 patients), and 1 VH4-59. These Mab CDR3s varied from 11 to 20 aacids, with 4–28 aacid mutations. Mab KD4-2H4 recognized multiple similar peptides from nonstructural protein 4A of hepacivirus C; pt KD4 sera was negative for hepatitis C by fourth-generation ELISA. Amino acid substitution analysis yielded an optimized peptide, and 6 KD Mab recognized this peptide by ELISA. These 6 Mab derived from 3 KD patients, all of whom had coronary aneurysms, and were VH3-74 (n = 1), VH3-33 (n = 2, single patient), VH1-45 (n = 1), and VH3-72 (n = 2, single patient). Strong binding of KD Mab KD4-2H4 and KD6-2B2 to ICI was totally blocked by pre-incubation with optimized peptide. KD but not control sera react with optimized peptide expressed as a glutathione S-transferase fusion protein by western blot. Conclusion Children with KD make antibodies to a hepacivirus-like protein, and KD ICI contain this protein. These results strongly suggest that a previously unidentified hepacivirus with a respiratory portal of entry is etiologically related to KD. Disclosures All Authors: No reported Disclosures.

Identification and phylogenetic analysis of clade C Avipoxvirus in a fowlpox outbreak in exotic psittacines in southern Brazil

Fowlpox is one of the oldest diseases reported in birds. The causative genus Avipoxvirus affects ~232 domestic and wild species. We present herein the history, clinical findings, and macroscopic and histologic lesions caused by a clade C poxvirus in an exotic psittacine breeding colony in southern Brazil. Clinical signs included yellow nodular lesions at the commissure of the beak and on the periocular skin, loss of appetite, and death. Fifty birds were autopsied, and fragments of periocular skin, tongue, and trachea were examined histologically, which revealed hyperkeratosis associated with eosinophilic intracytoplasmic inclusion bodies. Tracheal fragments and periocular skin were subjected to nested PCR and phylogenetic analyses. The sequenced strain showed 99.58% identity with the nucleotide sequences of Avipoxvirus strains AY53011, KC018069, AM050383, and AM05382 isolated from birds in Germany, United States, and United Kingdom. The strain was grouped under clade C, which represents isolates exclusively from the Psittacidae family. The infection caused by clade C Avipoxvirus in the exotic psittacines examined ( Platycercus sp. and Psephotus haematonotus) demonstrates the circulation of this clade in this breeding colony.