Pathological and Immunohistochemical Study of Experimental Peste Des Petits Ruminants Virus Infection in Goats

Abstract

Peste des petits ruminants (PPR) is an emerging, economically important viral disease of goats and sheep in the Indian subcontinent. In the present investigation, 15 hill goats were experimentally infected with 2 ml of 10% splenic suspension of a virulent isolate of PPR virus (PPR/Izatnagar/94) that had caused heavy mortality (>75%) in goats during 1994 outbreaks in northern India. More than 86% (13 of 15) animals died between 9 and 13 days post inoculation at the height of temperature or when temperatures were declining. Necropsy findings included congestion of gastrointestinal tract (GIT), nasal sinuses, consolidation of antero-ventral lobes of lungs, engorged spleen, and occasionally oedematous lymph nodes. Histopathological examination of major organs of GIT revealed degeneration and necrosis of labial mucosa, severe mucosal and submucosal congestion, degeneration and necrosis of intestinal epithelium and lymphoid cell depletion from Peyer's patches along with presence of syncytia at times. Lungs showed broncho-interstitial changes and presence of intracytoplasmic and intranuclear eosinophilic inclusions in alveolar macrophages and syncytial cells. These changes in lungs were frequently complicated with serofibrinous pneumonia (57%, eight of 14). Lymphocytolysis and occasional syncytia formation were evident in the lymphoid tissues. Immunohistochemical (IHC) findings included presence of PPR virus antigen in the labial, intestinal, and bronchiolar epithelial cells, pneumocytes, macrophages and syncytial cells in lungs, and lymphoid (intact and necrotic) and reticular cells in lymphoid organs. The findings of the study indicated the highly virulent nature of the PPR virus isolate (PPR/Izatnagar/94), causing 100% mortality and characteristic pathological changes in the target organs such as lungs, intestines and lymphoid tissues. The results of the IHC study suggested that indirect immunoperoxidase could be an alternative method in the absence of more sophisticated methods of laboratory diagnosis of PPR virus infection in goats.

Diagnosis and control of peste des petits ruminants: a comprehensive review

“…The clinical features or signs are better described under experimental condition rather than the natural infection. Both in natural as well experimental PPR infection, the incubation period ranged from 2 to 6 days [74,75,95,153]. In experimentally infected kids, the first clinical sign of pyrexia (40.6-44.2°C) was observed on days 5, followed by diarrhea (between day 5 and 8) and death within 10 days [143].…”

“…In experimentally infected kids, the first clinical sign of pyrexia (40.6-44.2°C) was observed on days 5, followed by diarrhea (between day 5 and 8) and death within 10 days [143]. Further, Kumar et al [75] observed rise in the temperature at 3rd days post infection (dpi) (104.5°F) to 10th dpi with general congestion, erosion and ulceration of oral mucosa in the challenged goats. The different stages of the disease are (i) incubation period, (ii) Prodromal phase (febrile), (iii) mucosal phase (ocular and nasal discharges, hyperaemia of conjunctiva and mucosa of anterior nares, and erosions on the tongue, palate, lips and other parts of the oral mucosa- Fig.…”

“…Various reports have described gross pathological changes in naturally occurring PPR in goats and sheep [4, 74-76, 153, 154]. The prominent lesions in PPR infected animals include, consolidation, changes in colour of lungs and sometimes, frothy mucus is observed in cut pieces of lung on squeezing, antero-ventral areas of right lung are frequently involved; areas of lungs become dark red or purple, firm to touch mainly in the anterior and cardiac lobes [75]. Consolidation of lobes of lungs (Fig.…”

Natural Peste des Petits Ruminants Virus Infection: Novel Pathologic Findings Resembling Other Morbillivirus Infections

“…6,7,9,12,27,28 Among the characteristic histopathologic findings of PPRV infection are syncytial cells in affected oral mucosa and lungs, as well as eosinophilic nuclear and cytoplasmic inclusion bodies, especially in the respiratory and/or alimentary tract epithelia. 6,8,12,21,28 Noncharacteristic pathologic findings, such as multifocal necrosis in the liver and inclusion bodies in hepatocytes and abomasal epithelial cells, are rarely reported. 2,32 Little is known about the resemblance of the pathologic findings of PPRV infection to those resulting from the other morbillivirus infections in terms of lesions in the central nervous system, kidney, and abomasum.…”

“…2,32 Little is known about the resemblance of the pathologic findings of PPRV infection to those resulting from the other morbillivirus infections in terms of lesions in the central nervous system, kidney, and abomasum. 11,21,28,32,33 The first PPRV infection in Turkey was reported in 4 sheep 2 , and since then many outbreaks have been reported. 23,24,32,34 Ö zkul et al 24 isolated PPR viruses from 2 separate field cases in Turkey.…”