Mani Saminathan

Avian rotavirus enteritis – an updated review

Rotaviruses (RVs) are among the leading causes of enteritis and diarrhea in a number of mammalian and avian species, and impose colossal loss to livestock and poultry industry globally. Subsequent to detection of rotavirus in mammalian hosts in 1973, avian rotavirus (AvRV) was first reported in turkey poults in USA during 1977 and since then RVs of group A (RVA), D (RVD), F (RVF) and G (RVG) have been identified around the globe. Besides RVA, other AvRV groups (RVD, RVF and RVG) may also contribute to disease. However, their significance has yet to be unraveled. Under field conditions, co-infection of AvRVs occurs with other infectious agents such as astroviruses, enteroviruses, reoviruses, paramyxovirus, adenovirus, Salmonella, Escherichia coli, cryptosporidium and Eimeria species prospering severity of disease outcome. Birds surviving to RV disease predominantly succumb to secondary bacterial infections, mostly E. coli and Salmonella spp. Recent developments in molecular tools including state-of-the-art diagnostics and vaccine development have led to advances in our understanding towards AvRVs. Development of new generation vaccines using immunogenic antigens of AvRV has to be explored and given due importance. Till now, no effective vaccines are available. Although specific as well as sensitive approaches are available to identify and characterize AvRVs, there is still need to have point-of-care detection assays to review disease burden, contemplate new directions for adopting vaccination and follow improvements in public health measures. This review discusses AvRVs, their epidemiology, pathology and pathogenesis, immunity, recent trends in diagnostics, vaccines, therapeutics as well as appropriate prevention and control strategies.

Rabies – epidemiology, pathogenesis, public health concerns and advances in diagnosis and control: a comprehensive review

ABSTRACT Rabies is a zoonotic, fatal and progressive neurological infection caused by rabies virus of the genus Lyssavirus and family Rhabdoviridae. It affects all warm-blooded animals and the disease is prevalent throughout the world and endemic in many countries except in Islands like Australia and Antarctica. Over 60,000 peoples die every year due to rabies, while approximately 15 million people receive rabies post-exposure prophylaxis (PEP) annually. Bite of rabid animals and saliva of infected host are mainly responsible for transmission and wildlife like raccoons, skunks, bats and foxes are main reservoirs for rabies. The incubation period is highly variable from 2 weeks to 6 years (avg. 2–3 months). Though severe neurologic signs and fatal outcome, neuropathological lesions are relatively mild. Rabies virus exploits various mechanisms to evade the host immune responses. Being a major zoonosis, precise and rapid diagnosis is important for early treatment and effective prevention and control measures. Traditional rapid Sellers staining and histopathological methods are still in use for diagnosis of rabies. Direct immunofluoroscent test (dFAT) is gold standard test and most commonly recommended for diagnosis of rabies in fresh brain tissues of dogs by both OIE and WHO. Mouse inoculation test (MIT) and polymerase chain reaction (PCR) are superior and used for routine diagnosis. Vaccination with live attenuated or inactivated viruses, DNA and recombinant vaccines can be done in endemic areas. This review describes in detail about epidemiology, transmission, pathogenesis, advances in diagnosis, vaccination and therapeutic approaches along with appropriate prevention and control strategies.

Duck virus enteritis (duck plague) – a comprehensive update

ABSTRACT Duck virus enteritis (DVE), also called duck plague, is one of the major contagious and fatal diseases of ducks, geese and swan. It is caused by duck enteritis virus (DEV)/Anatid herpesvirus-1 of the genus Mardivirus, family Herpesviridae, and subfamily Alpha-herpesvirinae. Of note, DVE has worldwide distribution, wherein migratory waterfowl plays a crucial role in its transmission within and between continents. Furthermore, horizontal and/ or vertical transmission plays a significant role in disease spread through oral-fecal discharges. Either of sexes from varying age groups of ducks is vulnerable to DVE. The disease is characterized by sudden death, vascular damage and subsequent internal hemorrhage, lesions in lymphoid organs, digestive mucosal eruptions, severe diarrhea and degenerative lesions in parenchymatous organs. Huge economic losses are connected with acute nature of the disease, increased morbidity and mortality (5%–100%), condemnations of carcasses, decreased egg production and hatchability. Although clinical manifestations and histopathology can provide preliminary diagnosis, the confirmatory diagnosis involves virus isolation and detection using serological and molecular tests. For prophylaxis, both live-attenuated and killed vaccines are being used in broiler and breeder ducks above 2 weeks of age. Since DEV is capable of becoming latent as well as shed intermittently, recombinant subunit and DNA vaccines either alone or in combination (polyvalent) are being targeted for its benign prevention. This review describes DEV, epidemiology, transmission, the disease (DVE), pathogenesis, and advances in diagnosis, vaccination and antiviral agents/therapies along with appropriate prevention and control strategies.

Ebola virus – epidemiology, diagnosis, and control: threat to humans, lessons learnt, and preparedness plans – an update on its 40 year's journey

ABSTRACT Ebola virus (EBOV) is an extremely contagious pathogen and causes lethal hemorrhagic fever disease in man and animals. The recently occurred Ebola virus disease (EVD) outbreaks in the West African countries have categorized it as an international health concern. For the virus maintenance and transmission, the non-human primates and reservoir hosts like fruit bats have played a vital role. For curbing the disease timely, we need effective therapeutics/prophylactics, however, in the absence of any approved vaccine, timely diagnosis and monitoring of EBOV remains of utmost importance. The technologically advanced vaccines like a viral-vectored vaccine, DNA vaccine and virus-like particles are underway for testing against EBOV. In the absence of any effective control measure, the adaptation of high standards of biosecurity measures, strict sanitary and hygienic practices, strengthening of surveillance and monitoring systems, imposing appropriate quarantine checks and vigilance on trade, transport, and movement of visitors from EVD endemic countries remains the answer of choice for tackling the EBOV spread. Herein, we converse with the current scenario of EBOV giving due emphasis on animal and veterinary perspectives along with advances in diagnosis and control strategies to be adopted, lessons learned from the recent outbreaks and the global preparedness plans. To retrieve the evolutionary information, we have analyzed a total of 56 genome sequences of various EBOV species submitted between 1976 and 2016 in public databases.

Beneficial health applications and medicinal values of Pedicularis plants: A review

Pedicularis plants (Orobanchaceae), popularly known as lousewort, are found in Asia, Europe, and North America, and have been used in Sowa-Rigpa, the Himalayan art of healing and a traditional system of medicine for treating various ailments in humans. A comprehensive compilation on this valuable medicinal plant is not available, however. The present extensive review provides insight into the salient medicinal properties of Pedicularis plants with respect to various health issues and diseases. Our previous studies on Pedicularis plants from the Changthang region of Ladakh (India) and research advances leading to new developments in this field have prompted this review. The information presented here has been compiled and analyzed from authenticated published resources available on Medline, Pubmed, Pubmed Central, Science Direct, and other scientific databases. The Pedicularis genus consists of approximately 600 species (83 of which are found in India), with commonly reported species being Pedicularis longiflora Rudolph, P. bicornuta Klotzsch, P. oederi Vahl, P. cheilanthifolia, and P. pectinata. The major phytoconstituents of the Pedicularis sp. are phenols, phenylethanoids, phenylpropanoids, flavonoids, iridoids, lignans, and alkaloids, among others. The existing literature highlights that these compounds possess antioxidant, immunomodulatory, anti-inflammatory, antidiabetic, antibacterial, antifungal, analgesic, antitumor, hepatoprotective, neuroprotective, muscle-relaxing, antifatigue, diuretic, antipyretic, antithrombus, antihemolysis, and DNA-repairing properties. This medicinal herb is used in the treatment of leucorrhoea, fevers, sterility, rheumatism, general debility, collapse, and urinary problems, and for revitalizing the blood circulation, improving digestion, and maintaining vitality. This review emphasizes the various medicinal aspects of Pedicularis sp. plants containing a variety of phytoconstituents. Besides phenols, terpenoids, flavonoids, lignans, tannins, iridoid, and phenylpropanoid glycosides are among the active constituents responsible for multiple health effects. However, further extensive research is required to characterize the various phytoconstituents of Pedicularis to explore their modes of action at a molecular level and identify other beneficial applications that can exploit the tremendous medicinal potential of this important herb.

Comparative Evaluation of Different Test Combinations for Diagnosis of Mycobacterium avium Subspecies paratuberculosis Infecting Dairy Herds in India

A total of 355 cows were sampled (serum, n = 315; faeces, n = 355; milk, n = 209) from dairy farms located in the Punjab state of India. Faeces and serum/milk samples were screened by acid fast staining and “indigenous ELISA,” respectively. IS900 PCR was used to screen faeces and milk samples. Bio-load of MAP in dairy cows was 36.9, 15.6, 16.3, and 14.4%, using microscopy, serum ELISA, milk ELISA and milk PCR, respectively. Estimated kappa values between different test combinations: serum and milk ELISA, faecal microscopy and faecal PCR, milk ELISA and milk PCR, faecal PCR and serum ELISA were 0.325, 0.241, 0.682, and 0.677, respectively. Estimation of the relative sensitivity and specificity of different tests in the present study indicated that “serum ELISA” and “milk ELISA” were good screening tests, add “milk PCR” was “confirmatory test” for MAP infection. Combination of milk ELISA with milk PCR may be adopted as a model strategy for screening and diagnosis of JD in lactating/dairy cattle herds in Indian conditions.

Arcobacter: an emerging food-borne zoonotic pathogen, its public health concerns and advances in diagnosis and control – a comprehensive review

ABSTRACT Arcobacter has emerged as an important food-borne zoonotic pathogen, causing sometimes serious infections in humans and animals. Newer species of Arcobacter are being incessantly emerging (presently 25 species have been identified) with novel information on the evolutionary mechanisms and genetic diversity among different Arcobacter species. These have been reported from chickens, domestic animals (cattle, pigs, sheep, horses, dogs), reptiles (lizards, snakes and chelonians), meat (poultry, pork, goat, lamb, beef, rabbit), vegetables and from humans in different countries. Arcobacters are implicated as causative agents of diarrhea, mastitis and abortion in animals, while causing bacteremia, endocarditis, peritonitis, gastroenteritis and diarrhea in humans. Three species including A. butzleri, A. cryaerophilus and A. skirrowii are predominantly associated with clinical conditions. Arcobacters are primarily transmitted through contaminated food and water sources. Identification of Arcobacter by biochemical tests is difficult and isolation remains the gold standard method. Current diagnostic advances have provided various molecular methods for efficient detection and differentiation of the Arcobacters at genus and species level. To overcome the emerging antibiotic resistance problem there is an essential need to explore the potential of novel and alternative therapies. Strengthening of the diagnostic aspects is also suggested as in most cases Arcobacters goes unnoticed and hence the exact epidemiological status remains uncertain. This review updates the current knowledge and many aspects of this important food-borne pathogen, namely etiology, evolution and emergence, genetic diversity, epidemiology, the disease in animals and humans, public health concerns, and advances in its diagnosis, prevention and control.

Prevalence, diagnosis, management and control of important diseases of ruminants with special reference to Indian scenario.

India possess huge livestock population, which is endangered by different endemic infectious diseases (bacterial, viral, protozoan and parasitic), which collectively causes significant economic losses to the landless poor farming community. Infectious diseases impose economic losses by causing morbidity, mortality, decreased production (milk, meat, wool etc.), decreased feed conversion ratio which results in reduced weight gain, decreased draught power and fertility. Furthermore, economic burden is also due to the cost of treatment, abortion, consequences on internal livestock movement, germplasm and international trade. In addition, some of the diseases are zoonotic and inflicts considerable impact on public health. Uncertain agrarian climate, unpredictable weather, drought, floods, migration of livestock, scarcity of fodders, and unhygienic zoo-sanitary and healthcare practices together resulted in endemicity of diseases ultimately leads to more incidence and prevalence of livestock and poultry diseases throughout the year. Synchronized monitoring and surveillance of disease throughout the country is a fundamental requirement for sustainable livestock production. With fairly developed telecommunication in India, following technologies like interactive voice response system, SMS through mobile/cell phones and toll-free landline phones (voice mail) are required for enhancing the effectiveness and efficiency of

Molecular epidemiology of rabies virus circulating in domestic animals in India

Rabies is a neglected viral zoonotic disease affecting humans, domestic and wild animals and is endemic in most parts of the India. Dog mediated rabies is more predominant than other forms of rabies and molecular epidemiology is poorly understood in both reservoir and susceptible hosts. In the present study, a total of 140 rabies suspected brain samples from different species of animals from different geographical regions of India were used. The samples were parallelly tested by direct fluorescent antibody test, reverse transcriptase PCR and real-time PCR. Thirty positive samples were subjected for partial nucleoprotein gene sequencing and phylogenetic analysis. On sequence and phylogenetic analysis, it was observed that all Indian rabies viruses belonged to classical rabies virus of genotype 1 of Lyssavirus and formed two distinct groups. The majority of isolates were in group-1 and are closely related to arctic/arctic like lineage, whereas group–II isolated are closely related to cosmopolitan lineage. These results indicated there is simultaneous existence of two distinct lineages of rabies viruses in Indian subcontinent. Further whole genome studies are needed for better understanding of molecular epidemiology of rabies virus circulating in animals for control and prevention of rabies in India.

ZIKA VIRUS / ZIKA FEVER : A COMPREHENSIVE UPDATE

Zika virus (ZIKV) has attracted global attention after its first large-scale outbreak in Pacific, Micronesian island of Yap (Year 2007). The virus spreads rapidly and owes increased virulence than the ZIKV which appeared nearly six decades ago, where it was associated with sporadic cases and mild illness. The World Health Organization declared ZIKA as a „Public Health Emergency of International Concern” due to severe illness and associated several complications such as neurological disorders, autoimmune disorder, fetal anomalies, impaired central nervous system (CNS) of the fetus, microcephaly * Corresponding author KEYWORDS