scholarly journals Bovine Pestivirus Heterogeneity and Its Potential Impact on Vaccination and Diagnosis

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1134 ◽  
Author(s):  
Victor Riitho ◽  
Rebecca Strong ◽  
Magdalena Larska ◽  
Simon P. Graham ◽  
Falko Steinbach
Keyword(s):  
Disease Control ◽  
Control Measures ◽  
Economic Losses ◽  
Border Disease Virus ◽  
Bovine Viral Diarrhoea ◽  
Middle Income ◽  
Middle Income Countries ◽  
Border Disease ◽  
Control Programmes ◽  
Potential Impact

Bovine Pestiviruses A and B, formerly known as bovine viral diarrhoea viruses (BVDV)-1 and 2, respectively, are important pathogens of cattle worldwide, responsible for significant economic losses. Bovine viral diarrhoea control programmes are in effect in several high-income countries but less so in low- and middle-income countries where bovine pestiviruses are not considered in disease control programmes. However, bovine pestiviruses are genetically and antigenically diverse, which affects the efficiency of the control programmes. The emergence of atypical ruminant pestiviruses (Pestivirus H or BVDV-3) from various parts of the world and the detection of Pestivirus D (border disease virus) in cattle highlights the challenge that pestiviruses continue to pose to control measures including the development of vaccines with improved cross-protective potential and enhanced diagnostics. This review examines the effect of bovine pestivirus diversity and emergence of atypical pestiviruses in disease control by vaccination and diagnosis.

scholarly journals Global Distribution and Genetic Heterogeneity of Border Disease Virus

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 950
Author(s):  
Cecilia Righi ◽  
Stefano Petrini ◽  
Ilaria Pierini ◽  
Monica Giammarioli ◽  
Gian Mario De Mia
Keyword(s):  
Disease Virus ◽  
Significant Risk ◽  
Small Ruminants ◽  
Control Measures ◽  
Interspecies Transmission ◽  
Economic Losses ◽  
Border Disease Virus ◽  
Diarrhea Virus ◽  
Geographical Regions ◽  
Border Disease

Border disease virus (BDV) belongs to the genus Pestivirus of the family Flaviviridae. Interspecies transmission of BDV between sheep, cattle, and pigs occurs regularly, sometimes making diagnosis a challenge. BDV can yield substantial economic losses, including prenatal and postnatal infections in lambs, which are the primary source of infection and maintenance of the virus in the population. Since BDV is antigenically and genetically related to bovine viral diarrhea virus (BVDV), it might pose a significant risk to cattle, influencing BVDV eradication campaigns. Similarly, the presence of BDV in swine herds due to pestivirus spillover between small ruminants and pigs might cause uncertainty in classical swine fever virus (CSFV) diagnostics. Therefore, knowledge of BDV epidemiology in different geographical regions will help prevent its spread and optimize control measures. Previous epidemiological studies have shown that various BDV genotypes are predominant in different countries. This review provides an overview of the spread of BDV world-wide in different host species.

scholarly journals Eradication of Bovine Viral Diarrhoea (BVD) in Cattle in Switzerland: Lessons Taught by the Complex Biology of the Virus

2021 ◽  
Vol 8 ◽  
Author(s):  
Matthias Schweizer ◽  
Hanspeter Stalder ◽  
Anja Haslebacher ◽  
Martin Grisiger ◽  
Heinzpeter Schwermer ◽  
...  
Keyword(s):  
Horizontal Transmission ◽  
Bovine Viral Diarrhoea Virus ◽  
Control Programme ◽  
Economic Losses ◽  
Border Disease Virus ◽  
Cattle Population ◽  
Bovine Viral Diarrhoea ◽  
Main Challenge ◽  
Border Disease ◽  
Diarrhoea Virus

Bovine viral diarrhoea virus (BVDV) and related ruminant pestiviruses occur worldwide and cause considerable economic losses in livestock and severely impair animal welfare. Switzerland started a national mandatory control programme in 2008 aiming to eradicate BVD from the Swiss cattle population. The peculiar biology of pestiviruses with the birth of persistently infected (PI) animals upon in utero infection in addition to transient infection of naïve animals requires vertical and horizontal transmission to be taken into account. Initially, every animal was tested for PI within the first year, followed by testing for the presence of virus in all newborn calves for the next four years. Prevalence of calves being born PI thus diminished substantially from around 1.4% to <0.02%, which enabled broad testing for the virus to be abandoned and switching to economically more favourable serological surveillance with vaccination being prohibited. By the end of 2020, more than 99.5% of all cattle farms in Switzerland were free of BVDV but eliminating the last remaining PI animals turned out to be a tougher nut to crack. In this review, we describe the Swiss BVD eradication scheme and the hurdles that were encountered and still remain during the implementation of the programme. The main challenge is to rapidly identify the source of infection in case of a positive result during antibody surveillance, and to efficiently protect the cattle population from re-infection, particularly in light of the endemic presence of the related pestivirus border disease virus (BDV) in sheep. As a consequence of these measures, complete eradication will (hopefully) soon be achieved, and the final step will then be the continuous documentation of freedom of disease.

scholarly journals Climate drivers of plague epidemiology in British India, 1898–1949

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200538
Author(s):  
Warren S. D. Tennant ◽  
Mike J. Tildesley ◽  
Simon E. F. Spencer ◽  
Matt J. Keeling
Keyword(s):  
Predictive Models ◽  
Control Measures ◽  
Climate Data ◽  
British India ◽  
Middle Income ◽  
Middle Income Countries ◽  
Complex Interactions ◽  
The World ◽  
Spatio Temporal

Plague, caused by Yersinia pestis infection, continues to threaten low- and middle-income countries throughout the world. The complex interactions between rodents and fleas with their respective environments challenge our understanding of human plague epidemiology. Historical long-term datasets of reported plague cases offer a unique opportunity to elucidate the effects of climate on plague outbreaks in detail. Here, we analyse monthly plague deaths and climate data from 25 provinces in British India from 1898 to 1949 to generate insights into the influence of temperature, rainfall and humidity on the occurrence, severity and timing of plague outbreaks. We find that moderate relative humidity levels of between 60% and 80% were strongly associated with outbreaks. Using wavelet analysis, we determine that the nationwide spread of plague was driven by changes in humidity, where, on average, a one-month delay in the onset of rising humidity translated into a one-month delay in the timing of plague outbreaks. This work can inform modern spatio-temporal predictive models for the disease and aid in the development of early-warning strategies for the deployment of prophylactic treatments and other control measures.

Lantana camara (lantana).

2021 ◽  
Author(s):  
Sarah E. Thomas ◽  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Control Measures ◽  
Economic Losses ◽  
Pests And Diseases ◽  
Control Programmes ◽  
Agricultural Weed ◽  
Successful Control ◽  
The Tropics ◽  
Ornamental Shrub

Abstract L. camara is a highly variable ornamental shrub, native of the neotropics. It has been introduced to most of the tropics and subtropics as a hedge plant and has since been reported as extremely weedy and invasive in many countries. It is generally deleterious to biodiversity and has been reported as an agricultural weed resulting in large economic losses in a number of countries. In addition to this, it increases the risk of fire, is poisonous to livestock and is a host for numerous pests and diseases. L. camara is difficult to control. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures. This species has been the target of biological control programmes for over a century, with successful control only being reported in a few instances.

scholarly journals Molecular analysis of bovine viral diarrhoea virus isolates from South Africa

2003 ◽  
Vol 70 (4) ◽  
Author(s):  
N. Kabongo ◽  
C. Baule ◽  
M. Van Vuuren
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Calf Serum ◽  
Bovine Viral Diarrhoea Virus ◽  
Border Disease Virus ◽  
Foetal Calf Serum ◽  
Type I ◽  
Bovine Viral Diarrhoea ◽  
Border Disease ◽  
Diarrhoea Virus

The presence of bovine viral diarrhoea virus in South Africa has been confirmed by several serological surveys. However, little is known about its biological properties. Twenty five isolates obtained by isolation in tissue culture and detected by means of the antigen capture ELISA from clinically sick cattle and from foetal calf serum in South Africa were characterized on the basis of analysis of the 5' non-translated (NTR) region of the genome. A reverse-transcription polymerase chain reaction (RT-PCR) was used to amplify specific sequences from the 5'NTR of the genome. The oligonucleotide primers corresponding to positions 105-125 and 399-378, respectively, in the sequence of BVDV strain NADL were used to generate the PCR products. Both strands were sequenced directly with these primers and fluorescence-labelled dideoxynucleotides in an automated nucleic acid sequencer. Reference strains of pestiviruses [(BVDV type I, BVDV type II, border disease virus (BDV) and hog cholera virus (HCV)] and isolates from a previous investigation on BVDV in southern Africa were included for comparative purposes. All the BVDV strains obtained during this study belong to subgroups of BVDV genotype I. No association could be demonstrated between the geographic origin of the isolates. A number of isolates formed another branch separate from the existing branches Ia, Ib and Ic. These findings suggest that extensive genetic diversity can be found within BVDV type I isolates from southern Africa. Isolates that group with the classical BVDV type I strains, particularly of American origin, coexist with variants that appear to represent a local genetic pool and or variants evolving from the classical strains.

scholarly journals Two cases of cholera O1 in South Batinah, Oman, April 2019: lessons learned

2019 ◽  
Vol 41 ◽  
pp. e2019033
Author(s):  
Zayid K. Al Mayahi ◽  
Nasser Al-Shaqsi ◽  
Hamid A. Elmutashi ◽  
Ali Al-Dhoyani ◽  
Azza Al Hattali ◽  
...  
Keyword(s):  
Infection Control ◽  
Low Income ◽  
Lessons Learned ◽  
Control Measures ◽  
Care Level ◽  
Middle Income ◽  
Primary Care Level ◽  
Middle Income Countries ◽  
Infection Control Measures ◽  
Detection Point

Cholera represents an ongoing threat to many low-income and middle-income countries, but some cases of cholera even occur in high-income countries. Therefore, to prevent or combat cholera outbreaks, it is necessary to maintain the capacity to rapidly detect cholera cases, implement infection control measures, and improve general hygiene in terms of the environment, water, and food. The 2 cases, 1 imported and 1 secondary, described herein are broadly indicative of areas that require improvement. These cases were missed at the primary health care stage, which should be the first detection point even for unusual diseases such as cholera, and the absence of strict infection control practices at the primary care level is believed to contribute to secondary cases of infection. This report also encourages countries to ensure that rapid diagnostic stool tests are available to enable quick detection, as well as to provide information to people travelling to areas where cholera is endemic.

scholarly journals Estimating the Impact and Cost of the WHO 2010 Recommendations for Antiretroviral Therapy

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
John Stover ◽  
Lori Bollinger ◽  
Carlos Avila
Keyword(s):  
Antiretroviral Therapy ◽  
Cd4 Count ◽  
Eligibility Criterion ◽  
Eligibility Criteria ◽  
Art Programs ◽  
Middle Income ◽  
Middle Income Countries ◽  
Country Level ◽  
Potential Impact ◽  
The Impact

In July 2010, WHO published new recommendations on providing antiretroviral therapy to adults and adolescents, including starting ART earlier, usually at a CD4 count of 350 or lower, specific regimens for first- and second-line therapies, and other recommendations. This paper estimates the potential impact and cost of the revised guidelines by first, calculating the number of people that would be in need of antiretroviral therapy (ART) with different eligibility criteria, and second, calculating the costs associated with the potential impact. Results indicate that switching the eligibility criterion from CD4 count <200 to <350 increases the need for ART in low- and middle-income countries (country-level) by 50% (range 34% to 70%). The costs of ART programs only to increase coverage to 80% by 2015 would be 44% more (range 29% to 63%) when switching the eligibility criterion to CD4 count <350. When testing and outreach costs are included, total costs increase by 62%, from US$26.3 billion under the previous eligibility criterion of treating those with CD4 <200 to US$42.5 billion using the revised eligibility criterion of treating those with CD4 <350.

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