Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

Clinical perspectives of emerging pathogens in bleeding disorders.

As a result of immunological and nucleic-acid screening of plasma donations for transfusion-transmissible viruses, and the incorporation of viral reduction processes during plasma fractionation, coagulation-factor concentrates (CFC) are now judged safe in terms of many known infectious agents, including hepatitis B and C viruses, HIV, and human T-cell lymphotropic virus. However, emerging pathogens could pose future threats, particularly those with blood-borne stages that are resistant to viral-inactivation steps in the manufacturing process, such as non-lipid-coated viruses. As outlined in this Review, better understanding of infectious diseases allows challenges from newly described agents of potential concern in the future to be anticipated, but the processes of zoonotic transmission and genetic selection or modification ensure that plasma-derived products will continue to be subject to infectious concerns. Manufacturers of plasma-derived CFC have addressed the issue of emerging infectious agents by developing recombinant products that limit the need for human plasma during production. Such recombinant products have extended the safety profile of their predecessors by ensuring that all reagents used for cell culture, purification steps, and stabilisation and storage buffers are completely independent of human plasma

Soil Viruses: A New Hope.

As abundant members of microbial communities, viruses impact microbial mortality, carbon and nutrient cycling, and food web dynamics. Although most of our information about viral communities comes from marine systems, evidence is mounting to suggest that viruses are similarly important in soil. Here I outline soil viral metagenomic approaches and the current state of soil viral ecology as a field, and then I highlight existing knowledge gaps that we can begin to fill. We are poised to elucidate soil viral contributions to terrestrial ecosystem processes, considering: the full suite of potential hosts across trophic scales, the ecological impacts of different viral replication strategies, links to economically relevant outcomes like crop productivity, and measurable in situ virus-host population dynamics across spatiotemporal scales and environmental conditions. Soon, we will learn how soil viruses contribute to food webs linked to organic matter decomposition, carbon and nutrient cycling, greenhouse gas emissions, and agricultural productivity

The Novel Coronavirus Outbreak: a Challenge Beyond Borders

Coronaviruses infect mammals and birds worldwide, and some of these viruses infect humans to cause mild to moderate lower-respiratory tract illnesses and rarely a severe illness. Like other viruses, coronaviruses evolved (change their genetic material and protein structure) and spread from animals to humans. The world has witnessed coronavirus evolving into severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003 and the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012. Other recent examples include Dengue, Ebola, Chikungunya, Influenza and Zika virus outbreaks. It may or may not be relevant to note that first cases of both SARS-CoV in 2003 avian influenza virus (H5N1) in 1997 were isolated and identified at the same hospital in Hong Kong where the first case of the current outbreak of the Wuhan coronavirus has been identified. The new virus has been named as the Novel coronavirus (2019 nCoV)

Review of Rabies Preventions and Control

Rabies is an acute viral infection of the central nervous system, caused by a lyssavirus in the family Rhabdoviridae. It is zoonotic viral disease that can affect all mammals, including humans, cats, dogs, and wildlife and farm animals. The virus is present in the saliva of affected animals, and the most frequent method of transmission to humans is by bites, scratches or licks to broken skin or mucous membranes. The disease has a long incubation period (six months) and symptoms may take several weeks to appear after infection. The first clinical symptom is neuropathic pain at the site of infection or wound due to viral replication. Diagnosis can only be confirmed by laboratory tests preferably conducted post mortem on central nervous system tissue removed from cranium. This paper reviews the possible prevention and control of rabies. Essential components of rabies prevention and control include ongoing public education, responsible pet ownership, routine veterinary care and vaccination, and professional continuing education. Control strategies include quarantine, confirmation of diagnosis, determining the origin and spread of an outbreak. Since rabies is invariably fatal and deadly viral disease that can only be prevented the collaborative effort between Veterinarians and human health care professionals are needed in the prevention and control of rabies

The Zika outbreak of the 21st century.

The Zika virus outbreak has captivated the attention of the global audience and information has spread rapidly and wildly through the internet and other media channels. This virus was first identified in 1947, when it was isolated from a sentinel rhesus monkey placed by British scientists working at the Yellow Fever Research Laboratory located in the Zika forest area of Uganda, hence its name, and is transmitted primarily by the mosquito vector, Aedes aegypti. The fact that the rhesus macaque is an Asian species being placed in an African forest brings to mind the possibility of rapid adaptation of the virus from an African to Asian species, an issue that has not been considered. Whether such adaptation has played any role in acquiring pathogenicity due to cross species transmission remains to be identified. The first human infection was described in Nigeria in 1954, with only scattered reports of about a dozen human infections identified over a 50-year period. It was not until 2007 that Zika virus raised its ugly head with infections noted in three-quarters of the population on the tiny island of Yap located between the Philippines and Papua New Guinea in the western Pacific Ocean, followed by a major outbreak in French Polynesia in 2013. The virus remained confined to a narrow equatorial band in Africa and Asia until 2014 when it began to spread eastward, first toward Oceania and then to South America. Since then, millions of infected individuals have been identified in Brazil, Colombia, Venezuela, including 25 additional countries in the Americas. While the symptoms associated with Zika virus infection are generally mild, consisting of fever, maculopapular rash, arthralgia and conjunctivitis, there have been reports of more severe reactions that are associated with neurological complications. In pregnant women, fetal neurological complications include brain damage and microcephaly, while in adults there have been several cases of virus-associated Guillain-Barre syndrome. The virus was until recently believed to only be transmitted via mosquitoes. But when the Zika virus was isolated from the semen specimens from a patient in Texas, this provided the basis for the recent report of possible sexual transmission of the Zika virus. Due to the neurological complications, various vectors for infection as well as the rapid spread throughout the globe, it has prompted the World Health Organization to issue a global health emergency. Various governmental organizations have recommended that pregnant women do not travel to countries where the virus is epidemic, and within the countries affected by the virus, recommendations were provided for women of childbearing age to delay pregnancy. The overall public health impact of these above findings highlights the need for a rapid but specific diagnostic test for blood banks worldwide to identify those infected and for the counseling of women who are pregnant or contemplating pregnancy. As of this date, there are neither commercially licensed diagnostic tests nor a vaccine. Because cross-reactivity of the Zika virus with dengue and Chikungunya virus is common, it may pose difficulty in being able to quickly develop such tests and vaccines. So far the most effective public health measures include controlling the mosquito populations via insecticides and preventing humans from direct exposure to mosquitoes

Balancing Network Security and Privacy: One Organization\u27s Effort

An organization with internet access runs a high risk of compromising their computer network. Data can be corrupted, confidential information can be stolen, and viruses can paralyze an entire network. Monitoring employee activity involves questionable legal issues and risk of violating the employees’ privacy. An organization must balance the need for monitoring against possible damage to morale, because even an innocent employee may feel spied on. According to American Management Association’s annual survey on workplace monitoring released in April 2001, 78% of large firms in the U.S. are monitoring their employees, but 10% do not notify their employees of this. Monitoring is most common in the for-profit organizations, however 62% of public administrative organizations monitor their employees, and it may have increased since then. Of the 78% of monitoring organizations, 2/3 have disciplined employees for abusing their internet privileges, and more than 1/3 have dismissed employees for these abuses (Skelton)