Miscellaneous

Miscellaneous - An Interesting 'Virus'
While doing random websurfing today, I found this interesting picture of a 'virus'.
From the descriptions it says: This is the 'Flickr Virus', a microvirus that is affecting so many throughout the world. Little is known about its structure and how it transmitted, although recent work indicates that it is a small sphere of energy (possibly light) that travels via the internet. Infection usually occurs soon after a Flickr 'Pro Account' has been acquired.

Symptoms:
1. The patient has a craving for 'viewings' and 'comments' on his/her images and develops a compulsion to upload images to satisfy this need.
2. Obsessive checking for inclusion in 'Scout' and 'Explore'.
3. A compelling desire to add the tag 'interestingness'.

Treatment:
There is no real effective or permanent cure. Total abstinence from Flickr may work for short periods while the patient returns to a normal life style but this is usually only a temporary situation. Long term research, funding, and recognition as an illness is needed.Of course this might just be another one of my 'Refractographs' created out of light and only an image on your computer screen to be treated as a a bit of fun. On the other hand don't stare at it for too long or view large - it could be contagious! ;)

SARS!

Severe Acute Respiratory Syndrome (SARS)
Severe acute respiratory syndrome (SARS) is a respiratory illness caused by SARS coronavirus (SARS-CoV), which are positively stranded RNA enveloped viruses, with 8,096 known infected cases and 774 deaths (a case-fatality rate of 9.6%) worldwide between November 2002 and July 2003, listed in World Health Organisation(WHO) report in April 2004, originating from Guangdong China, where a farmer contracted symptoms and died soon after, without a definite diagnosis on his death. The disease soon spreads to other provinces of China like Shanxi and Tianjin. Several countries like Hong Kong, Toronto, San Fransisco, Taiwan and Singapore have local transmissions. Mortality by age group as of 8 May 2003 is below 1 percent for people aged 24 or younger, 6 percent for those 25 to 44, 15 percent in those 45 to 64 and more than 50 percent for those over 65. For comparison, the case fatality rate for influenza is usually around 0.6 percent (primarily among the elderly) but can rise as high as 33 percent in locally severe epidemics of new strains. The mortality rate of the primary viral pneumonia form is about 70 percent.
What is main source of virus? It was found by Chinese researchers from animals like palm civets (cat-like animal), that SARS coronavirus can spresd from the civets to humans. Other animals like raccoon dogs, ferret badgers, cats and Chinese Bats are also likely to have isolated the viruses, in which bats are aymptomatic to virus, but are possibly reservoirs for transmission of SARS-like coronavirus.

Viral replication
Replication takes place in cytoplasm in membrane-protected microenvironment and starts with the translation of the genome to produce the viral replicase. CoV transcription involves a discontinuous RNA synthesis (template switch) during the extension of a negative copy of the subgenomic mRNAs. The requirement for base pairing during transcription has been formally demonstrated in arteriviruses and CoVs. The CoV N protein is required for coronavirus RNA synthesis and has RNA chaperon activity that may be involved in template switch. Both viral and cellular proteins are required for replication and transcription. CoVs initiate translation by cap-dependent and cap-independent mechanisms. Cell macromolecular synthesis may be controlled after CoV infection by locating some virus proteins in the host cell nucleus. Infection by different coronaviruses cause in the host alteration in the transcription and translation patterns, in the cell cycle, the cytoskeleton, apoptosis and coagulation pathways, inflammation and immune and stress responses. The balance between genes up- and down-regulated could explain the pathogenesis caused by these viruses. Coronavirus expression systems based on single genome constructed by targeted recombination, or by using infectious cDNAs, have been developed. The possibility of expressing different genes under the control of transcription regulating sequences (TRSs) with programmable strength and engineering tissue and species tropism indicates that CoV vectors are flexible. CoV based vectors have emerged with high potential vaccine development and possibly for gene therapy.[19]

Symptoms of SARS are similar to influenza together with fever, muscle pain, lethargy, gastrointestinal symptoms, cough, sore throat, shortness of breath and other non-specific ones, in which the most common symptom is fever above 38 °C (100.4 °F). They usually appear between 2 days to at most 13 days following infection, usually within 2–3 days. About 10–20% of cases require mechanical ventilation.
Phlegm present in lungs can be an indication of SARS. This can be examined from Chest X-Ray.
There are also high white blood cell and platelet counts, some likely reasons are: tendency to relative neutrophilia and a relative lymphopenia, raised lactate dehydrogenase and creatine kinase and C-Reactive protein levels.
Some approved tests to identify SARS are: ELISA (Enzyme-Linked Immunosorbent Assay), Immunosorbent Assay and Polymerase Chain Reaction (PCR). However, there are some pros and cons to each test. For example, ELISA is reliable only 21 days after symptoms occur in patient, while immunosorbent assay takes only 10 days, but requires sophisticated equipment, like immunoflourescence microscope and PCR may not be sensitive, which means that patient may still suspect of infected from SARS even though tested negative.
The process of finding cause of virus was initially hypothesized that SARS was caused by paramyxovirus-like particles, from Hong Kong and German researchers, while Chinese researchers reported Chlamydia-like disease a likely cause. French and Hong Kong scientists soon found out that a newly discovered subtype of coronavirus was a likely cause of SARS, after cultivating virus in vitro and invent a test to identify virus. This was confirmed by Dutch scientists in 2003, by demonstrating that SARS coronavirus fulfilled Koch's postulates, using macaques as hosts, which developed same symptoms as SARS patients.
So far, antipyretic drugs with oxygen supplemental and ventilator support can treat SARS. Antiviral drugs like ribavirin and corticosteroids are the most common drugs to treat disease. Iminocyclitol 7 has also been found to have inhibited SARS-CoV by disrupting envelope assembly and inhibits production of human fucosidase. In vitro trials yielded promising results in treatment of SARS, but lacking of fucosidase can lead to fucosidosis which is a decrease in neurological function.
Acknowledgement
http://en.wikipedia.org/wiki/SARS

Here are links to World Health Organisation to guides of SARS surveillances and recommendations, plus risk assessment and preparedness framework to prevent a SARS pandemic:
http://www.who.int/csr/resources/publications/SARSNEWGUIDANCE/en/index.html
It may be dated to 2004, but is still quite useful to learn more about SARS.
Wilson reported.

Eradication of polio virus in the year 2014?

Did you know that in the year 2014 polio virus MIGHT get wiped out from the surface of mother earth?

The Bill & Melinda Gates Foundation, Rotary International and the British and German governments today pledged $630 million over the next five years to vaccine and other programs designed to wipe out polio.

"I am urging everyone to redouble their commitment and see the eradication effort to the end," Bill Gates said today during a teleconference with reporters. Gates said he's confident that polio will become the second viral disease that humankind eradicates (the first being smallpox in 1979), but he was loath to predict when that might happen.

The Gates Foundation, which has contributed $655 million toward polio eradication since 1999, today pledged an additional $255 million over the next five years. Rotary has promised $100 million, and the U.K. and Germany are forking over $150 million and $130 million, respectively. This money will go to a variety of resources and activities essential to the eradication effort, from purchasing vaccines to training programs for health workers.

A disease that attacks the nervous system, polio most commonly strikes children under age five, causing nothing more than flulike symptoms in most but permanent paralysis in others. One in every 200 cases results in paralysis, according to the World Health Organization (WHO). The virus is easily spread through dirty drinking water in areas with poor sanitation systems and continues to thrive in four countries—Nigeria, India, Afghanistan, and Pakistan, where it annually paralyzes about 2,000 children.

The disease came close to being wiped out in the U.S. in the 1960s, but there were sporadic outbreaks in pockets where the vaccine was shunned—such as among the Amish in Lancaster County, Pa., in 1979. The WHO finally declared the Americas polio-free in 1994.

Since 1988, the WHO, the U.S. and other governments as well as charitable orgs such as Gates and Rotary have contributed $6 billion to eradicating polio. The international effort has cut polio cases by over 99 percent, from some 350,000 in 1988 to about 1,600 last year.

The infusion of new funds will focus on overcoming specific hurdles in each of the four countries where the disease still exists. Afghanistan, for instance, is embroiled in a war, which makes it dangerous for vaccinators to distribute the medicines, and Nigeria has fallen behind in its eradication campaign, because local government officials in some of the country's northern states have failed to provide training for health workers or programs to educate parents on the import of vaccinating their children.

"We need new efforts from the leaders in these countries where polio is still endemic," Gates said. "There's no target date yet for eradication because nobody knows what it will take."

Source: http://www.sciam.com/blog/60-second-science/post.cfm?id=bill-gates-hands-over-millions-more-2009-01-21
By Amas goh

RABBIT?

Rabies virus (RV) rotating virion
Rabies viruses have a characteristic bullet shape. Their genomes are single stranded negative sense RNA. This RNA is combined with a nucleoprotein to create a nucleocapsid. The nucleocapsid is wound tightly as a helix (yellow in this graphic). The nucleocapsid helix is organised during morphogenesis and stabilised by matrix proteins. The matrix layer is surrounded by a viral envelope derived from the host cell during budding. The surface of the rabies virus is covered by spikes or knobs formed from glycoprotein. These are connected to the matrix by a transmembrane region.
Rabies viruses can infect mammals and are best known for causing rabies in dogs (rabid or mad dogs). It used to be called hydrophobia since the sight of water would cause terrible fear in those infected. Rabies is generally lethal unless treatment is given very quickly. Transmission to humans can occur from bats and other wild mammals in infected areas.

Bats might be a carrier?

Natural reservoir for emerging viruses may be bats. They are creatures of the night that are commonly held in fear. At first glance, those fears might seem to have some medical justification. Long known as vectors for rabies, bats may be the origin of some of the most deadly emerging viruses, including SARS, Ebola, Nipah, Hendra and Marburg. Instead of demonizing bats, however, research shows the real culprit behind these outbreaks could be human error.

The Nipah and Hendra viruses were the first emerging diseases linked to bats. Hendra claimed two of its three victims in its first and so far only known appearance in Australia. Meanwhile Nipah has in repeated Southeast Asian outbreaks killed nearly 200 people, and blood tests of wildlife have suggested that the viruses came from the largest bats, flying foxes.

The connection to SARS, or severe acute respiratory syndrome, was less direct. During the outbreak that began in China in 2002, investigators found that civets and two unrelated species harbored the SARS coronavirus, prompting mass culling of the mongooselike civets by the Chinese government.

Subsequent research, however, found no widespread SARS infection among wild or farmed civets, indicating that the disease arose in another species and might remain in wait there.
Want to know more? Visit this website
http://www.sciam.com/article.cfm?id=going-to-bat

By Amas Goh

Harmless little deer mouse...or not? (Remerging viruses)

Do you think that this deer mouse is cute? Do not let it’s cute look mislead you…
Hantavirus pulmonary syndrome (HPS) is a deadly disease from rodents. Humans can contract the disease when they come into contact with infected rodents or their urine and droppings.

HPS was first recognized in 1993 and has since been identified throughout the United States. Although rare, HPS is potentially deadly. Rodent control in and around the home remains the primary strategy for preventing Hantavirus infection. These incidents are used to remember that these re-merging viruses could appear once again…

The deadliest United States outbreak was on May 14, 1993 in the Four Corners area. Incubation is similar to Yellow Fever. Symptoms include mild onset with flu-like symptoms that rapidly progresses into kidney failure with intestinal bleeding (which is the hallmark of the disease).

The most common symptom in the United States is hypertension with chronic kidney failure. In the Four Corners outbreak, the disease had a very mild onset with flu-like symptoms, developing into lung hemorrhaging causing the infected person to suffocate in his or her own blood.

The mortality rate varies with the strain; the most deadly strain had a 62.5% mortality rate.
Transmission is from animal to human. Over 63 bird and rodent vectors have been identified for the 70 known strains of the virus. Scientists have concluded that the outbreak in the Four Corners area was due to a ten-fold increase in the population of the deer mouse and not to a virus mutation.
By Amas goh

Emerging Virus!

NEW AND EMERGING VIRUS
An emerging virus is defined as a disease of infectious origins with an incidence that has increased within the last 2 decades or threatens to increase in the near future by Centres for Disease Control (CDC).
Attention has been given to viruses which cause incurable, fatal disease such as haemorrhagic fever or AIDS. The term ‘emerging disease’ is used for diseases which have historically been rarely seen. The emergence of infections is not new. It has been happening throughout history and it covers the whole range of infections.

Where does emerging virus come from?
There are many ways in which virus can emerge from. A zoonosis is the transfer of infectious agent from an animal to human. Other sources can be mutation of genes, recombination like influenza antigenic shift, geographical contact like smallpox (now eradicated), rabbit haemorrhagic disease and reappearance (shingles). A true zoonosis is poorly transmissible between humans since human borne disease transmission come to dominate spread of the virus. One example is HIV (human immunodeficiency virus) which is zoonotic (transferred from African monkey to human. But even though HIV is a zoonotic origin, it can also be transmitted from human to human. Many viruses have the ability to adapt to co-existing normal host and cause relatively mild disease. Thus a virus may circulate around the animal and be unnoticed. If this virus were to be able to infect human it would be a severe disease. Environmental changes can cause humans to come in contact with animals more.
Dengue Haemorrahgic Fever (DHF) which is under flaviviridae is an arthropod-borne viral zoonosis. It’s endemic to tropical areas which have high rain fall and hot climate throughout the year. The host for DHF is monkey by aedes mosquitoes which is the vector of DHF.

Mutation
While all viruses must have been arisen by mutations at base, the effects of this process in the limited time available to study viruses are necessarily limited. Recently there has been more evidence in virus rising like AIDS. Serological methods prove that this disease is not seen in humans before the second half of 20th century. The appearance of rabbit Haemorrahgic disease or rabbit calicivirus (RCV) also represents an apparent new disease followed by massive and rapid spread of it. Antigenic drift in influenza virus are not easily resolved from parental strains and are not considered as new or emerging viruses. A more relevant example would be appearance of drugs- resistant variants of all viruses that are treated with antiviral drugs. Drug resistance arises from mutations this does not have to occur after the drug is used. It is seen that mutation during normal replication results in viruses which differ in genetic material and physical properties.