“The pandemic potential of this novel virus should not be underestimated.”
PARIS: Chinese scientists sounded the alarm on Wednesday after a new bird flu virus, H10N8, killed an elderly woman in December and infected another individual last month.
The fifth novel influenza strain to emerge in 17 years, the virus has a worrying genetic profile and should be closely monitored, they reported in The Lancet medical journal.
It appears to be able to infect tissue deep in the lung and may have features allowing it to spread efficiently among humans, they said.
The warning stems from analysis of a virus sample taken from a 73-year-old woman who died in Nanchang, in southeastern Jiangxi province, on December 6 after being diagnosed with severe pneumonia and respiratory failure.
The Chinese authorities announced her death from H10N8 on December 18.
The Lancet study disclosed that a second case of H10N8 was recorded in Nanchang, on January 26. It did not give further details.
They are the first known human cases of H10N8, a virus that has been found only twice before in China — once in a water sample from a lake in Hunan in 2007, and the second time in live poultry in Guangdong province in 2012.
But this particular strain is different from the ones found in those two samples, the study said.
Genetic profile of virus
The big contributors to its genome are reshuffled genes from the H9N2 virus, the authors said.
This is a bird virus that erupted in Hong Kong in 1999 and has also contributed to the dangerous H5N1 and H7N9 flu viruses, the probe said.
Avian flu viruses pass from infected birds to humans in close proximity but typically do not transmit easily between humans.
The worry for health watchdogs is their potential to acquire an ability to jump easily from person to person.
H7N9, which emerged last year, has led to 159 human infections in China, including 71 deaths, according to a combined toll of official figures and an AFP tally of reports by local authorities.
H5N1, which first occurred among humans in Hong Kong in 1997, has caused 648 infections with 384 deaths since 2003, according to figures cited in The Lancet study.
The genome of H10N8, it said, pointed to a mutation in its so-called PB2 protein that, previous research has found, suggests an ability to adapt to mammals.
The virus also has a mutation in its haemagglutinin protein — a spike on the virus surface that enables it to latch onto other cells — that suggests it can infect deep in the lung, like H5N1, rather than the upper respiratory tract, the trachea.
Lab tests on the sample showed it could be attacked by Tamiflu, the frontline anti-viral drug.
Many questions remain, including how the woman was infected.
She had bought a live chicken at a poultry market several days before falling sick.
But she may have become infected beforehand, the scientists said. She did not handle the bird and no virus traces were found in poultry at the market.
In addition, the woman may have been an easy target for the virus because of poor health — she had coronary heart disease, high blood pressure and a muscle-weakening disease called myasthenia gravis.
Tests on people who had been in close contact with her concluded that no one else had been infected.
The second case of H10N8 “is of great concern”, said co-author Mingbin Liu of the Nanchang branch of China’s CDC.
“It reveals that the H10N8 virus has continued to circulate and may cause more human infections in the future.”
Broader global access to lifesaving antiretroviral therapies and wider implementation of proven HIV prevention strategies could potentially control and perhaps end the HIV/AIDS pandemic. However, a safe and at least moderately effective HIV vaccine is needed to reach this goal more expeditiously and in a more sustainable way, according to a new commentary from Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and colleague Hilary D. Marston, M.D., M.P.H.
In the piece, the authors note that behavioral, cultural and legal factors have hindered HIV prevention and treatment efforts and explain why those factors necessitate the development of an HIV vaccine. Although attempts to develop a vaccine have so far proven disappointing, recent advances offer encouraging areas for HIV vaccine researchers to pursue, according to the authors.
Notably, the discovery of naturally occurring broadly neutralizing antibodies against HIV and studies of their stimulation in infected individuals have opened new avenues in vaccine development. Using improved understanding of those antibodies and the specific sites on HIV to which they bind, the natural process of antibody evolution could be replicated and greatly expedited allowing protection against initial infection. Significant advances also have been made in understanding T-cell responses that may be important to vaccine-induced immunity against HIV.
The authors conclude that “the HIV prevention community should hold fast to its commitment to vaccine science. Ultimately, we believe, the only guarantee of a sustained end of the AIDS pandemic lies in a combination of nonvaccine prevention methods and the development and deployment of a safe and sufficiently effective HIV vaccine.”
FOLLOW THE SCIENCEDAILY POST HERE.
Applications of network theory for a plague outbreak:
Over the period of January 2012 to January 2014, 17 raccoons were submitted to the Animal Health Centre in Abbotsford, [British Columbia] for necropsy. 9 were juvenile, 5 were adult, and 3 were of undocumented age. The animals were free ranging and had been found either dead, injured, or weak and disoriented, by members of the public or employees of provincial agencies. Of the 17 raccoons, 12 carried patent roundworm infections (7/9 juvenile, 3/5 adults, and 2/3 of undocumented age).
The raccoon roundworm, Baylisascaris procyonis, is widespread throughout North America and commonly affects free ranging raccoons. In our 2 year review, 12/17 raccoons (71 per cent) were carrying the parasite. This agrees with other published infection rates, including those previously found in BC. This parasite has a fecal-oral life cycle. The raccoon ingests infective eggs from the environment which hatch to larvae. The larvae migrate into the intestinal wall and then emerge as adults into the intestine. Adults lay eggs which exit the intestinal tract via the feces and the cycle starts again. However, if an animal other than a raccoon ingests an infective dose, the larvae will likely migrate to areas outside of the intestine and may cause inflammatory disease in organs (visceral larva migrans), the eye (ocular larva migrans), and/or the brain (neural larva migrans). It is reported that 5 to 7 per cent of cases involve the brain and up to 90 species of [vertebrate] animals, both wild and domesticated, have been diagnosed with this disease.
Baylisascaris procyonis is regarded as an emerging zoonotic pathogen of humans. If an infective dose is ingested by a person, there may be aberrant migration resulting in inflammatory disease in organs, eyes, and/or brain. A dose of about 5000 eggs is considered infective. This sounds like a lot until you consider that the prevalence of infection in raccoons is high (71 per cent in our review), large numbers of worms are present in an infected raccoon and females are capable of producing up to 800 000 eggs per day.
Plus, the eggs are hardy and survive for long periods in the environment. Therefore, the chances of significant infection are high if a person is exposed to an area infected with raccoon feces.
Raccoons are common inhabitants of both rural and urban areas and frequent public and private garbage cans, pet food bowls, and other sources of food in close association with humans. Recognition of the potential for infection, particularly for young children, is critical for prevention. Security of garbage receptacles and feed sources in both rural and urban areas can minimize visits by raccoons and thereby reduce the environmental load of raccoon feces replete with eggs. Good hygiene (hand washing, wearing gloves, keeping hands away from the mouth) is especially important when working in an area frequented by raccoons and, of course, toddlers should never play in such areas. Remember that we always need to be mindful about what we can do to help improve human/wildlife coexistence in our urban areas.
TORONTO – February 4th, 2014 – The number of H7N9 bird flu infections continues to climb rapidly in China.
The Public Health Agency of Canada’s director general for immunization and respiratory infectious diseases said Canada is monitoring the situation in China, and continues work on an update of the national pandemic preparedness plan that was begun in the aftermath of the 2009 H1N1 pandemic.
“We’re very interested and watching very carefully what is going on in China,” Dr. John Spika said Monday in an interview.
“But the bottom line is that until the virus demonstrates some ability to more efficiently spread from person to person it remains something that we’re very interested in, watching carefully but still consider to be a low risk.”
Since the new H7N9 virus emerged last spring, there have been about 277 cases diagnosed; 63 of the infections have been fatal. After several months with no infections over the summer, new cases began to pop up in the fall as temperatures went down and conditions for the spread of influenza viruses improved. Since then, there have been 142 new cases, and 18 deaths, according to the United States Centers for Disease Control.
Canada has not asked its pandemic vaccine suppliers to make and test H7N9 vaccine, opting instead to wait for the results of clinical trials being done in the U.S.
The U.S. Biomedical Advanced Research and Development Authority — BARDA — has funded trials to test how much vaccine each person would need to gain protection against H7N9, and whether a boosting compound called an adjuvant would be needed to stretch supplies during a pandemic.
Past studies of H7 flu viruses have shown they are poorly immunogenic; without an adjuvant, even large doses produced poor results.
The U.S.-funded studies of H7N9 vaccine have confirmed that two doses per person would be needed to get a protective response, and that an adjuvant would be needed.
The U.S. has decided to stockpile H7N9 vaccine, though it will not reveal how many doses it plans to have on hand. Spika said to this point there has been no decision taken on whether Canada should add H7N9 vaccine to a national stockpile, which already includes some H5N1 vaccine.
FOLLOW
Nearly half of HIV-infected teenagers and young adults forego timely treatment, delaying care until their disease has advanced, which puts them at risk for dangerous infections and long-term complications, according to a study led by the Johns Hopkins Children’s Center.
The researchers say their findings, published Feb. 3 in JAMA Pediatrics, are particularly troubling in light of mounting evidence that starting treatment as early as possible can go long way toward keeping the virus in check and prevent the cardiovascular, renal and neurological damage characteristic of poorly controlled HIV infection over time. Those most likely to show up in clinic with advanced infections were male and members of a minority group, the study found.
While the researchers did not study specifically why patients were showing up in clinic with advanced infections, they believe some youth were simply unaware of their HIV status, while others had been diagnosed earlier but, for a variety of reasons, did not seek care.
“These are decidedly disappointing findings that underscore the need to develop better ways to diagnose teens sooner and, just as importantly, to get them into care and on therapy sooner,” says lead investigator Allison Agwu, M.D., an infectious disease specialist and HIV expert at the Johns Hopkins Children’s Center.
The researchers analyzed records of nearly 1,500 teens and young adults, ages 12 to 24, infected with HIV and seen between 2002 and 2010 in 13 clinics across the country. Between 30 percent and 45 percent of study participants sought treatment when their disease had reached an advanced stage, defined as having fewer than 350 CD4 cells per cubic millimeter of blood. CD4 cells are HIV’s favorite target and the immune system’s best trained sentinels against infection. Depletion or destruction of CD4 cells makes people vulnerable to a wide range of bacterial, viral and fungal organisms that generally cause no disease in healthy people, but lead to severe life-threatening infections in those with compromised immune systems. In a healthy person, the number of CD4 cells can range between 500 and 1,500 per cubic millimeter. HIV-infected people with CD4 counts below 500 require treatment with highly active anti-retroviral therapy that keeps the virus in check and prevents it from multiplying. Those with CD4 cell counts below 200 have full-blown AIDS.
Even though the U.S. Centers for Disease Control and Prevention recommend HIV testing for everyone between the ages of 13 and 64, many infected people continue to slip through the cracks, the investigators say, due to unwillingness to get tested, fear, stigma and clinicians’ biases.
“Clinicians need to get away from their own preconceived notions about who gets infected, stop risk-profiling patients and test across the board,” Agwu says. In addition, Agwu says, pediatricians should help teens view HIV testing as part of their regular physical — just as essential as checking their weight or blood sugar levels.
One finding of particularly grave concern, the investigators note, was that patients with lower CD4 cell counts tended to have more active virus circulating in their blood and bodily fluids, which makes them more likely to spread the infection to others.
Those diagnosed with HIV should start therapy early and be followed vigilantly, the researchers say, to ensure that the virus is under control, to prevent complications and to reduce the risk of spreading the infection to others.
“We have to become more creative in linking those already diagnosed with services so they are not deteriorating out there and infecting others,” Agwu says.
Males and members of racial and ethnic minorities were more likely than others to seek care at more advanced disease stages, the study showed. Black youth were more than twice as likely as their white counterparts to show up in clinic at more advanced stages, while Hispanic youth were 1.7 times more likely to do so. Boys and young men were more likely than girls to show up in clinic with lower CD4 cell counts. Males, as a whole, may be at higher risk for delaying treatment, the researchers say, because they tend to receive less regular care than teen girls and young women, whose annual OB/GYN exams make them more likely to get tested and treated sooner.
Males infected through heterosexual intercourse also tended to get to clinic for treatment at more advanced disease stages than homosexual males, a finding that suggests this population may underestimate its own HIV risk. This perception of low risk, the researchers say, may have been fueled inadvertently by public health campaigns that focus on men who have sex with men — the group at highest risk for HIV infection.
“In our study, heterosexual males emerged as this fall-through-the-cracks group,” Agwu says. “We’ve put a lot of emphasis on men who have sex with men in our screening and outreach, but one side effect of this may be that straight males perceive themselves as low risk.”
FOLLOW THE SCIENCEDAILY POST HERE.
Lyme disease is often evident by a rash on the skin, but infections do not always produce similar rashes. This can make it difficult to detect the disease early, when antibiotic treatment is most effective. In the February 4th issue of the Biophysical Journal, published by Cell Press, researchers describe a new mathematical model that captures the interactions between disease-causing bacteria and the host immune response that affect the appearance of a rash and the spread of infection.
“Our findings are important because they connect how the rash looks with the behavior of the bacteria in our body,” says co-author Dr. Charles Wolgemuth of the University of Arizona in Tucson.
Dr. Wolgemuth and graduate student Dhruv Vig developed a fairly simple mathematical model that can account for the growth and appearance of a Lyme disease rash and might be used to predict the densities of the disease-causing bacteria in relationship to the rash as a function of time during spreading.
In many cases, patients with Lyme disease develop a rash with a bull’s-eye appearance. The model reveals that in these cases, the rash begins as a small and uniform rash. Activation of the immune response is strongest at the center of the rash and clears most, but not all, of the bacteria from the center within about one week; however, bacteria at the edge of the rash continue to spread outward, further activating the immune response away from the edge. Therefore, the rash grows, but the center becomes less inflamed. As time progresses, though, the bacteria resurge at the center, leading to the characteristic bull’s-eye pattern.
By revealing that the bacteria and immune cell populations change as a rash progresses, the model may help guide Lyme disease treatment. “The model that we have developed can be used to predict how the bacteria move through our bodies and how they are affected by therapeutics,” explains Dr. Wolgemuth. To that end, the researchers simulated the progression of different rash types over the course of antibiotic treatment. They found that for all types of Lyme disease rashes, bacteria were cleared from the skin within roughly the first week; however, the dynamics of disappearance of the rash varied depending on the type of rash with which the patient presented. For example, while bull’s-eye rashes resolved within a week of treatment, uniform rashes tended to be present even after four weeks, likely due to prolonged inflammation. Such differences suggest that there may not be a one-size-fits-all treatment regimen for resolving Lyme disease and its effects on the body.
Dr. Wolgemuth also notes that there are a number of similarities between the bacterium that causes Lyme disease and the bacterium that causes syphilis, and that “therefore, it is likely that this model will also be applicable to understanding syphilis, as well as potentially other bacterial infections.”
Some noted of birds, pathogens, and pathogen dispersal via migration.
By Jonas Waldenström
Close your eyes and let your mind wander. Try to imagine the most beautiful place you can think of, fill it with scents and colors, let flowers blossom and birds sing, let there be volcanoes and old ruins! And let there be food, rich wonderful food, and wines that make your heart sing! Where would that be? What kind of paradise is that? The answer is simple: an Italian island in April and May! There are few places on this planet that are more endearing than the Mediterranean coast in spring, where the wing beats of history are present in the landscape itself, and where the stunning orioles and bee-eaters make any birder go bananas!
Recently, I wrote a post on how biologists are obsessed with grim, dirty and tedious fieldwork – the worse the better! I poured a lot of wisdom in that text and have…
View original post 963 more words
HIV infection has many unhealthy consequences on the body, but in particular it messes up the gut.
The human intestine has the highest concentration of HIV target cells, the majority of which are destroyed within days of infection, and before CD4 T cell counts drop measurably in the blood.
A study published on January 30th in PLOS Pathogens reports the first three-dimensional ultra-structural study of HIV infection in vivo. Not only does it reveal details on how the virus quickly infects immune cells in the gut, using them as virus-producing factories, but it also highlights where the virus “hides out” deep within the intestinal tissue.
Pamela Bjorkman, from the Howard Hughes Medical Institute and the California Institute of Technology, USA, and colleagues used electron tomography for a high-resolution study of HIV virus in the guts of “humanized” mice, whose immune system is made up to a large degree of human cells. They infected these “BLT mice” (so-called because they have human bone marrow, thymus, and liver cells) with HIV virus and developed methods that allowed them to safely examine and visualize the three-dimensional architecture of infected parts of the gut.
They saw HIV-infected human immune cells, caught virus particles in the act of budding from such cells, and also found groups of free immature and mature viruses. For one infected host cell (turned HIV factory) the researchers counted 63 virus particles it had likely released. The actual number is almost certainly much higher, because the method can only visualize virus particles surrounding the host cell within a relatively small part of the tissue. Nevertheless, they discovered that groups of viruses that were farther from the host cell were more mature than those closer to it, which suggested that the host cell releases new virus in a series of “semi-synchronized” waves.
Among the samples, the researchers found some where viruses released from one infected cell seemed directly to attach to a neighboring host cell, presumably infecting it. In addition to such “virological synapses,” they also observed free virus particles that appear to have covered some distance between their “mother” cell and the cell that would become their target to infect.
These images provide the first 3D ultrastructural details on HIV infection and virus production in a setting that closely resembles the gut of human patients. Some results confirm earlier findings from in vitro experiments—cells grown and infected in a petri dish—but others are seen for the first time and advance the understanding of how HIV infection spreads in real life.
“To me, an important finding is that the majority of the viral transmission events within tissue involved free virus rather than virological synapses”, says Bjorkman. “The spread of viruses through synapses had been speculated to be a major route of transmission in tissue, but our results reveal large pools of free virions. This discovery provides hope that possible therapeutics, such as antibodies, would be able to access infecting viruses that are not hidden within a virological synapse.”
FOLLOW THE EUREKALERT! SOURCE HERE.
FOLLOW THIS VIDEO CLIP OF THEIR PLOS PATHOGENS RESEARCH HERE.
The habit of Googling for an online diagnosis before visiting a GP can provide early warning of an infectious disease epidemic.
In a new study published in Lancet Infectious Diseases, internet-based surveillance has been found to detect infectious diseases such Dengue Fever and Influenza up to two weeks earlier than traditional surveillance methods.
Senior author of the paper titled Internet-based surveillance systems for monitoring emerging infectious diseases, QUT Senior Research Fellow Dr Wenbiao Hu said when investigating the occurrence of epidemics, spikes in searches for information about infectious diseases could accurately predict outbreaks of that disease.
Dr Hu, based at QUT’s Institute for Health and Biomedical Innovation, said there was often a lag time of two weeks before traditional surveillance methods could detect an emerging infectious disease.
“This is because traditional surveillance relies on the patient recognising the symptoms and seeking treatment before diagnosis, along with the time taken for health professionals to alert authorities through their health networks,” Dr Hu said.
“In contrast, digital surveillance can provide real-time detection of epidemics.”
Dr Hu said the study found by using digital surveillance through search engine algorithms such as Google Trends and Google Insights, detecting the 2005-06 avian influenza outbreak “Bird Flu” would have been possible between one and two weeks earlier than official surveillance reports.
“In another example, a digital data collection network was found to be able to detect the SARS outbreak more than two months before the first publications by the World Health Organisation (WHO),” he said.
“Early detection means early warning and that can help reduce or contain an epidemic, as well alert public health authorities to ensure risk management strategies such as the provision of adequate medication are implemented.”
Dr Hu said the study found social media and micoblogs including Twitter and Facebook could also be effective in detecting disease outbreaks.
“There is the potential for digital technology to revolutionise emerging infectious disease surveillance,” he said.
“While this study has looked at the effectiveness of digital surveillance systems retrospectively, Australia is well-placed to take the lead in developing a real-time infectious disease warning surveillance system.
“The next step would be to combine the approaches currently available such as social media, aggregator websites and search engines, along with other factors such as climate and temperature, and develop a real-time infectious disease predictor.”
He said it was also important for future research to explore ways to apply internet-based surveillance systems on a global scale.
“The international nature of emerging infectious diseases combined with the globalisation of travel and trade, have increased the interconnectedness of all countries and means detecting, monitoring and controlling these diseases is a global concern.”
THE OUTBREAK 