Connect with us

IN THE NEWS

DNA analysis of ancient mummy, thought to have smallpox, points to Hepatitis B instead

A team of scientists has sequenced the complete genome of an ancient strain of the Hepatitis B virus (HBV), shedding new light on a pervasive, complex and deadly pathogen that today kills nearly one million people every year.

While little is known about its evolutionary history and origin, the findings confirm the idea that HBV has existed in humans for centuries.

The findings are based on genomic data extracted from the mummified remains of a small child buried in the Basilica of Saint Domenico Maggiore in Naples, Italy.

Previous scientific analysis of the 16th century remains — which did not include DNA testing — suggested the child was infected with Variola virus, or smallpox. In fact, this was the oldest evidence for the presence of smallpox in Medieval remains and a critical time stamp for its origins.

Using advanced sequencing techniques, researchers now suggest otherwise — the child was actually infected by HBV. Interestingly, children infected with HBV infections can develop a facial rash, known as Gianotti-Crosti syndrome. This may have been misidentified as smallpox and illustrates the trickiness of identifying infectious disease in the past.

The findings are published online in the journal PLOS Pathogens.

“These data emphasize the importance of molecular approaches to help identify the presence of key pathogens in the past, enabling us to better constrain the time they may have infected humans,” explains Hendrik Poinar, an evolutionary geneticist with the McMaster Ancient DNA Centre and a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research.

Using small tissue samples of skin and bone, scientists were able to tease out tiny fragments of DNA and then stitch together pieces of genetic information to create a much more complete picture.

While viruses often evolve very rapidly — sometimes in just days — researchers suggest that this ancient strain of HBV has changed little over the last 450 years and that the evolution of this virus is complex.

While the team found a close relationship between the ancient and modern strains of HBV, both are missing what is known as temporal structure. In other words, there is no measurable rate of evolution throughout the 450-year period which separates the mummy sample from modern samples.

By some estimates, more than 350 million people living today have chronic HBV infections while approximately one-third of the global population has been infected at some point in their lives. Researchers suggest that the underline the importance of studying ancient viruses.

“The more we understand about the behaviour of past pandemics and outbreaks, the greater our understanding of how modern pathogens might work and spread, and this information will ultimately help in their control,” says Poinar.

Story Source:

Materials provided by McMaster UniversityNote: Content may be edited for style and length.


Journal Reference:

  1. Zoe Patterson Ross, Jennifer Klunk, Gino Fornaciari, Valentina Giuffra, Sebastian Duchêne, Ana T. Duggan, Debi Poinar, Mark W. Douglas, John-Sebastian Eden, Edward C. Holmes, Hendrik N. Poinar. The paradox of HBV evolution as revealed from a 16th century mummyPLOS Pathogens, 2018; 14 (1): e1006750 DOI: 10.1371/journal.ppat.1006750
Continue Reading
Advertisement
Click to comment

IN THE NEWS

The cambodian cure for resistant scabies mites

A member shares his story in how he was cured from resistant scabies mites in Cambodia. Where ivermectin and permethrin failed a local monk in a small town in Cambodia combated it with natural herbs and ancient remedies

www.humanparasites.org
Facebook group: Human Parasites Support Network

Continue Reading

IN THE NEWS

New Lyme disease tests could offer quicker, more accurate detection

New tests to detect early Lyme disease — which is increasing beyond the summer months -could replace existing tests that often do not clearly identify the infection before health problems occur.

In an analysis published on December 7 in Clinical Infectious Diseases, scientists from Rutgers University, Harvard University, Yale University, National Institute of Allergy and Infectious Diseases of the NIH and other academic centers, industry and public health agencies say new diagnostic methods offer a better chance for more accurate detection of the infection from the Lyme bacteria.

“New tests are at hand that offer more accurate, less ambiguous test results that can yield actionable results in a timely fashion,” said Steven Schutzer, a physician-scientist at Rutgers New Jersey Medical School and senior author. “Improved tests will allow for earlier diagnosis which should improve patient outcomes.”

Lyme disease is the most common tick-borne infection in North America and Europe. There are currently over 300,000 cases of Lyme disease annually in the United States alone and the disease is increasing and spreading into new regions. Lyme disease frequently, but not always, presents with a bull’s-eye rash. When the rash is absent, a laboratory test is needed.

The only FDA approved Lyme disease tests, based on technology developed more than two decades ago, rely on detecting antibodies that the body’s immune system makes in response to the disease. These antibody-based tests are the most commonly used tests for Lyme disease and are the current standard.

One problem, however, is that many people produce similar — called “cross-reactive” — antibodies in response to other bacteria not associated with Lyme disease, which causes confusing results and makes test accuracy more difficult.

“New tests are more exact and are not as susceptible to the same false-positive or false-negative results associated with current tests,” said Schutzer.

Schutzer and his colleagues say more accurate testing would help doctors decide when to prescribe the antibiotics used to clear the infection and help avoid severe long-term health problems. Antibody tests, can take three weeks or more for the antibody levels to reach a point where the tests can pick up a positive result.

Those involved in the paper joined forces after meeting at Cold Spring Harbor Laboratory’s Banbury Center, a nonprofit research institution in New York. The meeting organized and chaired by Schutzer and John A. Branda, assistant professor of pathology at Harvard Medical School, focused on current Lyme disease tests and new scientific advances made in increasing the accuracy of the diagnosis.

“This meeting and paper resulting from it are particularly significant,” said Jan Witkowski, professor in the Watson School of Biological Sciences at Cold Spring Harbor Laboratory who along with Nobel Laureate James Watson asked Schutzer to lead several symposia. “The participants noted that there are greatly improved diagnostic tests for Lyme disease that can be implemented now, and that the way is open to the development of further tests.”

Story Source:

Materials

provided by Rutgers University. Original written by Robin Lally.


Journal Reference:

  1. John A Branda, Barbara A Body, Jeff Boyle, Bernard M Branson, Raymond J Dattwyler, Erol Fikrig, Noel J Gerald, Maria Gomes-Solecki, Martin Kintrup, Michel Ledizet, Andrew E Levin, Michael Lewinski, Lance A Liotta, Adriana Marques, Paul S Mead, Emmanuel F Mongodin, Segaran Pillai, Prasad Rao, William H Robinson, Kristian M Roth, Martin E Schriefer, Thomas Slezak, Jessica Snyder, Allen C Steere, Jan Witkowski, Susan J Wong, Steven E Schutzer. Advances in Serodiagnostic Testing for Lyme Disease Are at HandClinical Infectious Diseases, 2017; DOI: 10.1093/cid/cix943
Continue Reading

IN THE NEWS

Possible new way to treat parasitic infections discovered

A chemical that suppresses the lethal form of a parasitic infection caused by roundworms that affects up to 100 million people and usually causes only mild symptoms has now been identified by researchers.

 

UT Southwestern Medical Center researchers have identified a chemical that suppresses the lethal form of a parasitic infection caused by roundworms that affects up to 100 million people and usually causes only mild symptoms.

“The approach we used could be applied generally to any nematode parasite, not just this one type,” said Dr. David Mangelsdorf, Chair of Pharmacology, an Investigator in the Howard Hughes Medical Institute (HHMI), and one of three corresponding authors of the study published in the Proceedings of the National Academy of Sciences. The study’s other corresponding authors are at two universities in Philadelphia.

“The plan is to develop better compounds that mimic the Δ7-dafachronic acid used in this study and eventually to treat the host to stop parasitic infection,” he added.

The Centers for Disease Control and Prevention (CDC) reports that the soil-dwelling Strongyloides stercoralis nematode, or roundworm, is the primary strongyloides species that infects humans. Experts estimate that between 30 million and 100 million people are infected worldwide, and most of them are unaware of it because their symptoms are so mild. The parasite can persist for decades in the body because of the nematode’s unique ability to reinfect the host, repeatedly going through the early stages of its life cycle. The nematode that causes the original infection exists in dirt on all continents except Antarctica, and it is most common in warmer regions, particularly remote rural areas in the tropics and subtropics where walking barefoot combined with poor sanitation leads to infection.

However, in people with compromised immune systems — such as those using long-term steroids for asthma, joint pain, or after an organ transplant — the mild form of the illness can progress to the potentially lethal form, a situation called hyperinfection. Studies indicate that mortality from untreated hyperinfection can be as high as 87 percent.

The World Health Organization reports that although the parasitic illness has almost disappeared in countries where sanitation has improved, children remain especially vulnerable in endemic regions due to their elevated contact with dirt. Further, the drug of choice, ivermectin, is unavailable in some affected countries.

“Ivermectin is used to treat the disease but is less effective in the lethal form of the infection,” said Dr. Mangelsdorf, a Professor of Pharmacology and Biochemistry. “We do not know exactly how the glucocorticoid [steroid] causes hyperinfection, but once it does, ivermectin is much less effective, prompting the search for new drugs. The new drug we used in our mouse model appears to be very effective,” he said.

To study the still unknown pathogenesis of the disease, the researchers developed a mouse model susceptible to the full range of infection by the human parasite. Because mice with intact immune systems are resistant to S. stercoralis infection, the researchers began with an immunocompromised strain of mice, and then exposed some to a synthetic steroid called methylprednisolone (MPA) that is commonly used to treat asthma in humans.

The mice were then exposed to the parasitic worms. Compared with untreated mice, those that received the steroid showed a tenfold increase in the number of parasitic female worms and a 50 percent increase in mortality, said Dr. Mangelsdorf, who holds both the Alfred G. Gilman Distinguished Chair in Pharmacology and the Raymond and Ellen Willie Distinguished Chair in Molecular Neuropharmacology in Honor of Harold B. Crasilneck, Ph.D.

In addition, third-stage larvae — the life cycle stage in which the worms can initiate hyperinfection — were found in higher numbers in the steroid-treated versus untreated mice, he added.

“Strikingly, treatment with a steroid hormone called Δ7-dafachronic acid, a chemical that binds to a parasite nuclear receptor called Ss-DAF-12, significantly reduced the worm burden in MPA-treated mice,” Dr. Mangelsdorf said. The Ss-DAF-12 receptor corresponds to a similar receptor in the long-studied C. elegans worm.

Dr. Mangelsdorf and colleagues previously showed (PNAS, 2009) that the DAF-12 receptor pathway is found in many parasitic species. They also showed that activating the receptor with Δ7-dafachronic acid could override the parasite’s development and prevent S. stercoralis from becoming infectious.

“Overall, this latest study provides a useful mouse model for S. stercoralis autoinfection and opens the possibility of new chemotherapy for hyperinfection by targeting the parasite’s own steroid hormone mechanism,” Dr. Mangelsdorf said.

Story Source:

Materials

provided by UT Southwestern Medical Center.


Journal Reference:

  1. John B. Patton, Sandra Bonne-Année, Jessica Deckman, Jessica A. Hess, April Torigian, Thomas J. Nolan, Zhu Wang, Steven A. Kliewer, Amy C. Durham, James J. Lee, Mark L. Eberhard, David J. Mangelsdorf, James B. Lok, David Abraham. Methylprednisolone acetate induces, and Δ7-dafachronic acid suppresses,Strongyloides stercoralishyperinfection in NSG miceProceedings of the National Academy of Sciences, 2018; 201712235 DOI: 10.1073/pnas.1712235114
Continue Reading

#Parasites

Q) How many #jews duhhhz it take ta’ turn the one-time world’z strongest constitu- tional republic, home to a majority of non-jew Germans into W 🐛 R M W O O D ? A) We’re learning, daily. #parasites #BackToTheBoat

test Twitter Media - Q) How many #jews duhhhz
it take ta’ turn the one-time
world’z strongest constitu-
tional republic, home to a
majority of non-jew Germans
into

     W  🐛  R  M  W  O  O  D  ?

A) We’re learning, daily.

#parasites
#BackToTheBoat https://t.co/cWt7Fl263J

@Katievanslyke My meat has tonbe cooked thoroughly because i dont want any #parasites growing in or taking over my body

#Ivermectin

Treatment with #azithromycin plus #ivermectin versus ivermectin alone provides equal protection against #scabies & #impetigo in at-risk communities, new @LSHTM study finds contagionlive.com/link/1284

test Twitter Media - Treatment with #azithromycin plus #ivermectin versus ivermectin alone provides equal protection against #scabies & #impetigo in at-risk communities, new @LSHTM study finds
https://t.co/auqSSLXTgk https://t.co/Z2373jvlQO

Trending