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Shimojima M.,National Institute of Infectious Diseases
Uirusu | Year: 2015

Ebola virus causes Ebola virus disease (EVD) with high case fatality rates in humans and has caused sporadic outbreaks with less than 500 cases. An EVD outbreak in West Africa, which probably started at the end of 2013, has an unprecedented large-scale with more than 20,000 cases including more than 10,000 death and is still ongoing as of May 2015. National Institute of Infectious Diseases has developed laboratory diagnostic methods of EVD to detect pathogens (genes or protein) and antibodies. The methods have been recently used for suspected cases approximately once a year before the outbreak in West Africa, but after the outbreak for 7 times within this 6 months for suspected cases coming back from 3 countries of West Africa to Japan.


News Article | February 27, 2017
Site: news.yahoo.com

Europeans who came to the Americas inadvertently introduced germs — including smallpox and measles — that killed upward of 90 percent of the native people. But now a new study finds that these now-infamous germs weren't the only ones the Europeans were carrying. The Europeans (and their African slaves) also brought new strains of bacteria called Helicobacter pylori, known to cause gastric ulcers and stomach cancer, according to an international team of researchers. The twist is that these "foreign" H. pylori strains didn't kill the local people quickly, like the smallpox virus did. Instead, the strains supplanted the local strain of H. pylori already present in the Americas, and eventually, led to a near extinction of the local strains. [27 Devastating Infectious Diseases] The effects of this may be seen today. These Old World strains of H. pylori now infecting the multiethnic populations of the Americas may be one reason why South America, in particular, currently has some of the world's highest rates of ulcers and stomach cancer, the researchers said. The provocative new study — a mix of anthropology, genetics and public health — appears today (Feb. 23) in the journal PLOS Genetics. H. pylori is a bacterium found in the stomach, transmitted from person to person most commonly through exchange of saliva (oral-oral route) or poor hygiene in food preparation (oral-fecal route). More than half of the world's population is infected with the bacteria, although, globally, fewer than 20 percent of people will develop ulcers and fewer than 2 percent will develop stomach cancer as a result of the infection, according to the World Health Organization. The rates of disease resulting fromH. pylori infection tend to be lower in the wealthier countries of North America, Europe and East Asia, but the rates remain high in South America and Central Asia. People can be treated with a regimen of antibiotics if they are diagnosed with a gastric ulcer caused by H. pylori. In the new study, led by research fellows Kaisa Thorell of the Karolinska Institute in Sweden and Koji Yahara of the National Institute of Infectious Diseases in Japan, scientists analyzed more than 400 H. pylori genome sequences from strains collected in North, Central and South America. They found that European and African strains were mixed together across the Americas, with little sign of the original American strains, suggesting that after the arrival of the newcomers, the foreign bacterial populations spread rapidly to people of different ethnicities, wiping out the local H. pylori strains. "The pre-Columbian Americans had strains of East Asian ancestry [from their migration from Asia millennia ago], of which we nowadays only see traces of in remote communities," said Daniel Falush of the University of Bath in the U.K., the senior author on the study. "However, the reasons for the replacement will require more detailed investigation," he told Live Science. [Body Bugs: 5 Surprising Facts About Your Microbiome] But one reason why some populations living in the Americas today have high rates of ulcers and stomach cancer once infected may have to do with a "mismatch" between the ethnicity of the patient and the origin of the H. pylori strain they carry, Falush said. Studies have found a link between having such a mismatch and an increased risk of disease. For example, in 2014, researchers at Vanderbilt University Medical Center in Nashville reported that the African H. pylori strain was relatively benign in people of African ancestry yet far more disease-causing in people of mixed Amerindian ancestry. A similar study of this same group found that the European H. pylori strain was more likely to cause precancerous lesions in populations with native American ancestry than in European populations. Falush said the new findings may be useful for future research on the connection between individual bacterial strains and their associated risk of causing gastric ulcers and stomach cancer in different human populations. Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science.


Distinct new sub-populations of Helicobacter pylori have evolved in North, Central and South America. Credit: Kaisa Thorell, Koji Yahara and colleagues A genomic study of a harmful stomach bacterium finds that foreign strains intermingled with and replaced local strains after the arrival of Europeans and African slaves across the Americas. The study by Kaisa Thorell at the Karolinska Institutet in Sweden, Koji Yahara at the National Institute of Infectious Diseases in Japan and colleagues is published February 23rd, 2017 in PLOS Genetics. The Americas have been a melting pot, not only for diverse humans for the past 500 years, but also for strains of the microbe Helicobacter pylori carried along in the humans' stomachs. The bacterium persists for decades and commonly spreads from parent to child, but can also colonize new hosts and exchange DNA with local strains. Scientists analyzed 401 H. pylori genome sequences from strains collected in North, Central and South America. They found that European and African strains mixed together across the Americas, with little input from local strains, suggesting that the bacterial populations evolved quickly and spread rapidly to people of different ethnicities. Further analysis finds that the ability of a strain to adapt to a different ethnic group relies on a handful of human immune system genes. This study of H. pylori populations in the Americas sheds new light on the relationship between human migration and bacterial diversity, but also has implications for human health. H. pylori is a major health issue in Latin America where it contributes to ulcers and high rates of stomach cancer. Previous studies have identified a link between cancer risk and a mismatch between the ethnicity of the patient and the origin of the bacterial strain. The current findings may be useful for future explorations of the connection between individual bacterial strains and their associated risk of causing stomach cancer in different human populations. According to coauthor Daniel Falush "Helicobacter pylori has often beendescribed as a pathogen which is mostly passed from parent to child. Ourstudy shows that in the Americas its evolution has been much more dynamic.Native American strains have been largely outcompeted. Bacteria of Africanorigin seem to have done particularly well, hybridizing with strains ofEuropean origin and forming distinct new sub-populations, adapted to localconditions, in North, Central and South America." Explore further: Researchers find coevolution of Heliobacter pylori strains has affected gastric cancer risk More information: Thorell K, Yahara K, Berthenet E, Lawson DJ, Mikhail J, Kato I, et al. (2017) Rapid evolution of distinct Helicobacter pylori subpopulations in the Americas. PLoS Genet 13(2): e1006546. DOI: 10.1371/journal.pgen.1006546


News Article | February 23, 2017
Site: www.eurekalert.org

A genomic study of a harmful stomach bacterium finds that foreign strains intermingled with and replaced local strains after the arrival of Europeans and African slaves across the Americas. The study by Kaisa Thorell at the Karolinska Institutet in Sweden, Koji Yahara at the National Institute of Infectious Diseases in Japan and colleagues is published February 23rd, 2017 in PLOS Genetics. The Americas have been a melting pot, not only for diverse humans for the past 500 years, but also for strains of the microbe Helicobacter pylori carried along in the humans' stomachs. The bacterium persists for decades and commonly spreads from parent to child, but can also colonize new hosts and exchange DNA with local strains. Scientists analyzed 401 H. pylori genome sequences from strains collected in North, Central and South America. They found that European and African strains mixed together across the Americas, with little input from local strains, suggesting that the bacterial populations evolved quickly and spread rapidly to people of different ethnicities. Further analysis finds that the ability of a strain to adapt to a different ethnic group relies on a handful of human immune system genes. This study of H. pylori populations in the Americas sheds new light on the relationship between human migration and bacterial diversity, but also has implications for human health. H. pylori is a major health issue in Latin America where it contributes to ulcers and high rates of stomach cancer. Previous studies have identified a link between cancer risk and a mismatch between the ethnicity of the patient and the origin of the bacterial strain. The current findings may be useful for future explorations of the connection between individual bacterial strains and their associated risk of causing stomach cancer in different human populations. According to coauthor Daniel Falush "Helicobacter pylori has often been described as a pathogen which is mostly passed from parent to child. Our study shows that in the Americas its evolution has been much more dynamic. Native American strains have been largely outcompeted. Bacteria of African origin seem to have done particularly well, hybridizing with strains of European origin and forming distinct new sub-populations, adapted to local conditions, in North, Central and South America." In your coverage please use this URL to provide access to the freely available article in PLOS Genetics: http://journals. Citation: Thorell K, Yahara K, Berthenet E, Lawson DJ, Mikhail J, Kato I, et al. (2017) Rapid evolution of distinct Helicobacter pylori subpopulations in the Americas. PLoS Genet 13(2): e1006546. doi:10.1371/journal.pgen.1006546 Funding: The authors received no specific funding for this work. Competing Interests: The authors have declared that no competing interests exist.


News Article | February 27, 2017
Site: www.chromatographytechniques.com

More than 500 years ago, Europeans and African slaves colonized America, and brought deadly diseases such as smallpox and measles with them, decimating Native American populations. But a new study is focusing on another deadly bacteria brought over by Europeans that is still affecting certain groups in the Americas today. The stomach-dwelling bacteria Helicobacter pylori is known to cause ulcers and cancer, particularly in Latin America. To understand why this group of countries continues to be hit hard by the bacteria, researchers from the Karolinska Institute in Sweden and the National Institute of Infectious Diseases in Japan analyzed more than 400 H. pylori genome sequences from strains collected in North, Central and South America. The results, published in PLOS Genetics, showed that European and African strains of H. pylori were mixed together across the Americas, and the local American strains were rarely seen, suggesting the “foreign” strains took over and spread through various ethnic groups. More than half of the world carries the H. pylori bacteria, but fewer than 20 percent will have ulcers, according to the World Health Organization. Less than two percent will develop stomach cancer from a bacterial infection. But South America has one of the world’s highest rates of the two conditions, while Africa reports rare instances of stomach cancers, even though many people still have the bacteria in their bodies. The research team believes that “mismatches” between an individual’s ethnicity and the origin of the H. pylori strain they carry may be responsible for the high rate of ulcers and stomach cancer reported in South America. A 2014 study that focused on populations in Colombia supports the theory. The study, published in Science, found that people of Amerindian descent carrying African strains of H. pylori were five times more likely to have stomach cancer or precancerous lesions than people of African descent who carried similar strains. H. pylori can live in the stomach for decades, and can be inherited from parent to child. It can also be transmitted through saliva or because of contamination during food preparation. Additional studies could help explain exactly how individual bacterial strains affect different human populations.


Poliovirus (PV) is a small non-enveloped virus belonging to the family Picornaviridae, and is the causative agent of poliomyelitis. With established vaccines, the global eradication program for poliomyelitis is ongoing by the World Health Organization since 1988. In the eradication program, antivirals are anticipated to have some roles in the endgame and post-eradication era of PV. During our search for potent anti-PV compounds, we identified candidate compounds that are associated with a common resistance mutation in viral protein 3A similar to enviroxime (designated as enviroxime-like compounds). Recently, PIK93, an inhibitor of host phosphatidylinositol 4-kinase III beta (PI4KB), was identified as a potent anti-enterovirus compound (Hsu et al., Cell 141:799-811). We found that PIK93 is an enviroxime-like compound, and showed that T-00127-HEV1, which is a novel enviroxime-like compound identified in high-throughput screening, is a specific PI4KB inhibitor. We also showed that PI4KB is an enterovirus-specific host factor required for its viral RNA replication. Analysis of anti-enterovirus compounds would unravel novel host factors that could serve as promising antiviral targets of prophylaxis and therapy of the infection.


Suzuki S.,National Institute of Infectious Diseases
Nihon rinsho. Japanese journal of clinical medicine | Year: 2012

In 2010, a three months survey of multidrug-resistant Enterobacteriaceae was conducted by Ministry of Health, Labour and Welfare of Japan. A total of 153 isolates were obtained through this survey and we performed PCR using the NDM-1 type, KPC type, IMP-1 type, IMP-2 type and VIM-2 type carbapenemase genes specific primers. Of 153 analyzed isolates, 72 (47.1%) were positive for IMP-1 type bla(IMP), and two isolates from two patients were positive for bla(NDM-1). None of those patients had traveled abroad. Two isolates from a single patient who had traveled and hospitalized in abroad were positive for bla(KPC). 77 (50.3%) isolates were all negative for those five carbapenemase genes. It was shown that IMP-1 type is the most predominant carbapenemase gene among Enterobacteriaceae in Japan.


Shimizu H.,National Institute of Infectious Diseases
Uirusu | Year: 2012

To avoid the risk of vaccine-associated paralytic poliomyelitis (VAPP) and polio outbreaks due to circulating vaccine-derived polioviruses, an inactivated poliovirus vaccine (IPV) was introduced for routine immunization in a number of countries with a low risk of polio outbreaks. Currently, production and marketing of a standalone conventional IPV and two diphtheria-pertussis-tetanus-IPV (Sabin-derived IPV; sIPV) products have been submitted, and it is expected that the IPV products will be introduced in Japan in the autumn of 2012. At the same time, a decline in the OPV immunization rate became apparent in Japan due to serious public concerns about a remaining risk of VAPP and introduction of IPV in the near future. Therefore, the recent development of polio immunity gaps should be carefully monitored, and surveillance of suspected polio cases and laboratory diagnosis of polioviruses have to be intensified for the transition period from OPV to IPV in Japan. The development of sIPV is one of the most realistic options to introduce affordable IPV to developing countries. In this regard, further clinical studies on its efficacy, safety, and interchangeability of sIPV will be needed after the introduction of the sIPV products, which will be licensed in Japan for the first time in the world.


Sugawara T.,National Institute of Infectious Diseases
Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases | Year: 2011

Detecting of disease spread is an important task of public health and medical staff, especially in pandemics such as A/H1N1 flu (2009). This requires daily observation and estimation of the infected population. The fully automated real-time pharmacy survey we developed collects information electronically at pharmaceutical prescription. We used the data to analyze the pandemic A/H1N1 flu spread (2009) and to determine the system's and capability in estimating the infected population. Automatic collection of prescription information on antiinfluenza virus drugs from 3959 pharmacies provided the basis for calculating the number of influenza sufferers and determining shape of the epidemic curve compared to that of official influenza sentinel surveys and mandatory reports of A/H1N1 (2009) patients. We also compared infection estimates from the pharmacy survey to those of official sentinel survey and a one-week survey of all hospitals and clinics in Gifu prefecture not reported in sentinel, Fully automated real-time pharmacy surveillance began on April 20, 2009, and provided feedback at 07:00 daily. It estimated the infected population at 22,708 when official sentinel surveillance recorded an average of 0.99 influenza visits per week in epidemic week 32 when publicly announced that the pandemic had began in Japan. By the end of March, epidemic week 12 in 2010, infected-population estimates totaled 9,234,289, and peaked on November 24 at 234,519 in one day. All A/H1N1 (2009) sufferers reported mandatorily until mid-July numbered 25,526. The pharmacy survey indicated that there were influenza nationalwide by the time the very first outbreak emerged in the Kansai (western Japan) area. The correlation coefficient for the pharmacy and official sentinel survey was 0.992 nationwide, exceeding 0.95 in which only 33 of Japan's 47 prefectures were counted. The estimated infected population in the pharmacy survey was half of that of the official sentinel survey. The pharmacy survey yielded almost the same number as the complete survey in Gifu prefecture, however. Fully automated real-time pharmacy surveys are useful in long-term observation e.g. detection of rapid emergence, identifying the peak, and careful monitoring of reemergence. It was demonstrated as the leading indicator for the official sentinel surveillance because of high correlation among them. Information collected daily is very useful in early detection and estimating the affected population. The survey consistently uses the same estimation criterion and operates automatically and routinely, facilitating the comparison of the latest and past results. The pharmacy survey indicated that official sentinel survey estimates overestimate actual cases and thus require modification to ensure accuracy. The pharmacy survey thus appears to be very valuable as a tool in measuring for the second wave of A/H1N1 (2009) or whatever the next pandemic may be. It can, of course, be applied to diseases other than influenza, e.g., varicella, by following antivaricellazostervirus prescriptions and antibiotic drugs.


Silva M.T.T.,National Institute of Infectious Diseases
Arquivos de Neuro-Psiquiatria | Year: 2013

While systemic viral infections are exceptionally common, symptomatic viral infections of the brain parenchyma itself are very rare, but a serious neurologic condition. It is estimated that viral encephalitis occurs at a rate of 1.4 cases per 100.000 inhabitants. Geography is a major determinant of encephalitis caused by vector-borne pathogens. A diagnosis of viral encephalitis could be a challenge to the clinician, since almost 70% of viral encephalitis cases are left without an etiologic agent identified. In this review, the most common viral encephalitis will be discussed, with focus on ecology, diagnosis, and clinical management.

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