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Scientists have developed a vaccine that protects mice against a deadly form of the Ebola virus. First identified in 1976, Ebola fever kills more than 90% of the people it infects. The researchers say that this is the first Ebola vaccine to remain viable long-term and can therefore be successfully stockpiled. The results are reported in the journal Proceedings of National Academy of Sciences.
Ebola is transmitted via bodily fluids, and can become airborn. Sufferers experience nausea, vomiting, internal bleeding and organ failure before they die. Although few people contract Ebola each year, its effects are so swift and devastating that it is often feared that it could be used against humans in an act of terroism. All previously developed vaccines have relied on injecting intact, but crippled, viral particles into the body. Long-term storage tends to damage the virus, paralysing the vaccine's effectiveness.
The new vaccine contains a synthetic viral protein, which prompts the immune system to better recognise the Ebola virus, and is much more stable when stored long-term. The vaccine protects 80% of the mice injected with the deadly strain, and survives being "dried down and frozen," said biotechnologist Charles Arntzen from Arizona State University who was involved in its development. He said the next step is to try the vaccine on a strain of Ebola that is closer to the one that infects humans.
BBC News - Vaccine developed against Ebola
Sooner or later, says Abhay Satoskar, a professor of pathology at Ohio State University, drug resistance becomes a problem in the battle against disease-causing organisms or pathogens. Any time you have an agent that targets a pathogen, the pathogens are smart and eventually come up with a strategy to make that drug or agent ineffective, said Satoskar. Most bacteria, viruses and parasites must enter human immune system cells to reproduce and cause illness. Satoskar is leading an effort at Ohio State to develop a compound that blocks a pathogens entry into the cells.
The experimental drug targets a natural cell enzyme, called P13K, that allows pathogens to pass through the cell wall. The compound changes the chemical activity of P13K, blocking entry into cells. The team demonstrated the effectiveness of the cell-blocking strategy with the parasite that causes leishmaniasis, a tropical illness caused by a parasite transmitted in the bite of a sand fly. Also known as leishmania, an estimated 1.5 million new cases are diagnosed each year. The disease causes disfiguring open sores on the skin. Not only is the illness indigenous in many parts of the world, but experts say it is now turning up in U.S. troops returning home from Afghanistan.
There is a drug to treat leishmania, says Satoskar, thats up to 90 percent effective in curing the disease. But Satoskar says the medication has a lot of side effects, including anemia, weight loss and neurological problems, and many people dont complete the 21-day course of injections. Using laboratory mice, Satoskar says researchers compared the effectiveness of the existing drug to the targeted, therapy his team is developing. Satoskar says the new agent worked just as well in treating leishmania, and the cell-blocking strategy could potentially work against other disease-causing organisms or pathogens.
Now the issue is how to do you fine-tune it? And that could be fine tune(d) based on different pathogens, because different pathogens could use different pathways to get in, Satoskar said. Satoskar also is interested in learning whether the experimental compound could be used as a skin spray to prevent infection with leishmania when someone is bitten by a sand fly. An article on preventing leishmania by blocking parasites from mice immune cells is published in the journal Proceedings of the National Academy of Sciences.
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The vicious form of cholera has already killed 7,000 people in Haiti, where it surfaced in a remote village in October 2010. Leading researchers from Harvard Medical School and elsewhere told ABC News that, despite UN denials, there is now a mountain of evidence suggesting the strain originated in Nepal, and was carried to Haiti by Nepalese soldiers who came to Haiti to serve as UN peacekeepers after the earthquake that ravaged the country on Jan. 12, 2010 -- two years ago today. Haiti had never seen a case of cholera until the arrival of the peacekeepers, who allegedly failed to maintain sanitary conditions at their base. "What scares me is that the strain from South Asia has been recognized as more virulent, more capable of causing severe disease, and more transmissible," said John Mekalanos, who chairs the Department of Microbiology and Molecular Genetics at Harvard Medical School.
"These strains are nasty. So far there has been no secondary outbreak. But Haiti now represents a foothold for a particularly dangerous variety of this deadly disease." More than 500,000 Haitians have been infected, and Mekalanos said a handful of victims who contracted cholera in Haiti have now turned up in Venezuela, the Dominican Republic, and in Boston, Miami and New York, but only in isolated cases. How cholera landed in Haiti has been a politically charged topic for more than a year now, with the United Nations repeatedly refusing to acknowledge any role in the outbreak despite mounting evidence that international peacekeepers were the most likely culprits. The UN has already faced hostility from Haitians who believe peacekeeping troops have abused local residents without consequence. They now face legal action from relatives of victims who have petitioned the UN for restitution. And the cholera charge could further hamper the UN's ability to work effectively there, two years after the country was hobbled by the earthquake.
Over the summer, Assistant Secretary General Anthony Banbury told ABC News that the UN sincerely wanted to know if it played a part in the outbreak, but independent efforts to answer that question had not succeeded. He said the disease could have just as easily been carried by a backpacker or civilian aid worker. Banbury said the UN, through both its peacekeeping mission and its civilian organizations "are working very hard ... to combat the spread of the disease and bring assistance to the people. And that's what's important now." "The scientists say it can't be determined for certainty where it came from," Banbury said. "So we don't know if it was the U.N. troops or not. That's the bottom line." A UN spokeswoman repeated the answer when asked again last week: "The [scientists] determined it was not possible to be conclusive about how cholera was introduced into Haiti," said the UN's Anayansi Lopez.
Scientists Trace Cholera Superbug to UN Peacekeepers
African sleeping sickness is caused by a parasite called Trypanosoma brucei that is transmitted by the bite of a tsetse fly. Left untreated, the disease attacks the central nervous system and is often fatal. Sleeping sickness, or trypanosomiasis, is endemic throughout sub-Saharan Africa. It killed an estimated 48,000 people in 2008. Experts say trypanosomiasis cases are largely underreported, so the death rate could be higher. There are five drugs used to treat African sleeping sickness, but little is know about how and why they are effective, or how the parasite has managed to develop resistance to the drugs.
An older drug, called melarsoprol, is a highly toxic arsenic-based compound that can cause symptoms of arsenic poisoning - convulsions, fever, loss of consciousness, nausea and vomiting. But because sleeping sickness can be a lethal illness and because some of the other drugs are so expensive and difficult to administer, melarsoprol continues to be used to treat trypanosomiasis patients. David Horn is a molecular biologist at the London School of Hygiene and Tropical Medicine who led the effort to find the source of the parasite's resistance to existing treatments.
By understanding resistance, we can actually maybe develop tests for resistant parasites and that can guide the intervention strategies that are used in a particular patient, Horn said. The single-celled trypanosome contains 7,000 genes. Researchers used a special technique that switched off each gene individually. That enabled them to find 50 genes that produce proteins associated with the parasite's drug resistance.
Horn says the researchers immediate goal was to understand how the protozoan developed that resistance. In time, Horn says, the research could lead to the development of new drugs using the same mechanisms or pathways that render existing African sleeping sickness drugs ineffective. If we understand how the current drugs work, we may be able to exploit that information to make new drugs that exploit similar pathways, Horn said. An article on drug resistance in the treatment of African sleeping sickness is published in the journal Nature.
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No deaths have been reported in the past three weeks. The Zimbabwe Association of Doctors for Human Rights said Sunday that the nation's troubled coalition government lacked urgency in dealing with public health woes.
In a statement, the group said that amid heavy rains clean water supplies were still irregular or "completely absent" in most impoverished townships in Harare. It said burst sewers were left unattended and meat and fish were sold on streets nearby.
A cholera outbreak in 2009 blamed on the collapse of water, sanitation and prevention services in Zimbabwe killed more than 4,000 people.
Zimbabwe doctors report 800 typhoid cases - Yahoo! News
The discovery of bacteria that are massively resistant to antibiotics wont make the front page these days but when it happens in Antarctica, it is time to sit up and take notice, says an editorial in the New Scientist. The superbugs arent infecting penguins yet or even troubling the researchers who carried them there in their intestines and unwittingly deposited them in the sea via their sewage outfalls. But the discovery is further evidence that antibiotic resistance is no longer just a medical problem it is an environmental one, too. And that makes fighting it much harder.
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In an unprecedented show of unity, leaders of government, public and private health groups and major drug companies have pledged to work closely to combat neglected tropical diseases, or NTDs. These debilitating infections affect 1.4 billion people in the worlds poorest countries. The so-called London Declaration calls for the eradication and elimination of 10 of these tropical illnesses by the year 2020. The World Health Organization says NTDs cost billions of dollars in lost productivity. But the maladies have been largely overlooked by medical researchers because they affect relatively small and mostly poor populations.
Dr. Margaret Chan, WHO Director General, called the initiative a roadmap for an ambitious but achievable journey. Just think of the prospect of freeing millions of people - most of them are children and women - so that they could have a healthy and productive life. On that we need your support. Come with us. This is going to be a long journey but we have [taken] a very good first step, said Chan. With funds from various partners totaling $785 million, the project aims to eliminate many ancient scourges - such as leprosy, sleeping sickness, lymphatic filariasis, blinding trachoma, and guinea worm.
Microsoft chairman and philanthropist Bill Gates pledged $363 million through his namesake foundation. He called the London Declaration 'a milestone event.' We have very ambitious goals that we have set. For example, for guinea worm we have got that 2015 eradication so we have a nice little competition going on between polio and guinea worm to see which would get to be the second disease eradicated and which will get to be the third disease eradicated, and the sooner the better for both of those, said Gates. To speed the search for new drugs to fight the diseases, 13 drug companies have for the first time agreed to share their libraries of experimental compounds. And they also have agreed to donate and deliver billions of doses of drugs every year to aid the poorest of the poor, in the most remote corners of the world.
Dr. Mwele Malacela is director-general of Tanzanias National Institute of Medical Research in Dar es Salaam. She said people in her country have been suffering because drug delivery always has been a challenge, but the London pledges give her hope. Even when we have the donations, funding the delivery of the drugs has been a major problem. Now that we hear that there is more funding in the delivery side, we feel that we will be in a better position, said Malacela.
There have been many initiatives against NTDs, although on a small scale. Dr. Neeraj Mistry, Managing Director of Global Network for Neglected Tropical Diseases, said they were not very effective because access to drugs was limited. It's only now that with raised awareness and increased commitments from drug companies, as well as foundations like the Bill and Melinda Gates Foundation, and the US and UK government, that we can actually take the response to NTDs to scale - which means that we can treat more communities and more people, said Mistry. Experts hope that by decade's end, the focus this initiative brings to neglected tropical diseases will mean they will no longer have to be called neglected.
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Three years ago, his kidneys started to fail and flooded his body with toxins. He became too weak to work, wracked by cramps, headaches and vomiting. On Jan. 19, he died on the porch of his house. He was 51. His withered body was dressed by his weeping wife, embraced a final time, then carried in the bed of a pickup truck to a grave on the edge of Chichigalpa, a town in Nicaraguas sugar-growing heartland, where studies have found more than one in four men showing symptoms of chronic kidney disease.
A mysterious epidemic is devastating the Pacific coast of Central America, killing more than 24,000 people in El Salvador and Nicaragua since 2000 and striking thousands of others with chronic kidney disease at rates unseen virtually anywhere else. Scientists say they have received reports of the phenomenon as far north as southern Mexico and as far south as Panama. Last year it reached the point where Salvadoran Minister of Health Maria Isabel Rodriguez appealed for international help, saying the epidemic was undermining health systems.
Wilfredo Ordonez, who has harvested corn, sesame and rice for more than 30 years in the Bajo Lempa region of El Salvador, was hit by the chronic disease when he was 38. Ten years later, he depends on dialysis treatments he administers to himself four times a day. This is a disease that comes with no warning, and when they find it, its too late, Ordonez said as he lay on a hammock on his porch.
Many of the victims were manual laborers or worked in sugar cane fields that cover much of the coastal lowlands. Patients, local doctors and activists say they believe the culprit lurks among the agricultural chemicals workers have used for years with virtually none of the protections required in more developed countries. -However, a growing body of evidence supports a more complicated and counterintuitive hypothesis.
The roots of the epidemic, scientists say, appear to lie in the grueling nature of the work performed by its victims, including construction workers, miners and others who labor hour after hour without enough water in blazing temperatures, pushing their bodies through repeated bouts of extreme dehydration and heat stress for years on end. Many start as young as 10. The punishing routine appears to be a key part of some previously unknown trigger of chronic kidney disease, which is normally caused by diabetes and high-blood pressure, maladies absent in most of the patients in Central America.
Mystery disease attacks kidneys - Taipei Times
Scientists believe they have found a way to beat sleeping sickness using a bacterium against the tsetse fly host that spreads the disease to humans. In the same way that we have friendly bacteria in our intestines, the tsetse fly harbours bacteria in its midgut, muscle and salivary glands. Experts in Belgium have genetically modified these "good bugs" so they attack the culprit parasite carried by the fly. But work is needed to hone the process. The latest findings are published in the open access journal Microbial Cell Factories.
The disease
Sleeping sickness, or human African trypanosomiasis, is a potentially fatal disease that plagues many regions of Africa. Although the number of people being infected with the disease has been going down thanks to better diagnosis and treatment, there were still more than 7,000 new cases recorded in 2010. The parasite causing sleeping sickness is transmitted to humans through the bite of the infected tsetse fly. This causes fever, headaches, aching joints and itching. Then follows the second stage of disease as the parasites cross the blood-brain barrier to infect the central nervous system. The person then becomes confused, poorly co-ordinated and experiences the sleep disturbances which give the disease its name. Without treatment, sleeping sickness is fatal. But current therapies often have unpleasant side-effects.
Alternatives
The drug most commonly used to treat the condition is a derivative of arsenic developed more than 50 years ago. And the treatment can be excruciatingly painful and potentially fatal. Often described by patients as "fire in the veins," between 5% and 20% of those treated die of complications from the injected drug. And so scientists are seeking alternatives. The Belgium team at the Institute of Tropical Medicine in Antwerp have focused on finding a way to destroy the sleeping sickness parasite - trypanosome - that the tsetse fly carries.
They found bacteria called Sodalis glossinidius, which naturally live in the fly and can be used to mount an attack from the inside. Altering the genes of the bacteria led it to release fragments of antibodies known as nanobodies against the parasite. With more work, the researchers hope to be able to produce targeted nanobodies which could kill or block the development of trypanosome. Dr David Horn of the London School of Hygiene and Tropical Medicine said: "This is a neat and promising concept. The goal now will be to develop a deliverable toxin, not necessarily a nanobody, which exhibits anti-trypanosomal activity in the fly."
BBC News - Bacteria used to fight sleeping sickness
A family of illnesses called Neglected Tropical Diseases [NTDs] adds to the troubles in the Middle East and North Africa. These diseases traditionally affect poor countries, but the new study says NTDs also are prevalent in many middle-income countries, such as Egypt, Saudi Arabia, Morocco and Yemen. Cutaneous leishmanaisis, Dengue, Rift Valley fever, Crimean Congo hemorrhagic fever, said Dr. Peter Hotez of the National School of Tropical Medicine, listing some of the diseases.
Hotez, lead researcher of the study, said he and his colleagues found a huge hidden burden of tropical diseases in the region. Neglected Tropical Diseases disproportionately affect Egypt and Yemen. So these two countries have some of the greatest number of cases of intestinal worm infections, elephantiasis, and schistosomiasis, as well as diseases such as fascioliasis. I would like to call them the most important diseases that you have never heard of, said Hotez.
Researchers also were surprised by the reemergence and prevalence of infections like cutaneous leishmaniasis, caused by a sandfly, and infections transmitted from animals to humans, such as brucellosis - a bacterial infection originating in cattle and sheep. They say diseases of the poor are not a priority in conflict-ridden nations where community and public health systems often have broken down. Hotez said the immediate strategy for controlling the rising infection rate is to step up mass drug administration efforts, especially for schistosomiasis, intestinal helminthes infections, and leprosy.
Dr. Julie Jacobson is senior program officer at the Bill and Melinda Gates Foundation, a leading advocate of a global campaign to eliminate NTDs. She said the research points to a public health problem seen in many conflict-ridden countries, and it underscores the need for vigilance. People see most health problems as being too onerous, too difficult and unsolvable - and here we have some very solvable problems with not a huge price tag," said Jacobson. "It is very cost effective. Fifty cents per person, per year, on average will take care of seven of these diseases, and a lot of drugs are donated for the program outside of that. The elimination of NTDs also will require the development of new drugs, and new vaccines. Hotez said he is hopeful funds will be found to support more research in this area, especially on drugs to treat some of the deadliest and most prevalent of the tropical diseases, such as dengue fever and leishmanaisis.
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Rotavirus is the most common cause of severe diarrhea in babies worldwide. The pathogen kills more than 500,000 children each year, according to data from the U.S. Centers for Disease Control. A vaccine against rotavirus was in wide use until it was pulled from the market a few years ago because of safety concerns. A study in the Journal of the American Medical Association examines the safety and effectiveness of another rotavirus vaccine now being used. Nearly every child in the world gets infected with rotavirus by age three. The diarrhea it causes can result in severe dehydration and death. More than 85 percent of the deaths from this virus occur in Asian and African countries. As many as 2 million children are hospitalized each year because of rotavirus infections.
The younger a child is, the more life-threatening the infection can be, which is why an oral vaccine is given to babies. Babies normally get two or three doses starting when they are two months old. Several years ago, a rotavirus vaccine was taken off the market because it increased a baby's risk of developing a rare, but potentially deadly, intestinal blockage. Other vaccines have since taken its place. But a manufacturer's study of one of them, the RotaTeq vaccine, suggested it, too, might cause intestinal blockage after the first dose. Epidemiologist Irene Shui, at the Harvard School Of Public Health, decided to investigate. Because the rotavirus vaccine is given to almost every child in the United States, its crucial to monitor the vaccines safety, said Shui.
Shui and other researchers examined the records of almost 800,000 babies who received this vaccine, including 300,000 first doses. They were looking for incidents of intussusception, the medical term for this kind of blockage. We did not find an elevated risk of intussusception following any dose of the vaccine, and especially following the first dose, she said.
Shui said even though the intestinal blockage is rare, it is important to continue to monitor these vaccines with additional studies like hers. And she noted that the World Health Organization recommends the vaccine be included in all infant immunization programs. The benefits from rotavirus vaccine in terms of reducing the number of hospitalizations and deaths from rotavirus disease far outweigh the potential risk of intussusception that might exist. In the U.S., according to the Centers for Disease Control, the vaccines are up to 98 percent effective in preventing severe rotavirus disease in infants and young children.
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Clinton was asked after a hospital tour if he agreed with a statement by US Ambassador to the UN Susan Rice about holding accountable those who brought cholera to Haiti. Studies have suggested that peacekeepers from Nepal likely introduced the disease to Haiti for the first time, months after the January 2010 earthquake. First of all, the United Nations has spent a great deal of money in Haiti, Clinton told reporters. Secondly, I dont know that the person who introduced cholera in Haiti, the UN peacekeeper or soldier from South Asia, was aware that he was carrying the virus. It was the proximate cause of cholera. That is, he was carrying the cholera strain. It came from his waste stream into the waterways of Haiti, into the bodies of Haitians, he said.
However, Clinton added that what really caused the cholera outbreak was the countrys lack of proper sanitation. Unless we know that he knew or that they knew, the people that sent him, that he was carrying that virus and therefore that he could cause the amount of death and misery and sickness, I think its better to focus on fixing it, Clinton said. Clinton, the UN Special Envoy to Haiti, made the remarks after he toured a new public teaching hospital in the Central Plateau that was built by the Boston-based Partners in Health.
Partners in Health co-founder Paul Farmer, a public health expert who serves as Clintons deputy at the UN, hosted Clinton as the two toured the hospital, a fish farm and a smaller hospital. An international panel appointed by the UN produced a report that blamed the outbreak on a confluence of circumstances that included bad sanitation. The cholera outbreak prompted a Haitian law firm to file a complaint against the UN last year on behalf of the victims, which is under review by the world bodys legal office. Cholera has killed more than 7,000 people and sickened more than 526,000 others since 2010.
Clinton urges officials to stem Haiti cholera outbreak - Taipei Times
Debilitating tropical infections
Chagas is an infectious disease transmitted by the kissing bug. The kissing bug looks a little bit like a cockroach but it has the ability to feed on blood and it lives in the very poor quality dwellings, said Dr. Peter Hotez, dean of the National School of Tropical Medicine in Texas. He says a serious heart infection caused by the chagas trypanosome parasite now affects a million people in the United States and more than six million in Mexico. But he and his colleagues believe that the disease is often overlooked. It is a disease that could be associated with severe heart disease, often times aneurisms, even electrical disturbances and sudden death. So that if someone dies from what often times physicians or health care providers in Texas might think is a heart attack - its in fact chagas disease, Hotez explained.
Emerging health problem
Researchers say they are trying to understand the full extent of many of the debilitating tropical infections in the region. For example, cysticercosis is now one of the major causes of epilepsy in children in Texas and California. The report notes that another tropical disease, dengue fever, is an emerging problem from Texas to Florida.
It's called bone break fever. It causes severe pain in the joints and bones and rash - its a very severe fever, lasts for seven days and totally lays you out [severely weakens you], said Dr. Dan Stinchcomb, chief executive officer of Inviragen, which is developing a vaccine against the multiple dengue viruses. "In order for a vaccine to be safe and effective, it has to be able to induce a neutralizing antibody response - an antiboyd resp[onsde that will knock out four different viruses simultaneously," he said.
Researchers recommend developing a new generation of diagnostics and drugs to detect and control tropical diseases in the U.S. Dr. Hotez says there is also an urgent need to educate public health workers, cardiologists, and obstetricians about the growing incidence of these neglected infections.
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Deadly malaria that is resistant to drug treatment has spread rapidly from Cambodia to the border between Thailand and Myanmar, raising concerns of an uncontrollable epidemic, scientists said on Thursday. A pair of studies published in the Lancet and the journal Science showed how the disease is moving fast into new territory and identified a region of the parasites genome that may be responsible for mutating in order to survive. Malaria is a mosquito-borne disease commonly caused by a parasite, Plasmodium falciparum, that kills up to 1.2 million people a year, according to 2010 estimates by the Institute of Health Metrics and Evaluation at the University of Washington, Seattle.
Malaria that was resistant to treatment with the current standard therapy, artemisinin, was confirmed in Cambodia in 2006 and has since spread 800km westward to the Thailand-Myanmar border, the researchers said. By studying 3,202 patients along the northwestern border of Thailand near Myanmar from 2001 and 2010 and measuring the time it took them to clear malaria infections from their blood after treatment, scientists were able to show a steady increase in drug resistance. The number of slow-clearing infections rose from 0.6 percent of cases treated in 2001 to 20 percent in 2010.
In western Cambodia, 42 percent of malaria cases were resistant between 2007 and 2010, indicating that the Thailand-Myanmar region was swiftly catching up to Cambodias rates. Genetically determined artemisinin resistance in P. falciparum emerged along the Thailand-Myanmar border at least eight years ago and has since increased substantially, the Lancet study said. At this rate of increase, resistance will reach rates reported in western Cambodia in two to six years, it said.
The research in the journal Science focused on what was making these parasites different, and found that a region on chromosome 13 of the parasite was strongly associated with slow clearance of infection. They sequenced the genomes of 91 P. falciparum parasites from Cambodia and western Thailand and compared them with parasites from Laos, where resistance to the latest artemisinin-based drugs has not yet emerged. They found seven genes that may be responsible for making the parasite resistant to drugs and which may explain up to 35 percent of the growing resistance in Southeast Asia.
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