Bed bugs are a nuisance that is on the rise around the world, but the bugs don’t spread disease, according to new research. Because they feed on blood, there was a concern that the pests transmitted diseases like HIV and hepatitis, but it now seems that they don’t pose a health threat.
Led by entomologist Jerome Goddard, the study showed no sign of disease transmission by the bugs; it did confirm, however, the bugs’ increased resistance to insecticides and the lack of alternative methods to eradicate infestations, as well as the lack of effective treatment options for troublesome bites. Many people don’t even know they’ve been bitten: 7 in 10 people see no signs apart from an almost invisible puncture mark on their skin. When people do get a reaction, it usually takes the form of red, itchy patches a few millimetres across, each one the result of an individual bite [The Guardian]. Allergic reaction is also possible, but rare, and any rash that results will disappear on most people within a week, although scratching can prolong the symptoms.
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For the first time, researchers have filmed the HIV virus spreading from one cell to the next, and they say the process by which it moves to an uninfected cell may provide a new target for future vaccines or treatments. The videos show how an infected immune system T-cell hooks up with an uninfected cell, and passes a packet of viral particles through a structure called a virological synapse.
For decades it was believed that HIV was mostly spread around the body through freely circulating particles, which attach themselves to a cell, take over its replication machinery and make multiple copies of themselves…. Due to this, previous efforts to create an HIV vaccine have focused on priming the immune system to recognise and attack proteins of free-circulating virus [Telegraph]. While researchers discovered cell-to-cell transmission through the virological synapse earlier this decade, researchers say the videos highlight the extreme efficiency of this transmission process.
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Researchers now have solid evidence that male circumcision protects against three viral sexually transmitted diseases (STDs), and say their findings should encourage parents around the world to circumcise their infant boys. A large study in Uganda involving 5,534 men found that those who underwent circumcision as adults were 25 percent less likely to become infected with herpes and more than 30 percent less likely to catch human papillomavirus (HPV) than their uncircumcised peers…. Previous research has shown that circumcision reduces a man’s risk of acquiring HIV by as much as 60 percent [Scientific American].
Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, says that the area beneath the foreskin of an uncircumcised male provides the “perfect breeding ground for viruses and bacteria.” It can tear and develop sores easily, and if it becomes inflamed, he said, “it gives you much more fertile ground for HIV to be transmitted” [Scientific American], as well as the herpes and HPV viruses. However, the study did not show protection against syphilis, a bacterial STD.
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Before his plane even touched the ground, Pope Benedict XVI sparked a controversy on his first trip to Africa by denouncing the use of condoms and saying they even exacerbate the AIDS crisis. Despite insisting that the church is in the forefront of the battle against AIDS in Africa [AP], during his flight to Cameroon the Pope told reporters that AIDS is “a tragedy that cannot be overcome by money alone, that cannot be overcome through the distribution of condoms, which can even increase the problem” [BBC]. Instead, the solution lies in a “spiritual and human awakening” and “friendship for those who suffer” [AFP].
The seven-day pilgrimage is Benedict’s first trip as pontiff to Africa, the fastest-growing region for the Roman Catholic Church [AP]. But the Vatican’s controversial policy on condoms continues to be tested on a continent where AIDS has killed more than 25 million people since the 1980s [Reuters]. With an estimated 22 million people currently infected on the continent, Africa is home to approximately 67 percent of the world’s population living with AIDS, and claimed a full three-quarters of all AIDS deaths in 2007.
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A compound often used in cosmetics and foods like ice cream may soon find a loftier use: Researchers say a topical gel containing the compound has shown great promise in preventing HIV infection. An effective vaginal gel would be particularly useful in Africa, where the virus is most commonly passed through heterosexual contact. Researchers say that while the current formulation of the compound does not provide 100 percent protection, it might greatly reduce a woman’s risk of being infected, and she could use it privately and without hurting her chances of pregnancy [Reuters].
The compound, glycerol monolaurate (GML), already has FDA approval because it’s used as an emulsifier in some foods and cosmetics; it’s also found naturally in breast milk. What’s more, the price for the compound is right: each dose used in the experiment cost about one cent.
The research marks a new approach to microbicides, as most other gels under development try to kill the virus outright or prevent it from attaching to cells. In contrast, GML stifles the host’s own inflammatory response that typically summons the immune cells targeted by the virus. “Even though it sounds counter-intuitive, halting the body’s natural defence system might actually prevent transmission and and rapid spread of the infection,” said chief investigator Ashley Haase [AFP]. Since GML prevents the immune cells from gathering, the HIV virus can’t infect them all and spread through the body.
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Researchers have tweaked HIV virus to create a strain that can infect monkeys, and say the development will allow better testing of vaccines and AIDS drugs. Until now, AIDS researchers used monkeys infected with simian immunodeficiency virus, or SIV. The virus is similar to ours, but it’s far from a perfect research tool…. Though SIV and HIV wreak similar havoc on their hosts’ immune systems, drugs affect them differently. While that makes SIV useful for studying how the disease progresses, it’s less useful for studying potential treatments [Wired News].
The new strain of HIV was developed by altering a single gene in the human version to allow it to infect a type of monkey called a pig-tailed macaque [Reuters]. The researchers replaced one HIV gene with the SIV version of the gene, which blocks virus-killing proteins made by the monkey and allows the infection to take hold. Even this altered virus doesn’t make the monkeys very sick, but while animal lovers may see that as a benefit, researchers see it as the final hurdle to overcome.
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Cancer will be the world’s leading killer by 2010, edging out heart disease for the top spot, according to the latest report by the World Health Organization (WHO). Though cancer rates in the United States have just recently begun to decrease, elsewhere in the world cancer is on a steady rise. Experts cite tobacco, increasingly Western lifestyles, and inadequate medical care as the factors contributing to the cancer epidemic in developing countries. “In the U.S., we pay a lot of attention to cancer trends, and the trend has been encouraging,” says Dr. Richard Schilsky… “But we have forgotten that there is a big wide world out there. Cancer is a global problem” [TIME].
According to the WHO report, 12 million new cases of cancer will be diagnosed this year and 7 million will die from the disease. The group forecast a 1 percent increase globally each year, with emerging economies such as China, Russia and India being hit the hardest [CNN]. The report also projects a 38 percent population increase in less developed countries by 2030. Taken together, that means by 2030 an estimated 20 to 26 million new cases of cancer will be diagnosed annually and 13 to 17 million deaths will be cancer-related.
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A new device smaller and cheaper than a postage stamp could be used to diagnose diseases in developing countries, Harvard researchers report. The sophisticated microfluidic diagnostic devices, called microPADS, are made out of little more than paper and sticky tape and cost about three cents each. “The starting point with us was asking, ‘What’s the simplest, cheapest [material] we could think of?’ … And that was paper,” [The Scientist] said co-author George Whitesides.
The microPADs, described in the Proceedings of the National Academy of Sciences [subscription required], are made with layers of paper and water-proof tape. Tiny holes and channels etched into the paper lead from a small number of single wells on top and branch out through the stack to an array of microwells on the bottom [IEEE Spectrum]. When liquids such as urine or blood is placed in the upper wells, they are absorbed through the channels into the microwells, which contain proteins, antibodies, or other chemicals. A color-change reaction indicates the absence or presence of a disease. Because the device splits one sample into dozens of separate microwells, several tests can be performed simultaneously. The prototype microPADs transported four separate liquid samples to 64 designated reservoirs within 5 minutes. In 27 out of 30 tries, the devices moved the liquids without mixing them [ScienceNOW Daily News].
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To mark World AIDS Day yesterday, researchers engaged in a “thought experiment” meant both to demonstrate the challenges and the possibilities confronting a world beset by the HIV virus. What would happen, they asked, if everyone was tested annually for HIV, and all people with positive results were immediately put on antiretroviral drugs? In a new study published in the journal The Lancet [subscription required], researchers predicted what the effects of such a policy would be in South Africa. They worked out that treating everyone with the virus with antiretroviral drugs would reduce incidence from 20 per 1000 people to just 1 per 1000 within 10 years…. That’s because the drugs keep levels of the virus in the blood down, making people less infectious – even if they have unsafe sex [New Scientist].
Currently, people have to seek out HIV tests, and those who don’t engage in high-risk behavior (like unsafe sex or intravenous drug use) often never get tested. In addition, the expensive antiretroviral drugs currently aren’t prescribed to HIV-positive patients until their immune systems are compromised and they begin to show symptoms of AIDS. The researchers argue in their article that present policies aren’t working, as 33 million people around the world are currently infected with HIV. The American College of Physicians also released new recommendations this week, advising doctors to routinely screen all patients if possible.
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Indonesia’s Papua province may be the first region in the world to force some HIV/AIDS patients to be implanted with microchip trackers. A controversial bill requiring the extreme measures already has full backing from the provincial parliament and will become law with a majority vote from the provincial legislative body. The microchips are meant to monitor “aggressive” sexual behavior in an effort to control the spread of the disease. Lawmaker John Manangsang said, “It’s a simple technology. A signal from the microchip will track their movements and this will be received by monitoring authorities” [Reuters].
The bill does not specify who would qualify as “sexually aggressive” patients, but if the bill is passed, a committee will be formed to decide who will be implanted; the executive director of the committee will be a physician with a knowledge of epidemiology. Supporters say authorities would be in a better position to identify, track and ultimately punish those who deliberately infect others with up to six months in jail or a $5,000 fine [AP]. Meanwhile, health care workers and AIDS activists called the proposal “abhorrent” and a clear violation of human rights. “No one should be subject to unlawful or unnecessary interference of privacy,” [said Nancy Fee, the UNAIDS country coordinator], adding that while other countries have been known to be oppressive in trying to tackle AIDS, such policies don’t work. They make people afraid and push the problem further underground, she said [AP].
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In a remarkable announcement, German researchers have declared that they “functionally cured” a patient of AIDS, eradicating all traces of the virus from his body. The feat was accomplished with a bone marrow transplant from a donor who had a genetic resistance to the virus, and researchers say that 20 months later they can find no trace of the virus in the patient’s blood, bone marrow, or organ tissue.
But the accomplishment shouldn’t be taken as a sign that a cure for the 33 million people living with AIDS is around the corner, researchers are hasty to add. Professor Rodolf Tauber from the [German] clinic said: “This is an interesting case for research. But to promise to millions of people infected with HIV that there is hope of a cure would not be right” [BBC News]. Reasons for this caution include the small number of potential donors with the HIV-resistant mutation, and the difficulty and expense of bone marrow transplants.
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Scientists say they have bred super immune cells that are able to recognize and destroy many variants of HIV-infected cells. The news comes after a bleak year for AIDS research that saw the failure of the Merck HIV vaccine trial and the cancellation of another. “I think the field as a whole has been taking a step back and thinking we need some different ideas all together,” [New Scientist] said immunologist Philip Goulder.
The researchers’ novel idea was to create a mutant type of immune cells, called T-cells, that would target SL9, a protein that is part of HIV and also appears on the surface of HIV-infected cells. They started with particularly strong T-cells taken from a patient who had resisted HIV infection. “When we tested the T cells from this patient, it looked as if he was responding to a number of those variants that normally escape the immune system,” [The Guardian] said researcher Brent Jakobsen. Through a process of directed evolution, the researchers selected for T-cell mutants that had receptors enhanced to recognize and latch onto SL9. In Nature Medicine [subscription required], the researchers report that in lab cultures of human cells, the souped-up T-cells easily destroyed HIV-infected cells and even recognized tricky variants of the SLP9 protein.
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For many people diagnosed with a sexually transmitted disease, notifying past sexual partners of their health risk is a task that’s just too humiliating to face. That’s why the inSPOT service was created four years ago, a new report explains. With just a few clicks, people can send an anonymous (or signed) e-card to past partners, letting them know that a trip to the doctor is in order. The email includes links to health clinics and STD information, and no information about the sender or the recipient is collected.
The project began when Dr. Jeffrey Klausner of the San Francisco Department of Public Health got together with the tech-savvy nonprofit Internet Sexuality Information Services (ISIS), and brainstormed ideas for a response to an STD outbreak in the gay community. “In 1999, I discovered an outbreak of syphilis related to an AOL chatroom,” Klausner said. Just a year before, San Francisco had eight cases of syphilis a year. By the end of 2004, Klausner said, the city had 550 reported cases. After tracing the outbreaks to the chatroom, Klausner and colleagues at I.S.I.S. Inc decided to use the same type of communication that facilitated the hook-ups to help resolve the situation [ABC News].
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This week, South African health minister Barbara Hogan got her country up to speed with the rest of the world with one statement: “We know that HIV causes AIDS” [Time]. The country’s new health minister has been in office for less than a month, but she has already broken with the health policies of the previous government, which questioned the scientific consensus on HIV and AIDS, and discouraged the use of life-saving AIDS drugs.
Her pronouncement at an international AIDS vaccine conference marked the official end to 10 years of denial about the link between HIV and AIDS by former President Thabo Mbeki and his health minister Manto Tshabalala-Msimang. Activists also accused Tshabalala-Msimang of spreading confusion about AIDS through her public mistrust of antiretroviral medicines and promotion of nutritional remedies such as garlic, beetroot, lemon, olive oil and the African potato [AP]. Tshabalala-Msimang earned the nickname “Dr. Beetroot” from frustrated activists for her recommendations.
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Three researchers who discovered viruses that cause serious diseases have been awarded the Nobel Prize in medicine, the Nobel Foundation announced today. The prize was awarded jointly to France’s Francoise Barre-Sinoussi and Luc Montagnier, who worked together to identify the HIV virus that causes AIDS, and also to the German scientist Harald zur Hausen who discovered the human papilloma viruses (HPV) that can cause cervical cancer.
Barre-Sinoussi, who is the eighth woman to win the medicine prize since the first Nobel Prizes were handed out in 1901, worked with Montagnier to discover the HIV virus. Shortly after reports in the early 1980s of a new immunodeficiency syndrome, researchers all over the world raced to find the cause. The two [researchers] cultured cells from lymph nodes of patients. They first detected the enzyme reverse transcriptase, which meant that a retrovirus was active. Further searching turned up retroviral particles, which could kill white blood cells and which also reacted with antibodies from infected patients [Scientific American].
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