Blogs / 80beats

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 that 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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New genetic evidence shows that people were first infected with the HIV virus around the beginning of the 20th century, and researchers say the virus was able to take hold in human populations because of the growth of colonial cities in sub-Saharan Africa at that time. The evidence comes from a newly discovered tissue sample taken in 1960 from an HIV-infected woman who lived in Leopoldville–the city now known as Kinshasa, the capital of the Democratic Republic of the Congo.

Lead researcher Michael Worobey says that the virus may have crossed over from chimpanzees to rural humans repeatedly in the timeframe he identified, from 1884 to 1924; however, it didn’t take off in human populations until people in sub-Saharan Africa crowded together in cities. When the team looked at the region’s political history, they were struck by parallels between HIV’s spread and population expansion. The first major cities - Kinshasa, Douala, Brazzaville, Yaounde, Bangui - were founded by European colonialists in the late 1800s. Their populations started booming around 1910. “I was stunned by the timing,” says Worobey. “I would bet that cities, and the high-risk [sexual] behaviours found in them, are necessary to allow one of these sporadic viral jumps to get a toehold in the human population” [New Scientist].

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Tiny parasitic worms that cause chronic illness in millions of sub-Saharan Africans may increase their chances of contracting HIV, according to a new report. This study comes just a week after another set of researchers announced a different theory regarding a factor that could increase Africans’ susceptibility to the HIV virus, hypothesizing that a genetic variant found in people of African descent raises the risk of HIV infection.

In the latest study, researchers infected monkeys with the worms that cause schistosomiasis, and then injected them with a form of the HIV virus. They found that much lower amounts of the virus were necessary to give AIDS to the monkeys that had the parasitic worms, as compared to parasite-free monkeys. The phenomenon… needs to be verified in humans. But with primates a generally reliable model of AIDS pathology, it could help explain why sub-Saharan Africa, where 160 million people are infected with schistosomiasis, has 10% of the world’s population and 62% of its AIDS cases [Wired News].

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In a sign of the slow progress in the medical fight against the HIV virus and AIDS, a federal health agency has canceled plans for an ambitious clinical trial of an experimental HIV vaccine. Although this candidate vaccine was once thought very promising, researchers lost confidence in it after the failure last September of a similar candidate from drugmaker Merck & Co. that may have left some volunteers more vulnerable to HIV infection [San Francisco Chronicle].

Researchers at the National Institute of Allergy and Infectious Diseases had hoped to begin enrolling 8,500 volunteers in the vaccine trial last fall, but the trial was postponed after the Merck vaccine was shown to be failing in its two main objectives: to prevent infection and to lower the amount of H.I.V. in the blood among those who became infected…. After a safety monitoring committee detected the problems with the Merck vaccine in September, the company quickly halted its study [The New York Times].

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It’s a mind-boggling piece of medical news: A genetic variant that’s commonly found in people of African descent raises the risk of HIV infection by about 40 percent, but also causes HIV-infected people to live longer. Researchers say the trait is extremely common because it used to have a beneficial effect; it protected people against a form of malaria that is now fairly rare.

The genetic variant may partially account for the high HIV rates in sub-Saharan Africa, where over 24 million people are currently living with the disease. While the differences in HIV prevalence in different parts of the world can be partly explained by different social conditions and sexual behaviour, scientists have long suspected that there may be genetic reasons why the virus is rife in certain communities [BBC News].

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When an experiment finds out that a treatment doesn’t work as expected and that a cherished hypothesis just isn’t right, it’s not considered as newsworthy as an amazingly effective treatment that sparkles with potential. But the negative findings are just as important in their contributions to medical knowledge.

In that category, a new study dismisses the theory that treating herpes reduces patients’ risk of HIV infection, a strategy that was believed to hold promise. Researchers wrote in a commentary: It is time to reassess the hypothesis and to adjust prevention policy accordingly [The Lancet, subscription required].

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Almost 3 million AIDS patients in developing nations are now receiving treatment from the life-extending antiviral drugs, according to a new report. It sounds like good news, until you realize that the World Health Organization (WHO) had hoped to reach that milestone in 2005.

AIDS advocates say the international community was slow to commit to the monumental task of providing drugs to rural patients around the world, many of whom don’t even know that they’re infected. But in the past few years, boosted by the Bush administration’s five-year, $15 billion AIDS program and an organized international effort, the project began to have effect.

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