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Needle-exchange programs designed to cut injection drug users’ risk of HIV, the virus that causes AIDS, and other infections do seem to reduce needle sharing, but there is only limited evidence that they lower disease transmission, a new research review concludes.

Reporting in the journal Addiction, researchers say that based on their study — an analysis of five previous reviews of needle-exchange programs — the evidence for the programs’ effectiveness is weaker than generally thought.

However, they also stress that their review did not find needle-exchange programs to be ineffective either.

“The findings of this review should not be used as a justification to close NSPs (needle and syringe programs) or hinder their introduction,” write the researchers, led by Norah Palmateer, of Health Protection Scotland, part of the UK National Health Service.

“Insufficient or weak evidence of an effect is not evidence of no effect,” Palmateer told Reuters Health in an email. “It is more a reflection of the studies and evidence available.”

It is not that studies on needle-exchange programs have been “poor,” Palmateer said, but they are limited by the nature of their design.

Studies looking at needle-exchange programs have been observational, rather than controlled clinical trials where researchers would, for example, randomly assign some communities to start a program, and then compare them over time with program-free communities.

Observational studies, Palmateer noted, are subject to limitations like “selection bias.” For example, if those injection drug users at greatest risk of HIV are most likely to use the programs, then a study may find that program attendees have a higher rate of infection than drug users not involved in needle-exchange.

Needle-exchange programs have always been controversial, with opponents arguing that they sustain people’s addictions and send the wrong message about drug use. The U.S. just recently repealed a ban on federal funding for needle-exchange programs, though some cities have long had their own programs.

Advocates of the programs, including many public-health and HIV experts, point to studies showing that needle and syringe exchange can cut HIV transmission — such as a 2004 review by the World Health Organization (WHO) that concluded there is “compelling evidence” that the programs reduce HIV infections.

However, individual studies have come to mixed conclusions, including those covered by the WHO review, according to the current study.

Palmateer and her colleagues found that of the 10 studies in the WHO review focusing on HIV transmission, five had positive findings; of those five, four had weaknesses in their design that limit the conclusions that can be drawn.

Palmateer’s team also looked at two other reviews that covered many of the same studies as the WHO review. One research team came to similar conclusions as the WHO, while the other was more guarded — saying that the evidence that needle-exchange programs reduce HIV transmission is “modest.”

Overall, Palmateer and her colleagues conclude, there appears to be “tentative” evidence that needle-exchange programs reduce HIV transmission among injection-drug users.

When it came to hepatitis C, a liver infection usually spread through infected blood, there was insufficient evidence to say whether the programs are effective or not, according to Palmateer’s team. Of the five reviews she and her colleagues analyzed, the three major ones did not examine hepatitis C “in any depth,” the researchers write.

There was also insufficient evidence of the effectiveness of alternatives to standard needle-exchange programs — including vending machines that sell syringes and needles, and outreach programs that go to drug users rather than having them come to a clinic.

On the other hand, there was “strong” evidence across the reviews that needle-exchange programs reduce the sharing or reuse of dirty needles, and no evidence of harmful effects, according to Palmateer’s team.

Exactly why the evidence for disease prevention is not as strong is not entirely clear. Studies may have failed to detect an impact, but limitations of the programs themselves may also be at work.

For example, many of the needle-exchange programs studied in these reviews had strict limits on the number of syringes and needles they could give clients, Palmateer and her colleagues note. So while they might have reduced users’ needle sharing and reuse, it might not have been adequate.

It is not known what “level of coverage” — that is, the amount of injecting equipment given to clients — is needed to lower HIV and hepatitis C rates, according to Palmateer’s team. And at any rate, the optimal level will vary from one locale to another.

“The main public health implications of the findings are that a higher level of coverage of interventions, including (needle and syringe programs), is likely required to reduce blood-borne virus transmission,” Palmateer said.

She noted that this may be especially true of hepatitis C, which is most commonly transmitted through drug-equipment sharing. In the U.S., injection drug use is believed to account for most new cases of hepatitis C and about one-fifth of new HIV cases.

Scientists studying the Anopheles gambiae mosquito — the main vector of malaria — have found that when the mosquito takes a blood meal, that act triggers two enzymes to form a network of crisscrossing proteins around the ingested blood. The formation of this protein barrier, the researchers found, is part of the normal digestive process that allows so-called “healthy” or commensal gut bacteria to grow without activating mosquito immune responses. But there is a downside: The barrier also prevents the mosquito’s immune defense system from clearing any disease-causing agents that may have slipped into the blood meal, such as the Plasmodium malaria parasite, which in turn can be passed on to humans.

Disrupting the protein barrier, however, can trigger mosquito immune defenses to intervene and protect the insect from infection, notes the research team from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The enzymes involved in the protein barrier are called immunomodulatory peroxidase (IMPer) and dual oxidase (Duox). The researchers believe it might be possible to prevent the formation of the protein barrier by immunizing people with IMPer or the proteins that crisscross. This vaccine would generate antibodies that, after a mosquito feeds on a human, could disrupt the barrier, reduce parasite survival in the mosquito and prevent malaria transmission.

The role of IMPer-Duox in forming a protective barrier was unexpected — and previously unrecognized, according to Carolina Barillas-Mury, M.D., Ph.D., the senior study author. When her research group silenced, or turned off, the gene for either IMPer or Duox, the mosquito’s midgut immune system took over and greatly reduced Plasmodium infection, indicating that IMPer and Duox are both required for parasite survival.

The IMPer-Duox system also is found in the mucous membrane of some human tissues, such as the colon. Dr. Barillas-Mury’s group is investigating whether a protective protein barrier similar to that seen in mosquitoes also forms in vertebrates, including humans. If so, the barrier could be part of the process that normally prevents the colon from activating immune responses against commensal bacteria, as this would be harmful and lead to chronic inflammation. The existence of such a barrier in humans could have broad implications for the prevention and treatment of diseases such as chronic inflammatory bowel disease.

New research suggests that signs of autism don’t appear in infants before they’re 6 months old but do start emerging by the time they reach the age of 1 year.

“This study tells us that screening for autism early in the first year of life probably is not going to be successful because there isn’t going to be anything to notice,” Sally Ozonoff, a professor of psychiatry and behavioral sciences at the University of California, Davis, and the study’s lead author, said in a university news release. “It also tells us that we should be focusing on social behaviors in our screening, since that is what declines early in life.”

Researchers tracked 50 children until the age of 3 years, recording the number of times that they communicated — by smiling, babbling and making eye contact — during exams. By the time the children were 1 year old, attempts at communication decreased in those who were autistic but increased in the others.

Children in the study included 25 who had autistic siblings, boosting their risk of developing the condition, and 25 others who were at low risk for the disorder.

Autism affects an estimated 1 percent of children in the United States.

“Until now, research has relied on asking parents when their child reached developmental milestones,” Ozonoff explained in the news release. “But that can be really difficult to recall, and there is a phenomenon called the ‘telescoping effect,’ where people usually say that they remember something happening more recently than when it occurred.”

The study was released online in advance of publication in the March print issue of the Journal of the American Academy of Child & Adolescent Psychiatry.

Tinnitus (ringing in the ears) isn’t a highly inherited disorder, Norwegian researchers conclude.

While tinnitus has been reported to cluster in families, little is known about the role that genes play in the condition.

In the new study, researchers analyzed data gathered from almost 13,000 spouses, more than 27,600 parents and offspring, and close to 11,500 siblings. A subgroup of more than 28,000 people completed a second questionnaire designed to collect more information about tinnitus.

About 20.9 percent of the study participants reported definite or probable tinnitus symptoms. The researchers found no indication that tinnitus is passed down through families.

“Our results do not necessarily mean that genetic effects are unimportant for all forms of tinnitus, because this symptom can arise from a wide variety of underlying diseases,” wrote Dr. Ellen Kvestad, of the Norwegian Institute of Public Health, Oslo, and Akershus University Hospital, and colleagues.

“Considering the [varied] origin of tinnitus, rather than searching for the genes responsible for tinnitus in general, future investigators need to identify subgroups of individuals affected by tinnitus with specific causes,” the group wrote. “Our results do not support the spending of large amounts of time and resources to identify the genes that code for tinnitus in general.”

The study appears in the February issue of the journal Archives of Otolaryngology — Head & Neck Surgery.

One health care worker from each of the participating countries traveled to the United States to learn essential newborn care techniques. That person returned home to train other trainers, with the training ultimately reaching 3,600 health care workers in rural communities — physicians, nurses, midwives, and birth attendants with no formal training.

Coordinators and attendants collected data on the births in their communities. In 99.2 percent of cases, they also documented whether babies were alive after one week. The researchers then compared statistics before and after the emergency newborn care training.

The study authors found that the overall rate of infant death during the first 7 days of life did not change among infants who had been administered the essential newborn care regimen. However, the rate of stillbirths dropped sharply — from 23 per 1,000 deliveries to 15.9 per 1,000. The researchers believe these improvements were seen in infants who had not drawn a breath on their own and would have been considered to have been born dead by birth attendants who had not received the early newborn care training.

“The reduction in stillbirth is extremely encouraging,” Dr. Carlo said. “Stillbirths among births attended by midwives and traditional birth attendants declined to nearly the same levels seen among births attended by physicians.”

Dr. Carlo explained that many infants do not take a breath when they are first born. In the majority of these cases, some kind of stimulation — rubbing the back or tapping the soles of the feet — will start the baby breathing on its own. Other infants need air pushed into their lungs. Birth attendants without training in recognizing and resuscitating newborns who do not breathe at birth may consider the babies to be stillborn and not attempt to revive them. The researchers found a decrease in the rates of fresh stillbirth — or death immediately before or at the moment of birth. The study did not find a decrease in macerated stillbirths — those assumed to have died before the beginning of labor.

The study authors concluded that the essential newborn care training was most effective in providing attendants needed skills and expertise in newborn resuscitation. The greatest decrease in stillbirth rates was among deliveries attended by nurses, midwives, and traditional attendants, all of whom, the researchers believe, would likely not have received such training.

“Our results show that training in essential newborn care can play a role in improving birth outcomes in the developing world,” Dr. Wright said.

In a subsequent phase of the study, trainers led in-depth sessions focused exclusively on neonatal resuscitation techniques in 88 randomly selected communities, where attendants had already undergone the ENC program. The researchers found this additional training did not further reduce infant mortality from stillbirth or other causes.

The rate of stillbirths in rural areas of six developing countries fell more than 30 percent following a basic training program in newborn care for birth attendants, according to a study funded by the National Institutes of Health and the Bill and Melinda Gates Foundation. The study tracked more than 120,000 births.

The study tested the efficacy of a three-day Essential regimen that covers basic newborn care techniques, the importance of early breastfeeding, how to keep infants warm and dry, and signs of serious health problems.

The study, the largest of its kind, is one of the first to track the rate of infant deaths following the implementation of such a regimen. The World Health Organization (WHO) estimates that, in addition to more than 3 million stillbirths worldwide each year, nearly 4 million infants die in their first month of life. (http://whqlibdoc.who.int/publications/2006/9241563206_eng.pdf(PDF - 794 KB) )

The results appear in the Feb. 18 issue of The New England Journal of Medicine.

“These findings suggest that a low-cost instructional regimen for birth attendants can be effective in reducing stillbirths in parts of the world where most births are not attended by a physician,” said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH institute, that, along with the Bill and Melinda Gates Foundation, funded the study.

The research was conducted at study sites in Argentina, the Democratic Republic of Congo, Guatemala, India, Pakistan, and Zambia as part of the Global Network for Women’s and Children’s Health Research. The network is a partnership of the NICHD and the Bill and Melinda Gates Foundation.

Waldemar A. Carlo, M.D., of the University of Alabama at Birmingham, led the research team. The study’s senior author was Linda L. Wright, M.D., scientific director of the NICHD Global Network for Women’s and Children’s Health Research (http://www.nichd.nih.gov/research/supported/globalnetwork.cfm)

Before data collection on births began, research staff taught local health care workers how to collect data, assess infant health, and diagnose stillbirth and other conditions. In addition, the researchers provided local health care workers with scales to accurately measure birth weight, hand-held pumps and masks to fill babies’ lungs with air, and clean-delivery kits to prevent infection.

Blacks with diabetes who consume too many calories and too much sodium increase their risk for eye disease, a new study finds.

The research involved 469 black participants who had type 1 diabetes. Six years later, they underwent blood testing, had a complete eye examination and had photos taken of their eyes to determine the progression of diabetic retinopathy, which is the leading cause of blindness among Americans aged 20 to 64 who have diabetes.

People who had high caloric and sodium intake at the start of the study were more likely to have vision-threatening retinopathy after six years. The disease includes proliferative retinopathy (growth of new blood vessels in the retina) and macular edema (leakage of fluid into the macula, the part of the eye responsible for sharp vision).

“In African-American patients with type 1 diabetes, high caloric and sodium intakes are significant and independent risk factors for progression to severe forms of diabetic retinopathy,” concluded study authors Dr. Monique S. Roy, of the University of Medicine and Dentistry of New Jersey, and Malvin N. Janal, of the New York University College of Dentistry.

“These results suggest that low caloric and sodium intakes in African-American individuals with type 1 diabetes mellitus may have a beneficial effect on the progression of diabetic retinopathy and thus might be part of dietary recommendations for this population,” they wrote.

Their study is in the January issue of the Archives of Ophthalmology.

The U.S. Food and Drug Administration and other U.S. health agencies are pledging $30 million toward short- and long-term research aimed at clarifying the health effects of the plastics chemical bisphenol A (BPA).

The chemical is ubiquitous in plastic products, including baby bottles and sippy cups, as well as metal linings of some cans, including those containing infant formula. And it has come under close scrutiny in the past year or two with studies linking it to a host of health and developmental problems.

“Recent reports show subtle effects of low doses of BPA in laboratory animals and that has raised concerns so we now are taking a much closer look at BPA,” said Bill Corr, deputy secretary of the U.S. Department of Health and Human Services (HHS), the umbrella organization for the U.S. Food and Drug Administration and other agencies. “We need more research to understand the potential effects on children,” he said.

Corr and other officials spoke at a Friday afternoon news conference.

The FDA stopped short of stating that it was raising its level of concern about the chemical.

“BPA has not been proven to harm either children or adults,” Corr said. “But the data deserves a much closer look because children are being exposed at early states of development.”

“In a word, FDA does support the use of bottles with BPA because the benefit of nutrition outweighs the potential of risk of BPA,” said Dr. Joshua Sharfstein, principal deputy commissioner of the FDA. “If we thought it was unsafe, we would be taking strong regulatory action.”

Sharfstein added that 90 percent of baby bottles manufactured for the U.S. market no longer contain BPA.

In studies released over the past two years, BPA has been linked to heart disease, sexual dysfunction, cancer, diabetes and hyperactivity, as well as aggression in girls. There is also concern that it could have an effect on the developing fetus.

According to FDA Commissioner Dr. Margaret Hamburg, the agency “shared the perspective of the National Toxicology Program of some concern of health effects of BPA.”

The National Toxicology Program’s 2008 report on BPA used more current data and raised more concern than an FDA report on BPA, leading to criticism of the FDA document.

In the NTP report, experts expressed “some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A.”

“What’s happening today is the FDA is saying that our perspective is now in line with [the NTP assessment],” Scharfstein said. “We have some concern in areas they had some concern and are taking action based on that level of concern to understand more about BPA.”

Sharfstein said the agency was also looking also at new regulatory frameworks for BPA, so that officials could act more quickly on the chemical if warranted.

Until the agencies “answer key question and clarify uncertainties about BPA,” the FDA is “taking reasonable steps to reduce human exposure to BPA, supporting industry’s action to remove BPA from baby bottles and cups, facilitating alternatives to BPA for lining of cans, and supporting efforts to remove or minimize BPA in other food can linings,” Hamburg said.

Corr detailed four steps that consumers can take to reduce their BPA exposure:
As recommended by the American Academy of Pediatrics, babies should be breast-fed for 12 months if possible. The safest and most nutritious alternative is iron-fortified infant formula, even if there are trace amounts of BPA.
Discard scratched baby bottles and cups as they may harbor germs and may release small amounts of BPA.
Very hot infant formula should not be put into BPA-containing bottles as BPA could leach from the container to the food.
Check labels of all bottles and cups to make sure they are microwave and dishwasher safe.

SOURCES: Jan. 15, 2010 teleconference with William Corr, deputy secretary, U.S. Department of Health and Human Services; Margaret Hamburg, M.D., commissioner, U.S. Food and Drug Administration; and Josh Sharfstein, M.D., principal deputy commissioner, FDA

E. coli bacteria in food — commonly linked to food poisoning and the stomach pain and diarrhea that result — might also be the cause of some urinary tract infections.

Researchers have found the same strains of the bacteria in chicken from stores and restaurants and in women with the infections.

There’s no evidence that the germs were transmitted directly to the women through the food they ate, although that’s possible. Still, the findings are the first to suggest a possible link between the food supply and urinary tract infections, said Amee R. Manges, an assistant professor at McGill University in Montreal and lead author of a report on the discovery. It is published in the January issue of Emerging Infectious Diseases.

“This may be happening more frequently then we expected,” Manges said. In addition, she said, the transmission through food could boost the number of urinary tract infections that are resistant to drugs.

Though most strains are harmless, dangerous strains of E. coli germs can be transmitted through food that was contaminated in the field or was not properly handled or cooked, causing problems in the intestinal system. It’s less known that the germs can also spread to the urinary tract in women and men.

In women, that can happen during sex, Manges said. “It’s possible for bacteria to travel from the anus to the vagina and urethra, and that’s where it ultimately causes the infection,” she said.

Urinary tract infections caused by transmission from feces “are most common in older and debilitated individuals in whom the risk of fecal contamination of the urethral orifice is a significant risk, especially in a setting of fecal incontinence,” added Dr. Pascal James Imperato, dean of the School of Public Health at the State University of New York Downstate Medical Center in Brooklyn, N.Y.

It’s also possible for the germs to be transmitted through use of the restroom after handling of contaminated food, said Marion Nestle, a professor in the nutrition, food studies and public health department at New York University.

In their study, Manges and her research colleagues wanted to find out if the same strains of E. coli were present in both meat and in women with urinary tract infections.

They studied 353 samples from Canadian women, ages 18 to 45, who had suspected urinary tract infections. They also examined samples of chicken and honeydew melon from stores and restaurants in Canada.

The researchers found that several strains of E. coli found in the women and in the food were indistinguishable or closely related.

But there’s a big caveat. “We haven’t demonstrated that this woman ate this piece of chicken meat, and therefore her infection was caused by that piece of chicken,” Manges said.

That’s a problem, Imperato said. “Unless one has positive evidence, gathered through a thorough history, that someone ate an E. coli-contaminated food, one cannot definitively conclude that any of these foods were the source of their illness.”

What to do? As usual, “consumers should be careful to follow standard food-safety procedures when preparing meat or eating undercooked food, including frequent hand-washing,” Nestle advised.

Meningitis is a bacterial or viral infection that leads to inflammation of the meninges, tissues that surround the brain and spinal cord.

The U.S. Centers for Disease Control and Prevention says the following factors can increase your risk of contracting meningitis:
Being younger than age 5 (for viral meningitis) or being a pre-teen or young adult (for bacterial meningitis).
Living in a community environment, such as in a dorm or military barracks.
Being pregnant.
Being exposed frequently to farm animals.
Having a compromised immune system such as from a health condition, recent surgery or a side effect of certain medications.