British Columbia Drug and Poison Information Centre (BC DPIC)

New research has mapped the way that MRSA “superbug” bacteria spread, BBC News has reported. The results suggest that antibiotic-resistant bacteria may often spread from large, inner-city hospitals to smaller regional ones when patients are transferred.

The way that superbugs spread has been researched as part of an intricate study conducted by Scottish researchers, who looked at samples taken across the UK over 53 years. The researchers used genetic techniques to scan patterns and mutations within the various samples and to build up a “family tree” showing how a particular strain (called EMRSA-16) has spread between different hospitals across the country. They found that EMRSA-16 has generally spread by transmission from hospitals in large population centres in London and Glasgow to regional healthcare settings. The researchers suggested that patients’ referrals are an important cause of the spread of this bug across the country.

This type of study can provide useful estimates of transmission routes of MRSA, although there is still a need for further research incorporating a larger number of sampled hospitals to determine the wider UK pattern.

MRSA can be prevented through effective hand washing and screening before hospital admission. Find out more about preventing MRSA.

 

Where did the story come from?

The study was carried out by researchers from the University of Edinburgh and was funded by various research grants, as well as US governmental organisations including the National Institute of Allergy and Infectious Diseases, the National Institutes of Health and the Department of Health and Human Services. The study was published in the peer-reviewed journal Proceedings of the National Academy of Sciences USA (PNAS).

The story was covered accurately by BBC News.

 

What kind of research was this?

This study used genetic analysis of bacteria samples to map the way a particular form of MRSA spread between patients and hospitals across the UK. It collected information from infected patients in the UK over 53 years and looked at the emergence and transmission of EMRSA-16, a major clone (type) of MRSA. The study identified genetic elements and mutations of EMRSA-16 that allowed it to spread between patients and hospitals across the county.

MRSA (meticillin-resistant staphylococcus aureus) is a type of bacterial infection that is resistant to a number of widely used antibiotics. It is often referred to as a “superbug”. MRSA infections are more common in hospitals because patients often have an entry point, such as a surgical site, which allows the bacteria to enter the body. Also, bacteria can easily spread through direct contact with other patients and staff or contaminated surfaces.

Proper hand washing and screening are effective methods used to prevent MRSA infections from occurring. Rates of MRSA have fallen in recent years because of increased awareness of infection by both medical staff and the general public. However, it still places a considerable strain on the health system as it is more difficult to treat than other types of bacterial infection. Currently, all patients who go to hospital for a planned procedure are offered a swab test to see whether they are carrying MRSA bacteria.

 

What did the research involve?

Researchers looked at the genetic make-up of more than 80 variations of a major clone of MRSA called EMRSA-16 found in hospitals. Samples were collected from infected patients during a 53-year period. The EMRSA-16 clone of MRSA predominantly occurs in hospitals, and the researchers estimated that it has been present in UK hospitals for about 35 years. Researchers then identified genetic elements and mutations in the bug and tracked how these spread between patients and hospitals across the country.

Researchers used a specialist approach to map part of the genetic make-up of each sample, looking for changes and patterns in its genetics. In effect, this allowed them to build up a “family tree” showing how different strains had developed.

 

What were the basic results?

The key finding of this study was that EMRSA-16 has spread within the UK by transmission from central hospitals serving large populations to smaller, regional healthcare settings. It found that Glasgow in west Scotland was a hub for transmission to 16 surrounding regions in the north and east of Scotland. Similarly, in London EMRSA-16 spread from large city hospitals to smaller surrounding hospitals in south and southeast England.

 

How did the researchers interpret the results?

Study lead Dr Ross Fitzgerald reported that “our findings suggest the referral of patients to different hospitals is a major cause of MRSA transmission around the country.” He also said that “variants of MRSA circulating in regional hospitals probably originated in large city hospitals.”

The researchers concluded that these findings could help prevent the spread of drug-resistant infections such as MRSA.

 

Conclusion

This study estimates how a strain of MRSA (EMRSA-16) may spread from hospitals in major UK cities to smaller regional healthcare settings. Findings from this study are supported by findings of a recent US study, which estimated high transmission routes from large hospitals to long-term care facilities.

The researchers note that the dataset used is limited by the relatively small number of hospitals sampled. Despite its interesting findings, further research is required that incorporates a larger number of sampled hospitals to determine the pattern of spread elsewhere in the UK.

Collecting data on the prevalence and spread of superbugs such as MRSA (medically known as surveillance) plays an important role in containing and eradicating potentially harmful bacteria in medical settings, and ultimately reducing the number and severity of hospital-acquired infections. When used strategically, data of this type, along with simple but effective measures such as thorough hand washing, can make a difference to the spread of infections, as illustrated by the recent fall in MRSA in NHS hospitals.

Analysis by Bazian

Links To The Headlines

Large city hospitals 'breed and spread' MRSA. BBC News, May 15 2012

MRSA outbreaks start at major city hospitals. Daily Express, May 15 2012

Links To Science

McAdam PR, Templeton KE, Edwards GF et al. Molecular tracing of the emergence, adaptation, and transmission of hospital-associated methicillin-resistant Staphylococcus aureus. PNAS, Published online before print May 14 2012

Codexis, Inc., a developer of cost-advantaged processes for the production of biofuels, bio-based chemicals, and pharmaceutical intermediates, today announced that the United States Patent and Trademark Office (USPTO) has granted Codexis' patent covering the biocatalysts and biocatalytic processes used to make key pharmaceutical intermediates in the synthesis of leading hepatitis-C therapeutics.

For the first time, researchers at the University of California, San Diego have peered inside a living mouse cell and mapped the processes that power the celebrated health benefits of omega-3 fatty acids. More profoundly, they say their findings suggest it may be possible to manipulate these processes to short-circuit inflammation before it begins, or at least help to resolve inflammation before it becomes detrimental.

Reducing the non-FDA-approved use of antipsychotic drugs may be a way to save money while having little effect on patient care, according to a Penn State College of Medicine study.

"The world is facing two immediate health crises concerning drugs and vaccines: affordable and reliable access to life-sparing medicines and the safety and reliability of those medicines," Laurie Garrett, senior fellow for global health at the Council on Foreign Relations (CFR), writes in the council's Policy Innovation Memorandum No. 21, titled, "Ensuring the Safety and Integrity of the World's Drug, Vaccine, and Medicines Supply."

Pregnant women in poor communities in Bangladesh who received multiple micronutrients, including iron and folic acid combined with early food supplementation, had substantially improved survival of their newborns, compared to women in a standard program that included usual food supplementation, according to a study in the May 16 issue of JAMA, a theme issue on Global Health.

The New York Times and the Financial Times examine concerns expressed by AIDS activists and members of an FDA panel that last week recommended Gilead Sciences' antiretroviral drug Truvada be approved for pre-exposure prophylaxis (PrEP) to prevent HIV among healthy people at risk of contracting the virus.

"The worldwide counterfeit drug market is huge and growing," Tim Mackey and Brian Liang of the Institute of Health Law Studies at the California Western School of Law and Thomas Kubic of the Pharmaceutical Security Institute write in a Foreign Policy opinion piece, noting such "drugs occupy a wide spectrum of medications, and their quality is suspect; they can be mislabeled, tainted, adulterated, ineffective, or, in the worst cases, all of the above."

The American Academy of Dermatology (Academy) today reiterated the safety and effectiveness of sunscreens to protect against the damaging effects from exposure to ultraviolet (UV) radiation.

Bristol-Myers Squibb Company announced today that the U.S. Food and Drug Administration (FDA) has approved the company's biologics manufacturing facility in Devens, Massachusetts for commercial production of ORENCIA.

A vaccine that targets cancer cells in combination with the drug letrozole, a standard hormonal therapy against breast cancer, significantly increased survival when tested in mice, a team of UC Davis investigators has found.

“Overweight mothers-to-be could be condemning their unborn children to decades of ill health,” the Daily Mail reported.

The news is based on the results of large, long-term research that examined mothers’ body mass index (BMI) before and during pregnancy and how this was linked to various indicators of their children’s health when their children reached 32 years of age. These indicators included BMI, waist size and levels of fat and sugar in the blood, which are associated with the risk of conditions such as diabetes and heart disease.

Researchers found that higher maternal BMI before pregnancy was associated with increased BMI in children, as well as larger waistlines, raised blood pressure and increased blood levels of insulin and fat. Greater maternal weight gain during pregnancy was also associated with increased BMI, waist size and levels of fat in the blood.

This study adds to a growing body of evidence that mothers’ weight before and during pregnancy may affect a range of health-related factors in their children, perhaps even in the long-term. That said, this study’s design means that on its own it cannot prove that a mother’s weight or weight gain during pregnancy are responsible for the health effects seen in their grown-up children. For example, many complex environmental, social and genetic influences are known to determine who develops obesity.

Although the long-term effects of maternal weight are unclear from this study, excess weight is known to increase the risk of complications during birth, as well as making it harder to conceive in the first place. This study highlights the importance of maintaining a healthy weight for these reasons, rather than the potential long-term ones.

The Daily Mail also reported that “concern about the issue is so high that British doctors have started to medicate babies in the womb.” The newspaper appears to be referring to ongoing research into treating women for high blood sugar during pregnancy. This valuable study primarily aims to treat mothers, rather than their unborn babies, to cut potentially dangerous complications, rather than to improve their children’s long-term health.

 

Where did the story come from?

The study was carried out by researchers from the Hebrew University-Hadassah in Israel and the University of Washington in the US. It was funded by the US National Institutes of Health and the Israeli Science Foundation. The study was published in the peer-reviewed medical journal Circulation.

The story was accurately covered by the Daily Mail. However, it should be noted that this study measured factors that can contribute to various diseases, but did not determine the rates of negative health outcomes such as heart attacks, diabetes and strokes mentioned in the news coverage.

 

What kind of research was this?

This cohort study examined how mothers’ BMI and weight changes during pregnancy were associated with various markers of disease in their children once they reached adulthood. The disease markers of interest were waist circumference, BMI, blood pressure and levels of glucose, insulin, fats and lipoproteins in the blood. These were measured once the children reached 32 years of age. Maternal BMI and weight changes during pregnancy were reported by mothers in interviews conducted by nurses while they were in hospital after having their baby.

This is the ideal study design to examine a possible association between maternal weight and children’s health. The study’s strengths also included its large size and long follow-up. However, this type of study can only find associations between factors, and cannot prove a cause-and-effect link. This is because researchers cannot exclude the possibility that another factor is responsible for the association seen.

 

What did the research involve?

This research drew on data from a large, long-running study called the Jerusalem Perinatal Study. The research collected the following information on births in Jerusalem between 1974 and 1976:

• demographic and socioeconomic information
• medical conditions of the mother during current and previous pregnancies and gynaecological history
• smoking status of the mother
• height, pre-pregnancy weight and end-of-pregnancy weight of the mother
• child’s birth weight and gestational age

This information was obtained from maternity ward logbooks, birth certificates and interviews with mothers while they were hospitalised after having their baby.

In this study, a sample of 1,400 individuals born during this period was interviewed and examined again between 2007 and 2009 (when they reached 32 years of age). Individuals who had been born as part of a multiple birth, who were premature or who had congenital malformations were excluded. The researchers collected data on:

• height
• body weight
• waist circumference
• blood pressure
• levels of glucose, insulin and fats in the blood

The researchers looked at associations between maternal pre-pregnancy BMI and weight gain during pregnancy and children’s outcomes at 32 years of age. During their calculations, they accounted for gender, ethnicity and other factors that could explain any relationship seen, including:

• how many previous pregnancies a mother had had
• the mother’s age at the birth
• maternal smoking, and smoking status of the children as adults
• socioeconomic status
• maternal education, and education of the children
• maternal medical condition
• the children’s birth weight and gestational age
• physical activity of the children 

 

What were the basic results?

The researchers found that greater maternal BMI before pregnancy was associated with the following factors in grown-up children at the age of 32:

• increased BMI
• increased waist circumference
• increased blood pressure
• increased blood levels of insulin and fat 
• lower levels of high-density lipoprotein cholesterol

These associations were independent of weight gain during pregnancy (i.e. were evident regardless of how much weight a mother gained during pregnancy).

Greater weight gain during pregnancy was associated with:

• increased BMI
• increased waist circumference
• increased blood levels of fat 

When calculating these various associations, the researchers split mothers into four evenly sized groups, based on their pre-pregnancy BMI. They found that, on average, the adult children of women in the group with the greatest BMI (maternal BMI more than 26.4kg/m2) went on to have a BMI of  five units (kg/m2) higher than the children of mothers in the lowest quarter (maternal BMI less than 21.0kg/m2).

 

How did the researchers interpret the results?

The researchers concluded that “maternal size both before and during pregnancy is associated with cardiometabolic risk factors in young adult offspring.”  In other words, mothers who have a high BMI before pregnancy or who gain a lot of weight during pregnancy are more likely to have children who have risk factors for various metabolic and heart-related health problems in adulthood.

The researchers added that these associations appear to be driven mainly by children’s body fat during adulthood.

 

Conclusion

The link between pregnant women’s weight and the health of their children has been in the public eye several times in recent months, with high-profile news stories questioning whether our mothers can “programme us to be fat” and the need to “treat babies for obesity while still in the womb”.

This latest study analysed potential links between mothers’ excess weight around the time of pregnancy and “cardiometabolic risk factors” in their children decades later. Cardiometabolic risk factors are factors such as raised BMI and blood sugar, which signal that a person has a higher risk of conditions such as diabetes and heart disease.

The study found a long-term relationship, with higher maternal weight (assessed using BMI) and greater weight gain during pregnancy associated with a number of factors in the mothers' children at the age of 32. These included increased BMI, waist circumference, blood pressure and blood levels of insulin and fats, and decreased levels of high-density lipoproteins (“good cholesterol”) in children. As the authors state, this study “adds to and extends accumulating evidence” of this relationship, as similar findings have been reported in other studies.

This study has shown associations between maternal weight and children’s later health, but it cannot show cause and effect. This is because it cannot rule out the possibility that another factor is responsible for the association seen. Also, both pre-pregnancy weight and weight gain were not directly measured but were reported by mothers in interviews conducted by nurses after delivery. This may have led to some inaccuracy in the calculation of BMI and makes the results less reliable.

The average pre-pregnancy BMI of women in this study was 24kg/m2 (within the healthy range) in mid-1970s Jerusalem. This population may not be typical of pregnant women in the UK today.

In addition, the exact mechanism by which maternal pre-pregnancy weight and weight gain during pregnancy might cause increased levels of cardiometabolic risk factors in children remains to be determined. Several mechanisms, including shared genetic and environmental characteristics or changes caused by exposures in the womb, have been proposed, although none is completely clear.

Analysis by Bazian

Links To The Headlines

Obesity legacy of mums-to-be: Carrying too many pounds in pregnancy can give your baby a life of weight problems. Daily Mail, May 15 2012

Links To Science

Hochner H, Friedlander Y, Calderon-Margalit R et al. Associations of maternal prepregnancy body mass index and gestational weight gain with adult offspring cardiometabolic risk factors/clinical perspective : The Jerusalem perinatal family follow-up study. Circulation, February 17 2012, 2012;125:1381-1389 (published online before print)

Women concerned about PIP breast implants can find all the latest NHS information about the issue in our Health A-Z section on PIP implants.

Worries about the implants have emerged since news of a major investigation into them in France was widely covered in the media in December 2011.

Initially it was thought that around 40,000 women in the UK had the implants but on March 15 the Department of Health said new evidence meant a further 7,000 women in the UK might have them. About 95% of the implants were provided privately for purely cosmetic reasons.

The French implants caused global concern after it was revealed they contained industrial silicone rather than medical-grade fillers and that they may be more prone to rupture and leakage than other implants.

Initially reports also linked the implants to a rare form of cancer known as ALCL. This cancer link has been now been firmly discounted by medical experts here and in Europe.

 

What type of implants are involved?

The implants involved are called Poly Implant Prosthèse (PIP) and were made by a French company of the same name.

In a Medical Device Alert in March 2010, the Medical and Healthcare products Regulatory Agency (MHRA) said: " ... most
breast implants manufactured by the company since 2001 have been filled with a silicone gel with a composition different from that approved".

That alert was based on advice from French regulators. However, after an investigation by the MHRA, the French authorities reported in March 2012 that PIP implants made before 2001 may also contain unauthorised silicone gel.

PIP gained approval to market its silicone implants in 1997 but it is not clear when it began using a cheap type of silicone gel intended for making mattresses.

The marketing, distribution and use of the PIP implants was suspended in March 2010.

 

Do the implants have to be removed early?

About one breast implant in five needs replacing within 10 years, whatever the make, so it is unlikely that all the 7,000 women who had PIP implants before 2001 still have the same implants.

An expert committee was set up recently to examine the specific risks associated with PIP implants. It concluded that there was not enough evidence to recommend their early removal. That advice has not changed. For more details, read the expert review group's report (PDF, 159kb).

Links To The Headlines

No Routine Removal For PIP Breast Implants. Sky News, January 6 2012

NHS will remove implants free of charge for their patients but private clinics must pay for operations themselves, Government says. Daily Mail, January 6 2012

Government will pay for women who had breast implants on NHS to have them removed. The Daily Telegraph, January 6 2012

Clinics 'should remove implants'. BBC News, January 6 2012

(Henry Ford Health System) Robot-assisted surgery has replaced another minimally invasive operation as the main procedure to treat kidney cancer while sparing part of the diseased organ, and with comparable results, according to a new research study by Henry Ford Hospital urologists.

(Massachusetts Eye and Ear Infirmary) The Mass. Eye and Ear Curing Kids fund has awarded grants for research projects that aim to help the brain locate sound, identify genes that cause congenital blindness, cure deafness through hair cell regeneration, and improve treatment for childhood eye cancer.

(University at Buffalo) An increasing number of highly educated women are opting for families, according to a national study co-authored by a University at Buffalo economist. The research clearly shows fertility rising for older, highly educated women since the 1990s.