Excessive antibiotics put health at risk

By Carol Aloysius

In recent years an increasing use of antibiotics by the public in general has raised serious concerns over grave health risks this dangerous practice could pose. Health officials are disturbed that the tendency for people to use antibiotics for even the most trivial ailment such as a minor cold or cough which could easily be cured by plenty of warm liquids such as tea and coriander with a slice of lemon, or ginger and a bit of honey, a well tried recipe for such ailments in our country. They have warned that taking strong medicinal drugs to ward of an infection or mild fever especially without advice from a medical practitioner, could not have diminish the beneficial effects of killing bacteria, but worse still it could make them antibiotic resistant.

Cases of antibiotic resistance have escalated in recent years prompting health authorities to raise more awareness among the public on the use of antibiotics and the danger of overuse. They have also warned pharmacists to refrain from handing antibiotics to patients over the counter and to insist on a doctor’s prescription. Health authorities are also urging family physicians and doctors manning OPD clinics to minimise prescribing antibiotics unless absolutely necessary. The Sunday Observer recently spoke to the Consultant Microbiologist, Sri Jayawardenapura Hospital, Dr Kushlani Jayatilleke for her views on the subject and the role of microbiologists in identifying infections that require antibiotics.

Excerpts…

Q. Although antibiotics have been around for several years, not many people know what an antibiotic is. So tell us, what are antibiotics?

A. An antibiotic is an agent that either kills or inhibits the growth of bacteria in high dilution.

Q. Are they used against any micro-organism?
A. Antibiotics are only effective against bacteria and some protozoa but they are not effective in treating infections caused by viruses or fungi.

Q. When were they first introduced. Tell us something about their history.

A. The first sulphonamide and first commercially available antibacterial, Prontosil, was developed by a research team led by Gerhard Domagk in 1932 at the Bayer Laboratories of the IG Farben conglomerate in Germany.

The effects of some types of mould on infection had been noticed many times over the course of history. In 1928 Alexander Fleming noticed the same effect in a petri dish where a number of disease-causing bacteria were killed by a fungus of the genus Penicillium.

Fleming postulated that the effect is mediated by an antibacterial compound he named penicillin, and that its antibacterial properties could be exploited for chemotherapy.

Florey and Chain succeeded in purifying the first penicillin, penicillin G, in 1942, but it did not become widely available outside the Allied military before 1945. Antibiotics and similar drugs, together called antimicrobial agents, have been used for the past 70 years to treat patients who have infectious diseases. Since the 1940s, these drugs have greatly reduced illness and death from infectious diseases. 

Q. What are the benefits of using antibiotics?

A. Antibiotic use has been beneficial and, when prescribed and taken correctly, their value in patient care is enormous.

The incidence of severe sepsis (serious infections) in the European Union has been estimated at 90.4 cases per 100,000 population, as opposed to 58 per 100,000 for breast cancer. Worldwide 1.8 million cases of severe infections are reported annually, but this is probably more, as some are not reported. These patients with severe infections will invariably die if correct antibiotics were not administered early.

Q. What are the negative aspects?

A. There are several negative aspects to use of antibiotics. The first problem is side effects and adverse reactions to antibiotics. None of the drugs that we use are free of side effects or adverse reactions. As you may know penicillin can cause serious allergic reactions such as anaphylaxis leading even to death. Some other antibiotics can affect the kidneys and patients can go into kidney failure.

They may also affect the hearing and balance. Some others can affect the liver and some can affect the bone marrow leading to low blood cell counts. Most patients feel nausea (feeling sick), loss of appetite and loose stools due to antibiotics.

These side effects may lead to death, especially diarrhoea (antibiotic associated colitis).Uses of antibiotics have led to the infectious organisms the antibiotics are designed to kill getting adapted to them, making the drugs less effective. Many fungi, viruses, and parasites have done the same. Some micro-organisms may develop resistance to a single antimicrobial agent (or related class of agent), while others develop resistance to several antimicrobial agents or classes.

These organisms are often referred to as multidrug-resistant or MDR strains. In some cases, the micro-organisms have become so resistant that no available antibiotics are effective against them.

Q. Is drug resistance one of these negative factors?

A. Antimicrobial drug resistance occurs everywhere in the world. Hospitals and other healthcare settings are battling drug-resistant organisms that spread inside these institutions.

Drug-resistant infections also spread in the community at large. Examples include drug-resistant pneumonias, sexually transmitted diseases (STDs), and skin and soft tissue infections.

People infected with drug-resistant organisms are more likely to have longer and more expensive hospital stays, and may be more likely to die as a result of the infection.

When the drug of choice for treating their infection doesn’t work, they require treatment with second - or third-choice drugs that may be less effective, more toxic, and more expensive. 

Trends in drug resistance 

• Reports of methicillin-resistant Staphylococcus aureus 

(MRSA) - a potentially dangerous type of staph bacteria that is resistant to certain antibiotics and may cause skin and other infections - in persons with no links to healthcare systems these infections have been observed with increasing frequency.

If this organism get into blood the patients can get serious complications such as endocarditis (infection of the heart valves), endophthalmitis (infections of the deep layers of the eye - this is very difficult to treat - may need to remove the eye) and brain abscesses.

• Multi-drug resistant Klebsiella species and Escherichia coli have been isolated in hospitals in Sri Lanka. They can cause urinary tract infections, blood stream infections and other infections.

• Multi-drug resistant Acinetobacter species are also prevalent in most of the hospitals in Sri Lanka and can cause respiratory tract infections and other infections especially in intensive care units.

•Antibiotic-resistant Streptococcus pneumoniae infections have also been reported. This is a bacterium which can cause meningitis, pneumonia and many other serious infections.

•Antimicrobial resistance is emerging among some fungi, particularly those fungi that cause infections in transplant patients with weakened immune systems.

•The agricultural use of antibiotics in food-producing animals also contributes to the emergence, persistence, and spread of resistant bacteria. Resistant bacteria may be transmitted to humans through the food we eat.

•Antimicrobial resistance has also been noted with some of the drugs used to treat human immunodeficiency virus (HIV) infections and influenza.

•The development of antimicrobial resistance to the drugs used to treat malaria infections has been a continuing problem in many parts of the world for decades.

Antimicrobial resistance has developed in a variety of other parasites that cause infections.

In Sri Lanka the antibiotic resistance is reported from different areas. In a surveillance study carried out by the Sri Lanka College of Microbiologists in several hospitals in 2009, 63 percent of the Escherichia coli isolated from blood of patients were resistant to cefotaxime, an antibiotic which is used to treat severe infections with this bacterium.

This means that if these patients were treated with this antibiotic there was very high chance of not responding to treatment and may even die of this infection.

According to another surveillance carried out on Streptococcus pneumonia isolates from severe infections such as meningitis (brain fever) and pneumonia (infections of the lung) nearly 50 percent were resistant to cefotaxime, the drug that is recommended for these infections.

Adding to this alarming situation, another important factor was revealed from a recently concluded study.

In a surveillance carried out in farm animals bacteria isolated from the broiler chicken had high degree of antibiotic resistance.

This is another source of antibiotic resistance bacteria which can come to humans through food chain.

Q. Why is antimicrobial resistance (AMR) a global concern?

A. The world’s premier health organisation, the World Health Organisation summarises the danger of AMR thus:

A. AMR kills
B. AMR hampers the control of infectious diseases
C.AMR threatens a return to the pre-antibiotic era
D.AMR increases the costs of health care
E.AMR jeopardises health-care gains to society
F.AMR threatens health security, and damages trade and economies

Q. How can we stop this? What are the most appropriate interventions?

* We have to stop inappropriate use of antimicrobial medicines, including in animal husbandry.

* Do not request antibiotics from doctors or buy antibiotics over the counter without consulting a qualified doctor.

*Practice good hygienic practices, such as hand hygiene, especially when working, getting treatment or visiting healthcare institutions (hospitals).

No danger from magnetic fields in electric cars

Many people are concerned that electric cars produce dangerous magnetic fields. New research shows that this is not the case.

Researchers from seven countries have concluded that we can feel safe both in electric-powered cars and in those powered by hydrogen, petrol and diesel. None of them exposes passengers to higher electromagnetic fields than those recommended in international standards. In fact, field intensity is well below the recommended value. The study is currently the most comprehensive ever carried out in this field.

SINTEF has led and participated in the research project, involving nine other European companies and research institutes.

“There is a good deal of public concern about exposure to magnetic fields. The subject crops up regularly in the media. With the number of electric-powered vehicles increasing, this project is very relevant,” says Kari Schjølberg-Henriksen, a physicist at SINTEF.

In addition to improving the public's confidence when it comes to magnetic fields in electric cars, the goal of this project was primarily to create a standardised method for measuring electromagnetic fields in such vehicles. The International Commission on Non-Ionising Radiation Protection (ICNIRP) defines the limiting values of acceptable exposure to magnetic fields at different frequencies.

Eleven types

The intensity of magnetic fields in seven different electric cars, one hydrogen car and one petrol car were measured to ascertain whether they approach the recommended limiting values for human exposure. The measurements were carried out using real cars in a laboratory and during road tests.The highest values in electric cars were measured near the floor, close to the battery itself and when starting the cars. In all cases, exposure to magnetic fields is lower than 20 percent of the limiting value recommended by the ICNIRP. Measurements taken at head-height are less than two percent of the same limiting value.

In the case of petrol and diesel powered cars, exposure was measured at around 10 percent of the limiting value. In other words, there is little difference between electric cars and petrol and diesel cars.

Limiting value

Hence the conclusion is that magnetic fields in electric cars are well below the limiting values, and that there is a good safety margin. “There is absolutely no cause for concern.

The difference between this research and similar earlier work is that we have taken into account what contributes to the magnetic fields.

The rotation of the wheels themselves generates considerable magnetic fields, irrespective of vehicle type,” Schjølberg-Henriksen points out. The EU-funded research project EM Safety is the most comprehensive study yet carried out to identify different sources of magnetic fields in electric cars.

Seven countries have been involved in the project, in which universities, the car industry, research institutions and laboratories are represented.

MNT

The end of hepatitis C?

A new report published in the Journal of Viral Hepatitis has shown for the first time that the elimination of hepatitis C could now be possible, if testing and treatment rates are increased.

Using new modelling techniques, clinicians responsible for the treatment of hepatitis C, statisticians and epidemiologists across 15 countries investigated how increasing treatment success and the number of patients treated per year could lead to a 90 percent reduction in the total infected population by 2030 - the clinical definition of disease elimination. The research was supported by an educational grant from Gilead Sciences. “This is the first analysis of its kind to establish how country health services and governments can work to eliminate a disease, within a predictable time frame”, commented Prof Graham Foster.

“Hepatitis C is a curable disease, but today, only three percent of people infected with the virus currently achieve cure.

The research shows that treating only 10 percent of the diagnosed population per year, would ultimately lead to disease elimination by 2030. At lower rates, new infections would keep prevalence higher.”

Each contributing country has determined their own local strategy to achieve the elimination of hepatitis C. Across the 15 countries, research concluded that if newer, more effective medicines are implemented but today's treatment rates remain the same, only moderate decreases in hepatitis C-related illness and death would be seen.

However, by taking a two pronged approach of improving treatment efficacy and increasing annual treatment rates from the current average of 2.2 percent to 10 percent, elimination of hepatitis C is achievable.

Hepatitis C is a global public health issue and is estimated to affect around nine million people across Europe. People infected with hepatitis C may not experience any symptoms for 20-30 years but by the time patients are symptomatic, the virus may have led to the development of severe complications including cirrhosis and liver failure.

Hepatitis C is the leading cause of liver transplantation in the EU, with 62 percent of all end stage liver disease costs associated with transplants.

In Europe the total medical cost to treat the complications of hepatitis C (hepatocellular carcinoma, liver transplant and cirrhosis) per person per year is €13,690, €118,162 and €12,196 respectively. “Hepatitis C prevalence in the majority of European countries has now peaked.

The number of new infections remains stable due to the success of some initiatives to reduce the risk of transmission (e.g. blood screening and needle exchange programs).

However, the ticking time bomb for governments and health systems is that the observed complications from hepatitis C infection are increasing as the population ages.

These complications are what will have the greatest cost impact and so timely identification and treatment ofhepatitis C is paramount to reduce the future costs to the health system and burden on the patient,” said Prof Graham Foster.

- MNT