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Showing posts with label Immunity. Show all posts
Showing posts with label Immunity. Show all posts

Monday 18 December 2023

Protect yourself and your community from disease; Remember to wash your hands

Getting vaccinated is not just about ensuring you don’t fall ill, but also about saving those around you from getting sick.


— Graphics: Positive Parenting This is how an infectious disease with an r-naught of four spreads from one patient.

herd immunity




VACCINATION directly protects individuals who are vaccinated against certain infections, but it can also provide indirect protection to the unvaccinated in a population.

This is what we call herd immunity or community immunity. It is a key aspect of epidemic control.

To understand herd immunity, we need to be familiar with certain terms.

Firstly, we have to know the infectiousness of a disease, indicated by its basic reproduction number (R-naught or R0).

This can be defined as the expected number of new infections generated by one infectious individual in a fully vulnerable population without any control measures.

For example, an infectious disease with an R-naught of four means that one case is expected to generate four other cases.

The higher the R-naught, the more infectious the disease is.

Each infectious disease has its own R-naught and it may vary across populations and over time, depending on various factors.

The R-naught in turn determines the herd immunity threshold (HIT), which is the minimum level of vaccination coverage or minimum number of immune individuals in a population that must be achieved to produce herd immunity against a certain infection.

An easy way to calculate HIT is by using this equation: HIT = 1 – 1/R-naught.

Hence, to achieve herd immunity against a disease with R-naught of four, at least 3/4 or 75% of the population have to be immunised.

This calculation assumes that susceptible and infectious individuals in a population are equally in contact with one another and spread the infection in the same way.

From this, we can deduce that the more infectious the disease, the higher the R-naught, and thus, the higher the HIT, and the more the people that need to be vaccinated to achieve herd immunity in a population.

When enough people are vaccinated against a particular disease, they will be able to ‘protect’ those who are unable to be vaccinated from those who are infected.

For optimal benefit


Various other factors play crucial roles to ensure that optimal herd immunity can be achieved via vaccination.

They include:

> High vaccine effectiveness


This is key to attaining optimal herd immunity.

Vaccine effectiveness varies between different populations and regions.

However, not all vaccines stimulate lifelong immunity and this may decrease herd immunity over time.

The effect of waning immunity can be mitigated by increasing vaccination coverage or taking booster shots. >

Reduced transmission potential (or force of infection)

Vaccination efforts need to target the main reservoir of infection, i.e. groups who are most likely to get and spread the infection.

Low vaccine coverage among these groups may compromise herd immunity, even though overall coverage is high.

This also depends on the route of transmission of the pathogen.

> Appropriate vaccine uptake

Optimal herd immunity is more likely to be achieved when vaccine coverage is at the higher end of the HIT.

Another important factor is appropriate distribution patterns.

This can be achieved by targeting those who are highly exposed to the infection (e.g. healthcare workers) and vulnerable populations (e.g. infants and the elderly).

The timeliness in receiving the vaccine also impacts the effectiveness of the vaccination programme, and thus, herd immunity.

For example, in the United Kingdom, the occurrence of invasive pneumococcal disease in unvaccinated adults aged over 65 years has been reduced by 81% after the pneumococcal conjugate vaccine (PCV) was included as part of routine immunisation for infants under two years old.

Protecting the vulnerable

The best-case scenario is to have 100% vaccine effectiveness and coverage, but the reality is far from perfect.

No vaccine is 100% effective, and there are people who cannot get vaccinated or do not elicit strong immune responses from vaccines.

These include newborns, people allergic to certain vaccines, people with weakened or failing immune systems, or elderly with chronic diseases.

This is where herd immunity comes into play, providing indirect protection to these groups.

Optimal herd immunity via vaccination also counteracts waning immunity.

Protection with certain vaccines can diminish with time, e.g. pertussis vaccination starts to weaken after two years.

Thus, people with waning immunity are exposed to infection unless herd immunity is strong and vaccine uptake is sustained.

Apart from the vulnerable population, the following groups of people should also get vaccinated:

> Families and close contacts of those considered as vulnerable

> Caregivers of children, elderly

and sick patients > Healthcare or hospital workers.

When you get yourself vaccinated, you’re not only protecting yourself, but also your loved ones and other vulnerable individuals in the population.

As you can see now, vaccination is crucial and the safest way to achieve optimal herd immunity!


 Datuk Dr Musa Mohd  a paediatrician and Universiti Putra Malaysia lecturer. Datuk Dr Musa Mohd Nordin is a consultant paediatrician and neonatologist. This article is courtesy of the Malaysian Paediatric Association’s Positive Parenting programme in collaboration with expert partners. For further information, please email starhealth@thestar.com.my. The information provided is for educational and communication purposes only, and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.

The Star Malaysia17 Dec 2023By Dr HUSNA MUSA and Datuk Dr MUSA MOHD NORDIN
By Dr HUSNA MUSA and Datuk Dr MUSA MOHD NORDIN

https://www.thestar.com.my/news/nation/2023/12/17/remember-to-wash-your-hands


 
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Tuesday 7 November 2023

Digestive Health & Immunity

 





What is the immune system?

Our immune system is made up of many different organs which contribute to our immunity:

Normal Skin vs Damage Skin
Our skin prevents pathogens from entering our body

 

Various internal organs (e.g. bone marrow, spleen, lymph nodes) produce cells/antibodies that specifically target pathogens.

Good Bacteria and Bad Bacteria

The digestive system helps defend against pathogens entering via the gastrointestinal tract. The digestive & immune systems work together to signal immune cells. The gut is also the largest immune organ in human body. The gut microbiota, which are the microbes living in the gut, enhances immunity by forming a protective barrier and signalling (communicating) with immune cells. Good bacteria (gut microbiota) also helps your body digest food and supports your child’s immune system. Keys to good digestive health:

Consume balanced, nutrient-dense diet rich in fruits, vegetables and whole grains

Eat a variety of food as they provide important vitamins, minerals, and dietary fibre. Some vegetables also contain prebiotics (i.e. indigestible fibres that good bacteria feed on). This will contribute to optimal digestive health, which in turn helps improve the digestive process.

Exercise & hydrate

Helps improve diversity of gut microbiota. Try simple exercises, e.g. brisk walking around the house compound or indoor exercises such as stationary bike workouts, yoga, tai chi, and light stretching exercises.

Drink plenty of water to stay well-hydrated. Exercise and staying hydrated help ensure proper food digestion, bowel movement and also helps maintain a healthy balance of good vs bad bacteria.

Manage stress & get enough sleep

Stress and lack of sleep can negatively affect both digestive health and mental wellbeing. To prevent this, manage stress effectively and get sufficient sleep daily.

Include probiotic-rich foods in our diet

This includes food such as cultured milk drinks, yoghurt that contains probiotic live cultures, and fermented food (e.g. kimchi, sauerkraut, tempeh). Studies have found that probiotics promote good digestive health and can both directly and indirectly enhance our immune system.

Take oral nutritional supplements with live probiotic cultures

Supplementing your probiotic intake is usually not a worry. It is good to consult your doctor first to learn if supplementation is necessary and to see the most suitable probiotic supplement for you or your family.

How probiotics help:

  • Inhibits pathogenic (bad) bacteria by competing for nutrients.
  • Forms a protective barrier preventing harmful pathogens from entering our body.
  • Modulates our body’s immune responses (e.g. stimulates production of antibodies, signals immune cells) in response to infection.

Tips for consuming probiotics:

  • The probiotic strain in a product or supplement must be clinically proven and supported by studies and data that show the safety and efficacy of the product. E.g. Bifidobacterium lactis BB-12 and Lactobacillus paracasei L.CASEI 431.
  • Choose products with minimal or no added sugar.
  • Store probiotic products properly to optimise their effectiveness. This helps to maximise the viability of live strains before consumption. Some products require no refrigeration while others need to be refrigerated.
  • Consult your doctor for further information.

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Tuesday 6 May 2014

Clean hands save lives, wash your hands to combat germs!

PETALING JAYA: The role of hand hygiene in preventing the spread of drug-resistant germs is the focus of the World Health Organisation’s annual “SAVE LIVES: Clean Your Hands” campaign this year.

Launched yesterday, the campaign is in line with WHO’s recently-released report on Antimicrobial Resistance: Global Report on Surveillance.

How bacteria become resistant
Bacteria grow resistant to antibiotics through natural selection. When drugs are used, some organisms may have ways of surviving. As they reproduce or pass DNA to other bacteria, those traits become more common, weakening antibiotics’ power.

The report states that there are increasingly more types of bacteria which cannot be killed by antibiotics. The report also stated that no one in the world is safe from this menace.

However, WHO also reported that should compliance with hand hygiene in health facilities increase from under 60% to 90%, there could be up to a 24% reduction in the infection of methicillin-resistant Stap­hylococcus aureus (MRSA).

MRSA, most commonly contracted in hospitals, is rapidly becoming more difficult to treat with current drugs.

“Whether it is the hands of the patient, their visitors or the healthcare team, people must remember to practise good hand hygiene in a healthcare setting, especially in hospitals,” said Patient Safety Council of Malaysia member Dr Milton Lum.

Good hand hygiene means washing the hands thoroughly with soap and water before and after touching a patient.

“Everyone has germs on his or her body so despite our good intentions in visiting our sick relatives or friends, we may actually pass on a bug unintentionally,” said Dr Lum.

Patients for Patients Safety Malaysia chairman J. Manvir said he believed that patients should also wear masks to protect themselves from airborne infections.

“Children under 12 should not be visiting patients, especially in hospitals.

“You may not be able to teach them to practise good hand hygiene but you can keep them at home to prevent them from passing on an infection to the patient as well as preventing them from getting ill,” said Manvir.

Antibiotic resistance has been around since the 1940s when the first antibiotic, penicillin, allowed doctors to kill off the many bacteria that were the source of different infections.

However, subsequent misuse of penicillin accelerated the natural evolution of the bacteria, resulting in the microbes becoming resistant.

Contributed by Tan Shiow Chin The Star/Asia News Network

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The world's leading health organization is sounding serious alarm bells about the problem of antibiotic resistance.

Monday 5 May 2014

WHO's Alarm Bells: Antibiotic Resistance Now a 'Major Threat to Public Health'

The world's leading health organization is sounding serious alarm bells about the problem of antibiotic resistance.


In its first report on the issue ever, the World Health Organization (WHO) is sounding alarms about the issue of antibiotic resistance and the global public health threats it poses to our increasingly interconnected world.

"The problem is so serious that it threatens the achievements of modern medicine. A post-antibiotic era—in which common infections and minor injuries can kill—is a very real possibility for the 21st century," the report states.

Antibiotic resistance occurs when bacteria no longer die when treated with antibiotics. As a result, doctors have to use stronger, more potent antibiotics, and the more those are used, the more resistance bacteria develop to those as well. The WHO is warning that we're reaching a point in which the strongest antibiotics doctors have in their arsenal, the "treatment of last resort" drugs as they're called, no longer work.

And in fact, it's no longer just bacteria that are becoming resistant. The WHO has stopped referring to the problem as "antibiotic resistance" and now calls it "antimicrobial resistance," to encompass other organisms, such as viruses and parasites, that no longer respond to the drugs of choice. Namely, treating the viruses tuberculosis and HIV, and malaria (a parasite), has become harder as these diseases become resistant to medications. Even H1N1, the so-called "swine flu" that reached pandemic levels in 2009, has begun developing resistance to potent antiviral drugs.

Resistance Is a Worldwide Problem

One of the major points of the report is that diseases that used to be restricted to certain locales are now spreading internationally:

Among their key findings:
• Resistance to the treatment of last resort for life-threatening infections caused by a common intestinal bacteria, Klebsiella pneumonia—carbapenem antibiotics—has spread to all regions of the world. K. pneumoniae is a major cause of hospital-acquired infections such as pneumonia, bloodstream infections, infections in newborns and intensive-care unit patients. In some countries, because of resistance, carbapenem antibiotics would not work in more than half of people treated for K. pneumoniae infections.

• Treatment failure to the last resort of treatment for gonorrhea—third generation cephalosporins—has been confirmed in Austria, Australia, Canada, France, Japan, Norway, Slovenia, South Africa, Sweden and the United Kingdom. More than 1 million people are infected with gonorrhoea around the world every day.

• People with MRSA (methicillin-resistant Staphylococcus aureus) are estimated to be 64 percent more likely to die than people with a non-resistant form of the infection. MRSA, which can cause septic bloodstream infections when exposed to broken skin, is one of the most common "community-acquired" resistant infections, meaning you're likely to pick it up anywhere other people are—your gym, place of worship, a nearby park or even at schools. In the Americas, as many as 90 percent of staph infections are reported to be MRSA.

• There hasn't been a new class of antibiotics developed since the late 1980s.

We Can't Track What We Don't Know

The WHO is calling on countries all over the world to step up their surveillance of these deadly infections, something that happens rarely, if at all. An investigative report, "Hunting the Nightmare Bacteria," that ran on the PBS program Frontline in October 2013 revealed that public health officials in the U.S. have little to no data on the extent of antimicrobial resistance in this country. Healthcare facilities aren't required to report outbreaks, the report found, and many don't because they don't want to scare people or have to deal with bad PR.

“It is frankly embarrassing that we as a country do not know where resistance is occurring, how bad the problem is for various organisms or who’s using what antibiotics when,” Brad Spellberg, MD, an infectious disease doctor at Harbor-UCLA Medical Center, said in the documentary.

The Centers for Disease Control and Prevention has estimated that antimicrobial resistant infections hit two million people a year and kill at least 23,000. But the WHO notes that in most countries around the world, including the U.S., often only the most severe infections are documented and minor community-acquired infections (which can get passed along repeatedly and wind up as a severe infection) go unreported.

Clean Up the Food Supply!

For quite possibly the first time, the WHO also called out the food industry for its contribution to antimicrobial resistance. " The use of antibiotics in animal husbandry—including in livestock, poultry and fish farming—are leading to increasing recognition that urgent action is needed to avoid inappropriate use, and to reduce antibiotic usage in animal husbandry and aquaculture, as well as in humans," the report states. In the U.S., 80 percent of antibiotics sold go into animal feed to prevent infections in healthy animals or to speed growth. And we're not alone. "In many countries, the total amount of antibiotics used in animals (both food-producing and companion animals), measured as gross weight, exceeds the quantity used in the treatment of disease in humans," the authors found.

The same classes of antibiotics used on these animals are the same as those given to humans. In particular, fluoroquinolones, antibiotics used widely in the poultry industry, are increasingly ineffective against urinary tract infections caused by drug-resistant E. coli bacteria, which have been detected on all forms of supermarket meat, and against MRSA soft-tissue and skin infections.

Numerous groups in the U.S. have sued the Food and Drug Administration to revoke its approvals in animals for antibiotics that are valuable for humans. The agency's only response has been to set voluntary guidelines for the industry.

What You Can Do

Despite the damage factory farming has done to antibiotic effectiveness, the WHO and other public health officials insist that the first line of defense in controlling the problem of antimicrobial resistance is the healthcare setting: Stopping doctors from giving patients antibiotics for conditions they aren't designed to treat, for instance, when you're given antibiotics for a cold that's caused by a virus, not bacteria.

• Don't automatically ask for antibiotics when you feel sick and visit a doctor.

• If your doctor prescribes an antibiotic, ask if there's an alternative before just accepting the advice. Some doctors feel compelled to offer the drugs to make people feel better, but asking for an alternative can open up a dialogue about other options.

• When you do need an antibiotic, take the full course, even if you're feeling better.

• Wash your hands frequently to protect yourself from community-acquired infections, and keep your hands away from your nose, eyes and mouth, where infections can enter.

Contributed by  By EMILY MAIN

 Where Health Meets Life


Alarm bells over antibiotic resistance 

The World Health Organisation’s most comprehensive report to date sounds a warning that we are entering a world where antibiotics have little effect.

THE World Health Organisation (WHO) has sounded a warning that many types of disease-causing bacteria can no longer be treated with the usual antibiotics and the benefits of modern medicine are increasingly being eroded.

The comprehensive 232-page report on anti-microbial resistance with data from 114 countries shows how this threat is happening now in every region of the world and can affect anyone in any country.

Antibiotic resistance – when bacteria evolve so that antibiotics no longer work to treat infections – is described by the report as “a problem so serious that it threatens the achievements of modern medicine”.

“A post-antibiotic era, in which common infections and minor injuries can kill, far from being an apocalyptic fantasy, is instead a very real possibility for the 21st century,” said Dr Keiji Fukuda, WHO assistant director-general who coordinates its work on anti-microbial resistance.

“Without urgent, coordinated action, the world is headed for a post-antibiotic era in which common infections and minor injuries which have been treatable for decades can once again kill.

“Effective antibiotics have been one of the pillars allowing us to live longer, live healthier, and benefit from modern medicine.

“Unless we take significant actions to improve efforts to prevent infections and also change how we produce, prescribe and use antibiotics, the world will lose more and more of these global public health goods and the implications will be devastating.”

The report, “Antimicrobial Resistance: Global Report on Surveillance”, shows that resistance is occurring in many bacteria causing different infections.

It focuses on antibiotic resistance in seven bacteria responsible for common, serious diseases, such as bloodstream infections (sepsis), diarrhoea, pneumonia, urinary tract infections and gonorrhoea.

What is especially alarming is that the bacteria’s resistance has also breached “last resort” antibiotics, which are the most powerful medicines that doctors resort to when the usual ones do not work.

When patients do not respond to the usual medicines (known as first-line or first-generation medicines), doctors prescribe newer (second line medicines) which also usually also cost more.

When these also don’t work, newer and often more powerful (but sometimes with also more side effects) antibiotics are used, and they are even more expensive.

If these third-line or “last resort” medicines are not available or too costly for the patient, or if they don’t work on a patient because of antibiotic resistance, the patient remains ill or dies if the infection is a serious one.

New antibiotics have been discovered in the past to treat infections when the old ones became useless due to resistance.

But these discoveries dried up in the past 25 years.

The last completely new classes of anti-bacterial drugs were discovered in the 1980s.

Pathogens that are becoming increasingly resistant including to the more powerful antibiotics include E. coli, K. pneumonia, S. aureus, S. pneumonia, salmonelia, shigella and n. gonorrhoeae.

Key findings from the report include:

> Resistance to the treatment of last resort for life-threatening infections caused by a common intestinal bacteria, K. pneumonia — carbapenem antibiotics — has spread worldwide.

K. pneumoniae is a major cause of hospital-acquired infections such as pneumonia, bloodstream infections, infections in newborns and intensive-care unit patients.

In some countries, because of resistance, carbapenem antibiotics would not work in more than half of people treated for K. pneumoniae infections;

> Resistance to one of the most widely used antibacterial medicines for the treatment of urinary tract infections caused by E. coli – fluoroquinolones – is very widespread.

In the 1980s, when these drugs were first introduced, resistance was virtually zero.

In many countries today, this treatment is ineffective in more than half of patients;

> The sexually transmitted disease, gonorrhoea may soon be untreatable unless there are new drugs. Treatment failure to the last resort of treatment for gonorrhoea – third generation cephalosporins – has been confirmed in several countries; and

> Antibiotic resistance causes people to be sick for longer and increases the risk of death.

For example, people with MRSA (methicillin-resistant Staphylococcus aureus) are estimated to be 64% more likely to die than people with a non-resistant form of the infection.

There are many cases of patients being infected by MRSA in hospitals.

The report also gives useful information on the worrisome building up of resistance in four serious diseases — tuberculosis, malaria, HIV and influenza.

A major factor accelerating resistance is in the animal husbandry sector, where there is a liberal use of antibiotics mainly to promote the growth of the animals used for food, for commercial purposes.

This builds up resistance in the bacteria present in the animals.

These resistant germs are passed on to humans who consume the meat.

The report has a small section on the animal-food chain, which has been identified as a major problem.

The European Union has banned the use of antibiotics as growth promoters in animals, but it is still allowed in other countries.

A WHO press release on the report calls for some actions. These include:

> Setting up basic systems in countries to track and monitor the problem;

> Preventing infections from happening in the first place to reduce the need for antibiotics;

> Only prescribing and dispensing antibiotics when they are truly needed, and prescribing and dispensing the right antibiotic(s) to treat the illness;

> Patients using antibiotics only when prescribed by a doctor and completing the full prescription; and

> Developing new diagnostics, antibiotics and other tools to stay ahead of emerging resistance.

Contributed by Global Trends by Martin Khor

Martin Khor is executive director of the South Centre, a research centre of 51 developing countries, based in Geneva. You can e-mail him at director@southcentre.org. The views expressed are entirely his own.

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Thursday 20 February 2014

Do You need jabs, antibiotics?


OUR population is getting more and more educated and knowledgeable. With the convenience of internet and smart phone, information can be assessed anytime and anywhere.

Facebook and Google have become the source of reference for most people. Many can now be “experts” in many specialised fields, including engineering, law and even medicine.

Nowadays, the medical practitioners enounter some patients who are so-called internet savvy, and refuse antibiotics and vaccines.

This issue arose due to the spread of such information in the internet, claiming antibiotics could lead to “superbug” and are associated with many adverse effects, while vaccines could cause autism or death.

Well, the risks of administration of both drugs are certainly debatable.

What we know for a fact is that since Alexander Flemming discovered penicillin and the pox vaccine, many lives were saved.

Nevertheless, I am not in the position to comment on the good and bad of both antibiotics and vaccines. But, it is more important for the general public to understand more about the need for antibiotics and vaccines.

Antibiotics or more specifically antibacterial, is a medicine indicated to kill (bactericidal) or inhibit the growth (bacteriostatic) of the bacteria.

There are various types of antibiotics with different mode of actions and indications. Strictly speaking, the mechanism of action for antibiotics is rather complicated.

However, it works mainly to counter attack the rapid reproduction of bacterial colonies, so that our immune system has enough time to defeat the illness.

Thus, the usage of antibiotics is strictly limited to the bacterial infection. In common clinical conditions, like acute exudative tonsillitis, abscess formation and urinary tract infection, antibiotics are strongly prescribed.

It must be understood that antibiotics have no role in curing diseases caused by fungus, virus or other parasites.

Therefore, it should not be overprescribed in cases like common cough and cold, flu and fungal infection of skin.

As for vaccines, they are biological preparations that help to boost immunity. Its primary focus is on disease prevention. It is always better to prevent a disease than to treat it.

Vaccines work by introducing the weakened form of “disease germ” into the body. The body will respond by producing antibodies to fight these invaders. At this stage, technically, the immune system is being sensitised. If the actual disease germ attacks the body, more antibodies will be produced to destroy the real enemy.

Vaccines are responsible for the control of many infectious diseases that were once common in this country and around the world, including polio, measles, diphtheria, pertussis (whooping cough), rubella (German measles), mumps, tetanus, Hepatitis B and Haemophilus influenzae type b (Hib).

Many patients question the need for further vaccination as diseases such as diphtheria, pertussis are very rare these days.

Furthermore, there are people that do not get vaccination, yet able to live healthily until old age. This is the myth behind “herd immunity”.

Herd immunity serves as a preventive barrier as most of the population had been vaccinated, thus, the disease is contained from spreading. If herd immunity is compromised, the widespread of the disease may occur.

A piece of advice to all, a little knowledge is a dangerous thing. Before you start to tell doctors about the negative effects of antibiotics and vaccines, why not, give them a chance to explain to you before you make a decision.

Contributed by DR H.B. CHEE, Muar, Johor The Star/Asia News Network

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