I was trying to explain to a public health physician why I prefer reactive rather than positive for serology results.
The problem with assays used to detect antibodies to antigens from pathogens is that the antibodies detected can be cross reacting and just detecting them doesn’t always mean the patient has the infection. This is especially true for assays looking for IgM antibodies. This is why serologists tend to prefer reporting results as reactive or non-reactive rather than positive or negative. While the result may be positive, it doesn’t mean the patient positively has the disease in question.
It’s an important distinction and one I should never forget.
On Friday at the hospital I was asked to see a patient who had a referral to the practice for a sticky tape test. The specimen collection team weren’t familiar with the test.
Rather than go into details on the interaction I had on Friday I thought I’d let you know about how a humble piece of sticky (or scotch) tape can help make a diagnosis.
Enterobius vermicularis is better known as a pinworm. It causes Enterobiasis or pinworm infestation.
Pinworm usually affects children but can cause illness in adults especially institutionalised adults.
The disease manifests as itchiness around the anus and causes sleeplessness and restlessness.
The worm is transmitted via the faecal-oral route. Pinworm eggs get deposited on the skin around the anus and these get transferred to others, especially those who like to rim but more commonly as a result of poor toilet hygiene. It’s easy to understand why this is a disease common in childhood and why families become infested easily.
Worms emerge at the anal verge a few hours after falling asleep. To make a diagnosis it’s best to get the worms and eggs as soon as the patient wakes up before any bathing or bowel movement. On waking, a short strip of sticky tape is applied to the skin close to the patient’s anus and applied to a glass slide. The slide can be sent into a pathology laboratory where it will be stained and examined using a light microscope.
Pinworm infestation gets treated with over-the-counter worming medications.
A couple of weeks ago I wrote a piece on Yummy Lummy about a meal Bron and I shared at Jamie’s Italian Canberra. In the middle of the post I ranted a little about the use of raw milk in some cheese, viz., bocconcini. As a clinical microbiologist with an interest in food, food safety and public health I’ve always appreciated the balance between taste and desires of food advocates and the need for safety. In that regard, Australia excels when it comes to using risk management principles to minimise harm to Australians. On balance and with some exceptions, raw milk is not permitted for commercial use in Australia. You can find the regulations at FSANZ.
A couple of days ago ProMED-mail posted a piece on unpasteurised milk in the USA. The ProMED-mail piece provides food for thought and some great references to excellent articles. To be fair, these articles relate to the USA and as I’ve stated, in Australia our regulatory process is very good.
For my money, I’d prefer pasteurised milk to be used at the small cost of some loss of flavour. For the raw milk devotees, I’m sorry but while your enthusiasm is great, in the greater public good, I think Australia should continue to tightly regulate diary products.
Dangers of Raw Milk: Minnesota Study Documents 1 in 6 Become Ill
Nonpasteurized Dairy Products, Disease Outbreaks, and State Laws—United States, 1993–2006
Raw or heated cow milk consumption: Review of risks and benefits
When anyone says CBR or whenever I read CBR two things come to mind.
Chemical Biological Radiological and the code for Canberra airport.
I’ve been involved in Chemical Biological Radiological related work since about 2000. It’s one the main things I work on in my current role. I’ve had an interest in biological warfare and terrorism, that is, countermeasures and response planning even before 2000. As a young microbiologist before studying medicine I was fascinated by the use of microorganisms as weapons.
So when I read or hear CBR my mind turns to
Clinically I think of
Now that I’ve lived in Canberra since 2007, I’ve come to know the Canberra airport very well and its code is CBR.
So what do you think I think of when I see this
2013-12-06 08.34.59 AEDT It’s even being used as wallpaper on ACT Government PC monitors.
I don’t think Confident Bold Ready. When I see the bright yellow background and the stylised letters it sends my mind back to the 1970s and 1980s to this
So rather than make me think of Canberra as confident bold ready, the logo makes me look to the past. Apparently the ACT Government has budgeted $2.6 million for this work. I’m expecting Molly Meldrum to materialise and start spruiking Canberra.
For me, CBR is always going to mean Chemical Biological Radiological or Canberra airport.
The Australian Medical Handbook is a terrific resource for healthcare professionals and others.
Check out the product list here AMH Product Brochure
Every year I update the book I buy. It’s easy to read and the CD-ROM and on-line products are very good.
I’ve just posted this page at another site. I’ll add to it from time to time.
- Pet Peeves! (nkatie30.wordpress.com)
- pet peeves (trencherteo.wordpress.com)
- Do you have a writing/grammar/communication pet peeve? What is it? Why? (debradent3160.wordpress.com)
- Grammar Pet Peeve #3 – Misspellings (quillandinkblog.wordpress.com)
- Pet Peeves (cynenway.wordpress.com)
- Weasel, the Pet Peeve (plumwrite.wordpress.com)
- Pet Peeves (tangiblefantasy.wordpress.com)
One of my pet peeves is when the media contracts a scientific or established official name into something very shorthand. In my mind it’s disrespectful to the people who investigated the microorganism and the disease. To be fair, it’s not something I’m going to sacrifice myself over, after all it’s just a peeve and nothing more. What is more annoying is when we see this creep into official writing, but again, it’s more peeve and annoyance and I have no real influence on anyone but myself.
So in this post I’ll accept manflu as a word but rather than use the common shorthand of flu I will always prefer influenza.
The Internet (Oh how I love the Internet) is replete with descriptions and short videos on manflu, all you need to do is go to YouTube and search manflu for some very funny video clips.
My concern today is the difference between the common cold and influenza. You hear it so often in the workplace. Someone takes a call from an ill colleague who has called in to say they have the influenza. The vast majority of people who call in sick have a common cold. When you’re infected with an Influenza virus you will know it.
The Royal Australian College of General Practitioners has in its emergency management planning a really nice table describing the difference. It references the Center for Disease Control and Prevention in the US.
Symptoms of influenza and the common cold
||Often high, lasting 3 to 4 days
|Aches and pains
||Common; can be severe
||Common; can become severe
||Sometimes; mild to moderate
||May show moderate to extreme signs of weakness
||A littler lower than usual
||Pneumonia, kidney failure and heart failure. Can be life-threatening
||Sinus or ear infection
Does manflu exist? Of course not. It’s just the common cold. That hasn’t stopped me tweeting about it though when I’m suffering :-)