The Microbiologist was doing his daily Critical Care ward round. The next patient to see had been admitted with severe abdominal pain and been diagnosed with a perforated appendix. They had had an urgent laparotomy the night before and had come to the Critical Care Unit as they were a bit unstable after the operation and needed close monitoring. They had improved steadily.
 
The Registrar mentioned that the patient had been on antibiotic prophylaxis since the operation, and they wondered whether it should stop after 24 hours.
 
“It’s not prophylaxis” said the Microbiologist.
 
“Yes, it is” replied the Registrar, “the Surgeons have written that they want the antibiotic prophylaxis to continue, but they haven’t said for how long.”
 
“No, it’s not prophylaxis” said the Microbiologist again, “it’s treatment. They are different things with different purposes”.
 
“Oh, here we go” muttered the Registrar, “pedantics again!”
 
“I heard that!” Exclaimed the Microbiologist, smiling, at least he knew someone had read his blog. “Let me explain…” he said in that manner of, shhh…listen!
 
The Registrar groaned inwardly, knowing a mini-lecture was coming and there was nothing he could now do to stop it…

​What is the difference between prophylaxis and treatment?
Prophylaxis is the use of antibiotics to prevent infection of a previously uninfected site. There are 2 types of prophylaxis, primary and secondary:

• Primary prophylaxis - aims to prevent initial infection e.g. surgical prophylaxis, duration usually required for <24 hours, whilst ongoing entry of bacteria into sterile body sites e.g. at the time of surgery
• Secondary prophylaxis - aims to prevent recurrent episodes of infection, duration usually requires long courses of antibiotics at reduced doses e.g. post-splenectomy, rheumatic fever, recurrent UTIs in children

 
Treatment is the use of antibiotics to eliminate infection from an already infected site. Treatment and duration of treatment varies between clinical conditions.
 
Types of surgery
When considering whether to give antibiotics as primary prophylaxis to cover a surgical procedure it is important to think about what it is you are trying to achieve with those antibiotics. It helps to split surgical situations into four categories:

1. Ultraclean – risk of infection <0.3% - this type of surgery is often done in an ultraclean operating theatre with HEPA filtered air being blown directly down over the patient and surgical team, and extracted away, without any airborne contamination being able to settle in the operative site. This is often used for operations where implants are being inserted and where post-operative infection is either life-threatening or requires further surgery e.g. heart valve replacements, prosthetic joint insertion – antibiotic prophylaxis given for 24 hours to prevent infection secondary to bacteria getting into the operative site during the procedure
2. Clean – risk of infection 3% - the operation involves sterile tissue where the overlying surface has been cleaned and the risk of infection is very low, and the consequence of post-operative infection is minor e.g. removal of a skin lump – no antibiotic prophylaxis required
3. Clean-contaminated – risk of infection 13% - the operation involves a site where the number of bacteria has been reduced as much as possible pre-operatively but which still contains bacteria that can leak out during the operation e.g. planned elective surgery on the bowel which has been emptied pre-operatively using laxatives and enemas, or leakage occurs during the operation but it is immediately controlled and the contaminated area cleaned – antibiotic prophylaxis given for 24 hours to deal with small amounts of bacterial leakage during the operation
4. Contaminated – risk of infection >40% - operative site heavily contaminated with micro-organisms pre-operatively e.g. perforated appendix or bowel with faecal soiling into the abdomen or traumatic injury with environmental contamination from soil – antibiotic TREATMENT required, this is no longer a prophylaxis situation as the infection is already established

 
Endocarditis prophylaxis
Endocarditis prophylaxis is a somewhat controversial topic in medicine. It’s essentially one of these areas where there is no good evidence either way. Most hospitals have their own guidelines for antibiotic prophylaxis to prevent endocarditis in at-risk patients undergoing certain procedures. There is a guideline from the National Institute for Health and Care Excellence (NICE) that now suggests “considering” antibiotic prophylaxis to prevent endocarditis but NICE does not give specific recommendations… basically they have shifted responsibility to the prescriber which isn’t overly helpful in my opinion.
 
The following is based upon the American Heart Association Guidelines, and is based on risk factors in patients PLUS risk factors associated with the type of procedure they are having. REMEMBER endocarditis is rare therefore there is insufficient evidence to draw firm conclusions on prophylaxis. Many Microbiologists and Cardiologists believe “absence of evidence does not mean evidence of absence” and as endocarditis is a life-threatening infection prevention is more effective than treatment.
 
At-Risk Patients:

• Previous infective endocarditis
• Prosthetic heart valve
• Acquired valvular heart disease with stenosis or regurgitation
• Cyanotic congenital heart disease

 
At-Risk Patients who are undergoing the Following Procedures:

• Dento-gingival manipulation or endodontics
• Surgery to the jaw and oral cavity
• Tonsillectomy and adenoidectomy
• Respiratory tract procedures with incision or biopsy of the respiratory mucosa

Gastrointestinal or urogenital procedures

​“Okay…okay…stop!” said the Registrar cutting his loses and interrupting the long talk about types of surgery, “how long should we continue the antibiotic treatment for?”
 
“Five days” replied the Microbiologist, smiling and moving on to the next patient.
 
The Registrar rolled his eyes to the ceiling behind the Microbiologists back and muttered under his breath “why didn’t you just say that?”
 
“Because I’m a Microbiologist and a pedant” called back the Microbiologist turning back and grinning at the Registrar, “now come on I haven’t got all day!”

The Microbiologist sat quietly eating his lunch, partially hidden behind a pot plant in the staff canteen, when he sensed someone standing behind him. “Damn!” he thought, thinking he had hidden well enough to prevent his lunch being interrupted with any clinical questions... but clearly not.
 
Looking around he met the gaze of the Cardiology Registrar who was clearly waiting to make eye contact before launching into “the patient’s story”!
 
…“I have a patient in her early twenties who came in with a fever and a rash, but over the last few days she has started to go into heart failure”.
 
The Registrar had been in the Microbiologist’s teaching session early in the week, and had clearly “swotted up” after being asked questions he didn’t know the answers too.
 
The Cardiology Registrar then delivered the “piece de resistance” and declared “I think this might be Rheumatic Fever”.

Home schooling looks like it’s over; schools are going back in two weeks. It’s amazing how much you can learn from Netflix but clearly, the constant “bubble burst” and “pingdemic” absence from school is not sustainable, there needs to be another solution.
 
Bring out the UK Government’s answer: change all the advice and guidelines… again!!! Don’t you just love them…so here’s a quick overview of the “new school rules”.
 
New guidance for school children who are contacts of Covid-19 cases:
As of now children are no longer required to self-isolate if they live in the same household as someone with Covid-19, or are a close contact of someone with Covid-19, if any of the following apply:

• they are fully vaccinated
• they are below the age of 18 years and 6 months (18 ½ years old)
• they have taken part in or are currently part of an approved Covid-19 vaccine trial
• they are not able to get vaccinated for medical reasons

 
So basically, all children at school will fall into the “less than 18 ½ years old” group and will no longer need to self-isolate. No more missing school! GREAT!!
 
Instead, children (or their parents) will be contacted by NHS Test and Trace (we are still all paying for it so the Government needs to keep using it…cynic!), informed their child has been in close contact with a positive case and advised to get the child to take a PCR test. The UK Government “encourage” all individuals to take a PCR test if advised to do so… but this appears to mean that it is now no longer mandatory. Oh! And hooray, face coverings are no longer “advised”… let’s hope we can actually ditch them as I believe they hamper teaching and communication… (have you noticed more people seem to be “opting” to wear a face mask now they are not mandatory… we are a contrary nation!)

​So, back to school, is this a good idea or will it lead to thousands of sick children across the country? Did we ever answer the question “do children spread Covid-19 in schools?”, and “do they get sick and die from the infection?”
 
Are schools a hot bed of Covid-19?
At the beginning of the pandemic, children were blamed for spreading Covid-19 amongst each other, “infecting teachers with plague” and then taking it back to their families. It was claimed that schools were a major source of cross infection between households, but it appears that that hasn’t really been the case after all.
 
The UK Government quote figures of attack rates for a number of situations where someone has come into contact with a case of Covid-19. The attack rate is the % number of new cases of Covid-19 due to contact with an infected person; the higher the number the higher the risk:

• Primary school 0.84%
• Secondary school 1.2-1.9%
• Social contact outside of school 5.9%
• Household contact 21%

 
These figures suggest that school transmission is NOT the major source of spread of Covid-19, but rather that “social” and “household contact” IS the main source… However they don’t show how these figures were calculated, so I’d suggest caution, as statistics are easy to manipulate to show whatever you want them to show!
 
So, children going to school isn’t going to cause mass spread of the infection but do they get sick and die from the infection? Are we putting them at risk?
 
Do children die from Covid-19?
The simple answer to this rather disturbing question is YES… but it isn’t common. The overall mortality rate in children under 18 years old is about 1 in 500,000 and that is very low, apparently you are just as likely to die while bungee jumping. In the over 80s it is about 15% (that’s dying of Covid-19 not bungee jumping!) BUT 1 in 500,000 isn’t zero, and it’s important to remember that although the RISK is very low the CONSEQUENCE is absolute… at the end of the Covid-19 infection the child is either 100% alive OR 100% dead … not 1 in 500,000 parts dead. Please excuse the apparent callousness of that statement but it’s a really important concept that often gets lost when considering “outcomes of disease”; percentages can be misleading, things either “fully happen” or they “fully don’t happen”, death doesn’t partially happen.
 
So, reassuringly children going back to school are at very low risk of dying from Covid-19, Phew! BUT is there anything else other than severity of Covid-19 we need to take into account? What about long Covid?
 
Long Covid-19 in children
Do children suffer from long Covid? This is a really important question as up until now all we keep hearing is that severe Covid-19 in children is rare, but what about the less severe but equally debilitating long-term effects that might impact school attendance, disrupt physical activity and damage mental health. Surely in kids, these are just as important as severe infections, added to this, we know that in adults long Covid can happen whether you have a severe infection or no initial symptoms at all.
 
A large study from the UK, published in the Lancet, looked at 1743 children who tested positive for SARS CoV2 to see what symptoms they had and how long those symptoms lasted. The children (or their parents) reported symptoms via an online app. The study showed that only 1.8% of children with Covid-19 had symptoms that lasted up to 56 days, compared to the control group where 0.9% of children who hadn’t had Covid-19 but who reported feeling unwell (unsurprisingly, kids were still getting kids illnesses last year). The main symptoms of the Covid-19 group were fatigue and headache. So, in this study the “excess burden” of prolonged symptoms due to Covid-19 in children was only an additional 0.9% compared to “other children experiencing illnesses”.
 
Another study from Zurich, Switzerland, has also looked at the burden of prolonged symptoms in children following Covid-19. The Swiss team looked at 1355 children who had a serology sample taken between October and November 2020 and asked them questions about symptoms compatible with long Covid. They then tested the serum from these children to look for antibodies against SARS CoV2 which would indicate they had been infected in the past. This identified 109 children who had had Covid-19 and 1246 who had not. 4% of the Covid-19 children had symptoms lasting longer than 12 weeks compared to 2% of the children who, although had symptoms lasting longer than 12 weeks, had not had Covid-19 at all. The most common symptoms in the Covid-19 group were tiredness (3%), difficulty concentrating (2%) and increased need for sleep (2%). The Swiss team concluded that long Covid in children is uncommon, giving only a 2% increase in symptoms after 12 weeks.
 
A further, yet smaller study, from Australia showed no prolonged symptoms following Covid-19 in children at all. This would support the findings of the somewhat larger studies above; if something is so low then small studies won’t usually pick it up.
 
Results from the small number of other studies I have been able to find on this subject suggest long Covid symptoms in children are uncommon, up to about 2% perhaps. All of the studies are limited by the small numbers of children in the studies and so are all prone to bias and skewing of their data e.g. if you ask for people to report long Covid symptoms you are more likely to get responses from people with symptoms than without symptoms which will lead to higher apparent case numbers e.g. if you have 50 people in a study and 10 say they have symptoms this would be 20% even though it is possibly only 10 people out of the whole population. However, the studies all seem to suggest the same low rates of long Covid in children and that is reassuring.
 
So, what do I think? Am I in favour of the more relaxed rules around children going back to school?
 
Yes, I am in favour of a more relaxed approach to the return to school. I think the risk of severe disease in children is extremely low and the risk of long Covid is also very low. I think the risks associated with children missing school are considerable. And it’s not just the missing education that worries me; more importantly the lack of social interaction, play and physical activity can have very serious impacts on how children develop, not to mention that school meals are sometimes the main meal of the day for some children. And yes, as someone who is a product of the comprehensive school system in the UK, I think learning is important as well.
 
I just think we should be aware that there may be a risk with the more relaxed system, and we should keep an eye on what is happening, whether children are getting sick, or case rates are going up or long Covid in children is becoming more common, and we shouldn’t be afraid to change our minds if it’s all going wrong. One thing is for sure we all now know we need to wash our hands much more frequently! Maybe this generation will be top of the class on that lesson!
 
Now, I’m off to the shops to look for a new pencil case, some gym pumps and a satchel… yippee, back to school!!!! Don’t forget to sticky-back plastic your exercise books!!

There’s a story playing out over the news channels that is causing me some distress. There is an alpaca on death row who has tested positive for tuberculosis (TB) and therefore been sentenced to be culled as he poses a risk to other animals… He’s called Geronimo and he’s cute!

“Okay, this is going to sound odd, but can we test a baby for RSV?” asked the Paediatrician.
 
“You do realise it’s July, don’t you? I mean I know we’ve all been locked in our houses for months, it’s raining and the radio played a Christmas song this morning…but it’s still summer!” exclaimed the Microbiologist.

​Everyone, including the UK Government and the media, seems to be saying the Delta variant of SARS CoV2 is “more transmissible” than the original SARS CoV2 and it is starting to irritate me. Why? Well I object to them using the term “transmissible”? Am I pedantic or are they wrong? Let’s see….

The 19th of July 2021 is looming on the horizon; so-called “Freedom Day”! I’m not so sure about that (see last weeks blog), but another story that has been on my mind recently is about whether we will be having extra doses of Covid-19 vaccines this year.

So yesterday the UK Prime Minister and new Health Secretary announced that they plan to go ahead with opening up the UK on the 19th July. Hooray! The pandemic is over!!
 
Really? Is it? Or is this all going to go horribly wrong…?
 
What has been said?
So, yesterday the UK Government made the announcement that they are going ahead with their plans to relax the mandatory Covid-19 rules across the country. Clearly Boris didn’t read my earlier blog about R numbers suggesting that a “one-size-fits-all” approach is a bad idea… oh well.
 
As of the 19th July it will no longer be a legal requirement to:

• Wear a face mask on public transport or in shops – it will be down to “personal choice”, but how do we choose when we are told we should be wearing a mask to protect others? If we are not wearing a mask will people have a go at us because we are being socially irresponsible, or will people get aggressive if someone vulnerable asks them to wear a mask to help protect them? It seems like a recipe for social unrest to me.
• Meet with no more than 6 people in your home (rule of six) – I suspect with the England football matches, this one went out the window weeks ago, I think everyone either forgot about this when we could meet out of doors, or they just gave up on it anyway.
• Work from home wherever possible – I think this will be irrelevant as it will be down to employers most of the time to decide what they want their staff to do

“I have a patient in his 40s who has been coughing for several weeks and is starting to get fed up. The cough is keeping him, and his wife, awake, so he’s taken to sleeping in the spare room in order to give her some respite but it’s not ideal. I’ve done a chest x-ray and it looks okay, and he’s not really coughing anything up in order to send to it to the lab for culture. What antibiotics do you think I should give?” said the GP.

No, it’s not the fact that Euro 2020 is actually Euro 2021, nor is it a dodgy off-side decision or goal disallowed by the Video Assistant Referee… nope, I’m talking about Covid-19 and the need to self-isolate… What else would it be?!