The Best Australian Science Writing 2014 (30 page)

Dan sat in the waiting room. While his wife spoke to the triage nurse he slid off his chair onto the floor. He was taken by
wheelchair to a resuscitation cubicle, where his blood pressure was found to be low and his pulse was racing. His temperature was 39.8° Celsius. He noticed that he was starting to detach himself from the noise and action around him. He stopped worrying about things for the first time in 24 hours.

I first saw him a few hours later. The sequence of events that had led to his admission had been distilled into a single request from the emergency department consultant: ‘Would you accept the care of a 50-year-old man with septic shock?' Septic shock is one of the most serious conditions in medicine. It has a mortality rate ranging from 10–60 per cent, depending on the type of germ involved. By the time I saw Dan he had been transferred to the intensive care unit and he had a tube down his throat and a machine was helping him to breathe. The emergency doctors suspected that the shock was caused by a bowel germ that had entered his bloodstream at the time of his prostate biopsy. The most likely culprit would be a Gram-negative bacterium known as
E. coli
.

I went with the ICU doctor in charge of the shift to talk to Dan's wife. She asked if he was going to be all right. The ICU doctor managed to gently convey the gravity of the situation while leaving her with a sense of hope and qualified reassurance. Of all the germs to have circulating in your blood,
E.coli
is among the least worst. The mortality rate is around 10 per cent – so the odds were in his favour. He remained critically ill over the next 24 hours, but when I saw him the next morning he was sitting up in bed and eating lunch. The tube down his throat had been removed and his blood pressure and pulse were now normal. His wife was by his side. He couldn't remember much of what happened leading up to his hospital admission and it appeared that he hadn't connected the ICU admission with the prostate biopsy.

‘I've had some excellent news this morning, doctor,' he said between mouthfuls of corned beef and mashed potato. I assumed
he meant that he would be getting out of ICU later that day. ‘I asked one of the docs here to look up the result of my prostate biopsy,' he said, smiling. He grabbed his wife's hand. And then, with tears welling in his eyes, he told me that the biopsy was clear – which meant that he didn't have cancer. ‘I'm a very lucky man,' he said.

It was neither the time nor the place to do anything but agree.

* * * * *

Infection is one of the most important complications of prostate biopsy. (Others include blood in the urine and semen, rectal bleeding and difficulty passing urine, and these are usually referred to as ‘frequent' and ‘minor' in the urological literature.) Since the biopsy needle is passed through the wall of the rectum it is almost inevitable that some of the bacteria that live in the bowel will be carried with it.

The prostate gland is known as a ‘sterile site'. Under ordinary conditions it doesn't have any bacteria in it, unlike the mouth, nose, stomach and bowel, where the ‘good' germs and the ‘bad' germs live side by side. The plumbing of the male urinary tract is interconnected, so an infection in the prostate can spread to the bladder and the kidneys. Bladder infections are usually relatively benign, but kidney infections are more serious and almost always require hospitalisation. Sometimes, as in Dan's case, the infection moves directly from the prostate to the bloodstream. We see about 300 bloodstream infections each year in our hospital in Canberra, which serves a population of about 500 000. They are more common than a heart attack, and more lethal by a factor of at least two and as much as 12. As is the case with a heart attack, mortality rises if you don't institute the correct treatment as a matter of urgency.

In the early days of TRUS biopsies as many as 70 per cent of
men developed a urinary tract infection after the procedure. But it soon became clear that antibiotics taken before the procedure (known as ‘prophylaxis') would reduce the risk of infection. The choices of effective prophylaxis are limited, and until recently a drug known as ciprofloxacin has been the most popular in a very narrow field. With prophylaxis, 1–5 per cent of men undergoing TRUS biopsy develop a bladder or kidney infection and 0.5–2 per cent develop a bloodstream infection. Most urologists consider something that occurs at a rate of between 0.5 to 2 per cent to be rare.

Let's do some more maths, using 0.5 per cent, the low end of the estimated rate of bloodstream infection following TRUS biopsy. There were just over 29 000 prostate biopsies performed in Australia in 2012, giving a conservative calculated bacteraemia rate – the rate of bacterial infection – of 145 cases. Almost all of these patients will need hospital admission and many will end up in ICU. Most TRUS biopsies are performed in otherwise well men, so they would be expected to have a lower death rate from bacteraemia than patients with concomitant illnesses. There is currently no national surveillance of infections related to prostate biopsy so we don't know what that rate is. Let's assume it's a very small number. The deaths would be distributed across Australia and it is unlikely that any single urologist would see more than one or two in a professional career. Similarly, no single ICU will have a concentrated experience of TRUS-related septic shock. A distributed problem usually remains a hidden problem.

But this is all changing very rapidly. A Canadian study has shown a 400 per cent increase in the rate of serious infections following TRUS biopsy in the ten years up to 2005, and it is assumed that most of this rise is due to emerging antibiotic resistance. People who travel to India, China or South East Asia have roughly a 50 per cent chance of picking up a ciprofloxacin-resistant organism in their bowel that will stay there for up to six
months after they return home. As we have seen, germs can live happily in your bowel and cause you no harm. Unless, that is, we stick a needle through your rectum into your prostate.

The problem is that there is no other antibiotic that can be taken by mouth that works as well as ciprofloxacin. The alternatives need to be given by an intravenous infusion, adding to the cost and time that prophylaxis takes. And the more we use these previously reserved antibiotics, the faster we drive resistance to them.

It's important for infectious diseases doctors to give our urology colleagues antibiotic advice, but focusing on the microbiological detail misses the real point: the best way to prevent an infection associated with a TRUS biopsy is
to avoid doing the biopsy in the first place
. We don't know it for a fact yet, but it is plausible that the reason that there is no difference in the all-cause mortality between those who are screened for prostate cancer and those who aren't is that the reduction in cancer deaths is replaced by a corresponding rise in infection-related deaths. The emergence of more resistant bacteria will increase the risk of infection associated with every TRUS biopsy. Inevitably, the current drawn contest will turn into a one-sided bout, with infection winning hands down.

So, where does that leave us? We have seen how the PSA test misses people who do have cancer, incorrectly diagnoses it in those who don't, identifies it decades earlier than necessary, finds it even when it will never cause a problem and, in the majority of cases where it does identify cancer, does so too late for it to be cured. The TRUS biopsy is associated with pain, bleeding and life-threatening infection and turns the ‘what you don't know about won't hurt you' cancers into ‘what you
now
know
can
hurt you' cancers. If that isn't enough, the treatments for prostate cancer cause impotence and incontinence and cure only 2 to 3 per cent of the men who receive them.

I fear that prostate cancer screening is one of the most unfortunate medical examples of the Law of the Instrument: the idea that when all you have is a hammer, everything looks like a nail. Our current tools for diagnosis are inadequate and, in the case of biopsy, increasingly dangerous. (Some urologists are now using MRI scans instead of TRUS biopsies but the sensitivity and specificity of this approach is not known with any certainty. Others recommend passing the biopsy needle into the prostate through the skin of the perineum, the part of the body between the anus and the scrotum, to avoid the rectum.) It is clear that we need a better screening test and more effective therapies before we can safely and ethically recommend coordinated screening for prostate cancer.

* * * * *

I've tried here to confine my case against screening to scientific argument and to avoid ascribing anything but good intentions to those groups and individuals who promote it. This may be a little naive, so I've saved the last word for the person who made contemporary prostate cancer screening possible – the discoverer of PSA, Richard Ablin, now a professor at the University of Arizona. In a piece for the
New York Times
in 2010 titled ‘The great prostate mistake', he observed that the PSA test ‘is hardly more effective than a coin toss'. He went on:

As I've been trying to make clear for many years now, PSA testing can't detect prostate cancer and, more important, it can't distinguish between the two types of prostate cancer – the one that will kill you and the one that won't … So why is it still used? Because drug companies continue peddling the tests and advocacy groups push ‘prostate cancer awareness' by encouraging men to get screened … I never dreamed
that my discovery four decades ago would lead to such a profit-driven public health disaster. The medical community must confront reality and stop the inappropriate use of PSA screening. Doing so would save billions of dollars and rescue millions of men from unnecessary, debilitating treatments.

When the father disowns a scion this famous it is probably wise to pay attention.

From Alzheimer's to zebrafish

TB and me

TB and me:
A medical souvenir

Jo Chandler

In the warped currency of what we do as journalists, worst is best. When we weigh newsworthiness on the scales of disease and dysfunction, conflict and corruption, the bleaker the better. But for the reporter diving in, the maxim relies on a couple of critical perks of the job – the ticket home and the clean getaway.

The dismal conditions waiting at Daru Hospital back in August 2011 exceed my saddest expectations. We spend some days poking around overflowing wards and diseased shanties for
The Age
, investigating the insidious reach of deadly, drug-resistant tuberculosis across Papua New Guinea. More than 60 per cent of the global burden of TB occurs in the Asia-Pacific region, and PNG bears some of the worst of it.

My notebooks are soon crammed with misery and my colleague, photographer Jason South, has collected pictures to break your heart. We can't get out of town fast enough.

But then our flight home fails to turn up on the crumbling runway. Feeling duty-bound, we add to the catalogue of sick and dying, though we already have more than our editors would want or our readers might endure. Jason goes to the hospital morgue
and finds Edna Neteere wrapping her daughter in a shroud.

She was 19, her wasted body barely rumpling the sheet – consumed by disease, hence ‘consumption', as it was once so widely known. Her mouth is still drawn in a last grimace. Literature, history and the illustrious casualty list – several Brontes, Chekhov, DH Lawrence, Keats, Kafka, Orwell – might confer an aura of romantic dignity on TB diagnosis, but this young woman died ‘a terrible death', says the nurse. Likely those luminaries did too, albeit buffered by a few more comforts, like privacy and pain-relief.

Tuberculosis retains the distinction of being the greatest infectious killer in human history, claiming an estimated billion lives in the past 200 years. Its toll today is still second only to HIV (and it is the major killer of people with HIV). In 2011, 8.7 million people fell sick with TB. Edna's daughter was one of 1.4 million who died of it that year.

We ride with Edna and her family in the ambulance-cumhearse, a hard-lived troop carrier, back to their shack in the settlements at the island's edge. One of the things I love about PNG is the raw, instinctive way relationships are recognised, even fleeting ones. A handshake of greeting might graduate to the lingering clasp of friendship, of sisterhood, of bonds like motherhood. For the duration of the short ambulance journey Edna's hand weighs dry and warm in mine. She is bereft and silent.

Arriving at her home at ‘Madame Corner', Edna's young son – distraught at the loss of his sister – is swept up in the arms of waiting grief. Several thousand people live in ‘The Corners', rough villages of scrounged tin and timber, invisible borders demarcating the territory of each clan. They're cooking over choking fires; sharing an erratic, suspect water supply; shitting in holes – what option do they have? On our visit they're still burying their dead from a recent cholera outbreak.