TB or not TB?

I've always thought of tuberculosis as a disease of the lungs. I won't pretend that it's because of La Traviata and her persistent coughing which punctuates Puccini's work. Even after three and half years of medical school, I couldn't help associating TB with coughing, weight loss and a few other symptoms.
Of course, this isn't wrong: the lungs certainly are a site of predilection for Mycobacterium tuberculosis. It likes to set up camp there and hibernate for years, sometimes a whole lifetime. But despite this affinity for the draughty recesses of the chest, TB also enjoys going for a wander elsewhere. The spine, the kidneys, the eyes: no sites are really off limits for this bacterium if the conditions are right.
The conditions are definitely right in this patient. He contracted HIV many years ago and has not been receiving any antiretrovirals. Slowly, but surely, the virus has gained the upper hand over his immune system. Today, his body is essentially a very badly defended shelter for whichever micro-organism might choose to invade.
He came in to the hospital because he was having difficulty walking. On examination, he is weak all along his right-hand side. He has swollen lymph nodes throughout his body, along with headaches and fever. This picture is typical for toxoplasmosis, but the doctors here are convinced it will turn out to be TB in the brain. There's so much of the disease around, the investigations will probably prove them right.
A few weeks ago I would never have associated TB with hemiplegia, particularly if the patient didn't have any chest symptoms. Perhaps someone could have guided me there with some leading questions, but the two things just weren't linked in my mind. Having now seen nearly a dozen cases of TB meningitis, I'm starting to realise that most things could be due to this disease.

Scared of Air

The first thing I noticed about this patient was how well he looks. In an ICU full of emaciated, jaundiced and comatose patients, he stands out because he seems fine. He's fully conscious and notices us as we come to stand at his bedside, looking down at him. He begins to talk to Dr Nguyen - perhaps he's asking how much longer he has to stay here. He smiles and laughs, and then returns to his thoughts while we examine him.
His bed is oddly placed within the ward. He's not lined up with the other patients in the bays; instead he lies in the middle of the ICU despite there being ample space elsewhere. We probe Dr Nguyen for answers. "Afraid", he says, in very broken English. "Afraid, er, of... of wind". This doesn't make sense to me - I must have misunderstood. But Dr Nguyen illustrates the point: taking his notepad in his hand, he waves some air into the patient's face. Suddenly, everything changes. A terrified look is in the patient's eyes, and he draws in a sharp breath, as if he's seen a ghost. A few seconds of wide-eyed stares; and he's back to normal. Looking calmly around the bed, breathing quietly. He asks Dr Nguyen another question.
The look of terror that overcame our patient is probably matched only by the look of amazement on my face. "He's afraid of air?" I ask, still skeptical despite the obvious demonstration. Dr Nguyen repeats the process. Again, the patient gasps as soon as the air reaches him. The fear in his eyes is unlike anything I've ever seen before. And then it's gone again, melting away almost instantaneously.
That's it. That's all there is to see in this patient. He was brought in to the hospital this morning, because of his strange behaviour. His bed is strategically placed to avoid the drafts from the two large air conditioning machines: they would be unbearable for him. On questioning, it emerges that he was bitten by a dog two months ago.

Fear of air and water are pathognomonic for rabies: no other disease produces these symptoms. And while he may look well between the flashes of terror, he will be dead in a matter of days. Just as there is no doubt about the diagnosis, there is no doubt about the outcome: once symptoms appear, the mortality rate is 100%. An urgent course of vaccinations after the bite might have saved his life, but it is too late now.
For the past two months, the virus has been slowly making its way through his nervous system and up to his brain. Once there, the virus begins to replicate and then spreads back out via the neurones to most organs including the heart, eyes and kidneys. Signs and symptoms then begin to appear, including paralysis, confusion, agitation and the tell-tale phobias. The salivary glands are hijacked, churning out millions of virus particles in the hope of infecting a new host.
Patients with rabies don't usually stay in the hospital very long. Once the diagnosis has been explained to the family, patients are usually taken home: there is no point paying for medical treatment when it can ultimately do nothing for the patient.
Before leaving the ward, I take a last look at him. He still looks very well. The calm before the storm.

An Ancient Foe

Two days, two patients. The first is middle-aged and looks uncomfortable lying on his back. He was brought in unconscious and feverish. His hands are shaking despite the green restraints tied around his wrists. Lots of patients in the hospital have restraints such as these: there are no sidebars on the beds and hospital staff worry that they may fall off. Back to our patient. He has a big liver, and his skin bears an appropriate yellow tinge. I begin to list in my mind the viruses, bacteria and fungi which can cause liver failure.
Our second patient is much older, and much sicker. Similarly restrained for his protection, he is fast asleep, snoring, seemingly oblivious to the anxiety he is causing the pack of doctors gathered around his bed. An NG tube feeds him, while a ventilator attached to his tracheostomy breathes on his behalf. Despite the big liver, this patient isn't yellow. Admitted with fever, cough and difficulty breathing, he was found to have a bad chest infection; subsequent tests reveal the space around his lungs has filled with blood. His chest X-rays give us plenty to talk about.

Despite my list of microbes which target the liver, I'm wide of the mark (a pattern is emerging). Both alcoholic, these patients' ailments are self-induced. Their livers have suffered for years and are finally giving in. Unfortunately, I don't think a transplant is on the cards.
In the Hospital for Tropical Diseases, I could be forgiven for thinking that every presentation has an infectious agent behind it. But the source of both these patients' problems is not a tropical bug, it's a bottle.