J-horror imagery has become so clichéd that Hollywood has appropriated it, parodied it and moved on. Infection is a nice surprise as it expands the territory of J-horror by adding psychological horror, neat set-pieces using the hospital and the green gloop of the infection itself.
Infection takes place over a single night in a failing hospital where the doctors are late getting paid, supplies are running out, nurses are quitting, and those that are staying are either inexperienced or so overworked they fall asleep standing up. There are a lot of neglected patients including one covered in bandages, a man in constant pain, a victim of a hit and run accident and a senile old woman who sees ghosts. Trying to hold things together is Doctor Akiba but when a patient with a mysterious infection appears and a fatal medical blunder occurs, events spiral out of control.
Ochiai spends the first quarter creating a convincing and disconcerting sense of decay and claustrophobia in the hospital. The set is a lobby, some corridors and a few rooms which look run-down. The place is packed with a variety of patients with a variety of maladies that look difficult to treat. Equally varied are the hospital staff who look exhausted and, as the dialogue reveals, are pushed to the edge due to various crises and personal troubles.
Patients are mishandled and ignored while the staff members bicker amongst themselves, doctors upbraid the (foxy) nurses who bully less experienced (but equally foxy) nurses.