Table 2.

List of medium-infectivity tissues and corresponding OPCS-4 operation codes.

tissue	corresponding OPCS-4 code
peripheral nerves	AF: peripheral nerves
thymus & adrenall	BC: other endocrine glands
cornea	CE: conjunctiva and cornea (only C45–C51)
lung	EF: lung and mediastinum (only E53–E59)
gingival tissue	F20: operations on gingiva
tonsil	F34, F36: excision of & other operations on tonsil
salivary gland	FE: salivary apparatus (only F44–F48)
oesophagus	GA: oesophagus including hiatus hernia
stomach	GB: stomach pylorus & gen uppr gastr'inst'l tract endoscop
duodenum	GC: duodenum
jejunum	GD: jejunum
ileum	GE: ileum
large intestine	H: lower digestive tract
liver	JA: liver
pancreas	JD: pancreas
spleen	JE: spleen
blood vessels	L: arteries and veins
kidney	MA: kidney
lymph nodes	TG: lymphatic and other soft tissue (only T85–T88)
bone marrow	W34: graft of bone marrow