- Calco-Fluor white (schimmelkleuring)
- Campylobacter
- Candida
- CAPD vloeistof
- Carbapenem Resistente Enterobacteriaceae (CRE)
- Catheter tip
- Cervixuitstrijk
- Chagas
- Chikunguya virus
- Chlamydia pneumoniae (Chlamydophila pneumoniae)
- Chlamydia psittaci
- Chlamydia trachomatis
- Clostridium difficile
- Conjuctivitis
- Coronavirus
- Corynebacterium diphteriae
- Covid-19
- Coxiella burnetti (Q-koorts)
- Coxsackievirus
- Creutzfeldt-Jacob
- Cryptococcus neoformans
- Cryptosporidium en Cyclospora
- Cysten en wormeieren
- Cysticerocose
- Cytomegalovirus (CMV)

