- C. diff. Infection [Clostridium difficile Infection]
- C. gattii cryptococcosis
- C. neoformans cryptococcosis
- Campylobacter Infection [Campylobacteriosis]
- Campylobacteriosis — see Campylobacter Infection
- Capillaria Infection [Capillariasis]
- Capillariasis — see Capillaria Infection
- Carbapenem resistant Klebsiella pneumonia (CRKP) — see Klebsiella pneumoniae
- Carbapenem-resistant Enterobacteriaceae (CRE)
- Cardiovascular Health — see Heart Disease
- Carpal Tunnel Syndrome — see Ergonomic and Musculoskeletal Disorders
- Carrión’s disease [Bartonella bacilliformis Infection]
- Cat Flea Tapeworm — see Tapeworm, Dog and Cat Flea
- Cat Scratch Disease from Pets
- Cats, Infections from
- CCHF (Crimean-Congo hemorrhagic fever)
- CDI (Chronic Disease Indicators )
- Cercarial Dermatitis — see Swimmer’s Itch
- Cerebral Palsy
- CFS (Chronic Fatigue Syndrome)
- Chagas Disease [Trypanosoma cruzi Infection]
- Chapare Hemorrhagic Fever (CHHF)
- Chest Cold — see Bronchitis
- CHHF (Chapare Hemorrhagic Fever)
- Chickenpox [Varicella Disease]
- Chikungunya Fever (CHIKV)
- CHIKV (Chikungunya Fever)
- Childhood Arthritis
- Childhood Injuries
- Childhood Overweight and Obesity
- Children’s Cough and Cold Medicines — see Cough and Cold Medicines
- Chlamydia [Chlamydia trachomatis Disease]
- Chlamydia trachomatis Disease — see Chlamydia
- Chlamydophila (Chlamydia) pneumoniae Infection
- Cholera [Vibrio cholerae Infection]
- Chronic Disease Indicators (CDI)
- Chronic Disease Prevention
- Chronic Fatigue Syndrome (CFS)
- Chronic Kidney Disease (CKD)
- Chronic Obstructive Pulmonary Disease (COPD)
- Chronic Wasting Disease (CWD)
- Ciguatera Fish Poisoning
- Ciguatoxin — see Marine Toxins
- CJD, Classic (Classic Creutzfeldt-Jakob Disease)
- Classic Creutzfeldt-Jakob Disease (CJD, Classic)
- Clonorchiasis — see Clonorchis Infection
- Clonorchis Infection [Clonorchiasis]
- Clostridium botulinum Infection — see Botulism
- Clostridium difficile Infection — see C. diff. Infection
- Clostridium perfringens infection
- Clostridium tetani Infection — see Tetanus Disease
- Clotting Disorders
- CMV (Cytomegalovirus Infection)
- Coal Workers’ Pneumoconioses — see Black Lung
- Coccidioidomycosis — see Valley Fever
- Cold, Common
- Colorado Tick Fever (CTF)
- Common Cold — see Cold, Common
- Concussion — see Traumatic Brain Injury
- Conjunctivitis — see Pink Eye
- Cooley’s Anemia
- COPD (Chronic Obstructive Pulmonary Disease)
- Corynebacterium diphtheriae Infection — see Diphtheria
- Cough and Cold Medicines
- Coxiella burnetii Infection — see Q Fever
- CRE (Carbapenem-resistant Enterobacteriaceae)
- Creutzfeldt-Jakob Disease, Classic — see Classic Creutzfeldt-Jakob Disease
- Crimean-Congo hemorrhagic fever (CCHF) [Nairovirus Infection]
- CRKP (Carbapenem resistant Klebsiella pneumonia )
- Crohn’s Disease — see Inflammatory Bowel Disease
- Cronobacter Infection
- Cryptococcosis, C. gattii. — see C. gattii cryptococcosis
- Cryptococcosis, C. neoformans — see C. neoformans cryptococcosis
- Cryptosporidiosis — see Cryptosporidium Infection
- Cryptosporidium Infection [Cryptosporidiosis]
- CTF (Colorado Tick Fever)
- CWD (Chronic Wasting Disease)
- cyanobacterial algal bloom-associated illness — see Harmful Algal Bloom (HAB)-Associated Illness
- Cyclospora Infection [Cyclosporiasis]
- Cyclosporiasis — see Cyclospora Infection
- Cysticercosis
- Cystoisospora Infection [Cystoisosporiasis]
- Cystoisosporiasis — see Cystoisospora Infection
- Cytomegalovirus Infection (CMV)