Common Cold

Inflammation of the nasal passages due to any number of respiratory viruses. Usually not serious; vast majority are self-treated. Incidence/Prevalence in USA: Preschool children 6-10 colds/yr; kindergarten 12/yr; schoolchildren 7/yr; adolescents/adults 2-4/yr. National Ambulatory Survey: 31 episodes/100 persons/year (counting only colds that lead to medical attention or at least one day of restricted activity).

Coccidioidomycosis

Pulmonary fungal infection endemic to the Southwest USA. Can become progressive and involve extrapulmonary sites, including bone, CNS, and skin. Known as the “great imitator.” Incubation period is 1 to 4 weeks after exposure.

Chronic Fatigue Syndrome

Chronic fatigue syndrome (CFS) is characterized primarily by profound fatigue, in association with multiple systemic and neuropsychiatric symptoms, lasting at least 6 months. The fatigue must have a new or definite onset (i.e., not lifelong), is not relieved by rest, and results in a substantial reduction in previous activities (occupation, education, social, and personal).

Chronic Cough

Chronic cough is defined as cough of >3 weeks duration. Patients present for fear of underlying pathology (eg, cancer), annoyance, self-consciousness, hoarseness. Patients with stress urinary incontinence may find cough particularly troubling. COPD and smoking-related cough are most common etiologies at the primary care level.

Cholera

An acute infectious disease caused by Vibrio cholerae (El Tor type is responsible for current epidemic, the other type, classic, is found only in Bangladesh). (New serotype now in Bangladesh, India (0139). Important because of lack of efficacy of standard vaccine.) Characteristics include severe diarrhea with extreme fluid and electrolyte depletion, and vomiting, muscle cramps and prostration.

Chlamydia Pneumoniae

Chlamydia pneumoniae an obligate intracellular bacteria, has been established as an important cause of adult respiratory disease including pneumonia, bronchitis, sinusitis and pharyngitis. There is no animal reservoir. Incidence/Prevalence in USA: Estimated incidence of 100 to 200 cases of pneumonia/100,000/ year.

Chickenpox

The usual incubation period is 14-16 days (range 11-21). Patients are infectious from approximately 48 hours before appearance of the rash until the final lesions have crusted. Most people acquire chickenpox during childhood and develop long immunity.

Cervicitis, Ectropion & True Erosion

Cervicitis — Chlamydia trachomatis, Trichomonas vaginalis. Ectropion — hormonal changes with oral contraceptive use (especially with progesterone) or during pregnancy. True erosion — injury to atrophic epithelium due to estrogen deficiency in menopause.

Cervicitis

Infectious cervicitis may be caused by Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, ureaplasmas, Herpes simplex or Trichomonas vaginalis. Chronic cervicitis is characterized by inflammation of the cervix without an identified pathogen.