Infectious Diseases in Critical Care Medicine

Table 6

Assessing the Patient for Category A Agents (

Continued

)

Pathogen(incubation period)

Systemic symptoms

Central nervoussystem

Cardiorespiratory

Gastrointestinal

Skin and mucousmembranes

Miscellaneous

Smallpox

(V. major

)

Average incubation:

10–12 days; range:6–22 days.Incubation perioddependent oninoculum.

48–72 hour prodrome

although it may beas long as 5 days.Sudden onset offever, chills, lumbarpain.

Headache in prodromal

period. Delirium lessfrequent inprodrome.

Nausea, vomiting,

abdominal pain, anddiarrhea; lessfrequent inprodrome.

Transient

erythematous orpetechial rashlasting 12 hr may beconfused formeasles.

Ordinary smallpox

Fever, rigors,

backache, malaise,prostration,headache.

Delirium (15%).

Discrete or confluent

rash.

Nonimmune individuals:

20–50% mortality.

Modified smallpox

Less severe

symptoms.

Most patients complain

of splittingheadaches andspinal pain; somedevelophallucinations,delirium, depression,and manicdepression. This maypersist intoconvalescence.

Vaccine-modified disease:

Rare deaths.

Flat (malignant)

smallpox

More severe

symptoms,persistent fever.

Abdominal pain more

frequent.

Dusky erythema to

pleomorphic orpetechial rash.Papules not wellformed. Rash maybe discrete orconfluent.

Death occurs between 7th

and 15th day fromencephalitis orhemorrhage.

Mortality:Discrete: 85%Discrete-Immunized: 45%Confluent: 79%Confluent unimmunized:

99%.

Hemorrhagic

(fulminate) smallpox

Prodrome prolonged

and severe.Patients are toxicand restless andfevers are high.

Dusky rash appears

on chest followed bydiffuse petechiaeand bleedingfrom mucousmembranes. Thosewho survive after10 days developa confluenthemorrhagicvesiculation.

Mortality in immunized

patients: 98%.

Mortality in unimmunized

patients: 96%.

Variola sine eruptione

(variola sineexanthemata)

Immunized patients.

0% mortality

Pharyngeal form:

Spotty enathemaover soft palate,uvula and pharynx.

Influenza-like form.

Immunized but lowdegree of immunity.0% mortality

Pulmonary disease:

severe symptoms,cyanosis, bilateralinfiltrates.

Low or no immunity.

Mortality rates notavailable.

(Continued )

Bioterrorism Infections in Critical Care 447