Biomedical Engineering Reference
In-Depth Information
splenomegaly may occur in up to 45-63% of cases.
Meningitis occurs occasionally (<5% of cases).
Symptoms may persist from 3-6 months and some-
times for over a year [5,11].
4.6.5 Medical Management
Supportive care should be applied to the hemo-
dynamic, hematologic, pulmonary, and neuro-
logic manifestations of VHF. Intensive care is
the sole measure that can salvage severely ill
patients. Consideration of fluid resuscitation of
hypotensive patients must be tempered when
pulmonary capillary leakage occurs. Pressor agents
are frequently required. Risk of hemorrhage must
be considered when intravascular devices and
invasive hemodynamic monitoring are employed.
Analgesics and sedatives may be judiciously
employed for management of restlessness, confu-
sion, myalgia and hyperesthesia. Secondary infec-
tions may occur. Management of clinical bleeding
follows the same principles as for any patient
with systemic coagulopathy, assisted by coagula-
tion studies. Intramuscular injections, aspirin, and
anticoagulants should be avoided. Antiviral drugs
(e.g., ribavirin) may have compassionate use proto-
cols for therapy, and the hospital pharmacist should
be consulted for approved use [5].
4.7.3 Diagnosis
Definitive diagnosis is by the isolation of
Brucellae
from blood or bone marrow. Culture should only
be attempted under BSL-3 conditions. Antibody
detection via a serum agglutination method is an
alternative means of diagnosis [5].
4.7.4 Differential Diagnosis
A very broad differential diagnosis is necessary due
to the non-specific symptoms and include bacterial,
viral, and mycoplasmal infections. The symptoms
of viral and mycoplasmal infections are usually
present for a few days, while in brucellosis they
persist longer. Typhoidal tularemia and typhoid
fever may be indistinguishable clinically from
brucellosis. Radiographic findings similar to those
in tuberculosis infection may occur, including
disk space narrowing and epiphysitis. Unequivocal
diagnosis requires isolation of the organism. Blood
culture is the method of choice but specimens need
to be obtained early in the disease and cultures
may need to be incubated for up to four weeks.
Failure to grow the organism is common, and isola-
tion rates of only 20-50% are reported even from
experienced laboratories [5,11].
4.7 Disease: Brucellosis
4.7.1 Causative Agent
Brucella species are Gram-negative cocco-
bacillary organisms, of which four are pathogenic
in humans (
Brucella melitensis
,
B. abortus
,
B. canis
and
B. suis
) [5].
4.7.2 Clinical Symptoms
Brucellosis normally presents as a non-specific
febrile illness with a long and variable incubation
period (3-60 days). Characteristic “undulant”
fever, headache, chills, myalgias, arthralgias,
weakness, and malaise are the most common
complaints. Gastrointestinal symptoms can occur
with ingestion or inhalation; symptoms include
constipation, anorexia, nausea, and diarrhea. One
or both sacroiliac joints may become infected
causing low-back and buttock pain that is inten-
sified by stressing the sacroiliac joints on phys-
ical exam. Peripheral joint involvement may occur
and vary from pain on range of motion testing
to joint immobility and effusion. Hepatomegaly or
4.7.5 Treatment
Doxycycline 100mg bid po plus rifampin 600mg
qd po for a minimum of six weeks. Ofloxacin
400mg qd po plus rifampin 600mg qd po for
6 weeks is also effective [5,11].
4.8 Disease: Glanders
4.8.1 Causative Agent
Burkholderia mallei
, a Gram-negative bacilli,
exists in nature only in infected hosts (horses,
mules, and donkeys). The organism spreads to
man by invading the nasal, oral, and conjunc-
tival mucous membranes,
inhalation into the
