Case Study
Pathogenic Bacteriology 2009
Case #41
Angela Augustus
Case Summary
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13 month old
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Initial symptoms: runny nose, low grade fever
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HIV negative
Up to date on immunizations
Treated with Tylenol
Later in the day:
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Seizures
Lethargic, limp, unresponsive, post ictal
o
Temperature 39 C
Supple neck
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Blood and urine cultures were taken
Intravenous ceftriaxone
Case Summary (cont)
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Next Day:
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No improved mental status
CSF with:
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WBC count of 4650 cells/μl (95% neutrophils)
Low glucose level
Elevated protein level
Peripheral WBC count increased from 6,600 to
14,600 cells/ μl
Case Summary (cont)
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Transferred to University Hospital:
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Irritable, stiff neck
Blood culture: positive
CSF culture: negative
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Bacterial antigen test is consistent with blood culture
Normal:
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Antibodies for Hib and pneumococci
Complement
Immunoglobulin class and subclass levels
Lymphocyte function
Case Study (cont)
Gram Stain
Choc
CBA
Key Information Pointing to Diagnosis
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DISEASE:
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Fever
Decreased mental status
Stiff neck
Positive blood culture and bacterial antigen test
ORGANISM:
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Gram Stain
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Lack of growth on CBA, growth on Choc
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Eliminated S. aureus and S. agalactiae (Micrococcaceae and
Streptococcaceae)
Eliminated E. coli
Normal complement and lack of petechial rash
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Eliminated N. meningitidis
Diagnosis
Meningitis caused by Haemophilus influenzae
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Serotype b (vaccine failure)
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“32% of children aged 6-59 months with confirmed type b
disease had received 3 or more doses of the Hib vaccine”
(Atkinson, 2008)
Serotype a
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“No cross protection is afforded to type a by immunization with
Hib conjugate vaccines” (Jin, et al, 2007)
As “the incidence of Hib meningitis decreased by 69% during
the first year following initiation of Hib conjugate
immunization…the incidence of Hia meningitis increased
eightfold” (Jin, et al, 2007)
H. influenzae
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Classification: Pasteurellaceae
Gram Stain: Gram negative coccobacilli
Requires both X and V
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Grows on Choc
Grows poorly on CBA
Ferments xylose
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H. aegyptius is -
"The Normal Flora of Humans." The Microbial World . 11 Jan 2009. Kenneth Todar
University of Wisconsin-Madison Department of Bacteriology . 2 Mar 2009
<http://bioinfo.bact.wisc.edu/themicrobialworld/NormalFlora.html>.
Pathogenesis and Disease
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H. influenzae:
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Colonizes the nasopharynx
Invades local tissues and bloodstream to spread
Human carrier, possibly transmitted by respiratory droplets
Causes:
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Meningitis  2mo – 3 years
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Fever, decreased mental status, stiff neck
Epiglottitis  2-4 year old boys
Pneumonia
Septic arthritis
Cellulitis
Pericarditis
Change in Epidemiology
An increase in vaccine use has led
to a 99% decrease in Hib disease
CDC hopes to eliminate Hib disease by 2010
(Atkinson, 2008)
Diagnosis of H. influenzae
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Diagnosis requires:
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Isolation and culturing of MO from sterile body sites:
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Detection of Hib specific antigen in sterile site especially
after intravenous antibiotic treatment
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Blood, CSF, joint, pericardial, or pleural fluid
Latex agglutination
Counterimmunoelectrophoresis
Serotyping should also be done to identify specific
type causing the disease
Therapy, Prevention, and Prognosis
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Treatment: Hospitalization and 10 days of:
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Effective 3rd generation cephalosporin
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Chloramphenicol with ampicillin
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Cefotaxime
Ceftriaxone
Ampicillin resistant strains have now emerged
Prognosis: 2-5% mortality rate even with appropriate
antimicrobial therapy
Treatment, Prevention, and Prognosis
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Prevention: Hib vaccine
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2, 4, and 6 mo old with booster at 12-15 months
Safe for HIV patients (but immunogenicity varies) and
premature infants
Conjugate vaccines: poorly antigenic polysaccharide binds
to effective protein carrier
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PRP-T (ActHib)
PRP-OMP (Pedvax HIB)
Combination vaccines: combine two vaccines
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DTaP-Hib (TriHIBit)
Hepatitis B-Hib (COMVAX)
Childhood Immunizations
http://www.cdc.gov/vaccines/recs/schedules/child-schedule.htm#printable
Primary Research Article
Ellen Hyun-Ju Lee, et al, 2008, Haemophilus influenzae type b conjugate vaccine is
highly effective in the Ugandan routine immunization program: a case-control
study, Tropical Medicine and International Health, 13:495-502.
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Test Hib vaccine effectiveness in Uganda
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Case patients – 12 weeks to 59 mo w/ confirmed Hib disease
Control groups – 3/case patient, age matched from:
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Neighborhood
Hospital
Data regarding immunizations and environment were collected
using:
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Structured questionnaires
Written documentation and logbooks
Primary Research Article
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TABLE 2 FROM ARTICLE
Vaccine effectiveness increases with # of doses (as high as 98.7%)
Take Home Message
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Meningitis involves symptoms of fever, decreased mental status
and stiff neck
Though it is caused by a variety of agents, H. influenzae is a
common cause in young children (~2 mo to 3 years)
Potentially transmitted through aerosols, the organism
colonizes the nasopharynx and infects the bloodstream
Diagnosis involves culturing/ isolating the organism from sterile
body sites or a positive bacterial antigen test
Therapy includes a 10 day cycle of a 3rd generation
cephalosporin or a combination of chloramphenicol and
ampicillin.
Preventative measures with the Hib vaccine have led to a
decreased threat. In the future, this threat may be nonexistant.
References
Atkinson, William , Jennifer Hamborsky, Lynne McIntyre, and Charles Wolfe.Epidemiology and
Prevention of Vaccine-Preventable Diseases. 10th ed. Washington DC: Public Health
Foundation, 2008.
Jin, Zhigang, Sandra Romero-Steiner, George M. Carlone, John B. Robbins, and Rachel
Schneerson. "Haemophilus influenzae Type a Infection and Its Prevention." Infection and
Immunity. 75(2007): 2650-2654.
Lee, Ellen Hyun-Ju, Rosamund F. Lewis, Issa Makumbi, Adeodata Kekitiinwa, Tom D. Ediamu,
monic Bazibu, Fiona Braka, Brendan Flanery, Patrick L. Zuber, and Daniel R. Feikin.
"Haemophilus influenzae type b conjugate vaccine is highly effective in Ugandan routine
immunization program: a case-control study." Tropical Medicine and International Health
13(2008): 495-502.
"Recommended Immunization Schedule for Persons Aged 0 Through 6 Years." Centers for
Disease Control and Prevention . 26 Feb 2009. Centers for Disease Control and
Prevention . 2 Mar 2009
<http://www.cdc.gov/vaccines/recs/schedules/downloads/child/2009/09_06yrs_schedule_pr.pdf>.
Roush, Sandra W. , Lynne McIntyre, and Linda M. Baldy. Manual for the Surveillance of
Vaccine-Preventable Diseases. 4th ed. Atlanta, GA: Centers for Disease Control and
Prevention, 2008.
Seehusen, M.D., Dean, Mark M. Reeves, M.D., and Demitria A. Fomin, M.D. . "Cerebrospinal
Fluid Analysis." American Family Physician 68(2003): 1103-1108.