Case History: A 69 year old white male presented with a 6 month history of abdominal pain (primarily left-sided), nausea, and cramping relieved by bowel movements

DEPARTMENT OF PATHOLOGY
The Johns Hopkins Medical Institutions

Vol. 20, No. 11
THE JOHNS HOPKINS MICROBIOLOGY NEWSLETTER
Tuesday, March 13, 2001

Provided by Leslie Edwards Reger, Division of Outbreak Investigation, Maryland Department of Health and Mental Hygiene.

7 outbreaks were reported to DHMH during MMWR week 9 (Feb 25- Mar 3):
2 foodborne gastroenteritis outbreaks associated with food-service facilities (Anne Arundel Co, Calvert Co)
2 gastroenteritis outbreaks at health-care facilities;
1 at a long-term care facility (Baltimore Co)
1 at an assisted living facility (Baltimore Co)
2 influenza-like illness outbreaks at long-term care facilities (Washington Co, Garrett Co)
1 outbreak of acute febrile respiratory disease caused by respiratory syncytial virus at a daycare facility (Anne Arundel Co)

4 outbreaks were reported during MMWR week 10 (Mar 4-10, 2001):
1 outbreak of gastroenteritis at a nursing home (Allegany Co),
1 outbreak of foodborne gastroenteritis associated with a food-service facility (Anne Arundel Co), 1 outbreak of influenza-like illness at a nursing home (Carroll Co)
1 outbreak of a state-wide increase in salmonellosis (Salmonella bovis morbificans) (multiple counties)

The Johns Hopkins Hospital. Information provided by Denis M. McCarthy M.D., Department of Pathology.

Case Report: The patient is an eleven-year-old African American male who was in his previous state of good health until approximately one-month before presentation when he developed a swelling in his left groin that was progressively increasing in size. He was seen approximately three weeks later by his primary physician who diagnosed inguinal lymphadenitis and treated with Keflex. He was also immunized with the varicella vaccine. A PPD was placed which was negative. One day before presentation, he developed a headache, sore throat, and aching back and legs while at school. He was treated symptomatically at the school clinic and his headache resolved. The following day, he was noted to have a mild tremor in both hands and some dragging of his left foot. That evening he developed a generalized tonic-clonic seizure and was promptly brought to the ER. In the ER, he was actively seizing and apneic. He was intubated and loaded with phosphenytoin. He received a dose of ceftriaxone and a non-contrast head CT was normal. He was transferred to the PICU. Other than a mild leukocytosis, his initial labs were unremarkable and included a negative toxicology screen. His seizures remained difficult to control requiring multiple anti-seizure agents including propofol drip. He had intermittent fevers and was treated with acyclovir and cefepine beginning on the second hospital day. Bacterial and viral cultures from the blood and CSF were negative. Serology for HIV and EBV was negative and PCR testing for HSV was also negative. The patient never regained consciousness and he continued to decline with lactic acidosis and cardiac failure. He died on the fifth hospital day. Further history revealed that the patient had been exposed to a new kitten approximately 1.5 months before presentation. Serologic testing of his serum for Bartonella henselae and quintana (performed at the CDC) are shown in Table 1. Serologic tests and PCR tests of the CSF for Bartonella henselae were negative.

*Table 1. Serologic testing for Bartonella henselae* and B. quintana using IFA**
	B. henselae	B. quintana
IgG (H&L)	512	2048
IgG (gamma)	128	512
IgM	128	128

Bartonella henselae/Cat-scratch disease encephalopathy

Organism: The causative organism of cat-scratch disease encephalopathy is Bartonella henselae, a small, gram-negative and extremely fastidious rod. Bartonella species are oxidase negative and aerobic. Recovery of Bartonella spp. has been accomplished using chocolate agar or other media without antimicrobials incubated for at least 21 days in 5% CO2 at 35 to 37°C. B. bacilliformis, geographically confined to the South American Andes, is an erythrocyte-invasive bacterium associated with severe febrile illness and profound anemia. Its vector is the sand fly Lutzomyia verrucarum. B. quintana was first recognized as the cause of "trench fever" seen in battlefield troops of World War I and is transmitted by the body louse. Transmission of B. henselae has been firmly linked with felines and evidence suggests that the cat flea is a potential vector among animals.^, The incidence of Bartonella infections in immunocompromised patients is not known. In immunocompetent patients, approximately 10 instances of cat scratch disease (CSD) per 100,000 persons occur annually in the United States with approximately 60% of cases occurring in persons under 20 years of age.²

Clinical Manifestations: Symptoms associated with bacteremia in B. henselae in immunocompromised patients are characterized by insidious development of fatigue, malaise, body aches, weight loss, progressively worsening fevers and headache. Both B. henselae and B. quintana are associated with bacillary angiomatosis, vascular proliferative lesions seen almost exclusively in immunocompromised patients. Bartonella infection in immunocompromised patients can also cause bacillary peliosis hepatitis (formation of venous lakes in the liver), endocarditis, and bacteremia. Instances of Bartonella bacteremia and endocarditis have been reported in immunocompetent patients but the incidence is thought to be very low. More commonly, CSD is seen in immunocompetent patients infected by B. henselae. The primary cutaneous lesion of CSD occurs 3 to 10 days after a cat scratch or bite. This wound gradually resolves. Regional adenopathy, the hallmark finding in CSD, occurs approximately 10 days after the injury. One third of patients will also present with fever lasting 1 to 2 weeks. Approximately 2% to 3% of patients will develop Parinaud’s oculoglandular syndrome characterized by regional lymphadenitis and unilateral conjunctivitis. Neurologic involvement is seen in approximately 2% of cases.³ CSD encephalopathy has recently been reported as a cause of status epilepticus in children.

Diagnosis: As described above, diagnosis of Bartonella spp. by culture is slow and difficult. Antibodies to B. henselae have been demonstrated in between 88% and 95% of patients with CSD using both an indirect immunofluorescence assay and enzyme immunoassay. Using IFA, higher relative titers of B. quintana are frequently seen in CSD cases but are thought to represent cross-reactivity. PCR assays using 16S rDNA primers specific to Bartonella spp. have also been successful in diagnosis.³

Treatment:
Immunocompromised patients: Erythromycin 500mg q6h or Doxycycline 100mg q12h for 12 weeks.

Immunocompetent patients: No specific antimicrobial therapy recommended.