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1. Another mutation may be protective against infection with HIV-1. An homozygous deletion in the chemokine receptor gene CCR5 has previously been described as protective against infection with HIV-1. Researchers at the Pasteur institute have found another mutation that confers resistance to infection in vitro when associated with the one previously described. This is a single point mutation at position 303 on one allele of the same CCR5 gene.

(Quillent C, Oberlin E, Braun J. HIV-1 resistance phenotype conferred by combination of two separate inherited mutations of CCR5 gene. Lancet 1998;351:14-18). abstract

2.There are new guidelines for the prevention of bacterial endocarditis. A few of the new changes include: 1) stratification of cardiac conditions into high, moderate and negligible risk; 2) erythromycin is not longer recommended for penicillin allergic patients but clindamycin, cephalexin, cefadroxil or the new macrolides azithromycin or clarithromycin are now the other alternatives; 3) simplified regimens for GI procedures, 4) an algorithm for prophylaxis in patients with mitral valve prolapse.

(Dajani AS et al. Prevention of Bacterial Endocarditis: Recommendations by the American Heart Association.Clin Infect Dis 1997;25:1448-1458).

3. AIDS and Chagas’ disease. Chagas’ disease is an important parasitic infection in Latin America, there is a recent report by Ferreira et al in which 3 new cases and a retrospective review of additional 13 patients with Chagas’ disease reactivation associated to AIDS are presented. Their findings here suggest that Trypanosoma cruzi should be included among the opportunistic pathogens causing infection in severely immunocompromised patients with AIDS.

(Ferreira MS, Nishioka S, Silvestre MT. Reactivation of Chagas’ disease in patients with AIDS: Report of three new cases and review of the literature. Clin Infect Dis 1997;25:1397-1400).

4. More on epidemiology of Bartonella infections. Bartonella henselae and Bartonella quintana have been previously implicated as etiologic agents of bacillary angiomatosis. A recent study provides additional epidemiological information; infection with B.henselae seems to be related more directly with peliosis hepatis and exposure to cats and fleas whereas infection with B.quintana is associated to the presence of subcutaneous and lytic bone lesions as well as exposure to lice.

(Koehler JE, Sanchez MA, Garrido CS et al. Molecular epidemiology of Bartonella infections in patients with bacillary angiomatosis-peilosis. N Engl J Med 1997;337:1876-83). abstract

5. Viridans group streptococci joining the list of resistance. Until a few years ago resistance to penicillin was uncommon among these species. A study from Japan shows an increased level of resistance to penicillin in viridans streptococci isolated from patients with oncohematological problems who had received beta-lactamic antibiotics for neutropenia prophylaxis. The study also suggested a high prevalence of penicillin-resistant isolates in the oral cavity of healthy children.

(Mogi A, Nishi J, Yoshinaga M, et al. Increased prevalence of penicillin-resistant viridans group in Japanese children with upper respiratory infection treated by beta-lactam agents and in those with oncohematologic diseases.Pediatr Infect Dis J 1997;16:1140-1144).

6. Higher prevalence of cell-free HIV demonstrated in mature milk of infected women. Quantitative analysis of breast milk samples showed that the prevalence of cell-free HIV-1 was higher in mature milk than in calostrum (47% vs. 27%). HIV-1 was detected in 39% of specimens.

(Lewis P, Nduati R, Kreiss J. Cell- free human immunodeficiency virus type 1 in breast milk. J Infect Dis 1998;177: 34-39).

7.Judicious use of antibiotics for pediatric upper respiratory tract infections. There is an excellent publication edited by Scott Dowell, M.D. on the principles for the judicious use of antibiotics in pediatric upper respiratory tract infections (includes recommendations on the diagnosis and management of otitis media, acute sinusitis, pharyngitis, bronchitis and the common cold). Different important issues of which every one of us should be aware in this times of increasing antimicrobial resistance.

(Pediatrics.1998;101,supplement:163-184).

8.Immunizations in Health-Care workers. The CDC has released the new recommendations by the Advisory Committee on Immunization Practices (ACIP) and the Hospital Infection Control Practices Advisory Committe. You can look it up at the CDC internet site on the section on “Recommendations and Reports” of the MMWR.

(CDC Immunizations of Health-Care Workers. MMWR 1997;48: RR-18). click here

9. Mefloquine is still the drug of choice . Despite recent concerns about the potential neurotoxicity of the drug, it remains the drug of choice for malaria prevention in regions where there is chloroquine resistance. When given for prophylaxis the side effects are much less than when it is used to treat patients with malaria.

(Lobel HO, Kozarsky PE. Update on prevention of malaria for travelers. JAMA 1997;278:1767-1771). abstract

10. Perinatal infection with HIV linked to prematurity. A recent multicentric study has shown that there is a high incidence of prematurity and low birth weight in those infants born to mothers infected with HIV. It was also observed that HIV infection in the infant resulted in a higher rate of prematurity and lower mean gestational age.

(Martin R, Boyer P, Hammill H, et al. Incidence of premature birth and neonatal respiratory disease in infants of HIV-positive mothers. J Pediatr 1997;131:851-856).

WHAT’S THE BUG?
This patient is a 13 month old african-american male with fever ( Tm.103 F) and cough since four days prior to his admission. He began limping six hours before his initial evaluation. His past medical history was unremarkable. He was exposed to an older sibling with pharyngitis two weeks before. On physical exam he was febrile, had bilateral crackles and decreased range of motion of his right lower extremity. His chest x-ray showed bilateral perihiliary infiltrates. A hip ultrasound was normal and his ESR was 69 mm/hr. Two days after being admitted he developed right knee swelling and two blood cultures yielded positive results for a single organism. A bone scan performed (see image).

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Benjamin Estrada, M.D.
Assistant Professor of Pediatrics,
Division of Pediatric Infectious Diseases,
Department of Pediatrics and Adolescent Medicine,
University of South Alabama (*)

Last update January, 1998