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receive medical attention and be reported more frequently than singleton babies. Among children with known HIV status no association between birth type and risk of mother-to-infant HIV transmission was noted. 33% of both twins and singletons were uninfected, although reporting may be more complete for the twins than for singletons. Whether HIV-infected women have higher twinning rates, and whether twins are more frequently reported to a surveillance system, is best addressed by newborn heelstick HIV-seroprevalence studies to test every newborn baby. However, to maintain confidentiality, twinning information is generally unavailable. Further prospective studies of perinatally HIV-exposed infants investigating the effect of drug use and other factors will further elucidate the relation between HIV infection and twinning. Pediatric AIDS Surveillance Study, Los Angeles County Department of Health Services,

(313 no Figueroa, room 203), Los Angeles, California 90012,

USA

TONI FREDERICK LAURENE MASCOLA

1. Thomas

P, Ralston S, Bernard M, et al. Pediatric acquired immunodeficiency syndrome: an unusually high incidence of twinning. Pediatrics 1990; 86: 774-76. 2. Greene M, Gurdin P, Bolasogno P. Maternal HIV infection and drug use associated with an increased incidence of twin gestation. (Presented at the 6th International Conference on AIDS, San Francisco, June, 1990: abstract 2158). 3. 1988 Vital Statistics of Los Angeles County. Los Angeles: Department of Health Services, 1988. 4. Centers for Disease Control. Classification system for human immunodeficiency virus (HIV) infection in children under 13 years of age. MMWR 1987; 36: 225-30, 235.

Emergence of drug-resistant Mycobacterium tuberculosis in HIV-infected patients SIR,-Standard antituberculosis drugs are reported to be highly

Mycobacterium tuberculosis infection in anti-HIV positive patients.1-3The recommended regimen in adults is isoniazid (INH) up to 300 mg daily, rifampicin up to 600 mg daily, and pyrazinamide (20-30 mg/kg body weight per day).4 Ethambutol (15-25 mg/kg) may also be added when central nervous system (CNS) involvement or disseminated disease is suspected.4 With this regimen, we verified the failure of antituberculosis treatment in 10 of 23 HIV-seropositive patients in whom acid-fast bacilli were identified and who had symptomatic illness consistent with mycobacterial disease. We therefore reviewed data on antibiotic susceptibility of mycobacterium tuberculosis isolates from 12 patients who had never received antituberculosis drugs. All patients were admitted to our clinic between February, 1986, and November, 1990. All were caucasian, intravenous drug abusers, and anti-HIV positive, and met Center for Disease Control (CDC) criteria for HIV infection. In 4 patients AID S preceded diagnosis of tuberculosis. In these patients the presenting AIDS diagnoses were Kaposi’s sarcoma, Pneumocystis carinii pneumonia, cryptococcal meningitis, and oesophageal candidiasis, respectively. 3 had pulmonary M tuberculosis disease and in 1 patient pulmonary localisation was associated with CNS involvement. In 8 patients AID S and tuberculosis were diagnosed concurrently since all had at least one documented extrapulmonary acid-fast bacilli site of infection. The sites of extrapulmonary involvement were CNS (3 patients), musculoskeletal (1), urogenital (1), lymphatic (4), bone marrow or blood (2), and peritoneum plus pericardium (1). No patient showed evidence of other simultaneous opportunistic infection. The table shows drug susceptibility of isolates. As shown beforewe found a higher than expected frequency of resistance to rifampicin and isoniazid (25% and 8-3%, respectively). Surprisingly 4 isolates (2 from CSF) were resistant to ethambutol, and a high degree of resistance was also seen with streptomycin (33%) and ofloxacin 5 ug/ml (50%). Furthermore, 7 of the 12 isolates (58%) were resistant to more than one drug. These data were in accordance with clinical findings since 6 patients did not improve clinically, radiographically, and microbiologically after standard treatment, whereas rifabutine (450 mg daily) which is generally restricted to atypical mycobacteriosis4 seemed to be clinically effective. Our results emphasise the trend of mycobacterial drug resistance from 1980 to 1987 in HIV-negative subjects in our areaand effective for

DRUG SUSCEPTIBILITY OF M TUBERCULOSIS ISOLATES FROM 12 AIDS PATIENTS I

I

I

I

S=sensltlve, R=resistant, INH=isoniazid (02 2 g/ml). RFP=rifampicin (20 g/m!), STR=streptomycin (5 g/m!), ETB=ethambutol (3 g/mi), CYC=cyclosenne (30 g/ml), OFX= ofloxacln (*1 and 5 pg/ml on left and nghtof column, respectively), I node=lymph node

suggest that such resistance results from epidemiological factors rather than HIV-related conditions. The emergence of drug-resistance strains of M tuberculosis both in anti-HIV-positive subjects and in the general population is very alarming. Tuberculosis is more likely to develop and be more severe in HIV-seropositive individuals because of their immunity impairment than in the general population. Moreover, such individuals in Italy,’ as well as in other European countries, are mainly intravenous drug addicts who often live in confined environments (prison, therapeutic communities) where tuberculosis spread could be a real hazard. If tuberculosis becomes even more common in HIV-infected patients than at present the incidence of tuberculosis in the general population could soon begin to rise. Our data suggest that such infection would be resistant to standard drugs, at least in some areas. Clinic of Infectious Diseases, and Institute of Hygiene, University of Bari, 70124, Bari, Italy

L. MONNO G. ANGARANO S. CARBONARA S. COPPOLA D. COSTA M. QUARTO G. PASTORE

RE, Schecter GF, Theuer CP, et al. Tuberculosis m patients with acquired immunodeficiency syndrome. Am Rev Respir Dis 1987; 136: 570-74. 2. Theuer CP, Hopewell PC, Elias D, et al. Human immunodeficiency virus infection in tuberculosis patients. J Infect Dis 1990; 162: 8-12. 3. Chaisson RE, Slutkin G. Tuberculosis and human immunodeficiency virus infection J Infect Dis 1989; 159: 96-100. 4. US Department of Health and Human Services. Diagnosis and management of mycobacterial infection and disease in persons with human immunodeficiency 1. Chaisson

virus infection. Ann Intern Med 1987; 106: 254-56. 5. Pitchenik AE, Burr J, Laufer M, et al. Outbreaks of drug-resistant tuberculosis at AIDS centre. Lancet 1990; 336: 440-41. 6. Zubiani M. Present aspect of bacteriological diagnosis of tuberculous and nontuberculous mycobacteria Riv Tuberc Mal App Respir 1989; 21: 97-118. 7. Angarano G, Pastore G, Monno L, Santantonio T, Luchena N, Schiraldi O. Rapid spread of HTLV-III infection among drug addicts in Italy. Lancet 1985, ii:1302

Neuropathological evidence that zidovudine reduces incidence of HIV infection of brain SiR,—There is clinical and biological evidence that zidovudine reduce the incidence or improve features of HIV encephalopathy.1-3 We have studied the brains of 135 adults who died from AID S between August, 1982, and December, 1990, and can

have found further evidence for this view. In 43 cases (group 1) zidovudine had been administered for over 1 month and continued until death. Group 2 were patients not given zidovudine (77 cases), treated for less than 1 month (10), or having their treatment stopped because of myelotoxicity 3 months or more before death (5). At least twenty paraffin-embedded blocks from several regions and six large sections from the cerebral hemispheres and whole brainstem and cerebellum were examined. HIV infection of the brain was assessed by the presence of multinucleated giant cells (MGC), which are seen as the hallmark of productive HIV infection of the brain.4 MGC were found in 52 brains (11group 1, 41 group 2), and in these cases MGC or macrophages expressed HIV proteins gp41,