Showing papers in "The Journal of Infectious Diseases in 1991"

Cofactors in Male-Female Sexual Transmission of Human Immunodeficiency Virus Type 1

Abstract: A community-based cohort of 595 prostitutes from Nairobi was enrolled to study the epidemiology of sexually transmitted diseases (STDs) during January-August 1985. Subgroups were followed at interval of 2 weeks to 1 month during April 1985-March 1987. Reassessments were made during September-December 1985 March-August 1986; and October 1986-June 1987. Of the 595 women 196 were initially HIV-1 antibody-negative. Of these 196 women all who seroconverted to HIV-1 (n = 83) and all who remained HIV-1-seronegative during at least 12 months of follow-up (n = 41) were included in this report. Serology for HIV-1 was done using an enzyme immunoassay (HTLV-III ELISA). Positive specimens were confirmed by HIV-1 Western blot (HTLV-III Western blot). Seroconversion to HIV-1 occurred in 83 women (67%) by the end of June 1987. Annual HIV-1 incidence was 47%. Of 85 women who never used oral contraceptives (OCs) 51 (60%) seroconverted compared with 16 (76%) of 21 who either stopped or started using OCs during the observation period and 16 (89%) of 18 who used OCs throughout the study period (p < 0.05). OC use was associated with HIV-1 infection. Of 39 reporting any OC use 32 seroconverted (odds ratio [OR] 3.1; 95% confidence interval [CI] 1.1-8.6; P m< 0.03). Genital ulcers (mean annual episodes 1.32 +or- 0.55 in seroconverting women vs. 0.48 +or- 0.21 in seronegative women (p < .02) were associated with increased risk of HIV-1 infection. Condom use reduced the risk of HIV-1 infection (OR 0.11; CI 0.05-0.27; p < .0001). Stepwise logistic regression analysis confirmed independent associations between HIV-1 infection and OC use condom use genital ulcers and C trachomatis. The presence of other STDs and genital ulcer disease linked to HIV-1 epidemiology may explain the heterosexual HIV-1 epidemic in Africa. If genital ulcers alter susceptibility to HIV-1 by producing mucosal disruption it seems plausible that other STDs that cause such disruption such as C trachomatis infection also facilitate HIV-1 transmission. This would call for the inclusion of STD control in AIDS control programs.

Immunity to and Frequency of Reinfection with Respiratory Syncytial Virus

Abstract: To better understand the duration of immunity against respiratory syncytial virus (RSV) and the role of serum antibodies to the surface glycoproteins, F and G, in susceptibility to reinfection, 15 adults with previous natural RSV infection were challenged with RSV of the same strain group (A) at 2, 4, 8, 14, 20, and 26 months after natural infection. By 2 months about one-half and by 8 months two-thirds of the subjects became reinfected. Each challenge resulted in infection in at least one-fourth of the subjects. Within 26 months 73% had two or more and 47% had three or more infections. The duration of immunity tended to increase after two closely spaced infections. Higher neutralizing, F and GA antibody levels before challenge correlated significantly with protection against infection. However, even in subjects with the highest antibody levels, the risk of reinfection was 25%. Specific nasal IgA antibody titers did not correlate significantly with protection. This suggests that humoral neutralizing, F, and G antibodies correlate with resistance to reinfection, but protection is far from complete and is of short duration.

Control of the microbial flora of the vagina by H2O2-generating lactobacilli.

Abstract: H2O2-generating lactobacilli (LB+) are present in the vagina of most normal women but are absent from most women with bacterial vaginosis (BV). LB+ at high concentration was toxic to Gardnerella vaginalis (the predominant organism in the vagina of women with BV); when the LB+ was lowered to a level where it was ineffective alone, the addition of myeloperoxidase and chloride reinstituted toxicity. Toxicity was inhibited by catalase and was not seen when H2O2-negative lactobacilli were used, implicating H2O2 as the toxic molecule. LB+ could be replaced by H2O2 and chloride by iodide, bromide, or thiocyanate. The optimum pH for inhibition of G. vaginalis was 5.0-6.0 LB+ also was autoinhibitory when combined with myeloperoxidase and chloride. LB+ alone at low concentrations was toxic to Bacteroides bivius through the formation of H2O2. Adequate amounts of peroxidase were found in the vagina of 17 of 21 women. These findings suggest that LB+ may contribute to the control of the vaginal flora, particularly in the presence of peroxidase and a halide.

The proinflammatory cytokines interleukin-1 and tumor necrosis factor and treatment of the septic shock syndrome.

Abstract: Treating the septic shock syndrome with antibodies that block only endotoxin has its limitations. Other targets for treating septic shock include neutralizing antibodies to the complement fragment C5a, platelet-activating factor antagonists, and blockade of endothelial cell leukocyte adhesion molecules. Specific blockade of the proinflammatory cytokines interleukin-1 (IL-1) or tumor necrosis factor (TNF) reduces the morbidity and mortality associated with septic shock. Moreover, blocking IL-1 and TNF likely has uses in treating diseases other than septic shock. Use of neutralizing antibodies to TNF or to IL-1 receptors have reduced the consequences of infection and inflammation, including lethal outcomes in animal models. The IL-1 receptor antagonist, a natural-occurring cytokine, blocks shock and death due to Escherichia coli and ameliorates a variety of inflammatory diseases. Soluble TNF and IL-1 surface receptors, which bind their respective cytokines, also ameliorate disease processes. Current clinical trials are evaluating the safety and efficacy of these anticytokine therapies either alone or together.

Intercontinental Spread of a Multiresistant Clone of Serotype 23F Streptococcus pneumoniae

Abstract: Isolates of serotype 23F Streptococcus pneumoniae with high levels of resistance of penicillin have been commonly recovered in Spain for more than a decade. Recently penicillin-resistant serotype 23F S. pneumoniae strains were also isolated from children attending a day-care center in Cleveland. A number of Spanish and Cleveland isolates were compared by electrophoretic analysis of penicillin-binding protein (PBP) profiles and DNA restriction endonuclease cleavage profiles of the PBP 2X and 2B genes amplified with the polymerase chain reaction and by multilocus enzyme electrophoresis. All strains were identical by these criteria. The findings demonstrate that the Spanish and Cleveland isolates are clonally related and suggest that this antibiotic resistant clone of serotype 23F S. pneumoniae has spread intercontinentally from Spain to the United States.

Guidelines for the use of antimicrobial agents in neutropenic patients with unexplained fever.

Abstract: To THE EDITOR-In their recent review, Hughes et al. [1] discuss the use of empiric antibiotic therapy for unexplained fever in neutropenic patients. We are concerned about their recommendations regarding double 3-lactam regimens. There are three basic reasons for using antibiotic combinations: to provide synergy, to prevent the development of resistance, and to broaden the spectrum of empiric therapy. Double 3-lactam combinations (such as the ureidopenicillins with cephalosporins) have only rarely been found to provide synergy against gram-negative bacilli. In fact, the combination will more likely result in antagonism [2, 3]. A 3-lactam in combination with an aminoglycoside does produce synergy against various grampositive and gram-negative organisms, including Pseudomonas aeruginosa [4]. The development of antibiotic resistance by bacteria is a welldescribed problem [2, 3]. Double 3-lactam combinations have not been found to reduce the development of resistance [5]. This is a particular problem in organisms that produce Richmond-Sykes type 1 3-lactamases, such as P aeruginosa and Enterobacter cloacae. In contrast, aminoglycosides have been shown to decrease the resistance developed to 3-lactams when used in combination (and vice versa), although there are conflicting data. Experimentally, aminoglycoside-3-lactam combinations have been shown to prevent the emergence of resistance, whereas double 3-lactam regimens are no better than the individual 3-lactam alone [6]. A double 3-lactam combination is additive and will broaden the empiric coverage. However, the practitioner must feel comfortable with a broad-spectrum penicillin being used as monotherapy if a cephalosporin-resistant organism is the pathogen. It is well documented that the aminoglycosides are nephrotoxic. Those who promote the use of double 3-lactam combinations claim that the risk of using an aminoglycoside outweighs the benefits. We recognize that for most granulocytopenic patients double 3-lactam combinations are effective. However, in most of these cases monotherapy with ceftazidime should be sufficient [7]. The first and fourth EORTC studies [8, 9] and Winston et al. [10] provide strong evidence that aminoglycoside-containing regimens produce better results in patients with severe neutropenia (<100/mm3) or in patients infected with R aeruginosa. The benefit of using an aminoglycoside in these patient populations should outweigh the risk. It is our opinion that the antagonistic potential and the emergence of organisms resistant to 3-lactam antibiotics are reasons to avoid the use of double 3-lactams whenever possible. In addition, aminoglycosides should be used in combination with a broad-spectrum 3-lactam antibiotic in profoundly neutropenic patients or in those infected with P aeruginosa.

Reduction of Oropharyngeal Carriage of Haemophilus influenzae Type b (Rib) in Children Immunized with an Rib Conjugate Vaccine

Abstract: The oropharyngeal carriage of Haemophilus influenzae type b (Hib) was studied among 725 healthy 3-year-old children who had or had not been immunized with an Hib conjugate vaccine. Oropharyngeal swabs were collected during the childrens' well-child visit to their local child health center. Fourteen (3.5%) of the 398 unvaccinated children were oropharyngeal carriers of Hib, whereas none of the 327 children who had received Hib conjugate vaccine carried Hib (P less than .001). Carriage rates of non-type b H. influenzae (19%) or Streptococcus pneumoniae (18%) were the same irrespective of the Hib vaccination status of the children. Thus Hib conjugate vaccine, unlike Hib polysaccharide vaccine, seems to be able to prevent oropharyngeal colonization by Hib.

Prospective, Double-Blind, Concurrent, Placebo-Controlled Clinical Trial of Intravenous Ribavirin Therapy of Hemorrhagic Fever with Renal Syndrome

Abstract: A prospective, randomized, double-blind, concurrent, placebo-controlled clinical trial of intravenous ribavirin (loading dose of 33 mg/kg, 16 mg/kg every 6 h for 4 days, and 8 mg/kg every 8 h for 3 days) was conducted in 242 patients with serologically confirmed hemorrhagic fever with renal syndrome (HFRS) in the People's Republic of China. Mortality was significantly reduced (sevenfold decrease in risk) among ribavirin-treated patients, when comparisons were adjusted for baseline risk estimators of mortality (P = .01; two-tailed). HFRS typically consists of five consecutive but frequently overlapping clinical phases. Only occurrence of oliguric phase and hemorrhage was associated with severity of clinical disease in the placebo group. Ribavirin therapy also resulted in a significant reduction in the risk of entering the oliguric phase and experiencing hemorrhage. The only ribavirin-related side effect was a well-recognized, fully reversible anemia after completion of therapy.

Prevalence of resistance in patients receiving ganciclovir for serious cytomegalovirus infection.

Abstract: Seventy-two AIDS patients treated with ganciclovir for cytomegalovirus (CMV) disease were prospectively monitored for the development of drug-resistant virus. No resistant strains were found in 31 patients before therapy or among seven culture-positive patients treated for less than or equal to 3 months. Of 13 culture-positive patients treated for greater than or equal to 3 months, 5 excreted virus resistant (ED50, greater than 12 microM, or ED90, greater than 30 microM) to ganciclovir. Thus, 38% of patients and receiving ganciclovir for greater than 3 months and excreting virus or, overall, 7.6% of the patients were excreting CMV resistant to the drug.

Analysis of Interstrain Variation in Cytomegalovirus Glycoprotein B Sequences Encoding Neutralization-Related Epitopes

Abstract: Nucleotide sequences of a part of the envelope glycoprotein B (gB) gene of human cytomegalovirus (CMV), encoding epitopes recognized by virus-neutralizing monoclonal antibodies, were determined for 12 distinct clinical strains of CMV after amplification of suitable templates using the polymerase chain reaction. Sequence analysis of this region (codons 384-717) revealed that the clinical strains and previously sequenced laboratory strains Towne and AD169 belong to one of four variant groups, each with a characteristic nucleotide and peptide sequence. Peptide homology was greater than 99% for strains within a group, and varied from 91% to 98% for strains in different groups. Variation was most frequent between codons 448 and 480. The gB group of a CMV strain could be determined by restriction analysis of a small target sequence amplified from viral genomic DNA, and an additional 28 clinical strains were grouped in this manner. The existence of a limited number of variants of gB among clinical strains facilitates analysis of biologic function and cross-reactivity of immune responses.

An Epidemic of Hepatitis A Attributable to the Ingestion of Raw Clams in Shanghai, China

Abstract: An epidemic of hepatitis A in 1988 in Shanghai had an overall attack rate of 4083/100,000 population (292,301 cases). The epidemic curve showed three peaks in January and February. A case-control study of 1208 matched pairs supported that clams were the vehicle for the virus (summary odds ratio, 9.47; P less than .001). Analysis of subsets who had eaten clams indicated that only 3.5% with hepatitis A had cooked their clams compared with 18.1% without hepatitis A, and those with the disease consumed more clams. A historical cohort study indicated that approximately 31.7% of the population had eaten clams one or more times between 9 December 1987 and 3 January 1988. The estimated attack rates in those who had and had not eaten clams were 11.93% and 0.52%, respectively (relative risk, 22.94; attributable risk, 11.41%). The three peaks in the consumption curve correlated with those in the epidemic curve. Hepatitis A virus was demonstrated in clams taken from the Shanghai markets and from the catching area.

Granulocyte Colony-Stimulating Factor Enhances the Phagocytic and Bactericidal Activity of Normal and Defective Human Neutrophils

Abstract: Granulocyte colony-stimulating factor (G-CSF) stimulates proliferation of myeloid cells and may be a valuable adjunct in prevention and treatment of neutropenia-associated infections. Neutrophil (PMNL) phagocytic and microbicidal functions against Staphylococcus aureus and Candida albicans blastoconidia were therefore evaluated. Bacterial phagocytosis and bactericidal activity were significantly enhanced by approximately 50%-70% after preincubation of normal PMNL with G-CSF in concentrations of 1000-4000 units/ml for 10 min at 37 degrees C. G-CSF in similar concentrations enhanced the defective bactericidal activity of PMNL from HIV-1-infected patients by approximately 70%-150% and reached the baseline control PMNL killing. However, G-CSF enhanced neither phagocytosis nor fungicidal activity of normal PMNL against C. albicans blastoconidia. These data demonstrate that G-CSF enhances the antibacterial but not the antifungal activities of human PMNL in vitro and also improves the defective PMNL bactericidal activity of HIV-1-infected patients.

Rapid development of ciprofloxacin resistance in methicillin-susceptible and -resistant staphylococcus aureus

Abstract: The fluoroquinolones, particularly ciprofloxacin, have been suggested to treat methicillin-resistant Staphylococcus aureus (MRSA) infections and colonization and methicillin-susceptible S. aureus (MSSA) infections. The development of ciprofloxacin resistance in MRSA and MSSA was prospectively evaluated. After 3 months of ciprofloxacin use, high-level resistance (MIC90, 64 micrograms/ml) developed in MRSA and increased at an alarming rate, from none to 79% over a 1-year period. High-level ciprofloxacin resistance also developed in MSSA, increasing to 13.6% over the same period. Antibiograms, phage typing, and plasmid profile analysis suggest that more than one clone of MRSA developed resistance and that ciprofloxacin resistance is not associated with the acquisition of a new plasmid. Most patients had nosocomial acquisition and about one-half had a history of previous ciprofloxacin use. Ciprofloxacin resistance can develop rapidly in S. aureus; thus, ciprofloxacin appears to have limited usefulness in treating staphylococcal infections and colonization, especially those due to MRSA.

Lymphoid germinal centers are reservoirs of human immunodeficiency virus type 1 RNA.

Abstract: When radiolabeled RNA was used for in situ hybridization, human immunodeficiency virus type 1 (HIV-1) RNA was found in high concentrations in germinal centers of lymphoid tissues from patients with HIV-1 infection. Most of the signal from hybridized probe was independent of specific cells, being found in the extracellular space of germinal centers in all lymphoid tissues examined from adult patients with Centers for Disease Control (CDC) class II and III disease or pediatric patients with CDC class P-2A disease. Lymphoid tissues from adult patients with CDC class IV infections or pediatric patients with CDC class P-2D disease (including autopsy material) lacked intact germinal centers, and HIV-1 RNA was then found only in rare, isolated cells, with some tissues having no detectable HIV-1 RNA. Thus, in the early stages of HIV infection, germinal centers serve as important reservoirs of free virus in the interstitial spaces, and this reservoir disappears as the germinal centers involute with advancing disease.

Monitoring of Human Cytomegalovirus Infections and Ganciclovir Treatment in Heart Transplant Recipients by Determination of Viremia, Antigenemia, and DNAemia

Abstract: Fourteen heart transplant recipients were monitored for human cytomegalovirus (HCMV) infection based on determination of antigenemia, viremia, and DNAemia (by polymerase chain reaction [PCR]) in peripheral blood polymorphonuclear leukocytes (PMNL). Three patients had symptomatic primary, 10 had recurrent (3 asymptomatic), and 1 (seronegative) had no HCMV infection. Severe clinical symptoms appeared when levels of viremia/antigenemia were greater than 50 infected PMNL/2 x 10(5) cells examined. Of 200 blood samples examined, 93 (46.5%) were positive for viremia/antigenemia and DNAemia, whereas 48 (24.0%) were positive for DNAemia only; 59 (29.5%) were negative in all assays. Follow-up of HCMV infections in heart transplant recipients showed that PCR can detect viral appearance in blood 7-10 days earlier than assays for antigenemia/viremia. On the other hand, viral disappearance from blood, as assessed by PCR, occurred weeks or months later than revealed by other assays. Detection of virus by PCR only was never associated with overt HCMV-related clinical symptoms. Of the 8 symptomatic patients treated with ganiclovir, 2 became PCR-negative at the end of treatment and 1 cleared virus from blood in the following weeks, whereas 5 showed persistent or recurrent infection.

Clinical evaluation of the cysticercosis enzyme-linked immunoelectrotransfer blot in patients with neurocysticercosis.

Abstract: During the 3 years that the enzyme-linked immunoelectrotransfer blot (EITB) assay for the diagnosis of human cysticercosis has been in use at the Centers for Disease Control, 50 patients with both pathologically confirmed neurocysticercosis and computed tomographic (CT) or magnetic resonance imaging (MRI) scan results were identified. Of 32 patients with two or more lesions, 94% had detectable antibodies by EITB compared with 28% of 18 patients with single lesions. Patients with only calcified cysts (single or multiple) were less likely to have EITB-positive results than were those with noncalcified, enhancing lesions. Antibody was detectable more frequently in serum than in cerebrospinal fluid, regardless of the number or apparent condition of the cysts. These findings confirm that the EITB assay for cysticercosis antibodies is highly sensitive in patients with multiple, enhancing intracranial lesions but is less sensitive in patients with single lesions and in those with calcified lesions.

Divergent Efficacy of Antibody to Tumor Necrosis Factor-α in Intravascular and Peritonitis Models of Sepsis

Abstract: The role of tumor necrosis factor-alpha (TNF alpha) in the lethal consequences of intravascular lipopolysaccharide (LPS) or Escherichia coli sepsis was compared with that in bacterial peritonitis. Intravenous administration of E. coli LPS or E. coli (live or dead) resulted in large transient increases in serum TNF alpha levels, peaking at 90 min at 10,000-30,000 units/ml. In contrast, the serum TNF alpha response following the induction of bacterial peritonitis was substantially less, peaking at 200-500 units/ml. Sterile peritonitis (essentially nonlethal) and bacterial peritonitis (greater than 60% lethal) elevated TNF alpha levels to 1000-2000 units/lavage within the peritoneal cavity 2 h after challenge. Passive immunization with neutralizing goat anti-TNF alpha IgG improved survival from 8% to 75% in rats administered LPS intravenously but was completely ineffective in protecting rats from lethal E. coli peritonitis. Thus significant differences exist in the role TNF alpha plays in systemic intravascular models of sepsis and bacterial peritonitis.

Extremely High Incidence of Antibiotic Resistance in Clinical Isolates of Streptococcus pneumoniae in Hungary

Abstract: An epidemiologic survey of antibiotic resistance among pneumococcal isolates collected during 1988 and 1989 in Hungary indicated that as many as 58% of all isolates and 70% of isolates from children were resistant to penicillin. These figures surpass even the highest values reported thus far for Spain and South Africa for the same period. Almost or more than 70% of the penicillin-resistant isolates were also resistant to tetracycline, erythromycin, and cotrimoxazole and approximately 30% to chloramphenicol. Intravenous administration of ampicillin (30 mg/kg) did not interfere with the growth in the cerebrospinal fluid of three resistant strains introduced into the rabbit model of experimental meningitis. No resistant strain showed beta-lactamase activity. A representative highly resistant strain contained altered penicillin-binding proteins (low penicillin affinities and abnormal molecular sizes) and was also resistant to the lytic and killing effects of penicillin.

Placebo-Controlled Clinical Trial of Sodium Stibogluconate (Pentostam) versus Ketoconazole for Treating Cutaneous Leishmaniasis in Guatemala

Abstract: : To determine the relative efficacy and toxicity of stibogluconate and ketoconazole for the treatment of cutaneous leishmaniasis, we conducted a comparative trial in which 120 Guatemalan men with parasitologically proven cutaneous leishmaniasis were randomly divided into three treatment groups: sodium stibogluconate (20 mg of antimony per kg per day intravenously for 20 days); ketoconazole (600 mg per day orally for 28 days); and placebo. Stibogluconate was associated with occasional moderate but manageable adverse effects, including abnormal electrocardiograms and elevated transaminase values. Treatment outcome was influenced by species. Among patients infected with Leishmania braziliensis, 24 (96%) of 25 in the stibogluconate group responded. Among L. mexicana-infected patients, only four (57%) of seven in the stibogluconate group but eight (89%) of nine in the ketoconazole group responded. These differences emphasize the importance of specification in the treatment of leishmaniasis.

Enteropathogens Associated with Acute Diarrheal Disease in Urban Infants in São Paulo, Brazil

Abstract: To determine the prevalence and epidemiology of enteropathogens in acute infantile diarrhea, 500 infants less than or equal to 12 months of age with diarrhea and 500 age-matched control subjects coming to a Sao Paulo emergency room were studied. Enteropathogens were identified in 55% of case infants and 10% of controls; enteropathogenic Escherichia coli (EPEC) of classic EPEC serotypes producing EPEC adherence factor (EAF) (26% of case infants), rotavirus (14%), Salmonella species (8%), enterotoxigenic E. coli (7%), and Shigella species (5%) were associated with diarrhea. Isolation of EAF+ classic EPEC decreased with increasing age of cases and peaked in spring, whereas rotavirus was least common in early infancy and peaked in fall and winter. Bloody stool had a 36% positive predictive value for Shigella infection, EAF+ classic EPEC were highly resistant to antimicrobial drugs. Among poor Sao Paulo infants, EAF+ classic EPEC equaled or exceeded rotavirus throughout the year as a cause of diarrhea bringing children to medical attention.

Inhibition of Localized Adhesion of Enteropathogenic Escherichia coli to HEp-2 Cells by Immunoglobulin and Oligosaccharide Fractions of Human Colostrum and Breast Milk

Abstract: Secretory IgA (sIgA) purified from colostrum and breast milk obtained from 14 women inhibited the localized adherence of an enteropathogenic Escherichia coli (EPEC) to HEp-2 cells. Inhibition decreased as lactation continued even when the concentration of sIgA was maintained constant at 1 mg/ml. sIgA responded to a 94-kDa plasmid-encoded outer membrane protein implicated as the EPEC adherence factor. An oligosaccharide-enriched fraction (OEF) from these samples also inhibited the attachment of this EPEC. Inhibition by OEFs decreased as lactation continued because of a general reduction in oligosaccharide content. Localized adherence of six other EPEC was also inhibited by sIgA and OEF, whereas attachment of isolates with diffuse or aggregative adherence was not inhibited by these fractions. Experiments with purified oligosaccharide fractions revealed that EPEC attach to HEp-2 cells through a carbohydrate-mediated mechanism based on the preferential recognition of fucosylated residues in human milk.

Antimicrobial Resistance of Streptococcus pneumoniae in the United States, 1979–1987

Abstract: The increasing number of Streptococcus pneumoniae isolates identified as relatively or fully resistant to penicillin or fully resistant to other antimicrobials in the United States supports the need to monitor for this resistance. Thus, 5459 S. pneumoniae isolates submitted to the Centers for Disease Control in 1979-1987 by 35 hospitals in a hospital-based pneumococcal surveillance system were evaluated. The MIC to penicillin or ampicillin was greater than or equal to 0.1 micrograms/ml for 274 (5%) isolates; 1 had an MIC of 4.0 micrograms/ml to penicillin. Seventeen (0.3%) were resistant to erythromycin (MIC, greater than or equal to 8 micrograms/ml), 157 (2.9%) were resistant to tetracycline (MIC, greater than or equal to 16 micrograms/ml), and 34 (0.6%) were resistant to sulfamethoxazole/trimethoprim (MIC, greater than or equal to 76 and 4 micrograms/ml). Isolates relatively resistant to penicillin represented 1.8% of isolates in 1979, 8% in 1982, and 3.6% in 1987. Sixty-five multiply resistant isolates were identified. Pneumococci from the southwestern United States (region 4) were more likely to be relatively resistant to penicillin. Using logistic regression analysis, serotypes 14 and 19A, isolates from region 4, and isolates from middle ear fluid were associated with penicillin resistance (P less than or equal to .008, chi 2. These data confirm that antimicrobial resistance among pneumococcal isolates remained at low levels in the United States through 1987.

The Influence of Human Immunodeficiency Virus Type 1 Infection on the Development of the Hepatitis B Virus Carrier State

Abstract: To assess the influence of human immunodeficiency virus type 1 (HIV-1) infection on the natural history of acute hepatitis B virus (HBV) infection, a study was undertaken of the clinical records of all 77 homosexual men with documented seroconversion to anti-hepatitis B core antibody (anti-HBc) between visits to either of two Sydney clinics between 1985 and 1989. HIV-1-seropositive subjects developed chronic HBV infection (positive for hepatitis B surface antigen [HBsAg] greater than 6 months) more frequently (7/31, 23%) than HIV-1-seronegative ones (2/46, 4%; P = .026). HIV-positive subjects who cleared HBsAg had significantly more circulating CD4+ lymphocytes (mean, 547 x 10(6)/l) than those who did not (352 x 10(6)/l, P less than .005). A subset of subjects who acquired both viruses between visits had an even higher rate of chronic infection (4/10, 40%). Icteric illnesses were reported more frequently by HIV-1-seronegative (11/46, 24%) than -seropositive subjects (3/31, 10%; P = .20). These findings indicate a potential for an increased reservoir of HBV infection in the community as a consequence of the HIV-1 epidemic.

Outcome of Hepatitis B Virus Infection in Homosexual Men and Its Relation to Prior Human Immunodeficiency Virus Infection

Abstract: To investigate the effect of human immunodeficiency virus type 1 (HIV-1) infection on subsequent hepatitis B virus (HBV) infection, HIV antibody was sought in homosexual men who developed HBV infection during a hepatitis B vaccine trial. Among 134 unvaccinated HIV-1-negative men, 7% became HBV carriers, 64% had viremia, and 42% had clinical illness. Among vaccinated HIV-1-negative men, HBV infection severity decreased with number of vaccine doses administered. When adjusted for prior hepatitis B vaccination status, persons with HIV-1 infection preceding HBV infection had a significantly higher risk of developing HBV carriage, viremia, prolonged ALT elevation, and clinical illness. Among HIV-1-infected men, the risk of HBV carriage was increased in unvaccinated persons (21%) and those who failed to respond to vaccination (31%) and further increased in those who received vaccine doses at the time they developed new HBV infection (56%-80%), suggesting inactivated hepatitis B vaccine may temporarily impair the immune response to HBV infection in HIV-1-infected persons. HIV-1 infection was also associated with reduced alanine aminotransferase elevations during the first 36 months of follow-up of men who became HBV carriers.

Isolation and Characterization of a New Human Microsporidian, Encephalitozoon hellem (n. sp.), from Three AIDS Patients with Keratoconjunctivitis

Abstract: A new human microsporidian was isolated from cultures of Madin-Darby canine kidney cells incubated with conjunctival scrapings or corneal tissues from three AIDS patients with keratoconjunctivitis. The three isolates were morphologically similar to Encephalitozoon cuniculi. The spores averaged 1 x 1.5-2.0 microns, had six to eight polar filament coils, displayed monokaryotic nuclei, and possessed relatively thick endospores with irregularly shaped exospores. Organisms developed within a parasitophorous vacuole. By SDS-PAGE analysis, the three isolates appeared to be identical but were different from E. cuniculi. Identical banding patterns on Western blots of the three isolates were expressed by each patient's serum. By Western immunoblotting, murine antisera to E. cuniculi reacted to several antigens of the new AIDS-related microsporidian, whereas murine antisera bound weakly to Nosema corneum. The name Encephalitozoon hellem (n. sp.) is proposed to identify this new human microsporidian.

Isolation of cytopathic small round viruses with BS-C-1 cells from patients with gastroenteritis.

Abstract: Fecal extracts from 12 subjects in outbreaks of oyster-associated nonbacterial gastroenteritis were inoculated with BS-C-1 cells for isolation of the causative viruses. Cytopathic agents were isolated from 3 patients. No cross-neutralizing reactions were observed between the isolates and prototypes of human enteroviruses. The isolates were approximately 30 nm in diameter and had a distinct ultrastructure resembling that of astroviruses. Four polypeptide bands with molecular sizes of 42, 28, 27, and 22 kDa were seen on SDS-PAGE analyses. Seroconversion against the isolate was observed in 18 (31.6%) of 57 patients involved in five of seven outbreaks examined by neutralization test. A protein band characteristically reactive with the paired serum samples was detectable at 42 kDa by immunoblot assay. These results suggested that some small round viruses resembling astroviruses might show cytopathic effect in BS-C-1 cells and may be associated with an oyster-related gastroenteritis.

Mycobacterium avium Infection and AIDS: A Therapeutic Dilemma in Rapid Evolution

Abstract: Note from Dr. Merle A. Sande--The role of Mycobacterium avium as a pathogen in the human immunodeficiency virus-infected population has been confusing and controversial to clinicians who care for AIDS patients. The organism is commonly isolated from respiratory secretions of patients with other infections and often seems part of the resident flora; even when isolated from the bone marrow or bloodstream, its impact on the course of AIDS and contribution to systemic diseases are unknown. However, an increasing subset of patients without other documented opportunistic infections or malignancies has symptoms that respond to therapy directed against M. avium. Studies are in progress to evaluate chemotherapeutic agents. Accordingly, the subject is here reviewed and guidelines offered to infectious disease clinicians by one with a long-standing interest in mycobacterial disease who has made numerous contributions to the field.

Mucosal Immunity Induced by Enhanced-Potency Inactivated and Oral Polio Vaccines

Abstract: Oral polio vaccine (OPV) is recommended for routine immunization in the United States in part because of its ability to induce intestinal and pharyngeal immunity to reinfection. Mucosal immunity produced by OPV and enhanced-potency inactivated polio vaccine (E-IPV) was compared by challenging vaccines with type 1 OPV. Fewer OPV (25%) than E-IPV (63%) vaccinees excreted OPV virus in stool after challenge. The mean stool virus titer was higher and the duration of shedding longer among E-IPV excreters. Only one E-IPV and three OPV vaccinees shed virus in the pharynx after challenge. Prechallenge serum neutralizing antibody levels were not statistically different among E-IPV vaccinees who did and did not shed virus; these levels were much higher than those of OPV vaccinees. Poliovirus-specific IgA levels in stool did not correlate with viral excretion. E-IPV was less effective than OPV in preventing and limiting intestinal infection, even though it induced higher postvaccination serum antibody levels.

Clinical features and analysis of risk factors for invasive candidal infection after marrow transplantation.

Abstract: Of 1506 marrow transplant patients from 1980 through 1986 reviewed for risk factors for invasive candidal infection defined by positive blood cultures, biopsy, or histologic evidence of tissue invasion, 171 (114%) had invasive infection, with a significantly higher incidence in the more recent years of review; 40% (69 patients) had evidence of tissue-invasive disease without fungemia Of 102 patients with fungemia, 45% had candidemia alone with a mortality of 39% Mortality in patients with tissue involvement was 90% with or without fungemia Factors that increased infection were age, acute graft-versus-host disease, and donor mismatch Factors that decreased infection included conditioning with 12 Gy of fractionated irradiation and cyclophosphamide, transplantation for aplastic anemia, and more rapid engraftment Among fungemic patients, the number of days of fungemia was a risk factor for tissue invasion while more rapid engraftment was protective

Molecular basis of sequestration in severe and uncomplicated Plasmodium falciparum malaria: differential adhesion of infected erythrocytes to CD36 and ICAM-1.

Abstract: The CD36 and ICAM-1 glycoproteins on vascular endothelial cells have been implicated as cytoadherence receptors for Plasmodium falciparum-infected erythrocytes (IRBC). Adhesion of IRBC from Thai patients with uncomplicated and severe falciparum malaria to purified CD36 or ICAM-1 and to C32 melanoma cells was compared. All malaria isolates bound to solid phase-adsorbed CD36 and to fluid-phase 125I-labeled CD36. IRBC adhesion to purified ICAM-1 varied widely, and no correlation with clinical severity of disease was observed. The cytoadherent phenotype of IRBC was modulated by selective panning on plates coated with purified CD36 or ICAM-1. IRBC selected by panning on CD36+, ICAM-1+ melanoma cells bound to cells that express surface CD36 but not to CD36-deficient cells, indicating that CD36 exerts a strong selective pressure on the IRBC cytoadherent phenotype. IRBC adhesion to CD36 and ICAM-1 suggests that P. falciparum parasites may use these receptors in vivo to promote parasite survival and immune evasion.