Deferral of blood donors with risk factors for HIV infection saves lives and money in Zimbabwe

We compared the cost-effectiveness of three strategies to avert transfusion-associated HIV infection in Zimbabwe: HIV antibody testing, deferral of donors with HIV risk factors, and deferral of donors with risk factors followed by antibody testing ("Defer/Test"). The Defer/Test strategy averted the most HIV infections. Compared with antibody testing alone, the Defer/Test strategy, using history of genital ulcer or any sexually transmitted disease as a criterion for deferral, resulted in net savings. The cost per HIV-infected unit averted using history of paying for sex or having had multiple sex partners was $ 127 and $ 773, respectively. We discern four benefits of risk factor-based deferral before antibody testing. First, deferring donors at risk lessens collection of blood in the window period. Second, deferring donors likely to be HIV positive minimizes the number of units discarded. Third, ascertainment of donor risk provides an opportunity for AIDS education and prevention. Fourth, the number of false negatives is lower with a lower HIV prevalence among accepted donors. The Defer/Test strategy is cost-effective in Zimbabwe because additional recruitment costs are offset by discarding fewer HIV-positive units. We predict the Defer/Test strategy will be cost-effective in other sub-Saharan African donor populations.

Human immunodeficiency virus type 1 quantitative cell microculture as a measure of antiviral efficacy in a multicenter clinical trial

A quantitative cell microculture assay (QMC) was used to measure the human immunodeficiency virus type 1 (HIV-1) peripheral blood mononuclear cell (PBMC)-associated titer in 109 subjects rolled in an open-label phase I/II study of didanosine monotherapy or combination therapy with zidovudine. The titer was inversely correlated with CD4+ cell count at baseline (r = .37, P = .001). After 12 weeks of therapy, subjects showed a significant decreases in virus titer and those with the highest baseline virus titers had the greatest increase in CD4+ cell number (r = .430, P = .002). The QMC assay was more sensitive (98%) for assessing the antiretroviral effect of therapy than was immune complex-dissociated HIV p24 antigen (32%) or plasma culture (3.4%). Estimated sample sizes for phase I/II clinical trials were derived using the within-subject QMC SD of .72 log10 infectious units per 10(6) PMBC.

Failure of short-term CD4-PE40 infusions to reduce virus load in human immunodeficiency virus-infected persons

The safety, immunologic, and antiviral effects of a recombinant biologic product that combines the second and third domains of the CD4 molecule and Pseudomonas exotoxin A (PE40) were evaluated in 21 human immunodeficiency virus (HIV)-infected subjects in a phase III open-label dose-ranging study. Subjects with CD4+ lymphocyte counts of 100-500/mm3 received CD4-PE40 at 40, 80, or 160 micrograms/m2 by infusion three to seven times over 10 days. At the maximum tolerated dose (80 micrograms/m2), peak CD4-PE40 levels were 65-130 ng/mL with a serum half-life of 3.6 +/- 1.5 h. Toxicity, primarily increased hepatic transaminases, was dose-related and reversible. HIV DNA proviral levels in peripheral blood mononuclear cells and plasma HIV RNA remained stable during and after CD4-PE40 infusions. The relative resistance of clinical isolates of HIV, limits of the tolerated dose, and the immunogenicity and short half-life of the protein may explain the lack of in vivo antiviral effect of CD4-PE40.

Didanosine resistance in HIV-infected patients switched from zidovudine to didanosine monotherapy

OBJECTIVE

To determine the frequency and pattern of development of specific drug resistance mutations for human immunodeficiency virus (HIV) reverse transcriptase in patients switched from zidovudine to didanosine therapy and to examine the relation of the didanosine resistance mutation at codon 74 of the HIV reverse-transcriptase gene to CD4+ T-cell changes and virus burden.

DESIGN

Retrospective analysis of all patients enrolled at Stanford University in protocols where patients were switched from zidovudine to didanosine monotherapy.

SETTING

A university hospital.

PATIENTS

64 patients infected with HIV who were switched from zidovudine to didanosine monotherapy. Patients had the acquired immunodeficiency syndrome (AIDS), AIDS-related complex, or were asymptomatic (mean [+/- SD] starting CD4+ T-cell count of 129 +/- 88 cells/mm3).

MEASUREMENTS

Serial serum specimens were tested for the didanosine resistance mutation at codon 74 of the HIV reverse-transcriptase gene and for a zidovudine resistance mutation at codon 215 using selective polymerase chain reactions (PCR). Serum HIV RNA levels were determined by quantitative PCR. CD4+ T-cell counts were determined at serial time points.

RESULTS

By 24 weeks of didanosine therapy, the proportion of patients with the didanosine resistance mutation at codon 74 increased from 0% to 56% (36 of 64). In contrast, the proportion of patients with the zidovudine resistance mutation at codon 215 decreased from 84% at the start to 59% after 24 weeks of didanosine therapy (a 25% decrease, 95% lower CI, 15%; P < 0.0001). Patients who developed the codon 74 mutation had a greater decrease in CD4+ T cells after the development of the mutation than did patients without the mutation (P < 0.001). In addition, after 24 weeks of didanosine, patients who developed the codon 74 mutation had a greater serum HIV RNA burden than patients who remained wild type (did not have the mutation) at codon 74 (225,000 compared with 82,400 HIV RNA copies/mL serum; P = 0.01).

CONCLUSIONS

Among patients infected with HIV who had advanced disease and were switched from zidovudine to didanosine therapy, more than one half developed the didanosine resistance mutation at codon 74 by 24 weeks of didanosine therapy. Patients who developed the codon 74 mutation had a greater decline in CD4+ T cells after the development of the mutation and had a greater serum virus burden than did patients without the codon 74 mutation.

HIV-1 syncytium-inducing phenotype, virus burden, codon 215 reverse transcriptase mutation and CD4 cell decline in zidovudine-treated patients

The variable rate of disease progression in HIV-1-infected patients treated with zidovudine may be related to certain viral characteristics, such as, antiviral drug resistance, virus burden, and viral syncytium-inducing (SI) capacity. Thirty-two HIV-1-infected patients treated with zidovudine (mean of 34 months) were studied to determine the relationship of SI phenotype and the codon 215 pol gene mutation (a marker of zidovudine resistance) to virus burden and CD4 cell decline. Patients with SI strains and the codon 215 mutation in their proviral DNA had a 54% decline in CD4 cells and a virus burden of 21,480 proviral DNA copies/10(6) CD4 cells. In contrast, patients with non-SI (NSI) strains and wild-type at codon 215 had a 10% increase in CD4 cells and had a viral burden 1/46 that of patients with SI and the 215 mutation. Among patients with NSI strains, changes in CD4 cells depended on the presence of the codon 215 mutation (-160 CD4 cells/microliters), compared with those wild-type at codon 215 (+28 CD4 cells/microliters) (p < 0.01). There was a concordant rise in virus burden between proviral DNA and plasma HIV RNA depending on HIV phenotype and genotype. Using multiple linear regression, SI phenotype and the codon 215 mutation were found to independently predict CD4 cell decline and increased virus burden in zidovudine-treated patients.

Combination therapy with zidovudine and didanosine selects for drug-resistant human immunodeficiency virus type 1 strains with unique patterns of pol gene mutations

Drug resistance conferred by specific human immunodeficiency virus type 1 (HIV-1) pol gene mutations has been associated with clinical progression in HIV-infected patients receiving anti-retroviral therapy. This study examined drug susceptibilities and pol mutations of HIV-1 strains from patients treated for 1 year with zidovudine, didanosine (ddI), or zidovudine and ddI. Ten (42%) of 24 patients receiving combination therapy versus 8/26 (31%) receiving only zidovudine had HIV-1 strains with phenotypic zidovudine resistance or a zidovudine resistance pol mutation at codon 215 (P = .6). In contrast, a ddI resistance mutation at codon 74 was less common among patients receiving combination therapy (2/24) than among those receiving ddI only (17/26; P < .001). Two patients receiving combination therapy developed resistance to zidovudine and ddI; they had HIV strains with amino acid mutations at codons 62, 75, 77, 116, and 151. Combination therapy with zidovudine and ddI selects for zidovudine-resistant HIV-1 strains lacking a ddI resistance mutation and for multidrug-resistant strains containing novel pol mutations.

Quantitation of human immunodeficiency virus by culture and polymerase chain reaction in response to didanosine after long-term therapy with zidovudine

Measurements of human immunodeficiency virus by quantitative RNA and DNA polymerase chain reaction (PCR), cell and plasma infectivity dilution cultures, and immune complex-disassociated p24 antigen-capture ELISA were made repeatedly in 10 subjects receiving long-term zidovudine treatment before and after therapy was changed to didanosine. Comparison of baseline assays showed that quantitative cell cultures, plasma RNA, and proviral DNA were measurable in all subjects and that cell culture results were significantly correlated with measures of nucleic acids. Plasma viremia (as indicated by culture) and p24 antigen were detected in three measurements in 3 of 8 and 6 of 10 subjects, respectively. Significant decreases in plasma RNA and cell dilution cultures from baseline were maintained for up to 6 months after initiation of didanosine therapy. These findings demonstrate a decrease in virus burden with the use of didanosine; however, continued detection of plasma RNA suggests that additional antiviral therapy will be required to suppress viral replication.

Biological variation and quality control of plasma human immunodeficiency virus type 1 RNA quantitation by reverse transcriptase polymerase chain reaction

Quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in the plasma of seropositive individuals was performed by using an external control assay with techniques to standardize and control each measurement. Rigorous study of the variability of the assay showed that the median intraassay reproducibility was log10 0.15 RNA copies per ml of plasma, while the median interassay reproducibility on replicate plasma samples was log10 0.25 copies perml. Specimen stability studies showed reproducible recovery of RNA from plasma stored at -70 degrees C for up to 12 months. In clinically stable patients who were either untreated or taking zidovudine, the average week-to-week variation in plasma RNA levels, measured in real time, was log10 0.30 RNA copies per ml. In contrast, patients either initiating or changing antiretroviral therapy showed a fall of log10 0.8 to log10 2.0 copies per ml in plasma RNA levels. Overall, 105 of 110 (96%) HIV-1-seropositive individuals with CD4 counts of 36 to 868 cells per mm3 had quantifiable HIV-1 RNA over a range of log10 2.70 to log10 6.23 RNA copies per ml, including 81% (13 of 16) of the individuals with greater than 500 CD4 cells per mm3. Accurate and reproducible quantitation of plasma viremia in real time by reverse transcriptase polymerase chain reaction, particularly in asymptomatic HIV-1-infected individuals with high CD4 counts, provides a basis for the use of this virologic measure to monitor the short- and long-term effects of early intervention therapeutic strategies on viral burden.

Detection of human immunodeficiency virus type 1 in semen: effects of disease stage and nucleoside therapy

The effects of clinical stage of infection and antiviral therapy on the detection of human immunodeficiency virus type 1 (HIV-1) nucleic acids in semen were investigated by the polymerase chain reaction. HIV-1 was detected in 45 (87%) of 52 semen specimens from 29 (81%) of 36 men. Seventeen (77%) of 22 stage II or III subjects and 12 (86%) of 14 stage IV subjects had positive specimens. The CD4+ lymphocyte count was not significantly different comparing subjects with positive and negative semen. Moreover, 6 (67%) of 9 untreated men had positive specimens compared with 23 (85%) of 27 men treated with zidovudine, 2',3'-dideoxyinosine, or both for a mean of 20 months. Thus, the detection of HIV-1 in semen was independent of both stage of infection and long-term treatment. In a semiquantitative analysis of 6 men followed for 8 weeks after the start of nucleoside therapy, a decrease in HIV-1 RNA in seminal plasma was demonstrated in 2.

A mutation in human immunodeficiency virus reverse transcriptase and decline in CD4 lymphocyte numbers in long-term zidovudine recipients

A nested polymerase chain reaction assay was used to define the sequence of a specific codon, amino acid 215, of the human immunodeficiency virus (HIV) pol gene in DNA from peripheral blood mononuclear cells (PBMC) and viral RNA from serum from 38 patients treated with zidovudine for > or = 2 years. After treatment for a mean of 34 months, 17 patients with sequences with a codon 215 mutation had a mean 50% decrease in CD4 cells, compared with 21 patients with sequences wild-type at codon 215, who had a mean 11% increase in CD4 cells (P < .0001). Patients with a mutation at 215 had a ninefold higher provirus burden in PBMC. Detection of the codon 215 mutation in plasma viral RNA preceded detection of the mutation in DNA from PBMC and decline in CD4 cells. The appearance of a mutation at codon 215 in the HIV reverse transcriptase gene in patients receiving zidovudine may be a marker for impending immunologic decline.

Zidovudine susceptibility testing of human immunodeficiency virus type 1 (HIV) clinical isolates

Traditional antiviral susceptibility testing methods using cell lines can be applied to no more than about 30% of clinical HIV isolates (Larder et al., 1989a; Fenyo et al., 1989). We tested the cell-free supernatant from low passage clinical HIV isolates using donor peripheral blood mononuclear cells (PBMC). Drug susceptibility was assessed by measuring the effect of increasing zidovudine (ZDV) concentrations on HIV P24 antigen production. Susceptibility results were obtained on 24/27 consecutive clinical isolates and 6/6 laboratory isolates. The mean IC90 of isolates from untreated patients was 0.008 microM ZDV (range: 0.002-0.038). The IC90s of isolates from ZDV-treated patients ranged from 0.007 to greater than 10 microM ZDV. All isolates with an IC90 < 0.1 microM ZDV had a wild type sequence at codon 215 of the HIV pol gene; 11/12 isolates with an IC90 > 0.1 microM ZDV had a mutation at codon 215 (P < 0.001). Among 16 ZDV-treated patients, there was a modest correlation between the change in CD4 count from the start of ZDV treatment and the IC90 of the patient's isolate following treatment (r = 0.51). Susceptibility testing using donor PBMC can be a sensitive means of testing a broad range of clinical HIV isolates.

Quantification and comparison of HIV-1 proviral load in peripheral blood mononuclear cells and isolated CD4+ T cells

HIV proviral load was determined by quantitative DNA polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC) and lymphocyte subsets isolated by cell sorter. Provirus measured in PBMC, when expressed as HIV copy number per million CD4+ cells, resulted in values which approximated those obtained from sorted CD4+ T lymphocytes. A cross sectional analysis of HIV proviral load in CD4+ T cells from 25 previously untreated and 30 zidovudine-treated seropositive patients with CD4+ T-cell counts between 25 and 802/mm3 demonstrated HIV copy numbers ranging from 1 copy per 10,000 cells in early disease to 1 copy per 10 cells in advanced disease. HIV proviral load can be rapidly assayed by PCR to give a reproducible value which varies over a 1,000-fold range and is positively correlated with cell infectivity as measured by a quantitative micrococulture assay. A less technically demanding assay using PBMC as substrate can give similar results to those obtained with sorted CD4+ T cells.

Quantitative RNA and DNA gene amplification can rapidly monitor HIV infection and antiviral activity in cell cultures

We have developed a quantitative gene amplification procedure to assess the replication of human immunodeficiency virus (HIV) in cell cultures and evaluate the effect of drugs on viral replication. Increases in HIV gag RNA and DNA in phytohemagglutinin-stimulated normal peri-pheral blood mononuclear cells (PBMC) infected with HIV at very low multiplicity of infection paralleled the production of HIV p24 antigen in culture supernatants. Quantitative gene amplification was able to monitor the accumulation of viral nucleic acids in control cultures and demonstrate the effect of various concentrations of azidothymidine (AZT) on the replication of both AZT-sensitive and -resistant strains of HIV. The sensitivity of patient-derived virus strains to AZT could also be successfully measured by these procedures. The results of our studies suggest that quantitative measurement of HIV gag RNA and DNA can be used to monitor the kinetics of viral replication, antiviral activity, viral drug resistance, and mechanism of drug action.

Correlation of morphologic diagnosis of Pneumocystis carinii with the presence of pneumocystis DNA amplified by the polymerase chain reaction

We compared the presence of P. carinii in clinical specimens as detected by standard cytomorphologic techniques with amplification of P. carinii-specific DNA by the polymerase chain reaction (PCR). Results correlated in 33 of 37 instances (89%): nine specimens were positive by both PCR and morphology; 24 specimens were negative by both techniques. Two specimens from one patient were obtained 3 days apart. The first specimen was both cytologically and PCR negative, while the second specimen was both cytologically and PCR positive for P. carinii. At least in some instances, therefore, PCR is no more sensitive than morphology, and other factors such as specimen adequacy are more important. Twelve of the 24 negative specimens were from patients with prior histories of P. carinii pneumonia, suggesting that recurrent disease may be from reacquisition of organisms in previously exposed individuals, rather than reactivation of latent organisms. Discrepant results included three morphologically negative specimens that were positive by PCR. It remains to be determined whether the increased sensitivity of PCR in these cases is real or artifactual. One morphologically positive specimen was negative by PCR. Polymerase chain reaction correlates well with cytomorphologic diagnosis of P. carinii pneumonia and may be a valuable diagnostic and epidemiologic tool.

Reduction in plasma human immunodeficiency virus ribonucleic acid after dideoxynucleoside therapy as determined by the polymerase chain reaction

Cell-free HIV RNA in plasma was detected and quantitated after antiviral therapy by the polymerase chain reaction. RNA was extracted from plasma, reverse transcribed to cDNA, amplified by polymerase chain reaction, and quantitated by absorbance based on an enzyme-linked affinity assay. 72 HIV antibody-positive subjects had one plasma sample taken. 39 who were not receiving antiretroviral therapy at the time had a mean plasma HIV RNA copy number of 690 +/- 360 (mean +/- SEM) per 200 microliters of plasma, while 33 subjects who had been receiving zidovudine therapy for a minimum of 3 mo had a mean copy number of 134 +/- 219 (P less than 0.05). 27 additional HIV antibody-positive patients had two plasma samples taken before and 1 mo after initiating dideoxynucleoside therapy. Plasma HIV RNA copy number fell from 540 +/- 175 to 77 +/- 35 (P less than 0.05). Finally, nine of these subjects had two baseline samples obtained before initiating therapy and two posttreatment samples 1 and 2 mo after therapy was begun. Mean plasma RNA copy number declined from 794 +/- 274 to less than 40 (below the lower limit of sensitivity) after 1 mo of therapy, with suppression maintained after 2 mo of therapy. These results suggest that gene amplification can be used to detect and quantitate changes in plasma HIV RNA after dideoxynucleoside therapy. Plasma HIV polymerase chain reaction may be a more sensitive marker to monitor antiviral therapy, particularly in asymptomatic patients where measurement of p24 antigen or quantitative plasma cultures are negative.

Detection of human immunodeficiency virus DNA and RNA in semen by the polymerase chain reaction

Peripheral blood mononuclear cells (PBMC) and semen of 23 men infected with human immunodeficiency virus (HIV) were examined for the presence of HIV DNA and RNA using the polymerase chain reaction (PCR) and a nonisotopic detection assay. None of the men was receiving antiretroviral therapy at the time of collection. Semen samples were separated into cell-free seminal fluid, nonspermatozoal mononuclear cells (NSMC), and spermatozoa. All of the PBMC samples, 17 (74%) of 23 NSMC samples, and none of the spermatozoal samples were positive for HIV gag gene DNA. Of 23 cell-free seminal fluid samples, 15 (65%) were positive for HIV gag gene RNA by PCR. Cell-free HIV RNA was more likely to be present in the semen of men with less than 400 than in those with greater than or equal to 400 cells/mm3 (P less than .04) and was present in all patient with p24 antigen in serum. The presence of HIV DNA in NSMC samples was not related to CD4 cell count, disease status, or the presence of p24 antigen in the serum. This study shows that HIV nucleic acid can be detected by PCR in either the cell-free seminal fluid or NSMC of 87% of semen samples but not in the DNA of spermatozoa from HIV-infected men.

Detection and quantification of human immunodeficiency virus RNA in patient serum by use of the polymerase chain reaction

Human immunodeficiency virus (HIV) RNA was detected and quantified in the serum of HIV-seropositive individuals using the polymerase chain reaction (PCR) and a nonisotopic enzyme-linked affinity assay. Of 55 HIV-infected patients who were not receiving therapy, serum HIV RNA was detected in 9 of 19 who were asymptomatic, 11 of 16 with AIDS-related complex (ARC), and 18 of 20 with AIDS, with copy numbers ranging from 10(2) to greater than or equal to 5 x 10(4) 200 microliters of serum based on a relationship between absorbance and known copy number of gag gene RNA. Linear regression analysis demonstrated a correlation between infectious titer in 42 patient sera cocultured with donor peripheral blood mononuclear cells (PBMC) and PCR product absorbance (r = .70, P less than .01). Serum HIV RNA detected by PCR also correlated with serum p24 antigen positivity, CD4 counts less than 400/mm3, and the presence of HIV-related symptoms or disease. Quantification of infectious HIV RNA in cell-free serum by PCR may be useful as a marker for for disease progression or in monitoring antiviral therapy.

Relation of the pathogenesis of human immunodeficiency virus infection to various strategies for its control

This paper reviews functionally important insights into the pathogenesis of human immunodeficiency virus (HIV) infection. The major sequela of this infection is early and progressive involvement of the immune system, with widespread immune dysfunction. This pathogenetic feature has a major impact on strategies for control of the infection. The immunosuppression caused by the virus leads to higher levels of viral replication and enhanced potential for development or selection of variant viruses, including forms that are more virulent or even drug resistant. Therefore, control of HIV infection and disease may require antiviral agents and CD4 receptor competitors as well as recombinant DNA-derived lymphokines and subunit vaccine immunotherapies. To be successful, such therapies must work to counter infection in monocytes and nonlymphoid cells as well as in T4 lymphocytes. Because many limbs of the immune system are affected by HIV infection, the complexities of this pathogen can be unraveled only by the careful study of immune functions during the disease and of effective interventions to control infection and disease and to restore immune functions.

Possible beneficial effects of neutralizing antibodies and antibody-dependent, cell-mediated cytotoxicity in human immunodeficiency virus infection

We studied the relationship between early human immunodeficiency virus type 1 (HIV-1) specific immune responses and pathogenesis of infection in participants enrolled in the multicenter AIDS cohort study (MACS). Sera collected at 6-month intervals for 2 years (visit 1-5) from 39 persons who seroconverted by enzyme-linked immunosorbent assay (ELISA) 6 months (visit 2) after enrollment were examined for isotype-specific Western blot reactivity, neutralizing antibodies (NA) against two divergent strains of HIV-1 (HIV-1IIIB and HIV-1RF), and for antibodies capable of participating in antibody-dependent, cell-mediated cytotoxicity (ADCC). These results were compared with changes in CD4+ cell number and episodes of lymphadenopathy. Twenty-five subjects had antibodies of at least one isotype reactive to at least one HIV-1 protein by Western blot at visit 1, before they became ELISA positive. NA reactive with HIV-1IIIB were detected before those reactive with HIV-1RF. NA were first observed in 11 sera at visit 2, in 22 sera at visit 3, and in 3 sera at visit 4; sera from three patients remained nonneutralizing through visit 5. In most cases, NA were detected after a decline in CD4+ cell numbers. The data are consistent with the interpretation that NA develop after about 16 to 18 months of declining CD4+ cell numbers, following which the rate of decline in CD4+ cell numbers slows. In contrast, HIV-1 envelope antigen-specific ADCC responses were first observed in 11 subjects at visit 1 when all 39 were NA and ELISA negative, in 12 subjects at visit 2, in 13 subjects at visit 3, and 1 subject at visit 4. Early ADCC responses were associated with high mean % CD4+ cell numbers and absence of lymphadenopathy throughout the 2-year observation period. Not all subjects who developed ADCC developed NA. In some subjects, ADCC and NA were detectable for the first time at the same visit, for others ADCC was detectable prior to NA, and for a few NA was detectable prior to ADCC. These findings suggest that ADCC and neutralization are mediated by different antibody populations, that they may partially inhibit the progress of HIV-1 infection, and that the late appearance of NA may relate to the failure of immunity to effect recovery from this infection.

Genital ulcers and transmission of HIV among couples in Zimbabwe

Seventy-five married men found to be positive for HIV-1 in Harare, Zimbabwe, were interviewed in order to define behaviours associated with acquisition of infection and to determine factors associated with transmission of infection to their wives. The majority of infected men reported sexual intercourse with multiple heterosexual partners and female prostitutes, and gave a history of sexually transmitted diseases (STDs). All subjects denied homosexual activity and parenteral drug abuse. Serological testing of the wives of seropositive men showed that 45 (60%) were HIV-antibody-positive. Wives of men with AIDS and AIDS-related complex (ARC) and wives of men who gave a history of genital ulcer disease were more likely to be seropositive. The study demonstrates that HIV-1 infection in Zimbabwe occurs through heterosexual intercourse and is associated with other STDs. In addition, the study shows that male to female transmission of HIV-1 is facilitated by the presence of genital ulcers in infected men.

Microbial flora of the lower genital tract of women in labour at Harare Maternity Hospital. The Puerperal Sepsis Study Group

The vaginal flora of 214 women who had been referred, in labour, to Harare Maternity Hospital was investigated by examination of vaginal washings and of cervical and urethral swabs taken before and/or after delivery. Four groups of patients were studied: women who had a normal vaginal delivery (NVD), women who were referred because of meconium stained liquor (MSL), women with a history of prolonged rupture of membranes (PROM), and women who were delivered by cesarean section (CS). The first three groups had received no antibiotics during the 7 days preceding specimen collection, while specimens were collected from CS patients only after at least 48 hr of i.v. penicillin and chloramphenicol. T. vaginalis was identified in 19 percent of women, but was not associated with any specific patient group. Chlamydial antigen was detected in 13 percent of patients, but in only one patient (2 percent) in the MSL group. N. gonorrhoeae were isolated from 7 percent of women overall and 25 percent of the strains were penicillinase-producing. Gonococci were recovered significantly more frequently from the PROM patients than from NVD patients as were Group B streptococci and pigment-producing Bacteroides species. Lactobacilli were isolated from only 20 percent of women, despite the use of specific transport and isolation media for these organisms. Specimens from CS patients were taken after these had received parenteral penicillin and chloramphenicol and it was therefore not surprising to find major differences in their vaginal flora with a virtual absence of Gram-positive bacteria, and a high-rate of carriage of multi-resistant coliforms.(ABSTRACT TRUNCATED AT 250 WORDS)

Vaginal flora of women admitted to hospital with signs of sepsis following normal delivery, cesarean section or abortion. The Puerperal Sepsis Study Group

The microbial flora of the genital tract of 95 women who developed clinical signs of infection within 48 hr of vaginal delivery, Cesarean section delivery or abortion were compared with 111 women who delivered at the same hospital during the same time period but who showed no signs of sepsis. While there were no significant differences in the prevalence of most organisms in the lower genital tract of women with and without sepsis, there was evidence of a higher prevalence of gonococcal, chlamydial and anaerobic infection in the former. Gonococci were isolated from over 20 percent of untreated women with sepsis, more than three times the prevalence in controls. A third of the isolates were penicillinase-producing and another third showed in vitro resistance to penicillin. Chlamydial antigen was detected in 16-20 percent of women with sepsis following vaginal delivery or abortion, compared with 6 percent of controls. Neither gonococcal nor chlamydial infections were significantly associated with sepsis following Cesarean section delivery. Clue cells, indicative of G. vaginalis infection were noted in 20 percent of patients with sepsis compared with 7 percent of controls while amongst the other anaerobes only pigment producing Bacteroides were associated with sepsis. These findings suggest that antepartum investigations for clue cells, chlamydial antigen, gonococci and pigment producing anaerobes may identify patients most at risk from obstetric sepsis in Harare, and identify those for whom prophylactic administration of antibiotics may be of benefit.

Nosocomial adenovirus infections: molecular epidemiology of an outbreak due to adenovirus 3a

An immunocompromised woman died of disseminated infection due to adenovirus type 3. During her hospitalization and after her death, 38 hospital personnel developed an acute respiratory illness. Adenovirus type 3 infection was documented by culture in 18 of the 38 individuals and by seroconversion in one additional employee. Four of 34 asymptomatic hospital personnel exposed to the index case also seroconverted. Thus, 23 personnel were considered to have confirmed infections, and 22 of these 23 reported direct contact with the index case. Acquisition of infection was associated with the number and type of contacts. Protection against infection was associated with detectable serum-neutralizing antibody in the early serological sample. Restriction enzyme analysis using six different endonucleases indicated that all isolates of virus were type 3a and had identical genetic composition. This study underscores the importance of adenovirus as a cause of nosocomial infection and indicates that genetic analysis of viral DNA is a powerful tool for studying common-source outbreaks.

Successful treatment of murine cytomegalovirus disease does not prevent latent virus infection

9-(1,3-Dihydroxy-2-propoxymethyl)guanine (DHPG), a nucleoside analogue, inhibits the replication of human and murine cytomegalovirus (MCMV) in cell culture. We studied the effects of treatment with DHPG on acute MCMV infection in mice and assessed the impact of drug therapy on the eventual development of latent viral infection. In virus-susceptible Balb/c mice, DHPG treatment limited dissemination of virus infection and prevented death. In sublethal infection of both Balb/c and virus-resistant C3H/St mice, DHPG prevented recovery of infectious virus from visceral organs, including the spleen. Despite these effects of drug treatment on virus replication during acute infection, latent MCMV could be reactivated in vivo by immunosuppression and in vitro by spleen explantation in virtually all mice. These results indicate that successful treatment of MCMV infection and marked suppression of viral replication do not prevent establishment of viral latency.

Cytomegalovirus viremia detected by molecular hybridization and electron microscopy

Fatal cytomegalovirus interstitial pneumonitis developed in a patient with chronic leukemia. The diagnosis was suspected on the basis of cytologic examination of bronchial washings. The virus was subsequently recovered from saliva, urine, and blood leukocytes after 8, 9, and 18 days in culture respectively. Premortem cytomegalovirus DNA was found by molecular hybridization methods using a complete viral genome probe in blood leukocytes after 4 hours' reaction time. Electron microscopic examination showed herpes-like virions consistent with cytomegalovirus in 3% of the patient's granulocytes. Thus, DNA:DNA hybridization and ultrastructural methods can be used for rapid diagnosis of disseminated cytomegalovirus infection.

Lethal infection with murine cytomegalovirus after early viral replication in the spleen

In acute lethal murine cytomegalovirus (MCMV) infection the spleen and liver are the principal sites of early viral replication. MCMV titers increase rapidly in the spleen and liver, exceeding 10(6) and 10(5) plaque-forming units (pfu)/g of tissue, respectively, within 96 hr of viral inoculation. Experiments were performed to determine the impact of early splenic viral replication on disease pathogenesis. Splenectomized mice survived acute infection in significantly greater numbers (25 of 34 vs 14 of 33, respectively) than controls and had lower hepatic viral titers (1.9 X 10(4) vs 2.4 X 10(5) pfu/g, respectively). Examination of the spleen by electron microscopy after administration of phagocytic markers demonstrated that macrophages were the predominant site of viral replication. It is concluded that early replication of MCMV in splenic macrophages augments virus-induced hepatic injury and thus contributes to the pathogenesis of lethal MCMV infection.