Kenrad E. Nelson

Disseminated Penicillium marneffei infection in Southeast Asia

Disseminated infection with the fungal pathogen Penicillium marneffei is, after extrapulmonary tuberculosis and cryptococcal meningitis, the third most common opportunistic infection in HIV disease in northern Thailand. We report the clinical, microbiological, and therapeutic features of a large series of HIV-infected adults with disseminated P marneffei infection. From August, 1987, to June, 1992, 92 patients with P marneffei infection confirmed by culture were seen at Chiang Mai University Hospital, of whom 86 were also infected with HIV. Clinical information was available for 80 of these patients. The most common presenting symptoms and signs were fever (92%), anaemia (77%), weight loss (76%), and skin lesions (71%). 87% of patients presenting with skin lesions had generalised papules with central umbilication. Presumptive diagnosis was made in 50 patients by microscopic examination of Wrights-stained bone-marrow aspirate and/or touch smears of skin biopsy or lymph-node biopsy specimens. Most patients who were diagnosed responded initially to amphotericin or itraconazole, whereas most who were not diagnosed and treated died. 12 patients relapsed within 6 months of cessation of treatment. P marneffei has become an important pathogen of HIV-associated opportunistic infection in Thailand.

Specific identification of Penicillium marneffei by a polymerase chain reaction/hybridization technique

Penicillium marneffei has been described recently as a cause of an emerging mycotic infection in HIV-infected patients. A PCR/hybridization assay was developed to rapidly identify this pathogen. The nucleotide sequence of the 631-bp region of 18S ribosomal DNA of P. marneffei was determined using the standard dideoxy chain termination method. An oligonucleotide probe was designed on the basis of the analysed sequences of P. marneffei and 18S rDNA sequences of other fungi in the GenBank database. A 631-bp PCR product was amplified using primers RRF1 and RRH1 from P. marneffei and seven other fungi, Penicillium spp., Aspergillus fumigatus, A. flavus, Histoplasma capsulatum, Cryptococcus neoformans, Candida albicans and C. krusei. A 15 oligonucleotide segment (Pm3) which was specific for P. marneffei was synthesized and used as a probe. Only the PCR products of P. marneffei isolates hybridized with the Pm3 oligonucleotide probe. The sensitivity of the assay was approximately 0.5 pg/microl and 0.1 pg/microl of DNA by PCR and Southern hybridization, respectively. The usefulness of this method as a diagnostic tool will require further studies.

Western immunoblot analysis of protein antigens of Penicillium marneffei

Protein antigens of Penicillium marneffei prepared during the yeast and mould phases of in vitro growth were analyzed by gel electrophoresis and immunoblot assay. More than 20 yeast phase proteins were detected by Coomassie staining; among these, at least 10 reacted with IgG in the pooled sera of 28 AIDS patients with penicilliosis. Four immunogenic proteins of 200, 88, 54 and 50 kDa were produced in large quantity during the deceleration and early stationary phases of growth. When these proteins were reacted with individual sera derived from 33 AIDS patients with penicilliosis, reactivities to the 200, 88, 54 and 50 kDa protein were detected in 72.7, 93.9, 60.6 and 57.6%, respectively. The bands of 88, 54 and 50 kDa gave strong reactions with about a half of serum samples. In one serum derived from an AIDS patient, reactivities to the 54 and 50 kDa proteins could be strongly detected two months before the definite diagnosis by fungal culture. Protein components from the mould form were of lower yield and gave weaker signal in immunoblot analysis. These results indicate that at least two yeast-phase immunoreactive proteins (54 and 50 kDa) are relatively specific to the P. marneffei infection, thereby suggesting its potential for clinical application to the diagnosis of this emerging disease.

Viral infections in short-term injection drug users: the prevalence of the hepatitis C, hepatitis B, human immunodeficiency, and human T-lymphotropic viruses.

OBJECTIVESnThe purpose of this study was to estimate the prevalence and correlates of four blood-borne viral infections among illicit drug injectors with up to 6 years of injecting experience.nnnMETHODSnWe analyzed data from 716 volunteers recruited in 1988 and 1989. Test results for hepatitis C virus (HCV), hepatitis B virus (HBV), human immunodeficiency virus, type 1 (HIV), and human T-lymphotropic virus types I and II (HTLV) were examined across six sequential cohorts defined by duration of drug injection.nnnRESULTSnOverall, seroprevalence of HCV, HBV, HIV, and HTLV was 76.9%, 65.7%, 20.5% and 1.8%, respectively, and 64.7%, 49.8%, 13.9%, and 0.5%, respectively, among those who had injected for 1 year or less. Among the newest initiates, HCV and HBV were associated with injecting variables, and HIV was associated with sexual variables.nnnCONCLUSIONSnThe high rates of HCV, HBV, and HIV infections among short-term injectors emphasizes the need to target both parenteral and sexual risk reduction interventions early. Renewed efforts at primary prevention of substance abuse are indicated.

The Declining Risk of Post-Transfusion Hepatitis C Virus Infection

BACKGROUNDnThe most common serious complication of blood transfusion is post-transfusion hepatitis from the hepatitis C virus (HCV). Blood banks now screen blood donors for surrogate markers of non-A, non-B hepatitis and antibodies to HCV, but the current risk of post-transfusion hepatitis C is unknown.nnnMETHODSnFrom 1985 through 1991, blood samples and medical information were obtained prospectively from patients before and at least six months after cardiac surgery. The stored serum samples were tested for antibodies to HCV by enzyme immunoassay, and by recombinant immunoblotting if positive.nnnRESULTSnOf the 912 patients who received transfusions before donors were screened for surrogate markers, 35 seroconverted to HCV, for a risk of 3.84 percent per patient (0.45 percent per unit transfused). For the 976 patients who received transfusions after October 1986 with blood screened for surrogate markers, the risk of seroconversion was 1.54 percent per patient (0.19 percent per unit). For the 522 patients receiving transfusions since the addition in May 1990 of screening for antibodies to HCV, the risk was 0.57 percent per patient (0.03 percent per unit). The trend toward decreasing risk with increasingly stringent screening of donors was statistically significant (P less than 0.001). After we controlled for the method of donor screening, the risk of seroconversion was strongly associated (P less than 0.001) with the volume of blood transfused, but not with the use of particular blood components.nnnCONCLUSIONSnThe incidence of post-transfusion hepatitis C has decreased markedly since the implementation of donor screening for surrogate markers and antibodies to HCV. The current risk of post-transfusion hepatitis is about 3 per 10,000 units transfused.

Prevalence and incidence of hepatitis C virus infection among young adult injection drug users

Through community-based outreach, young adult injection drug users (IDUs) were enrolled in a prospective study of the prevalence, incidence, and risk factors for hepatitis C virus (HCV) infection. Demographics and information on sexual and injecting practices were collected during semiannual interviews, and HCV infection was evaluated using a second-generation antibody assay. Of the 229 participants, 86 (37.6%) were HCV-seropositive at baseline. After adjusting for injecting frequency and duration by logistic regression, HCV seroprevalence was independently associated with reusing syringes at least once in the past 6 months (odds ratio [OR]=3.81, 95% confidence interval [CI] 1.39-11.00), injecting the first time with someone > or =5 years older (OR=2.99; 95% CI, 1.43-6.23) or alone (OR=4.02; 95% CI, 1.12-14.43) versus with someone <5 years older, and injecting cocaine or speedball exclusively (OR=4.29; 95% CI, 1.53-12.01) or with other drugs (OR=5.27; 95% CI, 2.62-10.64) versus injecting no cocaine in the past 6 months. Of the 105 originally HCV-seronegative participants who returned for follow-up, 13 seroconverted (incidence rate=16.0/100 person-years). On bivariate analysis, HCV seroconversion was significantly associated with injecting for <2 years (relative risk [RR]=7.3; 95% CI, 1.6-32.8) and continuing to inject during follow-up (RR=4.4; 95% CI, 1.0-19.9). Young adult IDUs are at high risk for HCV infection. These data support the need for wider legal access to sterile syringes, as well as expanded community outreach education to this population to prevent transmission of HCV.

Correlates of hepatitis C virus infections among injection drug users.

Injection drug users are at high risk for hepatitis C virus (HCV) infection. In Baltimore, Maryland, the prevalence of anti-HCV is greater among injection drug users who are black, human immunodeficiency virus (HIV) infected, have injected longer, have injected more frequently, and have injected cocaine than among other injection drug users. HCV infection occurs quickly after the initiation of injecting illicit drugs, with 78% of study participants anti-HCV positive after 2 years of injecting. The prevalence of anti-HCV among injection drug users does not appear to be related to socioeconomic factors or sexual practices. Some injection drug users remain free of anti-HCV even after years of injecting and serologic evidence of other bloodborne pathogens. Some of these injection drug users have HCV infection, demonstrated by HCV RNA in their sera. However, the basis for viral persistence in the absence of anti-HCV and for the absence of HCV infection in long-term drug users is not known. Further studies are indicated to determine the mechanism or mechanisms for the absence of anti-HCV in persons exposed to the virus, because the biologic basis for this condition may elucidate the elements missing in the immune response of the majority of HCV-exposed persons who acquire persistent infection. In addition, interventions to prevent HCV infections should be applied in populations at risk for injection drug use early or before drug use begins.

The trading of sex for drugs or money and HIV seropositivity among female intravenous drug users

OBJECTIVESnData from 538 women in a cohort study recruited in 1988-1989 were analyzed to determined whether trading sex for drugs or money was independently associated with human immunodeficiency virus (HIV) seroprevalence in a population of female intravenous drug users.nnnMETHODSnThe women were grouped according to the number of partners with whom they reported trading sex for drugs or money during the previous 10 years: none, 1 through 49 (low), or 50 or more (high); the prevalence of HIV seropositivity in the three groups was 23.2%, 23.7%, and 47.6%, respectively. Logistic regression was used to compare the low- and high-trade groups separately with the group that reported no trading.nnnRESULTSnLow trading was not associated with seroprevalent HIV infection. In a multivariate model, high trading (compared with no trading) was significantly associated with HIV seropositivity after adjustment for cocaine use, history of sexually transmitted diseases, and duration of intravenous drug use.nnnCONCLUSIONSnThese data indicate that, among intravenous drug-using women, high levels of trading sex for drugs or money were independently associated with HIV infection. This group needs to be targeted for further intensive intervention.

Risk factors for shooting gallery use and cessation among intravenous drug users.

BACKGROUNDnShooting galleries, locations where intravenous drug users (IVDUs) can rent or borrow needles and syringes, are a high-risk environment for HIV-1 transmission. This study investigates risk factors for lifetime attendance at shooting galleries and differentiates characteristics of those who continue to frequent shooting galleries and those who have stopped.nnnMETHODSnWe interviewed 2615 active IVDUs in Baltimore in 1988 and 1989 and determined patterns of IV drug use, sociodemographics, and HIV-1 serostatus as related to persistence vs cessation of shooting gallery use.nnnRESULTSnOver half (52%) of active IVDUs reported ever using a shooting gallery, with 33% reporting use within the prior 3 months. In multivariate analysis, lifetime shooting gallery use was associated with male gender, homosexuality/bisexuality, low socioeconomic status, Black race, and heavier drug involvement. Persistent shooting gallery users were more frequently male, homosexual/bisexual, homeless, less educated, and started IV drug use more recently compared with those who ceased going to shooting galleries.nnnCONCLUSIONSnShooting gallery attendance may be pragmatic from a sociological and economic perspective, but it carries with it a heightened risk of acquiring HIV-1 infection.

The Influence of Human Immunodeficiency Virus (HIV) Infection on Antibody Responses to Influenza Vaccines

STUDY OBJECTIVEnTo ascertain whether subjects infected with human immunodeficiency virus (HIV) generally develop protective hemagglutination inhibition antibody responses to inactivated influenza vaccines.nnnDESIGNnProspective study of 104 persons before and after immunization.nnnSETTINGnOutpatient clinic and hospital ward.nnnPATIENTSnPersons with the acquired immunodeficiency syndrome (AIDS) (n = 25), AIDS-related complex (n = 14), and HIV-seropositive men with only lymphadenopathy or no symptoms (n = 27). Controls were HIV-seronegative homosexual men (n = 22) and HIV-seronegative heterosexuals (n = 16).nnnINTERVENTIONSnSubjects were immunized with inactivated vaccines containing 15 micrograms of each of the following influenza virus hemagglutinins: A/Taiwan/1/86 (HINI), A/Mississippi/1/85 (H3N2), A/Chile/1/83 (HINI), and B/Ann Arbor/1/86.nnnMEASUREMENTS AND MAIN RESULTSnFourfold or greater antibody responses occurred less frequently in subjects with HIV infections than in HIV-seronegative controls. Protective levels (1:64 or greater) of hemagglutination inhibition antibodies were attained by 94% to 100% of HIV-seronegative controls, 52% to 89% of HIV-seropositive asymptomatic subjects, and 13% to 50% of subjects with AIDS or AIDS-related complex. No increase in the prevalence or level of serum HIV p24 antigen or clinical deterioration was detected among HIV-infected persons after influenza immunization.nnnCONCLUSIONSnBecause of the poor antibody responses to influenza vaccines among HIV-infected subjects, even in many with no or minimal symptoms, alternative strategies for preventing influenza, such as booster doses of influenza vaccine, prophylaxis with amantidine, or both should be considered.