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Biomedical subjects

J T van der Meer

Publications and source records attributed to J T van der Meer.

At least 19 recordsLinked to original sources
PubMed2003

[Optimalization of antibiotic policy in the Netherlands. VII. SWAB-guidelines for antimicrobial therapy in adults patients with infectious endocarditis].

The Working Party on Antibiotic Policy (Dutch acronym: SWAB) has developed guidelines for in-hospital antimicrobial therapy of adult patients with infective endocarditis. The choice and the duration of antimicrobial therapy are determined by the infecting micro-organism, the sensitivity of this micro-organism to antimicrobial therapy, the location of the endocarditis (left- or right-sided) and the presence of intracardial prosthetic material. While waiting for the culture results, the antibiotic treatment of an infected native valve is benzylpenicillin (in cases which begin subacutely or have a long history) or flucloxacillin (cases which begin acutely, are fulminant or in i.v. drug users), and gentamicin. If a prosthetic valve is infected then treatment of choice is vancomycin and gentamicin. Further antibiotic treatment depends on the causative micro-organism. Streptococci, enterococci and staphylococci are the most frequently occurring of these.

Anti-Bacterial Agents↗
PubMed2001

A retrospective, cohort-based survey of patients using twice-daily indinavir + ritonavir combinations: pharmacokinetics, safety, and efficacy.

OBJECTIVE: To describe the pharmacokinetics, safety, and efficacy of twice-daily indinavir + ritonavir regimens DESIGN: A cohort-based survey of HIV-infected patients who either used indinavir 800 mg + ritonavir 100 mg twice daily or indinavir 400 mg + ritonavir 400 mg twice daily. METHODS: Data were extracted from a database of samples sent to our laboratory for measurement of indinavir + ritonavir plasma concentrations. Patient characteristics, safety, and efficacy measurements were collected by retrospective chart review. RESULTS: 100 Patients using 800-mg indinavir + 100-mg ritonavir twice daily and 32 patients using 400-mg indinavir + 400-mg ritonavir twice daily were eligible. Median peak and trough concentrations of indinavir were 6.8 and 0.77 mg/L in the 800/100 group and 2.6 and 0.45 mg/L in the 400/400 group. The most frequently found side effects were nausea and vomiting, which occurred in 22.1% and 34.9% of the patients in the 800/100 and the 400/400 groups, respectively. Viral load data were analyzed for patients who switched from 800-mg indinavir three times daily to one of the indinavir + ritonavir twice daily regimens. At the time of switch 63% (800/100 group) and 60% (400/400 group) had an undetectable viral load and this increased to 77% and 70%, respectively, during follow-up. Patients who switched to the 400/400 group discontinued treatment more frequently than patients who switched to the 800/100 group (70% vs. 26%, p =.008). CONCLUSIONS: Indinavir + ritonavir regimens show improved pharmacokinetic properties, allowing twice-daily dosing with food. Clinical data suggest that safety and efficacy is at least as good as with indinavir three-times-daily regimens without ritonavir. Prospective, comparative trials are needed to properly assess the role in HIV therapy of these twice-daily indinavir + ritonavir regimens.

Cohort Studies↗
PubMed1998

[Infections with Mycobacterium kansasii in the Academic Medical Center in Amsterdam: the changing clinical spectrum since the start of the HIV epidemic].

OBJECTIVE: Inventory of patients with a Mycobacterium kansasii infection. DESIGN: Descriptive, retrospective. SETTING: Academic Medical Centre, Amsterdam, the Netherlands. METHOD: Review of the medical records of all patients with a bacteriologically confirmed infection with M. kansasii from January 1987 until the end of December 1996. RESULTS: M. kansasii was isolated from 17 patients. Of 15 HIV-tested patients 13 were seropositive. Their median CD4 count was 10 x 10(6)/l. Ten HIV-positive individuals used trimethoprim-sulfamethoxazole prophylaxis. In 1 HIV-seropositive and in 1 HIV-seronegative patient no chest X-rays were made. Caverns were present in none of 12 HIV-positive patients and in 1 of 3 HIV-negative patients. Of the HIV-positive patients 1 fulfilled the criteria for pulmonary infection of the American Thoracic Society (ATS). According to these criteria 9 of the HIV-positive patients were colonized with M. kansasii. In 6 of these patients there were indications of infection: regression of pulmonary infiltrates with therapy (n = 3), positive histology and culture of lung tissue at autopsy (n = 1), and dissemination (n = 2). Disseminated infection occurred in a total of 4 HIV-infected patients. CONCLUSION: HIV-infected patients are at an increased risk for M. kansasii infection. Trimethoprim-sulfamethoxazole does not offer protection against this infection. The diagnostic criteria of the ATS are not applicable to these patients. M. kansasii infection confirmed by isolation in an HIV-positive individual should always be treated.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Mycobacterium genavense infection in 2 HIV seropositive patients in Amsterdam].

Two patients with an HIV-I infection, a man aged 47 with confusion, aphasia and diarrhoea, and a man aged 32 with dysphagia, a non-productive cough and diarrhoea, were diagnosed as having a disseminated Mycobacterium genavense infection. Both had low counts of CD4+ T lymphocytes. They responded to antimycobacterial treatment. M. genavense was recognized in Geneva in the early nineties as a causative agent of disseminated mycobacterial infections in HIV-seropositive patients with poor cellular immunity. The clinical picture resembles that of a generalized infection with M. avium-intracellulare. M. genavense is a slowly growing mycobacterium which can be isolated and identified using enriched nutrient media and molecular-biological techniques. The infection probably begins in the gastrointestinal tract after oral contamination. DNA of M. genavense can be demonstrated in 25% of the intestinal biopsy samples of non-HIV-seropositive patients.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Characterization of 100 patients with tuberculosis treated in the Academic Medical Center in Amsterdam].

OBJECTIVE: To inventory both clinical and demographical data of patients with tuberculosis in the AMC, as well as diagnostic procedures, response to therapy and rate of resistance. DESIGN: Retrospective, descriptive. SETTING: The Academic Medical Center. Amsterdam, the Netherlands. METHOD: The medical records of all patients with a bacteriologically confirmed infection with Mycobacterium tuberculosis complex between January 1993 and December 1995 were studied. RESULTS: 70 out of 100 patients with tuberculosis were not born in the Netherlands. Out of 50 patients tested 18 were HIV positive. The most common abnormality seen on X-rays of non-HIV positive patients were caverns. The X-ray of HIV positive patients showed no abnormalities in 39%; there was no correlation with CD4 cell count. In 74% of the patients with pulmonary tuberculosis the diagnosis was made by culture of the sputum. Treatment consisted of INH, rifampicin, pyrazinamide and ethambutol. Twelve patients were infected with resistant strains, of which two were multidrug resistant. Four patients died of tuberculosis. CONCLUSION: Tuberculosis was seen mostly among immigrants. Only half the patients with tuberculosis were tested for presence of HIV antibodies. Culture and staining of sputum played a key role in the diagnosis of tuberculosis. Multiresistant tuberculosis was present in 2% of the patients. Death due to tuberculosis in this population was 4%.

AIDS-Related Opportunistic Infections↗
PubMed1998

Optic neuritis heralding varicella zoster virus retinitis in a patient with acquired immunodeficiency syndrome.

We report on a 29-year-old severely compromised acquired immunodeficiency syndrome patient who developed retrobulbar optic neuritis 5 weeks after an episode of cutaneous herpes zoster infection. During the optic neuritis, varicella zoster virus could be demonstrated in the cerebrospinal fluid. The neuritis responded well to treatment with foscarnet, but, 3 weeks into therapy, varicella zoster retinitis developed. Additional treatment with intravenous acyclovir stopped progression of the retinitis and resulted in healing of the retinal lesions. This case suggests that retrobulbar optic neuritis can be regarded as a prodrome of imminent acute retinal necrosis. Early recognition and prompt therapy with combined antivirals may prevent the development of this devastating ocular complication of varicella zoster infection.

AIDS-Related Opportunistic Infections↗
PubMed1998

Risk of developing CMV retinitis following non-ocular CMV end organ disease in AIDS patients.

AIM: To describe the risk of developing cytomegalovirus (CMV) retinitis after a first episode of extraocular CMV disease in AIDS patients. METHODS: A review of the clinical records of 20 AIDS patients, without CMV retinitis, with histologically confirmed extraocular CMV disease, was performed. The main outcome measures were occurrence of CMV retinitis, time to development of CMV retinitis, relation to maintenance therapy, and survival. RESULTS: A CMV retinitis was diagnosed in 17 of 20 (85%) patients with an immunohistologically confirmed diagnosis of extraocular CMV disease after a mean follow up of 6.4 months. Four patients received maintenance therapy. Three of them developed retinitis after a mean of 9.6 months (range 2-16 months). Sixteen did not receive maintenance and retinitis was diagnosed in 14 of them after a mean of 5.7 months (range 2-11 months). Mean survival was 9.9 months after the diagnosis of extraocular disease, and 4.5 months after the diagnosis of retinitis. In the four patients receiving maintenance therapy, mean survival was 11.5 months, and in the 16 other patients mean survival was 9.5 months. Patients did not receive protease inhibitors. CONCLUSION: In the preprotease inhibitor era extraocular CMV disease strongly predisposes to the subsequent development of CMV retinitis. Although maintenance therapy did not prevent the occurrence of retinitis, the time period between both events seems to lengthen considerably. In patients receiving maintenance survival is also longer.

AIDS-Related Opportunistic Infections↗
PubMed1997

Risk of iatrogenic human immunodeficiency virus infection through transfusion of blood tested by inappropriately stored or expired rapid antibody assays in a Zambian hospital.

BACKGROUND: The purpose of this study was to estimate the risk of human immunodeficiency virus (HIV) infection via the transfusion of blood tested by inappropriately stored or expired rapid antibody assays in Zambia. STUDY DESIGN AND METHODS: Surgical patients (n = 370) were tested with antibody assays (HIV-spot and HIV 1+2) that had expired 3 to 6 months previously. Blood donors (n = 211) were tested by inappropriately stored but non-expired HIV-spot assay. Serum samples from both groups were retested with enzyme immunoassays, and the seropositivity of samples was confirmed by immunoblotting. RESULTS: Seroprevalence in surgical patients and blood donors was 19.8 and 11.6 percent, respectively. Sensitivity and specificity of HIV-spot (expired) were 88.2 and 98.1 percent; those of HIV 1+2 (expired) were 82.1 and 94.7 percent; and those of HIV-spot (non-expired) were 91.7 and 98.8 percent, respectively. The risk of HIV infection via the transfusion of blood tested by HIV-spot (expired), HIV-spot (nonexpired), or HIV 1+2 (expired) was calculated to be 1.4, 1.0, and 3.2 percent, respectively. CONCLUSION: Manufacturers of the HIV-spot and HIV 1+2 assays claim sensitivity and specificity of 98.8 and 100 percent and 100 and 99.5 percent, respectively. In this study, sensitivity and specificity were 11 to 18 percent lower. Moreover, in-date reagents also performed less well than the manufacturers claimed, but the worst results were with expired or improperly stored reagents. According to the manufacturers of HIV-spot and HIV 1+2, the risk of HIV infection would be 0.2 and 0 percent, respectively. However, the risk of contracting HIV through transfusion is at least six times higher than expected.

AIDS Serodiagnosis↗
PubMed1997

Cotrimoxazole is effective as primary prophylaxis for toxoplasmic encephalitis in HIV-infected patients: a case control study.

In a case-control study, prophylaxis with cotrimoxazole for toxoplasmic encephalitis (TE) in HIV-infected patients was evaluated. Cotrimoxazole had been given as PCP prophylaxis. 20 patients with TE were identified and 72 matching control cases were found. All patients had IgG-antibodies to Toxoplasma gondii and CD4+ T-cell counts < or = 100/microliter. The use and duration of cotrimoxazole prophylaxis were recorded. It was found that among the patients with TE, none had used cotrimoxazole for > 70% of the observation time, and that the 1-y incidence was 0% in the control group vs. 41% in those patients without sufficient cotrimoxazole use. The conclusion is that cotrimoxazole is effective as primary prophylaxis for TE, even in a dose of 480 mg daily.

AIDS-Related Opportunistic Infections↗
PubMed1997

Two patients with recurrent melioidosis after prolonged antibiotic therapy.

Melioidosis is a tropical infectious disease caused by Burkholderia (Pseudomonas) pseudomalleï. Clinically manifest melioidosis occurs mostly in people with underlying disorders. Melioidosis is a disease with protein manifestations and a high rate of relapse. Two patients with infection due to Burkholderia pseudomalleï after a visit to Thailand are described. Both patients presented with sepsis and appropriate therapy was initiated and continued for several months. Despite such long-term antimicrobial treatment, both patients had a relapse after cessation of therapy. It is unclear if recurrent melioidosis can be prevented by prolonging the treatment even further.

Anti-Bacterial Agents↗
PubMed1996

Value of laboratory investigations in clinical suspicion of cytomegalovirus-induced upper gastrointestinal tract ulcerations in HIV-infected patients.

To assess the value of laboratory investigations for the diagnosis and treatment of cytomegalovirus-induced upper gastrointestinal tract ulcerations, the medical records and biopsy material from HIV-infected patients were reviewed retrospectively during a 12-month period. Clinical diagnosis of cytomegalovirus (CMV) ulceration, based on characteristic endoscopic appearance of extensive ulceration of the mid- to distal esophageal or gastric mucosa and responsiveness to anti-CMV therapy, was compared with laboratory investigations of biopsies. Laboratory procedures consisted of both histopathological examination of the biopsy specimens and viral culture. Twenty episodes in 12 HIV-infected patients could be evaluated. Clinical diagnosis of CMV ulceration appeared to be justified in 14 of 20 episodes (70%), which were confirmed by laboratory investigations. Of the remaining six episodes, which showed partial or no response to anti-CMV therapy, laboratory investigations were negative in two episodes and discrepant in four episodes (histopathology or viral culture positive). A good response to anti-CMV therapy was more frequent in patients whose biopsies proved positive by histopathological examination and/or viral culture than in patients with negative tests (82% versus 0%), which indicates the importance of both investigations. In conclusion, laboratory diagnosis of CMV-induced upper gastrointestinal tract ulcerations supported the diagnosis and decisions on treatment of CMV-induced upper gastrointestinal tract ulcerations.

Cytomegalovirus↗
PubMed1996

Summary of the International Consensus Symposium on Advances in the Diagnosis, Treatment and Prophylaxis and Cytomegalovirus Infection.

CMV infection and CMV disease can be difficult to differentiate and the diagnosis is usually based on a compatible clinical picture and the results of a diagnostic test for CMV. The only exception to this rule is in HIV-infected patients where fundoscopy is sufficient to diagnose CMV retinitis. Of the current diagnostic tests, qualitative and quantitative PCR, branched DNA and Hybrid Capture, are the most promising. The pp65 antigenemia assay has the disadvantage of being more labor-intensive than the DNA based tests. Preliminary data show that a positive qualitative PCR in a HIV-infected patient has a predictive value for the development of CMV retinitis. However, of the patients positive by qualitative PCR, those with high viral loads in quantitative PCR were at the greatest risk of CMV disease. This might make it possible to identify with great certainty the patients who will go on to develop CMV retinitis, thereby decreasing the number of patients eligible for preemptive or prophylactic therapy and increasing the cost-benefit of this therapeutic measure. Quantitative test might also be useful in monitoring response to therapy, but randomized trials comparing the test are needed. Prophylactic antiviral agents should not be used in seronegative transplant recipients receiving organs from seronegative donors. In high-risk transplant recipients, ganciclovir should be used. CMV vaccines are useful for the protection of babies from CMV seronegative mothers against congenital CMV disease. It also may be useful in seronegative transplant recipients receiving a seropositive donor organ, although the benefit of chemo prophylaxis may surpass that of vaccine. HIV-infected patients with CMV retinitis who relapse under either ganciclovir or foscarnet benefit from subsequent combination therapy, rather than switching to the other drug. However, the cost is high in terms of quality of life. Intravitreal therapy for CMV retinitis is very efficacious, suggesting that drug delivery is a problem in systemic therapy. However, intravitreal therapy does not protect against the development of CMV retinitis in the contralateral eye or from CMV disease elsewhere. Therefore, systemic therapy should be added. CMV disease of the CNS should be diagnosed early and treated agressively, possible with combination therapy. A diagnosis of CMV disease should be based on a compatible clinical picture and the demonstration of CMV in CSF by DNA or antigen assays which are more sensitive than culture.

Animals↗
PubMed1996

Complications of varicella zoster virus reactivation in HIV-infected homosexual men.

OBJECT: To study the complication rate of varicella zoster virus (VZV) reactivation and the relationship between complications, presentation and localization of zoster and immune function in HIV disease. DESIGN AND METHODS: A total of 142 episodes of VZV reactivation in 113 out of 544 HIV-1-infected participants in the Amsterdam Cohort Study of homosexual men were studied. Persistent hyperkeratotic or necrotic skin lesions, post-herpetic neuralgia, other neurological events, ocular events and pneumonitis occurring within 6 months of the onset of the last episode of VZV reactivation were defined as complications, provided that other possible diagnoses were excluded and the event had been previously described in the literature as related to VZV reactivation. RESULTS: Twenty-four complications occurred in 15 (11%) of these 142 episodes. Complications occurred exclusively in the 40 episodes with either multidermatomal or disseminated presentation, or a trigeminal localization, or both. In the group of episodes of unidermatomal zoster at a non-trigeminal localization no complications occurred. Twenty-one episodes of herpes zoster were localized in the trigeminal area. Localization was not significantly associated with the level of immune function. Compared to unidermatomal presentation (n = 120), multidermatomal (n = 15) and disseminated presentation (n = 7) occurred at lower median CD4+ cell counts (330, 240 and 50 x 10(6)/l, respectively; P = 0.003) and significantly lower levels of CD3 monoclonal antibodies or phytohaemagglutinin-induced T-cell reactivity in vitro. Complications were related to CD4+ cell counts, but in the cases of disseminated, multidermatomal or trigeminal zoster a CD4+ cell measurement provided no additional information on the risk of complications. CONCLUSION: In HIV-infected individuals the extent of the clinical presentation and the occurrence of complications of VZV reactivation are related to the degree of immunodeficiency. In episodes of VZV reactivation with either multidermatomal or disseminated presentation or a trigeminal localization, or both the complication rate was high. CD4+ cell counts provided no additional information on the complication risk. Oral acyclovir appears to be sufficient as therapy for unidermatomal zoster at a non-trigeminal localization.

Acyclovir↗
PubMed1995

Prevention of bacterial endocarditis: current practice in The Netherlands. Netherlands Heart Foundation.

A working party of the Netherlands Heart Foundation has formulated guidelines which are simple and uniform in order to encourage maximum compliance. They have been widely publicised among medical and dental practitioners as well as patients. Cardiac conditions requiring or not requiring prophylaxis have been identified. Specific regimens for dental procedures, genito-urinary and gastrointestinal procedures, and drainage of infected tissue have been recommended. A case-control study revealed that compliance with recommendations was low even though patients were aware of the need. While prophylaxis may be worthwhile for the individual, it is concluded that even strict adherence will do little to decrease the incidence of endocarditis in the Netherlands.

Anti-Bacterial Agents↗