Molecular diagnosis and therapy for Plasmodium ovale infection of a returned traveler from East Africa.

Malaria is an infectious disease caused by Plasmodium parasites that are mainly transmitted through the bites of infected female Anopheles mosquitoes. The average annual number of malaria cases was less than ten in Taiwan in the last five years. Most of the cases were caused by Plasmodium vivax and Plasmodium falciparum, and were primarily diagnosed in travelers who returned from Southeast Asia and Africa. Here, we report the first case of Plasmodium ovale infection within five years that was confirmed by peripheral blood smear examination and molecular identification in a 25-year-old Asian female patient who returned from Uganda.

Assessment of Expert-Level Automated Detection of Plasmodium falciparum in Digitized Thin Blood Smear Images.

Importance: Decades of effort have been devoted to establishing an automated microscopic diagnosis of malaria, but there are challenges in achieving expert-level performance in real-world clinical settings because publicly available annotated data for benchmark and validation are required. Objective: To assess an expert-level malaria detection algorithm using a publicly available benchmark image data set. Design, Setting, and Participants: In this diagnostic study, clinically validated malaria image data sets, the Taiwan Images for Malaria Eradication (TIME), were created by digitizing thin blood smears acquired from patients with malaria selected from the biobank of the Taiwan Centers for Disease Control from January 1, 2003, to December 31, 2018. These smear images were annotated by 4 clinical laboratory scientists who worked in medical centers in Taiwan and trained for malaria microscopic diagnosis at the national reference laboratory of the Taiwan Centers for Disease Control. With TIME, a convolutional neural network-based object detection algorithm was developed for identification of malaria-infected red blood cells. A diagnostic challenge using another independent data set within TIME was performed to compare the algorithm performance against that of human experts as clinical validation. Main Outcomes and Measures: Performance on detecting Plasmodium falciparum-infected blood cells was measured by average precision, and performance on detecting P falciparum infection at the image level was measured using sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). Results: The TIME data sets contained 8145 images of 36 blood smears from patients with suspected malaria (30 P falciparum-positive and 6 P falciparum-negative smears) that had reliable annotations. For clinical validation, the average precision was 0.885 for detecting P falciparum-infected blood cells and 0.838 for ring form. For detecting P falciparum infection on blood smear images, the algorithm had expert-level performance (sensitivity, 0.995; specificity, 0.900; AUC, 0.997 [95% CI, 0.993-0.999]), especially in detecting ring form (sensitivity, 0.968; specificity, 0.960; AUC, 0.995 [95% CI, 0.990-0.998]) compared with experienced microscopists (mean sensitivity, 0.995 [95% CI, 0.993-0.998]; mean specificity, 0.955 [95% CI, 0.885-1.000]). Conclusions and Relevance: The findings suggest that a clinically validated expert-level malaria detection algorithm can be developed by using reliable data sets.

Antimicrobial resistance of Moraxella catarrhalis isolates in Taiwan.

BACKGROUND/PURPOSE: The prevalence of ampicillin-resistant Moraxella catarrhalis has been higher in Taiwan than in other countries, with reports of 97.7% in the 1990s. The aims of this study were to assess resistance trends for M. catarrhalis, which causes respiratory tract infections, against several classes of oral antibiotics and to compare the minimum inhibitory concentration (MIC) of antimicrobial agents against M. catarrhalis isolates between 1993-1994 and 2001-2004. METHODS: Clinical isolates of M. catarrhalis (n = 314) were collected from 11 large medical centers in Taiwan between 2001 and 2004. ß-Lactamase production tests were performed. The MICs for 13 different oral antibiotics were calculated using the agar dilution method. Pulsed-field gel electrophoresis (PFGE) was performed for 18 randomly selected high-level ampicillin-resistant (BRO-1 ß-lactamase-positive, MIC ≥ 32 µg/mL) isolates to investigate their genetic relatedness. RESULTS: The overall rate of ß-lactamase-producing isolates was 97.8% (307/314). All isolates were susceptible to amoxicillin + clavulanate, chloramphenicol, cefixime, ciprofloxacin, erythromycin, levofloxacin, moxifloxacin, and roxithromycin. The rate of resistance to cefaclor and cefuroxime was 8.3% and 1.3%, respectively, while no resistance was found in 1993-1994. Resistance to trimethoprim-sulfamethoxazole (SXT) and tetracycline was 18.5% and 19.8%, respectively. Comparison of 1993-1994 and 2001-2004 isolates revealed that the zone diameter for amoxicillin + clavulanate disks decreased from 43 mm in 1993-1994 to 32 mm in 2001-2004 (p < 0.001). However, MIC(50) (0.25 µg/mL in both 1993-1994 and 2001-2004) and MIC(90) (0.5 µg/mL in both 1993-1994 and 2001-2004) for amoxicillin + clavulanate did not differ between the study periods. The PFGE typing results demonstrate that at least two closely related BRO-1 clones are spreading in Taiwan. CONCLUSION: The rates of resistance to cefaclor, cefuroxime, tetracycline and SXT are now increasing in Taiwan. Molecular typing showed that at least two closely related BRO-1 clones are circulating. Although amoxicillin + clavulanate remains the antimicrobial therapy of choice for M. catarrhalis infections, continued surveillance of antimicrobial susceptibility and application of control measures against further transmission are required to inhibit the emergence of the resistant strains.

Clinical experience with tigecycline as treatment for serious infections in elderly and critically ill patients.

BACKGROUND: Tigecycline was approved for the treatment of complicated intra-abdominal and complicated skin/skin structure infections. Because of its in vitro effectiveness for multidrug-resistant (MDR) isolates, tigecycline has been prescribed more broadly. This study evaluated tigecycline use after its first introduction in Taiwan and experience with tigecycline for the treatment of MDR Acinetobacter baumannii (MDRAB) infection, especially for ventilator-associated pneumonia. METHODS: Patients treated with tigecycline were collected retrospectively from February 2008 to July 2008 in Taipei Veterans General Hospital, a 2,900-bed tertiary care medical center in Taiwan. Patients were divided into three groups according to the indications: Group 1, Food and Drug Administration-approved indications; Group 2, health care-associated pneumonia (HAP); and Group 3, urinary tract infection, osteomyelitis, bacteremia, etc. Cases of MDRAB were also identified. RESULTS: Among 66 cases, indications for the administration of tigecycline included Food and Drug Administration-approved indications (12, 18.2%), HAP (38, 57.6%), bacteremia (3, 4.5%), catheter-related infections (3, 4.5%), urinary tract infection (4, 6.1%), osteomyelitis (4, 6.1%), and others (2, 3%). Clinical outcome was positive in 20 cases, with higher clinical success rate for Group 1 than Group 2, which may correlate with higher Sequential Organ Failure Assessment score, older age, and more frequent intensive care admission in Group 2. Of the microbiologically evaluable cases, MDRAB predominated (33/51, 64.7%). Among infections with MDRAB (excluding pneumonia without ventilator), the clinical success rate was 12% (3/25). CONCLUSIONS: The most common indication for the prescription of tigecycline was HAP. Success rate for MDRAB infection was lower than that previously reported, possibly because of serious underlying conditions and comorbidities in our patients. Because of limited choices, physicians should weigh the risk and benefit for prescribing tigecycline.

Clinical manifestations of treatment-naive patients with acquired immunodeficiency syndrome and responses to highly active antiretroviral therapy in the Taipei Veterans General Hospital: a 5-year prospective study.

BACKGROUND: Taipei Veterans General Hospital, one of the medical centers in Taiwan, has provided highly active antiretroviral therapy (HAART) to human immunodeficiency virus/AIDS patients for more than 10 years. Five years ago, we began a prospective follow-up of our patients' clinical manifestations and responses to HAART by collecting their clinical data. In this study, we analyzed the morbidity, mortality, and responses to HAART of treatment-naive AIDS patients. The purpose was to provide local data that may be valuable in Taiwan. METHODS: Study cases were enrolled from January 1, 2004, to February 28, 2009, with inclusion criteria of newly diagnosed AIDS during hospitalization and being naive to HAART. Antiretroviral therapy was initiated. To evaluate the clinical responses to HAART, we excluded patients who were pregnant, died within 1 month after confirmation of an AIDS diagnosis, failed to initiate HAART, or were lost to follow-up for more than 6 months. Plasma viral loads and CD4(+) counts were quantified by reverse-transcriptase polymerase chain reaction and flow cytometry, respectively. Statistical analysis was performed using SPSS statistical software. RESULTS: A total of 49 patients were enrolled and 45 patients fulfilled the inclusion criteria for evaluating the efficacy of HAART. At 3 months, 12 months, and 30 months after the initiation of HAART, 64.4% (29 of 45), 88.2% (30 of 34), and 93.8% (15 of 16) had undetectable plasma viral loads, respectively, and 37.8% (17 of 45), 73.5% (25 of 34), and 81.2% (13 of 16) had CD4(+) counts of more than 200 cells/µL, respectively. Median CD4(+) counts increased from baseline at Month 3 by 171 cells/µL and at Month 30 by 375 cells/µL. The overall mortality was 22.4% (11 of 49). CONCLUSION: The virologic and immunologic responses after initiating HAART in this study demonstrated our achievements in providing care and treatment for AIDS patients during this 5-year period, which provides a strong evidence of the efficacy of HAART.