Clinical indicators for severe prognosis of scrub typhus

Pamornsri Sriwongpan,1,2 Pornsuda Krittigamas,3 Pacharee Kantipong,4 Naowarat Kunyanone,5 Jayanton Patumanond,1 Sirianong Namwongprom1,61Clinical Epidemiology Program, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; 2Department of Social Medicine, Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand; 3Department of General Pediatrics, Nakornping Hospital, Chiang Mai, Thailand; 4Department of Internal Medicine, 5Department of Medical Technology, Chiang Rai Prachanukroh Hospital, Chiang Rai, Thailand; 6Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, ThailandBackground: The study explored clinical risk characteristics that may be used to forecast scrub typhus severity under routine clinical practices.Methods: Retrospective data were collected from patients registered at two university-affiliated tertiary care hospitals in the north of Thailand, from 2004 to 2010. Key information was retrieved from in-patient records, out patient cards, laboratory reports and registers. Patients were classified into three severity groups: nonsevere, severe (those with at least one organ involvement), and deceased. Prognostic characteristics for scrub typhus severity were analyzed by a multivariable ordinal continuation ratio regression.Results: A total of 526 patients were classified into nonsevere (n = 357), severe (n = 100), and deceased (n = 69). The significant multivariable prognostic characteristics for scrub typhus severity were increased body temperature (odds ratio [OR] = 0.58, 95% confidence interval [CI] = 0.45&ndash;0.74, P < 0.001), increased pulse rate (OR = 1.03, 95% CI = 1.01&ndash;1.05, P < 0.001), presence of crepitation (OR = 3.25, 95% CI = 1.52&ndash;6.96, P = 0.001), increased percentage of lymphocytes (OR = 0.97, 95% CI = 0.95&ndash;0.98, P = 0.001), increased aspartate aminotransferase (every 10 IU/L) (OR = 1.04, 95% CI = 1.02&ndash;1.06, P < 0.001), increased serum albumin (OR = 0.47, 95% CI = 0.27&ndash;0.80, P = 0.001), increased serum creatinine (OR = 1.83, 95% CI = 1.50&ndash;2.24, P < 0.001), and increased levels of positive urine albumin (OR = 1.43, 95% CI = 1.17&ndash;1.75, P < 0.001).Conclusion: Patients suspicious of scrub typhus with low body temperature, rapid pulse rate, presence of crepitation, low percentage of lymphocyte, low serum albumin, elevated aspartate aminotransferase, elevated serum creatinine, and positive urine albumin should be monitored closely for severity progression.Keywords: severe scrub typhus, risk factors, rickettsial infection, complication

Feasibility of using dried blood spots for HIV viral load testing among HIV-infected individuals in Thailand using QIAGEN QIAsymphony-artus HIV-1 platform

In settings where plasma preparation and sample centralization are not feasible or inconvenient, dried blood spots (DBS) could be used as an alternative specimen to plasma to assess antiretroviral treatment response among HIV-infected individuals. This study was aimed to (1) validate the recent QIAsymphony-artus assay for DBS HIV viral load (VL) and (2) assess the feasibility of measuring HIV VL on DBS using this assay in Thailand. Ethylenediaminetetraacetic acid-blood samples from 99 HIV-infected individuals were used to prepare paired DBS and plasma. Also, DBS samples were shipped to three distant hospitals in the northern region. After short-term storage, DBS were returned by regular post to the AMS laboratory and were re-tested for HIV VL using the same platform. HIV VL results were compared using Pearson's correlation and Bland-Altman analysis. DBS HIV VL fairly correlated to plasma HIV VL (R = 0.62) with a mean difference of 0.02 log(10)IU/mL (SD = 1.06). A high correlation (R = 0.79) was observed between HIV VL in DBS before and after shipping (mean difference = 0.14 log(10)IU/mL, SD = 0.74), indicating good stability of HIV RNA in DBS. DBS can be used as an alternative specimen for HIV VL monitoring in Thailand. However, measurement of HIV VL with the QIAGEN QIAsymphony-artus assay should be improved, especially the DBS pre-extraction process