Nontakan Nuntachit

Streptococcus agalactiae in adults at chiang mai university hospital: a retrospective study

BackgroundInfection caused by Streptococcus agalactiae, a Group B streptococcus, is an emerging disease in non-pregnant adults. This study describes the epidemiological, clinical, and microbiological characteristics of S. agalactiae infection in adult patients in northern Thailand.MethodsA retrospective study was conducted between January 1, 2006 and December 31, 2009 at Chiang Mai University Hospital among patients aged ≥15 years, whose clinical specimens obtained from normally sterile sites grew S. agalactiae.ResultsOne-hundred and eighty-six patients and 197 specimens were identified during the 4-year period. Among 186 patients, 82 were documented as having invasive infection; 42 patients were male (51.2%) with the mean age of 48.5 ± 19.4 years (range 17, 83). Fifty-three patients (64.6%) had underlying medical conditions; 17 patients (20.7%), 10 (12.2%), 8 (9.7%) had diabetes, chronic renal diseases, and malignancy, respectively. Among 40 patients (48.8%) with bloodstream infection, no other site of infection was determined in 29 (35.4%) patients. In the remaining 11 patients, 5 patients (6.1%), 5 (6.1%), and 1 (1.2%) had meningitis, arthritis, and meningitis with arthritis, respectively. Forty-two patients (51.2%) presented with localized infection, i.e., subcutaneous abscess (19 patients, 23.2%), chorioamnionitis (10 patients, 12.2%), urinary tract infection (5 patients, 6.1%), arthritis (3 patients, 3.7%), meningitis (2 patients, 2.4%), and spontaneous bacterial peritonitis, uveitis, and tracheobronchitis (1 patient each, 1.2%). The overall mortality was 14.6% (12 patients).ConclusionsS. agalactiae infection is a growing problem in non-pregnant patients, particularly in those with underlying medical conditions. Physicians should add S. agalactiae infection in the list of differential diagnoses in patients with meningitis and/or septicemia.

Resistance-associated mutations after initial antiretroviral treatment failure in a large cohort of patients infected with HIV-1 subtype CRF01_AE.

The nucleoside reverse transcriptase inhibitors (NRTIs), zidovudine (AZT) and stavudine (d4T) are thymidine analog drugs recommended as first-line antiretroviral therapy in HIV-1-naive patients. Two thymidine analog mutation (TAM) pathways, TAM-1 and TAM-2, confer high levels of resistance with mutations in the viral RT. The relative prevalence of TAM pathways and their associations with other NRTI resistance mutations acquired under the pressure of drug treatment in a large cohort of 1,876 patients infected with HIV-1 CRF01_AE attending the Infectious Disease Clinic, Chiang Mai University Hospital, Chiang Mai, Thailand, were studied. From 117 patients infected with HIV-1 CRF01_AE who had plasma HIV-1 RNA of ≥500 copies/mL, 69 patients had at least one TAM. The most common mutation associated with NRTI resistance was M184V/I (89.9%). The TAM-2 (89.9%) pathway occurred approximately two times more frequently than the TAM-1 (43.5%) pathway. The presence of TAM and the TAM-1 pathway was significantly more frequent in the AZT- than the d4T-receiving group ((OR, 2.89; 95% CI, 1.12-7.46; P< 0.05) and (OR, 3.33; 95% CI, 1.19-9.37; P< 0.05), respectively). In conclusion, the TAM-2 pathway was selected more frequently than the TAM-1 pathway by thymidine analog drugs in HIV-1 CRF01_AE-infected patients, while the TAM-1 pathway occurred more frequently than the TAM-2 pathway in such patients with AZT-based treatment. Routine monitoring of plasma HIV-1 RNA may result in less exposure to failing regimens and reduce the opportunity for TAMs to accumulate. However, the low frequency of the TAM-1 pathway in our cohort data suggests that these patients should respond well to second-line regimens containing a ritonavir-boosted protease inhibitor.

Impact of the Frequency of Plasma HIV-1 RNA Monitoring on the Outcome of Antiretroviral Therapy

BACKGROUND Current guidelines for HIV management recommend monitoring plasma HIV-1 RNA level every 3-6 months in patients on a stable antiretroviral regimen. However, cost is the major obstacle to follow the guidelines in resource-limited settings. OBJECTIVE This study aimed to compare the outcome of antiretroviral therapy among HIV-infected patients on a stable regimen who had plasma HIV-1 RNA monitoring once vs. twice yearly. METHODS A retrospective cohort study was conducted among HIV-infected patients receiving antiretroviral therapy since 2002 at Chiang Mai University Hospital, Thailand. We evaluated the incidence of virological failure and number of reverse transcriptase (RT) mutations between groups. RESULTS Of 551 patients on a stable antiretroviral regimen, 405 (73.5%) and 146 (26.5%) patients had plasma HIV-1 RNA measurement once and twice yearly, respectively. Forty-seven of 405 patients (11.6%) in once-yearly group and 15 of 146 patients (10.3%) in twice-yearly group developed virological failure, giving the incidence rate of 2.03/100 and 1.95/100 person-years, respectively. The probability of virological failure did not differ between groups (p=0.897, log-rank test). The number of RT mutations was not statistically different between groups (all p-values>0.05). The predicting factors for virological failure from a multivariate analysis were adherence rate <95% and baseline CD4 cell count <50 cells/mm3 but not the frequency of HIV-1 RNA monitoring. CONCLUSIONS The incidence of virological failure and the number of RT mutations were not different between groups. Therefore, in resource-limited settings, the recommendation to perform plasma HIV-1 RNA measurement once yearly in patients on a stable antiretroviral regimen is justified.

Comparison of in-house HIV-1 genotypic drug resistant test with commercial HIV-1 genotypic test kit

Abstract Background: The use of combination antiretroviral therapy (cART) has become a standard of care in the treatment of HIV infection. However, antiretroviral drug resistance occurs in a substantial number of patients. In resource-limited settings, genotypic resistance assay using a commercial kit is costly. Objective: Focus on the validation of an in-house HIV-1 specific genotypic drug resistance assay in Thai patients failing cART. Materials and methods: Results of HIV-1 genotypic drug resistance assay was evaluated by comparing an inhouse method to a commercial test. The TRUGENE HIV-1 genotyping kit was used in 79 plasma specimens (49 from HIV patients failing cART therapy and 30 from proficiency testing panels). Results: The results from the in-house assay were comparable to those obtained from the TRUGENE HIV-1 genotyping kit with >99.0% codon-to-codon agreement. The lower limit of detection by the in-house assay was approximately 100 copies/mL of HIV-1 RNA. In addition, this in-house assay would allow testing of samples from patients infected with HIV-1 subtype other than B. Conclusion: The in-house HIV-1 genotypic drug resistance assay may be used as an alternative to commercial kits, particularly in resource limited settings.