Pharmacokinetics of Nevirapine, Stavudine and Lamivudine in Indian HIV-infected Children Receiving Generic Fixed Dose Combinations.

Objective: To determine the trough and two hour plasma levels of nevirapine, stavudine, and lamivudine when administered in fixed dose combinations (FDC). Design: Cross sectional Setting: Tertiary care hospital in Northern India. Participants: 79 HIV-infected children receiving antiretroviral therapy with FDCs for more than month. Intervention: Two-point sampling (0 and 2 hours after the morning dose). Outcome measures: Plasma concentrations of all three drugs were simultaneously assayed by liquid chromatography/mass spectroscopy. Results: Majority (77%) of children were receiving fixed dose combination of stavudine, lamivudine, nevirapine in the ratio of 6:30:50mg. The median (IQR) trough and 2-hour plasma levels (µg/mL) of nevirapine, stavudine and lamivudine were 5.2 (4.0, 6.3) and 7.9 (6.0, 9.7); 0.1 (0.06, 0.16) and 1.1 (0.59, 1.6); 0.1 (0.02, 0.2) and 2.5 (1.4, 3.1), respectively. Very few children had sub-therapeutic plasma drug levels of stavudine (2.5%), lamivudine (7.6%) and nevirapine (10%). Inadequate viral suppression at 6 months follow up was significantly associated with initial high viral load, low CD4 percentage at the time of enrolment in study, and lower doses of lamivudine and stavudine. Conclusion: The currently available generic pediatric fixed dose antiretroviral combinations in India provide adequate drug exposure in majority of children.

Persistently high HIV seroprevalence among adult tuberculosis patients at a tertiary care centre in Delhi.

BACKGROUND & OBJECTIVE: This study was designed to estimate HIV seroprevalence among tuberculosis patients presenting to tertiary care centre in Delhi. METHODS: Cross-sectional prevalence study among all patients presenting to the inpatient and outpatient departments of All India Institute of Medical Sciences (AIIMS), New Delhi, and receiving anti-tuberculosis treatment from May 2003 to April 2005. RESULTS: Of the 448 patients who presented to the TB clinic during the study period, 23 (5.1%) were previously tested HIV-positive. An additional 21 patients (4.6%) refused testing, and 30 (6.7%) were lost to follow up. Of the remaining 374 patients who consented to testing, 31 (8.3%) were found to be HIV-positive. Risk factors for HIV seropositivity included high-risk sexual behaviours (48% in HIV-TB co-infected vs. 6% in TB infected patients, P<0.001) and history of blood transfusion (23% vs. 5%; P=0.002). INTERPRETATION & CONCLUSION: Previous studies from the same hospital published in 2000 and 2003 reported HIV seroprevalence among TB patients to be 0.4 and 9.4 per cent respectively. The current study documents a persistently high seropositivity among TB patients. These results emphasize the acute need for improved detection and treatment for HIV among TB patients in northern India.

Evaluation of CD4 counts and percentages in the HIV infected Indian population.

This study was designed to evaluate the absolute CD4+ counts and percentages in HIV subtype C infected patients at a tertiary care hospital in northern India. The CD4+ counts of 377 HIV seropositive subjects were estimated by a FACS Calibur (BD) flow cytometer. Dual color immunophenotyping was performed on each sample, which was acquired and analysed using CellQUEST software. Discordance between CD4+ counts and percentages were found more in the early stage ie Group A (37.2%) when compared with Group B (31.6%) and Group C (28.8%), with the counts remaining in the normal range but percentages being severely depressed.

Comparative evaluation of various commercial assays for diagnosis of dengue fever.

Dengue fever (DF) is endemic in India and dengue hemorrhagic fever (DHF) has been reported with increasing frequency in the last decade. We evaluated three commercial assays for detection of antibodies to dengue virus, to assess their performance in a diagnostic laboratory. Sera from 58 patients collected during a febrile outbreak in New Delhi in 1997 were studied. The methods evaluated were MRL Diagnostic Dengue Fever Virus IgM Capture ELISA, Pan Bio Dengue Duo IgM and IgG Capture ELISA and Pan Bio Rapid Immunochromatographic test. The MRL ELISA correctly identified 97.8% (43 of 44) of samples as dengue positive while the Pan Bio Duo ELISA and Pan Bio RIT identified 95.45% (42 of 44). The sensitivities of both Pan Bio Duo ELISA and Pan Bio RIT for primary dengue and secondary dengue were 100% and 93.54% respectively. The specificity of three assays were MRL IgM ELISA 100%, Pan Bio Duo ELISA 92.8% and Pan Bio RIT 85.7%.

Dengue virus infection during post-epidemic period in Delhi, India.

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are major public health problems in India. During the period following an epidemic, a study was carried out using virological and serological tests for confirmation of suspected cases of dengue virus infection in fever cases presenting to the All India Institute of Medical Sciences. Serum samples of suspected DF/DHF cases were processed from January to December 1997. In 37 samples from patients with fever of less than 5-day duration, received on ice, virus isolation was attempted in C6/36 clone of Aedes albopictus cell line, followed by indirect fluorescent antibody staining with monoclonal antibodies to dengue viruses 1 to 4. One hundred and forty-three serum samples from patients with more than 5 days fever were tested for dengue specific IgM antibody by either MAC-ELISA or a rapid immunochromatographic assay. Dengue virus type 1 was demonstrated by culture in 8 (21.6%) of 37 serum samples and IgM antibody could be detected in 42 (29.4%) of the 143 serum samples by the serological methods. The peak of dengue virus infection was seen from September to November 1997.