Comparison of ELISA and dual stage real time RT-PCR to differentiate Sabin like and non-Sabin like poliovirus isolates.

Environmental surveillance of polioviruses has been used as an important tool in monitoring circulation of wild polioviruses and/or Vaccine derived polioviruses in sewage samples. It is important to distinguish Sabin like isolates from non-Sabin like; ELISA & dual stage real time RT-PCR have been used for the same. Current study was carried out on sewage isolates to compare ELISA & RT-PCR with sequencing to distinguish Sabin like from non-Sabin like. Out of 468 sewage specimens, 91 (19.44%) were non-polio enteroviruses positive and 377 (80.56%) were polio positive by virus isolation method. A total of 488 polio virus isolates were detected by L20B and RD route which were further subjected to ELISA and RT-PCR. The results were compared with sequencing. On comparison, the specificity of ELISA was only 66.67% in spite of very low sensitivity (3.43%). The sensitivity of RT-PCR was 97.71% which makes it a good primary screening test for detection of non-Sabin like viruses. However, the specificity was only 33.33%. RT-PCR appears to be a sensitive tool for detecting non-Sabin like viruses however; the isolates which are non-Sabin like by RT-PCR may not necessarily be mutated viruses. ELISA cannot be used for differentiation of Sabin likes from non-Sabin likes due to low sensitivity.

Environmental surveillance of polioviruses with special reference to L20B cell line.

With the eradication of poliovirus, the focus has now shifted to environmental surveillance of poliovirus to determine the circulating polioviruses in an area. L20B and RD cell lines are used for isolation of polioviruses. It is imperative to study the efficacy of these cell line in isolating polioviruses from environmental samples. The present study was carried out to determine the sensitivity and specificity of L20B cell line for isolation of polioviruses from environmental samples. L20B and RD cell lines are used for isolation of polioviruses. Molecular characterization was done by using real time RT-PCR. A total of 432 sewage samples from Delhi and Punjab were processed for the isolation of polioviruses during Jan-Dec 2015. 96.76% of the samples were positive in either of the cell lines. Non-polio enteroviruses were obtained in 50 samples on primary isolation. On RT-PCR, 347 (94.29%) samples yielded polioviruses and the rest (21) non-polio enteroviruses or non-enteroviruses. A total of 703 isolates were obtained. 635 isolates were found polioviruses by PCR (90.33%), 20 isolates were found to be NPEV (2.84%) and 48 (6.83%) were found to be NEV. Out of the 20 NPEV isolates, 14 were from RLR (RD-L20B-RD) route and six isolates were from LR (L20B-RD) route. All 48 NEV isolates were from LR route. Thus L20B cell line is more sensitive as compared to RD cell line for isolation of polioviruses however it is not absolutely specific for polioviruses.

Profiles of HIV-infected anti-retroviral therapy naïve children from Mumbai, India.

BACKGROUND: This study aimed to investigate the demographic profiles of human immunodifficiency virus (HIV) infected anti-retroviral therapy (ART) naïve children in our hospital and their relations to the clinical, immunological and nutritional status. METHODS: A cross-sectional study was conducted in an Integrated Counselling and Testing Center (ICTC) at a tertiary care hospital in Mumbai. ART naïve HIV positive children were enrolled in the study. The demographic profiles, clinical features, immunological (CD4%/CD4 count) and nutritional status of these children were recorded. The agreement between clinical, immunological and nutritional staging was determined using Cohen's kappa test. RESULTS: In 192 HIV-infected ART naive children enrolled with a median age of 9 years (range 3 months-14 years), 97.4% acquired infection through vertical transmission. The most common clinical presentation was fever (39.6 %), followed by generalized lymphadenopathy (32.3%), cough (22.4%) and diarrhoea (9.9%). Tuberculosis was seen in 22.9% of the children. The agreement was fair between clinical and immunological staging, and slight between nutritional, immunological and clinical staging. CONCLUSION: Perinatal transmission is the most common mode of acquiring HIV infection in children. The Prevention of Parent to Child Transmission (PPTCT) program should be strengthened for lowering the transmission rate by providing extended ART to mothers during pregnancy and breast-feeding. Tuberculosis remains a major concern in HIV-infected children. The poor correlation between WHO clinical and immunological staging emphasizes the importance of making CD4 facilities available in HIV prevalent areas. Malnutrition cannot be used as a surrogate marker for predicting stage or severity as it is common at all stages of HIV disease.

Monitoring HIV Epidemic in Pregnant Women: Are the Current Measures Enough?

Introduction. Burden of HIV in pregnant women follows overall epidemic in India. Hence, it is imperative that prevalence calculations in this group be accurate. The present study was carried out to determine prevalence of HIV in pregnant women attending our hospital, to determine trend of HIV infection and to compare our results with reported prevalence. Methods. All pregnant women are routinely counselled for HIV testing using opt-out strategy. Year-wise positivity and trend were determined in these patients over a period of five years. The positivity in different age groups was determined. Results. 31,609 women were tested of which 279 (0.88%) were positive. Positivity showed a declining trend over study period and significant quadratic trend (biphasic, P < 0.05) was observed. The positivity in older age group ≥35 years (1.64%) was significantly more than younger age groups (0.76% in 15-24-year and 0.94% in 25-34-year age group) (P = 0.0052). Conclusion. A significant decline in HIV positivity was seen over the study period. Taking into account heterogeneous nature of HIV epidemic even within the same district, analysis at local levels especially using the prevention of parent to child transmission of HIV program data is critical for HIV programming and resource allocation.

CD4 counts in laboratory monitoring of HIV disease--experience from western India.

BACKGROUND: CD4 counts vary in different populations. The present study was conducted to determine CD4 counts in different World Health Organization (WHO) clinical stages in antiretroviral therapy naive individuals and to find out optimum CD4 cutoffs. METHOD: Data of adult HIV seropositive patients who underwent CD4 count and total lymphocyte count (TLC) testing were included for analysis. The severity of immunosuppression was graded based on WHO criteria. To establish optimum CD4 cutoff values, receiver-operator characteristics (ROC) curves were generated. RESULTS: Of 754 patients, 52.2% had CD4 counts <200 cells/mm3, but only 2.3% belonged to WHO stage IV. Newer CD4 cutoffs generated were 280, 120-280, <120 cells/mm3. Spearman rank correlation between CD4 counts and TLC was found to be weak (r = .32). CONCLUSION: The cutoff values of CD4 counts for HIV disease may need to be revised for India. Regular CD4 count estimation is a must for monitoring disease progression in people living with HIV/AIDS.

CD4 counts in laboratory monitoring of HIV disease--experience from western India.

BACKGROUND: CD4 counts vary in different populations. The present study was conducted to determine CD4 counts in different World Health Organization (WHO) clinical stages in antiretroviral therapy naive individuals and to find out optimum CD4 cutoffs. METHOD: Data of adult HIV seropositive patients who underwent CD4 count and total lymphocyte count (TLC) testing were included for analysis. The severity of immunosuppression was graded based on WHO criteria. To establish optimum CD4 cutoff values, receiver-operator characteristics (ROC) curves were generated. RESULTS: Of 754 patients, 52.2% had CD4 counts <200 cells/mm3, but only 2.3% belonged to WHO stage IV. Newer CD4 cutoffs generated were 280, 120-280, <120 cells/mm3. Spearman rank correlation between CD4 counts and TLC was found to be weak (r = .32). CONCLUSION: The cutoff values of CD4 counts for HIV disease may need to be revised for India. Regular CD4 count estimation is a must for monitoring disease progression in people living with HIV/AIDS.

HIV-2 Infection: Where Are We Today?

CONTEXT: The choice of antiretroviral therapy for HIV-2 differs from that for HIV-1, underscoring the importance of differentiating between the two. AIMS: The current study was planned to find out the prevalence of HIV-2 infection at our center and to find out the utility of the current diagnostic algorithm in identifying the type of HIV infection. SETTING AND DESIGN: Retrospective analysis in a tertiary care teaching institute over a period of three years. MATERIALS AND METHODS: All patients diagnosed as HIV infected using NACO/WHO HIV testing strategy III were included in the study. They were classified as HIV-1 infected, HIV-2 infected and HIV-1 and HIV-2 co-infected based on their test results. For discordant samples, immunoblotting result from National Reference Laboratory was considered as final. STATISTICAL ANALYSIS USED: Comparison between HIV-1, HIV-2 and HIV-1+2 positive groups for age, gender, route of transmission was made using chi squared test. P value < 0.05 was considered as significant. RESULTS: Of the total of 66,708 patients tested, 5,238 (7.9%) were positive for HIV antibodies. 7.62%, 0.14%, 0.08% and 0.004% were HIV-1, HIV-2, HIV-1 and HIV-2 co-infected and HIV type indeterminate (HIV-1 Indeterminate, 2+) respectively. The current algorithm could not differentiate between the types of HIV infection (as HIV-1 or HIV-2) in 63 (1.2%) cases. CONCLUSION: In areas like the Indian subcontinent, where epidemic of both HIV-1 and HIV-2 infections are ongoing, it is important to modify the current diagnostic algorithms to diagnose and confirm HIV-2 infections.

Performance of immunological response in predicting virological failure.

In HIV-infected individuals on antiretroviral therapy (ART), the decision on when to switch from first-line to second-line therapy is dictated by treatment failure, and this can be measured in three ways: clinically, immunologically, and virologically. While viral load (VL) decreases and CD4 cell increases typically occur together after starting ART, discordant responses may be seen. Hence the current study was designed to determine the immunological and virological response to ART and to evaluate the utility of immunological response to predict virological failure. All treatment-naive HIV-positive individuals aged >18 years who were eligible for ART were enrolled and assessed at baseline, 6 months, and 12 months clinically and by CD4 cell count and viral load estimations. The patients were categorized as showing concordant favorable (CF), immunological only (IO), virological only (VO), and concordant unfavorable responses (CU). The efficiency of immunological failure to predict virological failure was analyzed across various levels of virological failure (VL>50, >500, and >5,000 copies/ml). At 6 months, 87(79.81%), 7(5.5%), 13 (11.92%), and 2 (1.83%) patients and at 12 months 61(69.3%), 9(10.2%), 16 (18.2%), and 2 (2.3%) patients had CF, IO, VO, and CU responses, respectively. Immunological failure criteria had a very low sensitivity (11.1-40%) and positive predictive value (8.3-25%) to predict virological failure. Immunological criteria do not accurately predict virological failure resulting in significant misclassification of therapeutic responses. There is an urgent need for inclusion of viral load testing in the initiation and monitoring of ART.