The Uptake of Integrated Perinatal Prevention of Mother-to-Child HIV Transmission Programs in Low- and Middle-Income Countries: A Systematic Review

BACKGROUND: The objective of this review was to assess the uptake of WHO recommended integrated perinatal prevention of mother-to-child transmission (PMTCT) of HIV interventions in low- and middle-income countries. METHODS AND FINDINGS: We searched 21 databases for observational studies presenting uptake of integrated PMTCT programs in low- and middle-income countries. Forty-one studies on programs implemented between 1997 and 2006, met inclusion criteria. The proportion of women attending antenatal care who were counseled and who were tested was high; 96% (range 30-100%) and 81% (range 26-100%), respectively. However, the overall median proportion of HIV positive women provided with antiretroviral prophylaxis in antenatal care and attending labor ward was 55% (range 22-99%) and 60% (range 19-100%), respectively. The proportion of women with unknown HIV status, tested for HIV at labor ward was 70%. Overall, 79% (range 44-100%) of infants were tested for HIV and 11% (range 3-18%) of them were HIV positive. We designed two PMTCT cascades using studies with outcomes for all perinatal PMTCT interventions which showed that an estimated 22% of all HIV positive women attending antenatal care and 11% of all HIV positive women delivering at labor ward were not notified about their HIV status and did not participate in PMTCT program. Only 17% of HIV positive antenatal care attendees and their infants are known to have taken antiretroviral prophylaxis. CONCLUSION: The existing evidence provides information only about the initial PMTCT programs which were based on the old WHO PMTCT guidelines. The uptake of counseling and HIV testing among pregnant women attending antenatal care was high, but their retention in PMTCT programs was low. The majority of women in the included studies did not receive ARV prophylaxis in antenatal care; nor did they attend labor ward. More studies evaluating the uptake in current PMTCT programs are urgently needed

The use of dried blood spots on filter paper for the diagnosis of HIV-1 in infants born to HIV seropositive women

Polymerase chain reaction (PCR) is the most sensitive test to diagnose HIV-1 infection among infants born to HIV seropositive mothers. The purpose of this study was to evaluate the use of dried blood spot (DBS) specimens for PCR and to compare it with whole-blood stored in tubes for HIV-1 DNA PCR. Five hundred and seventy-seven whole-blood infant samples were tested using HIV-1 qualitative in-house nested DNA PCR. Three hundred and fifty-nine samples were from infants at 48 hours of birth and 218 samples at second month. All positive samples tested from whole-blood and every fifth negative sample were coated onto filter paper. DNA was extracted from the filter paper and was amplified using in-house nested PCR. Among the whole-blood samples tested using HIV-1 DNA PCR, 19 of 359 (5.29%) samples were HIV-1 positive and 340 (94.7%) were negative at 48 hours of birth. At second month, 19 (8.7%) of the 218 samples were positive and 199 (91.2%) were negative. Using dried filter paper, 18 samples (95%) tested positive from 19 positive samples (using whole-blood) and 1 tested negative at 48 hours of birth. The 68 negative samples tested using whole-blood were also negative in the DBS test (sensitivity 95% and specificity 100%). At second month, 19 were positive and 40 samples (every fifth sample of 199) were negative (sensitivity and specificity, 100%). PCR performed using DNA extracted from filter paper permits the diagnosis of HIV-1 infection among infants born to HIV-1 seropositive mothers. This assay is simple, rapid, sensitive and specific and can be used in resource limited settings

Detection of HIV drug resistance mutations in pregnant women receiving single dose Nevirapine in south India

Background: Single dose of Nevirapine to prevent mother to child transmission of HIV is the commonest preventive regimen in resource-limited countries. Objectives: The objective of this study was to detect drug-resistant virus after single dose of Nevirapine (sdNVP) provided to delivering HIV seropositive (HIV+ve) women and to evaluate the time taken for its decay. Results: Of the 36 consenting HIV+ve pregnant women enrolled into the study, the mean hemoglobin and total lymphocyte counts were 10.8 g/dl and 1843 cells/mm 3 , respectively. Mean CD4 counts in 64% of women was 363 cells/mm 3 and mean viral load for 16/36 women was 28,143 copies/ml of plasma. Nevirapine-resistance mutations were detected in 28% of women at delivery; using OLA (Oligonucleotide Ligation Assay). K103N mutations were seen in 19.4% of women while the Y181C mutation was seen in 5%. Both the mutations were detected in 2.7% of women. Sequential blood samples collected at delivery, 7-10 days, 6 weeks, 4 months, 6 months and one year postpartum showed that 81% of K103N mutations and 66.7% of Y181C mutations were detected at 6 weeks postpartum . Wild-type virus had replaced the mutants by one year postpartum in all women except one. Conclusion : These observations are relevant for future treatment with antiretroviral therapy in these women for their HIV disease

Study on performance of cabbage (Brassica oleraceae var. capitata L.) under different production systems

Coimbatore is located in the western part of Tamil Nadu and nestled against the foothills of the Western Ghats. This region's cool climate and favourable terrain make it ideal for cultivating hill vegetables. Cabbage (Brassica oleracea var. capitata L.) is a significant cole crop known for its high nutritional value. Excessive chemical usage in cabbage cultivation leads to residual effects on soil and produce. This study aimed to identify the best production system for cabbage cultivation in the northwestern parts of Tamil Nadu. An experiment was conducted during the winter season of 2023-2024 at the Tamil Nadu Agricultural University, Coimbatore. The experiment was laid out in a randomized block design (RBD) with four treatments and five replications. The organic farming system exhibited the highest values for plant height (21.47 cm), stalk length (8.49 cm), dry matter accumulation (71.34 g per plant), days to head formation (18.75 days), days to harvest (56.25 days), head diameter (17.70 cm), head compactness (33.91), head weight (945.35 g per plant) and cabbage yield (24.92 t ha-1), surpassing both conventional and natural farming systems. A similar pattern was observed in quality parameters, including TSS (6.54 °Brix), shelf life (12.21 days) and ascorbic acid content (44.26 mg per 100 g). This study highlights an efficient cabbage cultivation system in the Coimbatore region, leading to improved yield, soil health and quality

Controlled and Selective Area Growth of Monolayer Graphene on 4H-SiC Substrate by Electron-Beam-Assisted Rapid Heating

A facile method for direct and selective area conversion of 4H-SiC substrates into homogeneous epitaxial graphene is demonstrated by the irradiation of a low energy (5 keV) electron beam (e-beam). The localized interactions like scattering, excitation, and ionization between the primary electrons and the SiC surface result in Si–C bond breaking, and the excess kinetic energy of electrons is dissipated as heat that results in the selective sublimation of the Si ion favoring the formation of epitaxial graphene. The thickness of the graphene layer is precisely controlled by varying the e-beam energy and the irradiation time. The number of graphene layers increases with irradiation due to thermally induced Si sublimation over the depth of a few atomic layers depending on the incident energy of the e-beam. The Hall mobility of large area single layer graphene formed on the Si-face is ∼6450 cm²V^–1s^–1 with a surface carrier density (n-type) of 1.5 × 10¹³ cm^–2. Our results demonstrate that the e-beam irradiation technique is a viable route to define wafer scalable selective area graphene structures directly on semi-insulating 4H-SiC substrates for electronic applications