Last data update: Apr 18, 2025. (Total: 49119 publications since 2009)
Records 1-11 (of 11 Records) |
Query Trace: Nasr S[original query] |
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HIV risk behaviour, viraemia, and transmission across HIV cascade stages including low-level viremia: Analysis of 14 cross-sectional population-based HIV Impact Assessment surveys in sub-Saharan Africa
Edun O , Okell L , Chun H , Bissek AZ , Ndongmo CB , Shang JD , Brou H , Ehui E , Ekra AK , Nuwagaba-Biribonwoha H , Dlamini SS , Ginindza C , Eshetu F , Misganie YG , Desta SL , Achia TNO , Aoko A , Jonnalagadda S , Wafula R , Asiimwe FM , Lecher S , Nkanaunena K , Nyangulu MK , Nyirenda R , Beukes A , Klemens JO , Taffa N , Abutu AA , Alagi M , Charurat ME , Dalhatu I , Aliyu G , Kamanzi C , Nyagatare C , Rwibasira GN , Jalloh MF , Maokola WM , Mgomella GS , Kirungi WL , Mwangi C , Nel JA , Minchella PA , Gonese G , Nasr MA , Bodika S , Mungai E , Patel HK , Sleeman K , Milligan K , Dirlikov E , Voetsch AC , Shiraishi RW , Imai-Eaton JW . PLOS Glob Public Health 2024 4 (4) e0003030 As antiretroviral treatment (ART) coverage for people living with HIV (PLHIV) increases, HIV programmes require up-to-date information about evolving HIV risk behaviour and transmission risk, including those with low-level viremia (LLV; >50 to ≤1000 copies/mL), to guide prevention priorities. We aimed to assess differences in sexual risk behaviours, distribution of viral load (VL) and proportion of transmission across PLHIV subgroups. We analysed data from Population-based HIV Impact Assessment surveys in 14 sub-Saharan African countries during 2015-2019. We estimated adjusted prevalence ratios (aPR) of self-reported HIV high-risk behaviour (multiple partners and condomless sex) across cascade stages via generalised estimation equations. We modelled the proportions of transmission from each subgroup using relative self-reported sexual risk, a Hill function for transmission rate by VL, and proportions within cascade stages from surveys and UNAIDS country estimates for 2010-2020. Compared to PLHIV with undetectable VL (≤50 copies/mL), undiagnosed PLHIV (aPR women: 1.28 [95% CI: 1.08-1.52]; men: 1.61 [1.33-1.95]) and men diagnosed but untreated (2.06 [1.52-2.78]) were more likely to self-report high-risk sex. High-risk behaviour was not significantly associated with LLV. Mean VL was similar among undiagnosed, diagnosed but untreated, and on ART but non-suppressed sub-groups. Across surveys, undiagnosed and diagnosed but untreated contributed most to transmission (40-91% and 1-41%, respectively), with less than 1% from those with LLV. Between 2010 and 2020, the proportion of transmission from individuals on ART but non-suppressed increased. In settings with high ART coverage, effective HIV testing, ART linkage, and retention remain priorities to reduce HIV transmission. Persons with LLV are an increasing share of PLHIV but their contribution to HIV transmission was small. Improving suppression among PLHIV on ART with VL ≥1000 copies/mL will become increasingly important. |
Over-expression of miR-183-5p or miR-492 triggers invasion and proliferation and loss of polarity in non-neoplastic breast epithelium.
Naser Al Deen N , Atallah Lanman N , Chittiboyina S , Fostok S , Nasr R , Lelièvre S , Talhouk R . Sci Rep 2022 12 (1) 21974 ![]() microRNAs (miRNAs) serve as novel noninvasive cancer biomarkers. In an HMT-3522 S1 (S1) breast epithelial risk-progression three-dimensional (3D) culture model, non-neoplastic S1 cells form a fully polarized epithelium. When silenced for the gap junction and tumor suppressor Cx43, Cx43-KO-S1 cells recapitulate pre-neoplastic phenotypes observed in tissues at risk for breast cancer in vivo. To delineate the role of miRNAs in breast tumorigenesis and identify key miRNA players in breast epithelial polarity, the miRNA profile specific to Cx43 loss in Cx43-KO-S1 compared to S1 cells was sequenced, revealing 65 differentially expressed miRNAs. A comparative analysis was conducted between these miRNAs and tumor-associated miRNAs from a young Lebanese patient validation cohort. miR-183-5p, downstream of Cx43 loss, was commonly upregulated in the patient cohort and the 3D culture model. miR-492, not attributed to Cx43 loss, was only specifically up-regulated in the young Lebanese patients. Ectopic expression of either miR-183-5p or miR-492 in S1 cells, through pLenti-III-miR-GPF vectors, resulted in the formation of larger multi-layered acini devoid of lumen, with disrupted epithelial polarity, as shown by an altered localization of Cx43, ß-catenin and Scrib, and decreased nuclear circularity in 3D cultures. Enhanced proliferation and invasion capacity were also observed. Over-expression of miR-183-5p or miR-492, therefore, induces pre-neoplastic phenotypes similar to those reported upon Cx43 loss, and may act as oncomiRs and possible biomarkers of increased breast cancer risk. |
Assessing whether universal coverage with insecticide-treated nets has been achieved: is the right indicator being used
Koenker H , Arnold F , Ba F , Cisse M , Diouf L , Eckert E , Erskine M , Florey L , Fotheringham M , Gerberg L , Lengeler C , Lynch M , Mnzava A , Nasr S , Ndiop M , Poyer S , Renshaw M , Shargie E , Taylor C , Thwing J , Van Hulle S , Ye Y , Yukich J , Kilian A . Malar J 2018 17 (1) 355 BACKGROUND/METHODS: Insecticide-treated nets (ITNs) are the primary tool for malaria vector control in sub-Saharan Africa, and have been responsible for an estimated two-thirds of the reduction in the global burden of malaria in recent years. While the ultimate goal is high levels of ITN use to confer protection against infected mosquitoes, it is widely accepted that ITN use must be understood in the context of ITN availability. However, despite nearly a decade of universal coverage campaigns, no country has achieved a measured level of 80% of households owning 1 ITN for 2 people in a national survey. Eighty-six public datasets from 33 countries in sub-Saharan Africa (2005-2017) were used to explore the causes of failure to achieve universal coverage at the household level, understand the relationships between the various ITN indicators, and further define their respective programmatic utility. RESULTS: The proportion of households owning 1 ITN for 2 people did not exceed 60% at the national level in any survey, except in Uganda's 2014 Malaria Indicator Survey (MIS). At 80% population ITN access, the expected proportion of households with 1 ITN for 2 people is only 60% (p = 0.003 R(2) = 0.92), because individuals in households with some but not enough ITNs are captured as having access, but the household does not qualify as having 1 ITN for 2 people. Among households with 7-9 people, mean population ITN access was 41.0% (95% CI 36.5-45.6), whereas only 6.2% (95% CI 4.0-8.3) of these same households owned at least 1 ITN for 2 people. On average, 60% of the individual protection measured by the population access indicator is obscured when focus is put on the household "universal coverage" indicator. The practice of limiting households to a maximum number of ITNs in mass campaigns severely restricts the ability of large households to obtain enough ITNs for their entire family. CONCLUSIONS: The two household-level indicators-one representing minimal coverage, the other only 'universal' coverage-provide an incomplete and potentially misleading picture of personal protection and the success of an ITN distribution programme. Under current ITN distribution strategies, the global malaria community cannot expect countries to reach 80% of households owning 1 ITN for 2 people at a national level. When programmes assess the success of ITN distribution activities, population access to ITNs should be considered as the better indicator of "universal coverage," because it is based on people as the unit of analysis. |
Poliovirus excretion following vaccination with live poliovirus vaccine in patients with primary immunodeficiency disorders: clinicians' perspectives in the endgame plan for polio eradication
Galal NM , Meshaal S , ElHawary R , Nasr E , Bassiouni L , Ashghar H , Farag NH , Mach O , Burns C , Iber J , Chen Q , ElMarsafy A . BMC Res Notes 2018 11 (1) 717 OBJECTIVE: Primary immunodeficiency (PID) patients are prone to developing viral infections and should not be vaccinated with live vaccines. In such patients, prolonged excretion and viral divergence may occur and they may subsequently act as reservoirs in the community introducing mutated virus and jeopardizing polio eradication. One hundred and thirty PID cases were included for poliovirus detection in stool with assessment of divergence of detected polioviruses from oral polio vaccine (OPV) virus. Clinical presentations of PID patients with detectable poliovirus in stool specimens are described. RESULTS: Six PID patients (4.5%) had detectable vaccine-derived poliovirus (VDPV) excretion in stool specimens; of these, five patients had severe combined immunodeficiency (two with acute flaccid paralysis, one with meningoencephalitis and two without neurological manifestations), and one patient had X-linked agammaglobulinemia (paralysis developed shortly after diagnosis of immunodeficiency). All six case-patients received trivalent OPV. Five case-patients had type 2 immunodeficiency-related vaccine-derived polioviruses (iVDPV2) excretion; one had concomitant excretion of Sabin like type 3 virus and one was identified as iVDPV1 excretor. Surveillance for poliovirus excretion among PID patients is critical as these patients represent a potential source to reseed polioviruses into populations. |
Comparison of routine health management information system versus enhanced inpatient malaria surveillance for estimating the burden of malaria among children admitted to four hospitals in Uganda
Mpimbaza A , Miles M , Sserwanga A , Kigozi R , Wanzira H , Rubahika D , Nasr S , Kapella BK , Yoon SS , Chang M , Yeka A , Staedke SG , Kamya MR , Dorsey G . Am J Trop Med Hyg 2014 92 (1) 18-21 The primary source of malaria surveillance data in Uganda is the Health Management Information System (HMIS), which does not require laboratory confirmation of reported malaria cases. To improve data quality, an enhanced inpatient malaria surveillance system (EIMSS) was implemented with emphasis on malaria testing of all children admitted in select hospitals. Data were compared between the HMIS and the EIMSS at four hospitals over a period of 12 months. After the implementation of the EIMSS, over 96% of admitted children under 5 years of age underwent laboratory testing for malaria. The HMIS significantly overreported the proportion of children under 5 years of age admitted with malaria (average absolute difference = 19%, range = 8-27% across the four hospitals) compared with the EIMSS. To improve the quality of the HMIS data for malaria surveillance, the National Malaria Control Program should, in addition to increasing malaria testing rates, focus on linking laboratory test results to reported malaria cases. |
Long-lasting insecticide-treated bed net ownership and use among children under five years of age following a targeted distribution in central Uganda
Wanzira H , Yeka A , Kigozi R , Rubahika D , Nasr S , Sserwanga A , Kamya M , Filler S , Dorsey G , Steinhardt L . Malar J 2014 13 (1) 185 BACKGROUND: Universal coverage of long-lasting insecticide-treated bed nets (LLINs) for prevention of malaria was adopted by the Uganda National Malaria Control Programme in 2007. The first mass distribution of LLINs was implemented in 2010. Initially, a campaign targeted to households with pregnant women and children aged <five years was carried out, prior to a planned fill-in campaign to achieve universal LLIN coverage. This survey was conducted after the targeted distribution in central Uganda to assess progress in LLIN ownership and usage among children <five years. METHODS: A two-stage, cluster-sample, cross-sectional household survey was carried out in early 2011 in Central region districts surveyed during the 2009 Malaria Indicator Survey (MIS). In the first sampling stage, 30 enumeration areas (EAs) were selected and all households were enumerated. Within each sampled EA, 20 households were randomly selected for interview using two questionnaires: a household questionnaire and a woman's questionnaire for all women aged 15-49 years, both modified from the MIS. RESULTS: When compared to 2009 MIS results, household ownership of at least one LLIN increased by 47%, from 22 to 69% after the targeted campaign. LLIN use among children <five years increased by 40%, from 11 to 51%. Households with a child <six years old at the time of the survey, a proxy for those targeted, were significantly more likely to have received a campaign bed net (80.7 vs 35.2%, p < 0.001). LLIN ownership and use was equitable after the targeted campaign, with no significant differences by household wealth status. However, the proportion of households with at least one LLIN per two people was still low after the first campaign phase, increasing from 8.5 to 25.9%. CONCLUSIONS: The first phase of the campaign led to substantial increases in both LLIN ownership and equitable use among children <five years in the Central region. However, access to an LLIN within the household was still low after the first phase of the campaign, indicating the need for the universal fill-in campaign. |
The effect of indoor residual spraying on malaria and anemia in a high-transmission area of northern Uganda
Steinhardt LC , Yeka A , Nasr S , Wiegand RE , Rubahika D , Sserwanga A , Wanzira H , Lavoy G , Kamya M , Dorsey G , Filler S . Am J Trop Med Hyg 2013 88 (5) 855-61 Indoor residual spraying (IRS) with insecticide is now recommended for malaria control in high-transmission settings. However, concerns about insecticide resistance have increased. We conducted a cross-sectional household survey in high-transmission northern Uganda in two districts previously sprayed with pyrethroids before documentation of pyrethroid resistance and at least one round of carbamates and one contiguous district that was not sprayed. Parasitemia prevalence among children < 5 years of age was lower in the two IRS districts compared with the non-sprayed district: 37.0% and 16.7% versus 49.8%, P < 0.001. Anemia prevalence was also significantly lower in the two IRS districts: 38.8% and 36.8% versus 53.0%, P < 0.001. Multivariable Poisson regression models indicated that a child living in a sprayed district had a 45% and 32% lower risk of parasitemia and anemia, respectively, than a child in a non-sprayed district (P < 0.001). Carefully managed IRS can significantly reduce malaria burden in high-transmission settings. |
Indoor residual spraying of insecticide and malaria morbidity in a high transmission intensity area of Uganda
Kigozi R , Baxi SM , Gasasira A , Sserwanga A , Kakeeto S , Nasr S , Rubahika D , Dissanayake G , Kamya MR , Filler S , Dorsey G . PLoS One 2012 7 (8) e42857 BACKGROUND: Recently the use of indoor residual spraying of insecticide (IRS) has greatly increased in Africa; however, limited data exist on the quantitative impacts of IRS on health outcomes in highly malaria endemic areas. METHODOLOGY/PRINCIPAL FINDINGS: Routine data were collected on more than 90,000 patient visits at a single health facility over a 56 month period covering five rounds of IRS using three different insecticides. Temporal associations between the timing of IRS and the probability of a patient referred for microscopy having laboratory confirmed malaria were estimated controlling for seasonality and age. Considering patients less than five years of age there was a modest decrease in the odds of malaria following the 1(st) round of IRS using DDT (OR = 0.76, p<0.001) and the 2(nd) round using alpha-cypermethrin (OR = 0.83, p = 0.002). Following rounds 3-5 using bendiocarb there was a much greater decrease in the odds of malaria (ORs 0.34, 0.16, 0.17 respectively, p<0.001 for all comparisons). Overall, the impact of IRS was less pronounced among patients 5 years or older. CONCLUSIONS/SIGNIFICANCE: IRS was associated with a reduction in malaria morbidity in an area of high transmission intensity in Uganda and the benefits appeared to be greatest after switching to a carbamate class of insecticide. |
Evaluation of a comprehensive refresher training program in malaria microscopy covering four districts of Uganda
Kiggundu M , Nsobya SL , Kamya MR , Filler S , Nasr S , Dorsey G , Yeka A . Am J Trop Med Hyg 2011 84 (5) 820-4 Microscopy remains the gold standard for malaria diagnosis. However, quality microscopy services are severely lacking in most African countries. To improve capacity for malaria microscopy in Uganda, a 3-day refresher training program was conducted in four districts. Training impact was measured through a written examination and evaluation of the quality of blood-slide preparation and accuracy of field microscopy. A total of 184 of 192 (96%) identified laboratory personnel participated in the training. Average test scores improved from 41% to 75% (P < 0.001). A total of 1,079 and 1,190 routinely made thick blood smears were collected before and after the training, respectively. Sensitivity improved from 84% to 95% (P < 0.001), and specificity improved from 87% to 97% (P < 0.001). The proportion of well-prepared blood smears improved from 6% to 75% (P < 0.001). Supplemental training can have a significant impact on the knowledge of staff, accuracy of microscopy, and quality of blood-slide preparation. |
Improved malaria case management through the implementation of a health facility-based sentinel site surveillance system in Uganda
Sserwanga A , Harris JC , Kigozi R , Menon M , Bukirwa H , Gasasira A , Kakeeto S , Kizito F , Quinto E , Rubahika D , Nasr S , Filler S , Kamya MR , Dorsey G . PLoS One 2011 6 (1) e16316 BACKGROUND: Heath facility-based sentinel site surveillance has been proposed as a means of monitoring trends in malaria morbidity but may also provide an opportunity to improve malaria case management. Here we described the impact of a sentinel site malaria surveillance system on promoting laboratory testing and rational antimalarial drug use. METHODOLOGY/PRINCIPAL FINDINGS: Sentinel site malaria surveillance was established at six health facilities in Uganda between September 2006 and January 2007. Data were collected from all patients presenting to the outpatient departments including demographics, laboratory results, diagnoses, and treatments prescribed. Between the start of surveillance and March 2010, a total 424,701 patients were seen of which 229,375 (54%) were suspected of having malaria. Comparing the first three months with the last three months of surveillance, the proportion of patients with suspected malaria who underwent diagnostic testing increased from 39% to 97% (p<0.001). The proportion of patients with an appropriate decision to prescribe antimalarial therapy (positive test result prescribed, negative test result not prescribed) increased from 64% to 95% (p<0.001). The proportion of patients appropriately prescribed antimalarial therapy who were prescribed the recommended first-line regimen artemether-lumefantrine increased from 48% to 69% (p<0.001). CONCLUSIONS/SIGNIFICANCE: The establishment of a sentinel site malaria surveillance system in Uganda achieved almost universal utilization of diagnostic testing in patients with suspected malaria and appropriate decisions to prescribed antimalarial based on test results. Less success was achieved in promoting prescribing practice for the recommended first-line therapy. This system could provide a model for improving malaria case management in other health facilities in Africa. |
Variation in immunoreactive trypsinogen concentrations among Michigan newborns and implications for cystic fibrosis newborn screening
Korzeniewski SJ , Young WI , Hawkins HC , Cavanagh K , Nasr SZ , Langbo C , Teneyck KR , Grosse SD , Kleyn M , Grigorescu V . Pediatr Pulmonol 2011 46 (2) 125-30 OBJECTIVE: To investigate variation in immunoreactive trypsinogen (IRT) concentrations by race, sex, birth weight, and gestational age and their implications for the use of percentile-based cutoffs for cystic fibrosis (CF) newborn screening (NBS) programs. PATIENTS AND METHODS: This cross-sectional population-based study of resident infants screened in Michigan investigates associations between demographic and perinatal variables and IRT concentrations after controlling for covariates. This study also analyzed how 96th and 99.8th IRT concentration percentiles values calculated by Michigan NBS vary by demographic and perinatal factors. Characteristics of infants having high (≥99.8th percentile) IRT concentrations and negative DNA tests are also explored. RESULTS: IRT mean concentrations and percentiles vary significantly by race, birth weight, gestational age, and to a lesser degree by sex. The greatest variation in mean IRT concentrations was observed among racial categories; black infants had an adjusted mean concentration of 36 ng/ml and Asian/Pacific Islander infants had a mean concentration of 25 ng/ml compared to an average concentration of 28 ng/ml in white infants and infants of other races. CONCLUSIONS: Variation in IRT concentrations resulted in the over-representation of certain groups referred for secondary testing, particularly referrals for sweat testing based on very high (≥99.8th percentile) concentrations alone, which is no longer recommended in Michigan. Further research may be warranted to evaluate initial IRT cutoffs used for CF NBS. |
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