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1.
Sensors (Basel) ; 23(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36850599

RESUMO

A detachable miniaturized three-element spirals radiator button antenna integrated with a compact leaky-wave wearable antenna forming a dual-band three-port antenna is proposed. The leaky-wave antenna is fabricated on a denim (εr = 1.6, tan δ = 0.006) textile substrate with dimensions of 0.37 λ0 × 0.25 λ0 × 0.01 λ0 mm3 and a detachable rigid button of 20 mm diameter (on a PTFE substrate εr = 2.01, tan δ = 0.001). It augments users' comfort, making it one of the smallest to date in the literature. The designed antenna, with 3.25 to 3.65 GHz and 5.4 to 5.85 GHz operational bands, covers the wireless local area network (WLAN) frequency (5.1-5.5 GHz), the fifth-generation (5G) communication band. Low mutual coupling between the ports and the button antenna elements ensures high diversity performance. The performance of the specific absorption rate (SAR) and the envelope correlation coefficient (ECC) are also examined. The simulation and measurement findings agree well. Low SAR, <-0.05 of LCC, more than 9.5 dBi diversity gain, dual polarization, and strong isolation between every two ports all point to the proposed antenna being an ideal option for use as a MIMO antenna for communications.

2.
Sensors (Basel) ; 23(6)2023 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-36991769

RESUMO

This article proposes the design, fabrication and measurement of a triple-rings complementary split-ring resonator (CSRR) microwave sensor for semi-solid material detection. The triple-rings CSRR sensor was developed based on the CSRR configuration with curve-feed designed together, utilizing a high-frequency structure simulator (HFSS) microwave studio. The designed triple rings CSRR sensor resonates at 2.5 GHz, performs in transmission mode, and senses shift in frequency. Six cases of the sample under tests (SUTs) were simulated and measured. These SUTs are Air (without SUT), Java turmeric, Mango ginger, Black Turmeric, Turmeric, and Di-water, and detailed sensitivity analysis is conducted for the frequency resonant at 2.5 GHz. The semi-solid tested mechanism is undertaken using a polypropylene (PP) tube. The samples of dielectric material are filled into PP tube channels and loaded in the CSRR centre hole. The e-fields near the resonator will affect the interaction with the SUTs. The finalized CSRR triple-rings sensor was incorporated with defective ground structure (DGS) to deliver high-performance characteristics in microstrip circuits, leading to a high Q-factor magnitude. The suggested sensor has a Q-factor of 520 at 2.5 GHz with high sensitivity of about 4.806 and 4.773 for Di-water and Turmeric samples, respectively. The relationship between loss tangent, permittivity, and Q-factor at the resonant frequency has been compared and discussed. These given outcomes make the presented sensor ideal for detecting semi-solid materials.

3.
Sensors (Basel) ; 23(21)2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37960695

RESUMO

In this paper, a low-cost resin-coated commercial-photo-paper substrate is used to design a printed reconfigurable multiband antenna. The two PIN diodes are used mainly to redistribute the surface current that provides reconfigurable properties to the proposed antenna. The antenna size of 40 mm × 40 mm × 0.44 mm with a partial ground, covers wireless and mobile bands ranging from 1.91 GHz to 6.75 GHz. The parametric analysis is performed to achieve optimized design parameters of the antenna. The U-shaped and C-shaped emitters are meant to function at 2.4 GHz and 5.9 GHz, respectively, while the primary emitter is designed to operate at 3.5 GHz. The proposed antenna achieved peak gain and radiation efficiency of 3.4 dBi and 90%, respectively. Simulated and measured results of the reflection coefficient, radiation pattern, gain, and efficiency show that the antenna design is in favorable agreement. Since the proposed antenna achieved wideband (1.91-6.75 GHz) using PIN diode configuration, using this technique the need for numerous electronic components to provide multiband frequency is avoided.

4.
Sensors (Basel) ; 23(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37896656

RESUMO

This article presents a quad-element MIMO antenna designed for multiband operation. The prototype of the design is fabricated and utilizes a vector network analyzer (VNA-AV3672D) to measure the S-parameters. The proposed antenna is capable of operating across three broad frequency bands: 3-15.5 GHz, encompassing the C band (4-8 GHz), X band (8-12.4 GHz), and a significant portion of the Ku band (12.4-15.5 GHz). Additionally, it covers two mm-wave bands, specifically 26.4-34.3 GHz and 36.1-48.9 GHz, which corresponds to 86% of the Ka-band (27-40 GHz). To enhance its performance, the design incorporates a partial ground plane and a top patch featuring a dual-sided reverse 3-stage stair and a straight stick symmetrically placed at the bottom. The introduction of a defected ground structure (DGS) on the ground plane serves to provide a wideband response. The DGS on the ground plane plays a crucial role in improving the electromagnetic interaction between the grounding surface and the top patch, contributing to the wideband characteristics of the antenna. The dimensions of the proposed MIMO antenna are 31.7 mm × 31.7 mm × 1.6 mm. Furthermore, the article delves into the assessment of various performance metrics related to antenna diversity, such as ECC, DG, TARC, MEG, CCL, and channel capacity, with corresponding values of 0.11, 8.87 dB, -6.6 dB, ±3 dB, 0.32 bits/sec/Hz, and 18.44 bits/sec/Hz, respectively. Additionally, the equivalent circuit analysis of the MIMO system is explored in the article. It's worth noting that the measured results exhibit a strong level of agreement with the simulated results, indicating the reliability of the proposed design. The MIMO antenna's ability to exhibit multiband response, good diversity performance, and consistent channel capacity across various frequency bands renders it highly suitable for integration into multi-band wireless devices. The developed MIMO system should be applicable on n77/n78/n79 5G NR (3.3-5 GHz); WLAN (4.9-5.725 GHz); Wi-Fi (5.15-5.85 GHz); LTE5537.5 (5.15-5.925 GHz); WiMAX (5.25-5.85 GHz); WLAN (5.725-5.875 GHz); long-distance radio telecommunication (4-8 GHz; C-band); satellite, radar, space communications and terrestrial broadband (8-12 GHz; X-band); and various satellite communications (27-40 GHz; Ka-band).

5.
J Food Sci Technol ; 60(2): 692-700, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36712214

RESUMO

This study aimed to evaluate the effect of the pH levels (5.8, 6.0, 6.2, and 6.4) on analogue pizza cheese (APC) rheological and physical characteristics. The APC formulation included 25% vegetable oil and 18.5% rennet casein. The APC samples were made using a Thermomix device and the cheese was stored at + 5 °C for 5 days before it was transferred to - 18 °C. Rotational rheometer measurements showed that all samples followed Herchel-Buckley viscoplastic Model with a different yield stress, highest apparent viscosity, and shear stress values were obtained at pH 6.4 followed by pH 6.2; then the values were dropped by 70%. Melting and stretching showed the best characteristics for the APC sample at pH 6.4, whereas at pH 6.0 stretching values decreased by 77%. The APC samples at pH ≥ 6.2 showed better stability after 6 months of frozen storage in the apparent viscosity than other cheeses. This study concluded that better rheological and physical properties were obtained for the APC at pH ≥ 6.20 and that significant variation for the rheological behavior of the APC can be based on the pH alone, as a slight alteration in the pH was found to affect product quality and acceptability.

6.
MMWR Morb Mortal Wkly Rep ; 71(15): 538-544, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35421079

RESUMO

Since the Global Polio Eradication Initiative (GPEI) was established in 1988, the number of reported poliomyelitis cases worldwide has declined by approximately 99.99%. By the end of 2021, wild poliovirus (WPV) remained endemic in only two countries (Pakistan and Afghanistan). However, a WPV type 1 (WPV1) case with paralysis onset in 2021, was reported by Malawi a year after the World Health Organization (WHO) African Region (AFR) was certified as WPV-free and circulating vaccine-derived poliovirus (cVDPV) cases were reported from 31 countries during 2020-2021 (1,2). cVDPVs are oral poliovirus vaccine-derived viruses that can emerge after prolonged circulation in populations with low immunity and cause paralysis. The primary means of detecting poliovirus transmission is through surveillance for acute flaccid paralysis (AFP) among persons aged <15 years, with confirmation through stool specimen testing by WHO-accredited laboratories, supplemented by systematic sampling of sewage and testing for the presence of poliovirus (environmental surveillance). The COVID-19 pandemic caused disruptions in polio vaccination and surveillance activities across WHO regions in 2020; during January-September 2020, the number of reported cases of AFP declined and the interval between stool collection and receipt by laboratories increased compared with the same period in 2019 (3). This report summarizes surveillance performance indicators for 2020 and 2021 in 43 priority countries* and updates previous reports (4). In 2021, a total of 32 (74%) priority countries† met two key surveillance performance indicator targets nationally, an improvement from 2020 when only 23 (53%) met both targets; however, substantial national and subnational gaps persist. High-performing poliovirus surveillance is critical to tracking poliovirus transmission. Frequent monitoring of surveillance indicators could help identify gaps, guide improvements, and enhance the overall sensitivity and timelines of poliovirus detection to successfully achieve polio eradication.


Assuntos
COVID-19 , Poliomielite , Poliovirus , Humanos , Erradicação de Doenças , Saúde Global , Programas de Imunização , Pandemias , Paralisia/epidemiologia , Poliomielite/diagnóstico , Poliomielite/epidemiologia , Poliomielite/prevenção & controle , Vacina Antipólio Oral , Vigilância da População
7.
Sensors (Basel) ; 22(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36298362

RESUMO

A printed monopole antenna for millimeter-wave applications in the 5G frequency region is described in this research. As a result, the proposed antenna resonates in three frequency bands that are designated for 5G communication systems, including 28 GHz, 38 GHz, and 60 GHz (V band). For the sake of compactness, the coplanar waveguide (CPW) method is used. The overall size of the proposed tri-band antenna is 4 mm × 3 mm × 0.25 mm. Using a watch strap and human tissue, such as skin, the proposed antenna gives steady results. At 28 GHz, 38 GHz, and 60 GHz, the antenna's gain is found to be 5.29 dB, 7.47 dB, and 9 dB, respectively. The overall simulated radiation efficiency is found to be 85% over the watch strap. Wearable devices are a great fit for the proposed tri-band antenna. The antenna prototype was built and tested in order to verify its performance. It can be observed that the simulated and measured results are in close contact. According to our comparative research, the proposed antenna is a good choice for smart 5G devices because of its small size and simple structure, as well as its high gain and radiation efficiency.


Assuntos
Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio , Humanos , Desenho de Equipamento , Registros
8.
MMWR Morb Mortal Wkly Rep ; 70(18): 667-673, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33956779

RESUMO

When the Global Polio Eradication Initiative (GPEI) was established in 1988, an estimated 350,000 poliomyelitis cases were reported worldwide. In 2020, 140 wild poliovirus (WPV) cases were confirmed, representing a 99.99% reduction since 1988. WPV type 1 transmission remains endemic in only two countries (Pakistan and Afghanistan), but outbreaks of circulating vaccine-derived poliovirus (cVDPV) occurred in 33 countries during 2019-2020 (1,2). Poliovirus transmission is detected primarily through syndromic surveillance for acute flaccid paralysis (AFP) among children aged <15 years, with confirmation by laboratory testing of stool specimens. Environmental surveillance supplements AFP surveillance and plays an increasingly important role in detecting poliovirus transmission. Within 2 weeks of COVID-19 being declared a global pandemic (3), GPEI recommended continuing surveillance activities with caution and paused all polio supplementary immunization activities (4). This report summarizes surveillance performance indicators for 2019 and 2020 in 42 priority countries at high risk for poliovirus transmission and updates previous reports (5). In 2020, 48% of priority countries* in the African Region, 90% in the Eastern Mediterranean Region, and 40% in other regions met AFP surveillance performance indicators nationally. The number of priority countries rose from 40 in 2019 to 42 in 2020.† Analysis of 2019-2020 AFP surveillance data from 42 countries at high risk for poliovirus transmission indicates that national and subnational nonpolio AFP rates and stool specimen adequacy declined in many priority countries, particularly in the African Region, suggesting a decline in surveillance sensitivity and quality. The findings in this report can be used to guide improvements to restore a sensitive surveillance system that can track poliovirus transmission and provide evidence of interruption of transmission.


Assuntos
Erradicação de Doenças , Saúde Global/estatística & dados numéricos , Poliomielite/prevenção & controle , Vigilância da População , Humanos , Poliomielite/epidemiologia
9.
MMWR Morb Mortal Wkly Rep ; 69(5152): 1648-1652, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33382673

RESUMO

On January 30, 2020, the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a Public Health Emergency of International Concern (1). On March 24, 2020, the Global Polio Eradication Initiative (GPEI) suspended all polio supplementary immunization activities and recommended the continuation of polio surveillance (2). In April 2020, GPEI shared revised polio surveillance guidelines in the context of the COVID-19 pandemic, which focused on reducing the risk for transmission of SARS-CoV-2, the virus that causes COVID-19, to health care workers and communities by modifying activities that required person-to-person contact, improving hand hygiene and personal protective equipment use practices, and overcoming challenges related to movement restrictions, while continuing essential polio surveillance functions (3). GPEI assessed the impact of the COVID-19 pandemic on polio surveillance by comparing data from January to September 2019 to the same period in 2020. Globally, the number of acute flaccid paralysis (AFP) cases reported declined 33% and the mean number of days between the second stool collected and receipt by the laboratory increased by 70%. Continued analysis of AFP case reporting and stool collection is critical to ensure timely detection and response to interruptions of polio surveillance.


Assuntos
COVID-19 , Saúde Global , Poliomielite/epidemiologia , Vigilância da População , Técnicas de Laboratório Clínico/estatística & dados numéricos , Erradicação de Doenças , Fezes/virologia , Humanos , Poliomielite/prevenção & controle , Poliovirus/isolamento & purificação , Vacinas contra Poliovirus/administração & dosagem
10.
Monaldi Arch Chest Dis ; 92(3)2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873901

RESUMO

To determine association of clinico-radiological factors and radiological activity with diagnostic yield in sputum-smear negative tuberculosis (TB). Prospective observational study in the Military Hospital Rawalpindi (Pakistan) from July to December 2018. Adult patients having no contraindications to bronchoscopy were included. HIV positive patients and those on anti-tuberculosis therapy for more than one week were excluded. High-resolution computed tomography (HRCT) findings were classified based on active and inactive tuberculosis features. Washings were sent for acid-fast bacillus (AFB) smear, GeneXpert assay and cultures. Out of 215 patients, 42.3% (91) were diagnosed with microbiological or histological evidence of TB. On univariate analysis, cavitation (p-value <0.001), soft-tissue nodules (p-value 0.04), and endobronchial mucosal changes (p-value 0.02) were associated with culture positivity. Presence of cavitation (OR= 4.10; CI= 2.18,7.73; p-value<0.001) was the only independent predictor of microbiological yield. Diagnostic yield was 70%, 50%, 12.5% and 8.6% in patients with definitely active, probably active, indeterminate and inactive tuberculosis HRCT features respectively. Sensitivity, specificity, positive predictive value and negative predictive value of HRCT active TB were 95.38% (95% CI 87.10-99.04), 48.00 % (95% CI 39.78-56.30), 44.29% (95% CI 40.31-48.33), 96.00 % (95%CI 88.70-98.66) respectively. There was no significant association between age groups, smoking status and gender with diagnosis of tuberculosis in our study. Radiological activity and certain visualized bronchoscopic changes were associated with good diagnostic performance and can be used as predictive factors in diagnosis of active smear negative tuberculosis.


Assuntos
Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Adulto , Humanos , Paquistão/epidemiologia , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose Pulmonar/diagnóstico por imagem , Tuberculose Pulmonar/epidemiologia
11.
MMWR Morb Mortal Wkly Rep ; 69(20): 623-629, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32437342

RESUMO

Since the Global Polio Eradication Initiative (GPEI) was launched in 1988, the number of polio cases worldwide has declined approximately 99.99%; only two countries (Afghanistan and Pakistan) have never interrupted wild poliovirus (WPV) transmission (1). The primary means of detecting poliovirus circulation is through surveillance for acute flaccid paralysis (AFP) among children aged <15 years with testing of stool specimens for WPV and vaccine-derived polioviruses (VDPVs) (genetically reverted strains of the vaccine virus that regain neurovirulence) in World Health Organization (WHO)-accredited laboratories (2,3). In many locations, AFP surveillance is supplemented by environmental surveillance, the regular collection and testing of sewage to provide awareness of the extent and duration of poliovirus circulation (3). This report presents 2018-2019 poliovirus surveillance data, focusing on 40 priority countries* with WPV or VDPV outbreaks or at high risk for importation because of their proximity to a country with an outbreak. The number of priority countries rose from 31 in 2018 to 40 in 2019 because of a substantial increase in the number of VDPV outbreaks† (2,4). In areas with low poliovirus immunity, VDPVs can circulate in the community and cause outbreaks of paralysis; these are known as circulating vaccine derived polioviruses (cVDPVs) (4). In 2019, only 25 (63%) of the 40 designated priority countries met AFP surveillance indicators nationally; subnational surveillance performance varied widely and indicated focal weaknesses. High quality, sensitive surveillance is important to ensure timely detection and response to cVDPV and WPV transmission.


Assuntos
Erradicação de Doenças , Saúde Global/estatística & dados numéricos , Poliomielite/prevenção & controle , Vigilância da População , Monitoramento Ambiental , Humanos , Laboratórios , Paralisia/epidemiologia , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação
12.
J Med Virol ; 91(3): 385-391, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30242854

RESUMO

Human adenoviruses (HAdVs) were previously detected at high prevalence by real-time reverse transcription-polymerase chain reaction (rRT-PCR) in the upper respiratory tract of residents of two Kenyan refugee camps under surveillance for acute respiratory infection (ARI) between October 2006 and April 2008. We sought to confirm this finding and characterize the HAdVs detected. Of 2148 respiratory specimens originally tested, 511 (23.8%) screened positive for HAdV and 510 were available for retesting. Of these, 421 (82.4%) were confirmed positive by repeat rRT-PCR or PCR and sequencing. Other respiratory viruses were codetected in 55.8% of confirmed HAdV-positive specimens. Species B and C viruses predominated at 82.8%, and HAdV-C1, -C2, and -B3 were the most commonly identified types. Species A, D, and F HAdVs, which are rarely associated with ARI, comprised the remainder. Viral loads were highest among species B HAdVs, particularly HAdV-B3. Species C showed the widest range of viral loads, and species A, D, and F were most often present at low loads and more often with codetections. These findings suggest that many HAdV detections were incidental and not a primary cause of ARI among camp patients. Species/type, codetections, and viral load determinations may permit more accurate HAdV disease burden estimates in these populations.


Assuntos
Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/isolamento & purificação , Refugiados , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/classificação , Adolescente , Adulto , Criança , Pré-Escolar , Coinfecção/epidemiologia , Coinfecção/virologia , Feminino , Genótipo , Humanos , Lactente , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Filogenia , Prevalência , Vigilância de Evento Sentinela , Análise de Sequência de DNA , Carga Viral , Adulto Jovem
13.
MMWR Morb Mortal Wkly Rep ; 68(13): 312-318, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-30946737

RESUMO

When the Global Polio Eradication Initiative (GPEI) began in 1988, cases of poliomyelitis were reported from 125 countries. Since then, only Afghanistan, Nigeria, and Pakistan have experienced uninterrupted transmission of wild poliovirus (WPV). The primary means of detecting poliovirus is through surveillance for acute flaccid paralysis (AFP) among children aged <15 years with testing of stool specimens for WPV and vaccine-derived polioviruses (VDPVs) in World Health Organization (WHO)-accredited laboratories of the Global Polio Laboratory Network (GPLN) (1,2). AFP surveillance is supplemented by environmental surveillance for polioviruses in sewage at selected locations. Analysis of genomic sequences of isolated polioviruses enables assessment of transmission by time and place, potential gaps in surveillance, and emergence of VDPVs (3). This report presents 2017-2018 poliovirus surveillance data, focusing on 31 countries* identified as high-priority countries because of a "high risk of poliovirus transmission and limited capacity to adequately address those risks" (4). Some of these countries are located within WHO regions with endemic polio, and others are in regions that are polio-free. In 2018, 26 (84%) of the 31 countries met AFP surveillance indicators nationally; however, subnational variation in surveillance performance was substantial. Surveillance systems need continued strengthening through monitoring, supervision, and improvements in specimen collection and transport to provide sufficient evidence for interruption of poliovirus circulation.


Assuntos
Erradicação de Doenças , Saúde Global/estatística & dados numéricos , Poliomielite/prevenção & controle , Vigilância da População/métodos , Doença Aguda , Adolescente , Criança , Pré-Escolar , Monitoramento Ambiental , Fezes/virologia , Humanos , Lactente , Laboratórios , Paralisia/epidemiologia , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação
14.
MMWR Morb Mortal Wkly Rep ; 68(20): 458-462, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31120868

RESUMO

Since the Global Polio Eradication Initiative (GPEI) began in 1988, transmission of wild poliovirus (WPV) has been interrupted in all countries except Afghanistan, Nigeria, and Pakistan. WPV type 2 (WPV2) was declared eradicated in 2015; WPV type 3 has not been detected since 2012 (1). After the certification of the eradication of WPV2, a global switch from trivalent oral poliovirus vaccine (tOPV, containing vaccine virus types 1, 2, and 3) to bivalent oral poliovirus vaccine (bOPV, containing types 1 and 3) was completed in April 2016. Nigeria last reported WPV type 1 (WPV1) cases in 2016. This report describes global progress toward poliomyelitis eradication during January 1, 2017-March 31, 2019, and updates previous reports (1,2). Afghanistan and Pakistan reported their lowest annual number of WPV cases (22) in 2017; however, 33 WPV1 cases were reported in 2018. During January-March 2019 (as of May 3), 12 WPV1 cases had been reported worldwide, four more than the eight reported during the corresponding period in 2018. The occurrence of polio cases caused by circulating vaccine-derived poliovirus (cVDPV) is rare and occurs where oral poliovirus vaccine (OPV) coverage has been low and vaccine virus reverts to neurovirulence (3). Eight countries (Democratic Republic of the Congo [DRC], Indonesia, Mozambique, Niger, Nigeria, Papua New Guinea, Somalia, and Syria) reported 210 cVDPV cases during 2017-2019 (as of May 3). Reaching children during supplemental immunization activities (SIAs), accessing mobile populations at high risk, and variations in surveillance performance represent ongoing challenges. Innovative efforts to vaccinate every child and strengthen coordination efforts between Afghanistan and Pakistan will help achieve eradication. For cVDPV outbreak responses to promptly stop transmission, intensified programmatic improvements are needed to make the responses more effective and limit the risk for generating future outbreaks.


Assuntos
Erradicação de Doenças , Saúde Global/estatística & dados numéricos , Poliomielite/prevenção & controle , Vigilância da População , Surtos de Doenças/estatística & dados numéricos , Doenças Endêmicas/estatística & dados numéricos , Humanos , Programas de Imunização , Poliomielite/epidemiologia , Vacinas contra Poliovirus/administração & dosagem
16.
MMWR Morb Mortal Wkly Rep ; 67(14): 418-423, 2018 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-29649187

RESUMO

Global efforts to eradicate polio began in 1988, and four of the six World Health Organization (WHO) regions currently have achieved poliofree certification. Within the remaining two regions with endemic poliomyelitis (African and Eastern Mediterranean), Afghanistan, Nigeria, and Pakistan have never interrupted transmission of wild poliovirus (WPV). The primary means of detecting poliovirus transmission is surveillance for acute flaccid paralysis (AFP) among children aged <15 years, combined with collection and testing of stool specimens for detection of WPV and vaccine-derived polioviruses (VDPVs)* in WHO-accredited laboratories within the Global Polio Laboratory Network (GPLN) (1,2). AFP surveillance is supplemented by environmental surveillance for polioviruses in sewage from selected locations. Genomic sequencing of isolated polioviruses enables the mapping of transmission by time and place, assessment of potential gaps in surveillance, and identification of the emergence of VDPVs (3). This report presents poliovirus surveillance data from 2016-2017, with particular focus on six countries in the Eastern Mediterranean Region (EMR) and 20 countries in the African Region (AFR) that reported WPV or circulating VDPVs (cVDPVs) during 2011-2017. Included in the 20 AFR countries are the three most affected by the 2014-2015 Ebola virus disease (Ebola) outbreak (Guinea, Liberia, and Sierra Leone), even though only one (Guinea) reported WPV or cVDPVs during the surveillance period. During 2017, a total of 14 (70%) of the 20 AFR countries and five (83%) of the six EMR countries met both surveillance quality indicators at the national level; however, provincial-level variation was seen. Surveillance strengthening activities are needed in specific countries of these regions to provide evidence supporting ultimate certification of the interruption of poliovirus circulation.


Assuntos
Erradicação de Doenças , Saúde Global/estatística & dados numéricos , Poliomielite/prevenção & controle , Vigilância da População , Monitoramento Ambiental , Humanos , Laboratórios , Paralisia/epidemiologia , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação
17.
MMWR Morb Mortal Wkly Rep ; 67(30): 833-837, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30070983

RESUMO

Afghanistan, Pakistan, and Nigeria remain the only countries where transmission of endemic wild poliovirus type 1 (WPV1) continues (1). This report describes polio eradication activities, progress, and challenges to eradication in Afghanistan during January 2017-May 2018 and updates previous reports (2, 3). Fourteen WPV1 cases were confirmed in Afghanistan in 2017, compared with 13 in 2016; during January-May 2018, eight WPV1 cases were reported, twice the number reported during January-May 2017. To supplement surveillance for acute flaccid paralysis (AFP) and laboratory testing of stool samples, environmental surveillance (testing of sewage samples) was initiated in 2013 and includes 20 sites, 15 of which have detected WPV1 circulation. The number of polio-affected districts increased from six in 2016 to 14 in 2017 (including WPV1 cases and positive environmental samples). Access to children for supplementary immunization activities (SIAs) (mass campaigns targeting children aged <5 years with oral poliovirus vaccine [OPV], regardless of vaccination history), which improved during 2016 to early 2018, worsened in May 2018 in security-challenged areas of the southern and eastern regions. To achieve WPV1 eradication, measures to maintain and regain access for SIAs in security-challenged areas, strengthen oversight of SIAs in accessible areas to reduce the number of missed children, and coordinate with authorities in Pakistan to track and vaccinate mobile populations at high risk in their shared transit corridors must continue.


Assuntos
Erradicação de Doenças , Poliomielite/prevenção & controle , Vigilância da População , Adolescente , Afeganistão/epidemiologia , Criança , Pré-Escolar , Humanos , Programas de Imunização , Esquemas de Imunização , Lactente , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação , Vacina Antipólio Oral/administração & dosagem , Vacinação/estatística & dados numéricos
18.
MMWR Morb Mortal Wkly Rep ; 67(44): 1242-1245, 2018 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-30408024

RESUMO

Among the three wild poliovirus (WPV) serotypes, only WPV type 1 (WPV1) has been reported in polio cases or detected from environmental surveillance globally since 2012. Pakistan remains one of only three countries worldwide (the others are Afghanistan and Nigeria) that has never had interrupted WPV1 transmission. This report documents Pakistan's activities and progress toward polio eradication during January 2017-September 2018 and updates previous reports (1,2). In 2017, Pakistan reported eight WPV1 cases, a 60% decrease from 20 cases in 2016. As of September 18, 2018, four cases had been reported, compared with five cases at that time in 2017. Nonetheless, in 2018, WPV1 continues to be isolated regularly from environmental surveillance sites, primarily in the core reservoir areas of Karachi, Quetta, and Peshawar, signifying persistent transmission. Strategies to increase childhood immunity have included an intense schedule of supplemental immunization activities (SIAs), expanding and refining deployment of community-based vaccination implemented by community health workers recruited from the local community in reservoir areas, and strategic placement of permanent transit points where vaccination is provided to mobile populations. Interruption of WPV1 transmission will require further programmatic improvements throughout the country with a focus on specific underperforming subdistricts in reservoir areas.


Assuntos
Erradicação de Doenças , Poliomielite/prevenção & controle , Vigilância da População , Pré-Escolar , Humanos , Programas de Imunização , Esquemas de Imunização , Lactente , Paquistão/epidemiologia , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação , Vacina Antipólio Oral/administração & dosagem
19.
BMC Med ; 15(1): 180, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-29017491

RESUMO

BACKGROUND: Pakistan is one of only three countries where poliovirus circulation remains endemic. For the Pakistan Polio Eradication Program, identifying high risk districts is essential to target interventions and allocate limited resources. METHODS: Using a hierarchical Bayesian framework we developed a spatial Poisson hurdle model to jointly model the probability of one or more paralytic polio cases, and the number of cases that would be detected in the event of an outbreak. Rates of underimmunization, routine immunization, and population immunity, as well as seasonality and a history of cases were used to project future risk of cases. RESULTS: The expected number of cases in each district in a 6-month period was predicted using indicators from the previous 6-months and the estimated coefficients from the model. The model achieves an average of 90% predictive accuracy as measured by area under the receiver operating characteristic (ROC) curve, for the past 3 years of cases. CONCLUSIONS: The risk of poliovirus has decreased dramatically in many of the key reservoir areas in Pakistan. The results of this model have been used to prioritize sub-national areas in Pakistan to receive additional immunization activities, additional monitoring, or other special interventions.


Assuntos
Erradicação de Doenças , Modelos Biológicos , Modelos Estatísticos , Poliomielite/prevenção & controle , Poliovirus , Teorema de Bayes , Pré-Escolar , Surtos de Doenças/prevenção & controle , Humanos , Programas de Imunização , Paquistão/epidemiologia , Poliomielite/epidemiologia , Vacinas contra Poliovirus/administração & dosagem , Probabilidade , Curva ROC , Risco
20.
MMWR Morb Mortal Wkly Rep ; 66(47): 1295-1299, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29190264

RESUMO

Following the declaration of eradication of wild poliovirus (WPV) type 2 in September 2015, trivalent oral poliovirus vaccine (tOPV) was withdrawn globally to reduce the risk for type 2 vaccine-derived poliovirus (VDPV2) transmission; all countries implemented a synchronized switch to bivalent OPV (type 1 and 3) in April 2016 (1,2). Any isolation of VDPV2 after the switch is to be treated as a potential public health emergency and might indicate the need for supplementary immunization activities (3,4). On August 9, 2016, VDPV2 was isolated from a sewage sample taken from an environmental surveillance site in Hyderabad, Sindh province, Pakistan. Possible vaccination activities in response to VDPV2 isolation include the use of injectable inactivated polio vaccine (IPV), which poses no risk for vaccine-derived poliovirus transmission. Fractional-dose, intradermal IPV (fIPV), one fifth of the standard intramuscular dose, has been developed to more efficiently manage limited IPV supplies. fIPV has been shown in some studies to be noninferior to full-dose IPV (5,6) and was used successfully in response to a similar detection of a single VDPV2 isolate from sewage in India (7). Injectable fIPV was used for response activities in Hyderabad and three neighboring districts. This report describes the findings of an assessment of preparatory activities and subsequent implementation of the fIPV campaign. Despite achieving high coverage (>80%), several operational challenges were noted. The lessons learned from this campaign could help to guide the planning and implementation of future fIPV vaccination activities.


Assuntos
Surtos de Doenças/prevenção & controle , Programas de Imunização/organização & administração , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/administração & dosagem , Humanos , Lactente , Paquistão/epidemiologia , Poliomielite/epidemiologia , Poliovirus/isolamento & purificação , Avaliação de Programas e Projetos de Saúde , Esgotos/virologia
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