ABSTRACT
Better access to tuberculosis testing is a key priority for fighting tuberculosis, the leading cause of infectious disease deaths in people. Despite the roll-out of molecular WHO-recommended rapid diagnostics to replace sputum smear microscopy over the past decade, a large diagnostic gap remains. Of the estimated 10·6 million people who developed tuberculosis globally in 2022, more than 3·1 million were not diagnosed. An exclusive focus on improving tuberculosis test accuracy alone will not be sufficient to close the diagnostic gap for tuberculosis. Diagnostic yield, which we define as the proportion of people in whom a diagnostic test identifies tuberculosis among all people we attempt to test for tuberculosis, is an important metric not adequately explored. Diagnostic yield is particularly relevant for subpopulations unable to produce sputum such as young children, people living with HIV, and people with subclinical tuberculosis. As more accessible non-sputum specimens (eg, urine, oral swabs, saliva, capillary blood, and breath) are being explored for point-of-care tuberculosis testing, the concept of yield will be of growing importance. Using the example of urine lipoarabinomannan testing, we illustrate how even tests with limited sensitivity can diagnose more people with tuberculosis if they enable increased diagnostic yield. Using tongue swab-based molecular tuberculosis testing as another example, we provide definitions and guidance for the design and conduct of pragmatic studies that assess diagnostic yield. Lastly, we show how diagnostic yield and other important test characteristics, such as cost and implementation feasibility, are essential for increased effective population coverage, which is required for optimal clinical care and transmission impact. We are calling for diagnostic yield to be incorporated into tuberculosis test evaluation processes, including the WHO Grading of Recommendations, Assessment, Development, and Evaluations process, providing a crucial real-life implementation metric that complements traditional accuracy measures.
Subject(s)
Tuberculosis , Humans , Diagnostic Tests, Routine , Sputum/microbiology , Tuberculosis/diagnosisABSTRACT
INTRODUCTION: In 2016, WHO estimated there were roughly 374 million new infections among adults of the following four curable sexually transmitted infections (STIs): chlamydia (caused by Chlamydia trachomatis (CT)), gonorrhoea (Neisseria gonorrhoeae (NG)), syphilis (Treponema pallidum) and trichomoniasis (Trichomonas vaginalis (TV)). Accurate point-of-care tests (POCTs) for screening of genital and extragenital CT, NG and TV infections are of great value and have been developed during recent decade. Several tests are commercially available and have shown encouraging performance compared with 'gold-standard' reference tests in laboratory-based studies. However, there is limited data on their clinical performance, including at the POC. Key populations, such as men who have sex with men (MSM), are at higher risk of these STIs at genital and extragenital sites and these STIs are often asymptomatic, especially in extragenital sites and in women. We will conduct a clinical-based evaluation to assess the performance characteristics and acceptability to end-users of molecular-based diagnostic technology for POC/near patient use of the Xpert CT/NG (Cepheid, Sunnyvale, California, USA) test for screening of genital, anorectal and pharyngeal CT and NG infections in MSM and the Xpert CT/NG and Xpert TV (Cepheid, Sunnyvale, California, USA) for screening of genital CT, NG and TV among women at risk for these STIs compared with gold-standard reference nucleic acid amplification tests. This master protocol outlines the overall research approach that will be used in seven countries. METHOD AND ANALYSES: Consecutive MSM and women at risk presenting at the clinical sites in high, and low- and middle-income countries will be enrolled. The POCTs to be evaluated are Xpert CT/NG and Xpert TV. All procedures will be carried out by trained healthcare staff and tests performed in strict accordance with the manufacturer's instructions. The sensitivity, specificity, positive and negative predictive values for each POCT will be calculated. The study is ongoing with recruitment expected to be completed in all countries by mid-2022 to late-2022. ETHICS AND DISSEMINATION: Prior to enrolment, this core protocol was independently peer-reviewed and approved by the research project review panel (RP2) of the WHO Department of Sexual and Reproductive Health and Research and by the WHO Ethics Review Committee (ERC). The core protocol has been slightly adapted accordingly to individual countries and adaptations approved by both RP2 and ERC, as well as all relevant institutional review boards at each participating site. Results will be disseminated through peer-reviewed journals and presented at relevant national/international conferences.
Subject(s)
Chlamydia Infections , Gonorrhea , Homosexuality, Male , Point-of-Care Testing , Humans , Male , Female , Chlamydia Infections/diagnosis , Gonorrhea/diagnosis , Prospective Studies , Mass Screening/methods , Trichomonas vaginalis/isolation & purification , Sexually Transmitted Diseases/diagnosis , Trichomonas Vaginitis/diagnosis , Trichomonas Vaginitis/epidemiology , Multicenter Studies as Topic , Sensitivity and Specificity , Adult , Point-of-Care SystemsABSTRACT
BACKGROUND: Southern African countries have the largest global burden of HIV and syphilis, with a high prevalence among women of reproductive age. Although antenatal screening is standard of care, syphilis screening has generally lagged behind HIV screening. We aimed to evaluate the performance and operational characteristics of two commercial dual HIV/syphilis point-of-care tests (POCTs) for simultaneous maternal HIV/syphilis screening. METHODS: A clinic-based evaluation of dual HIV/syphilis POCTs (SD Bioline and Chembio) was conducted at five primary healthcare centres (PHCs) in South Africa and Zambia. POCT results using capillary fingerprick blood were compared to reference laboratory syphilis and HIV serological assays. RESULTS: Three thousand four hundred twelve consenting pregnant women aged ≥ 18 years were enrolled. The prevalence of treponemal antibody seropositivity and HIV infection ranged from 3.7 to 9.9% (n = 253) and 17.8 to 21.3% (n = 643), respectively. Pooled sensitivity for syphilis compared to the reference assay was 66.0% (95%CI 57.7-73.4) with SD Bioline and 67.9% (95%CI 58.2-76.3) with Chembio. Pooled specificity for syphilis was above 98% with both POCTs. The sensitivities of SD Bioline and Chembio assays were 78.0% (95%CI 68.6-85.7) and 81.0% (95%CI 71.9-88.2), respectively compared to an active syphilis case definition of treponemal test positive with a rapid plasma reagin titre of ≥ 8. The negative predictive values (NPVs) based on various prevalence estimates for syphilis with both assays ranged from 97 to 99%. The pooled sensitivity for HIV was 92.1% (95%CI 89.4-94.2) with SD Bioline; and 91.5% (95%CI 88.2-93.9) with Chembio. The pooled specificities for HIV were 97.2% (95%CI 94.8-98.5) with SD Bioline and 96.7% (95%CI 95.1-97.8) with Chembio. The NPV based on various prevalence estimates for HIV with both assays was approximately 98%. Most participating women (91%) preferred dual POCTs over two single POCTs for HIV and syphilis, and healthcare providers gave favourable feedback on the utility of both assays at PHC level. CONCLUSIONS: Based on the need to improve antenatal screening coverage for syphilis, dual HIV/syphilis POCTs could be effectively incorporated into antenatal testing algorithms to enhance efforts towards elimination of mother-to-child transmission of these infections.
Subject(s)
HIV Infections , Pregnancy Complications, Infectious , Sensitivity and Specificity , Syphilis , Humans , Zambia/epidemiology , Female , Syphilis/diagnosis , Syphilis/epidemiology , HIV Infections/diagnosis , HIV Infections/epidemiology , Pregnancy , South Africa/epidemiology , Adult , Young Adult , Pregnancy Complications, Infectious/diagnosis , Pregnancy Complications, Infectious/epidemiology , Adolescent , Point-of-Care Systems , Primary Health Care , Point-of-Care Testing , Prevalence , Mass Screening/methods , Prenatal Care , Diagnostic Tests, Routine/methods , Rapid Diagnostic TestsABSTRACT
BACKGROUND: In 2018, the World Health Organization commenced a multi-country validation study of the Cepheid GeneXpert for a range of molecular-based point-of-care (POC) tests in primary care settings. One study arm focused on the evaluation of POC tests for screening 'women at risk' for chlamydia (CT), gonorrhoea (NG) and trichomonas (TV) in four countries - Australia, Guatemala, Morocco and South Africa. METHODS: Study participants completed a pre-test questionnaire which included demographics, clinical information and general questions on POC testing (POCT). Two vaginal swab samples (either self-collected or clinician collected) from each patient were tested on the GeneXpert at the POC and at a reference laboratory using quality-assured nucleic acid amplification tests (NAATs). RESULTS: One thousand three hundred and eighty-three women were enrolled: 58.6% from South Africa, 29.2% from Morocco, 6.2% from Guatemala, and 6.0% from Australia. 1296 samples for CT/NG and 1380 samples for TV were tested by the GeneXpert and the reference NAAT. The rate of unsuccessful tests on the GeneXpert was 1.9% for CT, 1.5% for NG and 0.96% for TV. The prevalence of CT, NG and TV was 31%, 13% and 23%, respectively. 1.5% of samples were positive for all three infections; 7.8% were positive for CT and NG; 2.4% were positive for NG and TV; and 7.3% were positive for CT and TV. Compared to reference NAATs, pooled estimates of sensitivity for the GeneXpert tests were 83.7% (95% confidence intervals 69.2-92.1) for CT, 90.5% (85.1-94.1) for NG and 64.7% (58.1-70.7) for TV (although estimates varied considerably between countries). Estimates for specificity were ≥96% for all three tests both within- and between-countries. Pooled positive and negative likelihood ratios were: 32.7 ([CI] 21.2-50.5) and 0.17 (0.08-0.33) for CT; 95.3 (36.9-245.7) and 0.10 (0.06-0.15) for NG; and 56.5 (31.6-101.1) and 0.35 (0.27-0.47) for TV. CONCLUSION: This multi-country evaluation is the first of its kind world-wide. Positive likelihood ratios, as well as specificity estimates, indicate the GeneXpert POC test results for CT, NG and TV were clinically acceptable for ruling in the presence of disease. However, negative likelihood ratios and variable sensitivity estimates from this study were poorer than expected for ruling out these infections, particularly for TV. TRIAL REGISTRATION: Ethics approval to conduct the ProSPeRo study was granted by the WHO Ethics Review Committee, as well as local ethics committees from all participating countries.
Subject(s)
Gonorrhea , Trichomonas vaginalis , Female , Humans , Trichomonas vaginalis/genetics , Chlamydia trachomatis/genetics , Gonorrhea/diagnosis , Gonorrhea/epidemiology , Guatemala/epidemiology , Morocco/epidemiology , South Africa/epidemiology , Neisseria gonorrhoeae/genetics , Australia , Point-of-Care TestingABSTRACT
INTRODUCTION: International guidelines recommend routine screening for syphilis (aetiological agent: Treponema pallidum subspecies pallidum) amongst key populations and vulnerable populations using tests detecting treponemal and non-treponemal antibodies. Whilst treponemal tests have high sensitivities and specificities, they differ regarding subjective or objective interpretation, throughput and workload. Chemiluminescence immunoassays (CLIAs) are cost- and time-effective automated methods for detecting treponemal antibodies. The Treponema pallidum particle agglutination assay (TPPA) has been considered the "gold standard" treponemal assay, however, this includes a highly manual procedure, low throughput and subjective interpretation. The present multi-country study evaluated the ADVIA Centaur® Syphilis CLIA (Siemens Healthcare) assay compared to the reference SERODIA-TP·PA® (Fujirebio Diagnostics) for the serodiagnosis of syphilis amongst men who have sex with men (MSM). METHOD: 1,485 MSM were enrolled in Brighton (UK), Malta, and Verona (Italy) as part of a larger WHO multi-country and multi-site ProSPeRo study. Ethical approval was obtained. Serum was tested with the ADVIA Centaur® Syphilis CLIA assay and SERODIA-TP·PA®, in accordance with the manufacturers' instructions, for a first round of validation. A second round of validation was carried out for discrepant results that were additionally tested with both Western Blot (Westernblot EUROIMMUN®) and an Immunoblot (INNO-LIA, Fujirebio Diagnostics). Sensitivity, specificity, positive and negative predictive value (PPV and NPV), likelihood ratios (positive/negative), and the Diagnostic Odds Ratio (DOR)/pre-post-test probability (Fagan's nomogram) were calculated. RESULTS: Out of 1,485 eligible samples analysed in the first phase, the SERODIA-TP·PA® identified 360 positive and 1,125 negative cases. The ADVIA Centaur® Syphilis CLIA assay (Siemens) identified 366 positives, missclassifying one TPPA-positive sample. In the second phase, the ADVIA Centaur® Syphilis CLIA resulted in 1 false negative and 4 false positive results. Considering the syphilis study prevalence of 24% (95% CI: 22-26.7), The sensitivity of the ADVIA Centaur® Syphilis CLIA assay was 99.7% (95% CI: 98.5-100), and the specificity was 99.4% (95% CI: 98.7-99.7). The ROC area values were 0.996 (95% CI: 0.992-0.999), and both the PPV and NPV values were above 98% (PPV 98.1%, 95% CI: 96.1-99.2; NPV 99.9%, 95% CI: 99.5-100). CONCLUSIONS: The ADVIA Centaur® Syphilis CLIA assay showed similar performance compared to the SERODIA-TP·PA®. Considering the study is based on QUADAS principles and with a homogeneous population, results are also likely to be generalisable to MSM population but potentially not applicable to lower prevalence populations routinely screened for syphilis. The automated CLIA treponemal assay confirmed to be accurate and appropriate for routine initial syphilis screening, i.e. when the reverse testing algorithm is applied.
Subject(s)
Sexual and Gender Minorities , Syphilis , Male , Humans , Treponema pallidum , Homosexuality, Male , Antibodies, Bacterial , Syphilis Serodiagnosis/methods , Serologic Tests/methods , Sensitivity and Specificity , Luminescent Measurements/methods , AgglutinationABSTRACT
BACKGROUND: Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and bacterial vaginosis have been associated with adverse maternal and perinatal outcomes, but there is conflicting evidence on the benefits of antenatal screening and treatment for these conditions. We aimed to determine the effect of antenatal point-of-care testing and immediate treatment of C trachomatis, N gonorrhoeae, T vaginalis, and bacterial vaginosis on preterm birth, low birthweight, and other adverse maternal and perinatal outcomes compared with current standard of care, which included symptom-based treatment without laboratory confirmation. METHODS: In this pragmatic cluster randomised crossover trial, we enrolled women (aged ≥16 years) attending an antenatal clinic at 26 weeks' gestation or earlier (confirmed by obstetric ultrasound), living within approximately 1 h drive of a study clinic, and able to provide reliable contact details at ten primary health facilities and their catchment communities (clusters) in Papua New Guinea. Clusters were randomly allocated 1:1 to receive either the intervention or control (standard care) in the first phase of the trial. Following an interval (washout period) of 2-3 months at the end of the first phase, each cluster crossed over to the other group. Randomisation was stratified by province. Individual participants were informed about trial group allocation only after completing informed consent procedures. The primary outcome was a composite of preterm birth (livebirth before 37 weeks' gestation), low birthweight (<2500 g), or both, analysed according to the intention-to-treat population. This study is registered with ISRCTN Registry, ISRCTN37134032, and is completed. FINDINGS: Between July 26, 2017, and Aug 30, 2021, 4526 women were enrolled (2210 [63·3%] of 3492 women in the intervention group and 2316 [62·8%] of 3687 in the control group). Primary outcome data were available for 4297 (94·9%) newborn babies of 4526 women. The proportion of preterm birth, low birthweight, or both, in the intervention group, expressed as the mean of crude proportions across clusters, was 18·8% (SD 4·7%) compared with 17·8% in the control group (risk ratio [RR] 1·06, 95% CI 0·78-1·42; p=0·67). There were 1052 serious adverse events reported (566 in the intervention group and 486 in the control group) among 929 trial participants, and no differences by trial group. INTERPRETATION: Point-of-care testing and treatment of C trachomatis, N gonorrhoeae, T vaginalis, and bacterial vaginosis did not reduce preterm birth or low birthweight compared with standard care. Within the subgroup of women with N gonorrhoeae, there was a substantial reduction in the primary outcome. FUNDING: UK Department of Health and Social Care; UK Foreign, Commonwealth and Development Office; UK Medical Research Council; the Wellcome Trust; the Australian National Health and Medical Research Council; and Swiss National Science Foundation.
Subject(s)
Premature Birth , Urinary Tract Infections , Vaginosis, Bacterial , Female , Humans , Infant, Newborn , Pregnancy , Birth Weight , Chlamydia trachomatis , Cross-Over Studies , Genitalia , Neisseria gonorrhoeae , Papua New Guinea/epidemiology , Point-of-Care Testing , Premature Birth/prevention & control , Vaginosis, Bacterial/diagnosis , Vaginosis, Bacterial/drug therapy , Adolescent , Young Adult , AdultABSTRACT
Current serologic tests for HIV screening and confirmation of infection present challenges to the adoption of HIV vaccines. The detection of vaccine-induced HIV-1 antibodies in the absence of HIV-1 infection, referred to as vaccine-induced seropositivity/seroreactivity, confounds the interpretation of test results, causing misclassification of HIV-1 status with potential affiliated stigmatization. For HIV vaccines to be widely adopted with high community confidence and uptake, tests are needed that are agnostic to the vaccination status of tested individuals (ie, positive only for true HIV-1 infection). Successful development and deployment of such tests will require HIV vaccine developers to work in concert with diagnostic developers. Such tests will need to match today's high-performance standards (accuracy, cost-effectiveness, simplicity) for use in vaccinated and unvaccinated populations, especially in low- and middle-income countries with high HIV burden. Herein, we discuss the challenges and strategies for developing modified serologic HIV tests for concurrent deployment with HIV vaccines.
Subject(s)
AIDS Vaccines , HIV Infections , HIV-1 , Humans , HIV Infections/diagnosis , HIV Infections/prevention & control , AIDS Vaccines/immunology , HIV-1/immunology , HIV Antibodies/blood , HIV Antibodies/immunology , Serologic Tests/methodsABSTRACT
INTRODUCTION: Globally, the incidence of HIV and syphilis can be reduced by the use of validated point of care tests (POCTs). As part of the WHO PRoSPeRo Network, we aimed to evaluate the performance, acceptability, and operational characteristics of two dual HIV/syphilis POCTs (Bioline HIV/Syphilis Duo (Abbott) and DPP® HIV-Syphilis assay (Chembio) for the screening of HIV and syphilis amongst men who have sex with men (MSM). METHOD AND ANALYSES: A cross sectional study of 2,577 MSM in Italy, Malta, Peru, and the United Kingdom (UK) presenting to seven clinic sites, were enrolled. Finger prick blood was collected to perform POCTs and results compared with standard laboratory investigations on venepuncture blood. Acceptability and operational characteristics were assessed using questionnaires. Diagnostic meta-analysis was used to combine data from the evaluation sites. RESULTS: Based on laboratory tests, 23.46% (n = 598/2549) of participants were confirmed HIV positive, and 35.88% of participants (n = 901/2511) were positive on treponemal reference testing. Of all participants showing evidence of antibodies to Treponema pallidum, 50.56% (n = 455/900) were Rapid Plasma Reagin (RPR) test reactive. Of HIV positive individuals, 60.62% (n = 354/584) had evidence of antibodies to T. pallidum, and of these 60.45% (n = 214/354) exhibited reactive RPR tests indicating probable (co)infection. For Bioline POCT, pooled sensitivities and specificities for HIV were 98.95% and 99.89% respectively, and for syphilis were 73.79% and 99.57%. For Chembio pooled sensitivities and specificities for HIV were 98.66% and 99.55%, and for syphilis were 78.60% and 99.48%. Both tests can detect greater than 90% of probable active syphilis cases, as defined by reactive RPR and treponemal test results. These dual POCTs were preferred by 74.77% (n = 1,926) of participants, due to their convenience, and the operational characteristics made them acceptable to health care providers (HCPs). CONCLUSIONS: Both the Bioline and the Chembio dual POCT for syphilis and HIV had acceptable performance, acceptability and operational characteristics amongst MSM in the PRoSPeRo network. These dual POCTs could serve as a strategic, more cost effective, patient and healthcare provider (HCP) friendly alternative to conventional testing; in clinical and other field settings, especially those in resource-limited settings.
Subject(s)
HIV Infections , Sexual and Gender Minorities , Syphilis , Male , Humans , Syphilis/diagnosis , Syphilis/epidemiology , Homosexuality, Male , Peru/epidemiology , Malta , Cross-Sectional Studies , Treponema pallidum , Point-of-Care Testing , Syphilis Serodiagnosis/methods , Sensitivity and Specificity , Antibodies, Bacterial , HIV Infections/diagnosis , HIV Infections/epidemiologyABSTRACT
BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections have increased globally. Asymptomatic infections represent a significant risk of long-term complications. Men who have sex with men (MSM) are disproportionally affected, underscoring the need to offer screening programmes to this population. CT/NG Point of Care Testing (POCT) constitutes a strategic tool to improve the continuum of STI care, however extensive real-life evaluations amongst at risk populations are lacking. The aim of this study is to estimate the GeneXpert CT/NG assay performance and usability for CT and NG at genital and extragenital sites for screening amongst MSM. METHODS: This study was a multi-site sexual health clinic-based evaluation (Italy, Malta and Peru) with consecutive enrolment. A first void urine sample (divided in two aliquots), two oropharyngeal and two anorectal swabs were collected for each study participant. One specimen set (one for each anatomical site) was tested with the dual index test (Cepheid) at the clinics by the healthcare staff, the other set with FDA/CE approved Nucleic Acid Amplification Tests (NAATs) at the laboratory. Clinical sites and reference laboratories participated in an internal and external quality control programme. Sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values for each anatomical site were estimated using a meta-analytic approach. RESULTS: One thousand seven hundred two MSM were recruited across all clinical sites for a total of 5049 biological specimens. NG and CT were respectively detected in 274 and 287 of samples. Overall, the NG POCT sensitivity and specificity was 91.43% and 99.75% in urine (LR + 372.80, LR- 0.09), 89.68% and 99.55% in rectal specimens (LR + 197.30, LR- 0.10) and 75.87% and 98.77% at the pharynx respectively (LR + 61.94, LR- 0.24). The CT component of the POCT sensitivity was 84.82% and specificity 99.63% in urine (LR + 228.68, LR- 0.15), 78.07% and 99.19% respectively on rectal site (LR + 96.23, LR-0.22), 67.79% and 99.88% respectively at pharyngeal site (LR + 554.89, LR- 0.32). 95.95% of MSM reported to be willing to wait for POCT results and no provider reported difficulties in terms of performance or interpretation of the results of the Xpert CT/NG. CONCLUSION: Rapid turnaround time, ease of use and high acceptability make the Xpert CT/NG testing system a strategic tool for increasing testing frequency, reaching those not yet tested and offering the possibility of immediate treatment if needed. The assay showed good negative likelihood ratios and confirms its use to rule out CT/NG infections. Sensitivity varied across sites and pathogens. Periodic staff training at the testing sites should be mandatory.
Subject(s)
Chlamydia Infections , Gonorrhea , Sexual and Gender Minorities , Male , Humans , Homosexuality, Male , Neisseria gonorrhoeae/genetics , Chlamydia Infections/diagnosis , Chlamydia Infections/epidemiology , Gonorrhea/diagnosis , Gonorrhea/epidemiology , Chlamydia trachomatis/genetics , Nucleic Acid Amplification Techniques , Tomography, X-Ray ComputedABSTRACT
Diagnostics are widely considered crucial in the fight against antimicrobial resistance (AMR), which is expected to kill 10 million people annually by 2030. Nevertheless, there remains a substantial gap between the need for AMR diagnostics versus their development and implementation. To help address this problem, target product profiles (TPP) have been developed to focus developers' attention on the key aspects of AMR diagnostic tests. However, during discussion between a multisectoral working group of 51 international experts from industry, academia and healthcare, it was noted that specific AMR-related TPPs could be extended by incorporating the interdependencies between the key characteristics associated with the development of such TPPs. Subsequently, the working group identified 46 characteristics associated with six main categories (ie, Intended Use, Diagnostic Question, Test Description, Assay Protocol, Performance and Commercial). The interdependencies of these characteristics were then identified and mapped against each other to generate new insights for use by stakeholders. Specifically, it may not be possible for diagnostics developers to achieve all of the recommendations in every category of a TPP and this publication indicates how prioritising specific TPP characteristics during diagnostics development may influence (or not) a range of other TPP characteristics associated with the diagnostic. The use of such guidance, in conjunction with specific TPPs, could lead to more efficient AMR diagnostics development.
Subject(s)
Diagnostic Tests, Routine , Drug Resistance, Microbial , Humans , Diagnostic Tests, Routine/methodsABSTRACT
BACKGROUND: In Africa, little is known about the role of telephone hotlines in outbreak response. We systematically reviewed the role and effectiveness of hotlines on outbreak response in Africa. METHOD: We used the Cochrane handbook and searched five databases. The protocol was registered on PROSPERO (CRD42021247141). Medline, Embase, PsycINFO, Global Health and Web of Science were searched from 30 June 2020 to August 2020 for studies on the use of telephone hotlines in outbreak response in Africa published between January 1995 and August 2020. The search was also repeated on 16 September 2022. Data on effectiveness (alerts generated, cases confirmed) were extracted from peer-reviewed studies. Meta-analysis of alerts generated, and proportion of cases confirmed was done using the random effects model. The quality of studies was assessed using the Joanna Briggs Institute (JBI) tools. The heterogeneity and publication bias were assessed using the Galbraith and funnel plots, respectively. RESULTS: Our search yielded 1251 non-duplicate citations that were assessed. 41 full texts were identified, and 21 studies were included in the narrative synthesis, while 12 were included in the meta-analysis. The hotlines were local (seven studies) or national (three studies). A combination of a local and national hotline was used in one study. The hotlines were set up for unusual respiratory events (one study), polio (one study), Ebola (10 studies), COVID-19 (two studies), malaria (one study), influenza-like illnesses (ILI) (one study) and rift valley fever in livestock (one study). Hotlines were mainly used for outbreak surveillance at the local level. A total of 332,323 alerts were generated, and 67,658 met the case definition, corresponding to an overall pooled proportion of alerts generated(sensitivity) of 38% (95%CI: 24-52%). The sensitivity was 41% (95% CI: 24-59%) for local hotlines and 26%(95%CI:5-47%) for national hotlines. Hotlines were also used for surveillance of rift valley fever in livestock (one study) vaccination promotion (one study), death reporting (five studies), rumour tracking and fighting misinformation (two studies) and community engagement (five studies). The studies were of low to moderate quality with high publication bias and heterogeneity(I2 = 99%). The heterogeneity was not explained by the sample size. CONCLUSION: These data suggest that telephone hotlines can be effective in outbreak disease surveillance in Africa. Further implementation research is needed to scale up telephone hotlines in rural areas.
Subject(s)
Rift Valley Fever , Virus Diseases , Humans , Animals , Hotlines , Disease Outbreaks/prevention & control , Africa/epidemiologyABSTRACT
According to the World Health Organization, blood must be screened for major transmitted infections before transfusion to prevent the possibility of passing an infection to the recipient. For accurate detection of infectious disease pathogens in the blood of donors, in-vitro diagnostic medical devices (IVDs) of high specificity and sensitivity should be used. In mature healthcare systems, the regulatory authorities authorize the usage of devices with the highest performance capabilities, which are also controlled through active market oversight. However, in Sub-Saharan African countries, the regulation of IVDs is often poorly developed. With the lack of stringent regulatory oversight, IVDs of poor quality can be put on the market and used for blood donor screening, which, ultimately, poses a great public health threat. The BloodTrain is a humanitarian project from the Germany Federal Ministry of Health that aims to help strengthen the regulatory authorities in Sub-Saharan partner countries. Here, we present the status of IVD regulation in the partner countries and the objectives that the BloodTrain project aims to achieve in the region toward regulating IVDs.
ABSTRACT
Objective: To consolidate recent information on elimination and eradication goals for infectious diseases and clarify the definitions and associated terminology for different goals. Methods: We conducted a systematic search of the World Health Organization's Institutional Repository for Information Sharing (WHO IRIS) and a customized systematic Google advanced search for documents published between 2008 and 2022 on elimination or eradication strategies for infectious conditions authored by WHO or other leading health organizations. We extracted information on names of infectious conditions, the elimination and eradication goals and timelines, definitions of goals, non-standardized terminology, targets and assessment processes. Findings: We identified nine goals for 27 infectious conditions, ranging from disease control to eradication. In comparison with the hierarchy of disease control, as defined at the Dahlem Workshop in 1997, six goals related to disease control with varying levels of advancement, two related to elimination and one to eradication. Goals progressed along a disease-control continuum, such as end of disease epidemic to pre-elimination to elimination as a public health problem or threat. We identified the use of non-standardized terminology with certain goals, including virtual elimination, elimination of disease epidemics, public health threat and public health concern. Conclusion: As we approach the 2030 target date to achieve many of the goals related to disease control and for other infections to become candidates for elimination in the future, clarity of definitions and objectives is important for public health professionals and policy-makers to avoid misperceptions and miscommunication.
Subject(s)
Communicable Diseases , Goals , Humans , Disease Eradication , Public Health , Global HealthABSTRACT
Syphilis is a sexually and vertically transmitted bacterial infection caused by the bacterium Treponema pallidum. Its prevalence is high in low-income and middle-income countries, and its incidence has increased in high-income countries in the last few decades among men who have sex with men. Syphilis is a major cause of adverse pregnancy outcomes in low-income and middle-income countries. Clinical features include a primary chancre at the point of inoculation, followed weeks later by the rash of secondary syphilis, a latent period, and in some cases, involvement of the eyes, CNS, and cardiovascular systems. It is diagnosed serologically. A single intramuscular dose of long-acting benzathine penicillin is recommended for people who have had syphilis for less than 1 year and longer courses for people with late latent syphilis. Control strategies include screening and treatment of all pregnant women, and targeted interventions for groups at high risk. Vaccine development, research on antibiotic prophylaxis, and digital messaging as prevention strategies are ongoing.
Subject(s)
Chancre , Sexual and Gender Minorities , Syphilis , Pregnancy , Male , Female , Humans , Syphilis/diagnosis , Syphilis/drug therapy , Syphilis/epidemiology , Homosexuality, Male , Treponema pallidum , PenicillinsABSTRACT
Chikungunya virus is widespread throughout the tropics, where it causes recurrent outbreaks of chikungunya fever. In recent years, outbreaks have afflicted populations in East and Central Africa, South America and Southeast Asia. The virus is transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Chikungunya fever is characterized by severe arthralgia and myalgia that can persist for years and have considerable detrimental effects on health, quality of life and economic productivity. The effects of climate change as well as increased globalization of commerce and travel have led to growth of the habitat of Aedes mosquitoes. As a result, increasing numbers of people will be at risk of chikungunya fever in the coming years. In the absence of specific antiviral treatments and with vaccines still in development, surveillance and vector control are essential to suppress re-emergence and epidemics.
Subject(s)
Aedes , Chikungunya Fever , Chikungunya virus , Animals , Humans , Chikungunya Fever/complications , Chikungunya Fever/epidemiology , Quality of Life , Mosquito VectorsABSTRACT
Throughout the COVID-19 pandemic, we have witnessed the critical and expanding roles of testing. Despite the development of over a thousand brand of tests - with some close to fulfilling the 4As (accuracy, access, affordability, and actionability via quick time to result) of an ideal diagnostic test - gaps persisted in developing tests to fit public health needs, and in providing equitable access. Here, we review how the use cases for testing evolved over the course of the COVID-19 pandemic, with associated engineering challenges (and potential lessons) at each phase for test developers. We summarise lessons learnt from the recent epidemic and propose four areas for future cooperative effort among test developers, government regulators and policy makers, public health experts, and the public: 1) develop new models for public sector funding and research and development; 2) increase testing capacity by investing in adaptable open-platform technologies at every level of the healthcare system; 3) build data connectivity infrastructures to support a connected diagnostic system as a backbone for surveillance; and 4) facilitate the rapid translation of innovation into use through a coordinated framework for regulatory approval and policy development.
Subject(s)
COVID-19 , Humans , Pandemics , Delivery of Health Care , COVID-19 TestingSubject(s)
Mpox (monkeypox) , Humans , Mpox (monkeypox)/epidemiology , Monkeypox virus , Disease OutbreaksABSTRACT
Background: Development and evaluation of diagnostics for diseases of epidemic potential are often funded during epidemics, but not afterwards, leaving countries unprepared for the next epidemic. United Nations Children's Emergency Fund (UNICEF) partnered with the United States Agency for International Development (USAID) to address this important gap by investing in an advance purchase commitment (APC) mechanism to accelerate the development and evaluation of Zika rapid diagnostic tests (RDTs) for case detection and surveillance. This paper describes the performance evaluation of five Zika RDTs eligible for procurement. Methods: A network of European Union-funded ZikaPLAN sites in Africa, Asia, Latin America with access to relevant serum specimens were selected to evaluate RDTs developed for the UNICEF APC mechanism. A standardised protocol and evaluation panels were developed and a call for specimens for the evaluation panels issued to different sites. Each site contributed specimens to the evaluation from their biobank. Data were collated, analysed and presented to the UNICEF Procurement Review Group for review. Findings: Three RDTs met the criteria for UNICEF procurement of sensitivity and specificity of 85% against a refence standard. The sensitivity/specificity of the ChemBio anti-Zika Virus (ZIKV) immunoglobulin M (IgM) test was 86.4 %/86.7% and the ChemBio ZCD system for anti-ZIKV IgM was 79.0%/97.1%, anti-dengue virus (DENV) IgM 90.0%/89.2%, anti-Chikungunya virus (CHIKV) IgM 90.6%/97.2%. The sensitivity/specificity of the SD Biosensor anti-ZIKV IgM was 96.8 %/90.8%, anti-DENV IgM 71.8%/83.5%, the DENV nonstructural protein 1 (NS1) glycoprotein 90.0%/90.2%, anti- yellow fever virus (YFV) IgM 84.6%/92.4%, anti-CHIKV IgM 86.3%/97.5%. Interpretation: Three RDTs fulfilled the performance thresholds set by WHO and were eligible for UNICEF procurement. These tests will improve the diagnosis of ZIKV and other arboviral infections as well as providing countries with better tools for surveillance and response to future epidemics. Funding: This work was supported by the USAID grant GHA-G-00-07-00007 and ZikaPLAN (European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement No. 734584).