Evaluation of remote radiologist-interpreted point-of-care ultrasound for suspected dengue patients in a primary health care facility in Colombia

Background Early identification of plasma leakage may guide treatment decisions in dengue patients.This study evaluated the value of point-of-care ultrasound(POCUS)to detect plasma leakage and predict hospitalization or referral to a higher level of care in suspected dengue patients under routine conditions at a primary care facility in Colombia.Methods We conducted a cohort study between April 2019 and March 2020 in a primary care hospital in Cali,Colombia.We prospectively included and followed 178 patients who were at least 2 years old with fever of less than 10 days and clinician-suspected dengue.A trained general practitioner performed a standardized POCUS protocol.Images were quality-rated and overread by an expert radiologist,and her results and those of the general practitioner were compared using the Kappa index.Logistic regression was used to identify factors associated with plasma leakage at enrollment and explore its prognostic value regarding hospital admission or referral to a higher level of care.Results Half(49.6%)POCUS images were of suitable quality to be interpreted.The proportion of plasma leakage reported by the radiologist was 85.1%(95%CI:78.6-90.2%)and 47.2%by the study physician(Kappa=0.25,95%CI:0.15-0.35).The most frequent ultrasound findings were ascites(hepatorenal 87.2%,splenorenal 64%,or pelvic 21.8%)and gallbladder wall thickening(10.5%).Plasma leakage was higher in subjects with thrombocytopenia(aOR=4,95%CI:1.3-12.1)and lower in patients 30-59 years old(aOR=0.1,95%CI:0.0-0.4)than in those 18 years old or younger.POCUS evidence of plasma leakage(aOR=8.2,95%CI:2.2-29.9),thrombocytopenia(aOR=6.3,95%CI:2.4-16.0)and pulse pressure(aOR=1.1,95%CI:1.07-1.2)were associated with hospital admission or referral to a higher level of care.Conclusions Ultrasound is useful to detect plasma leakage in primary care and,challenges remain to guarantee high-quality images and diagnostic accuracy,for which a standardized dengue POCUS protocol and training program is needed.

A scoping review on the field validation and implementation of rapid diagnostic tests for vector-borne and other infectious diseases of poverty in urban areas

Background:Health personnel face challenges in diagnosing vector-borne and other diseases of poverty in urban settings.There is a need to know what rapid diagnostic technologies are available,have been properly assessed,and are being implemented to improve control of these diseases in the urban context.This paper characterizes evidence on the field validation and implementation in urban areas of rapid diagnostics for vector-borne diseases and other diseases of poverty.Main body:A scoping review was conducted.Peer-reviewed and grey literature were searched using terms describing the targeted infectious diseases,diagnostics evaluations,rapid tests,and urban setting.The review was limited to studies published between 2000 and 2016 in English,Spanish,French,and Portuguese.Inclusion and exclusion criteria were refined post hoc to identify relevant literature regardless of study design and geography.A total of 179 documents of the 7806 initially screened were included in the analysis.Malaria(n=100)and tuberculosis(n=47)accounted for the majority of studies that reported diagnostics performance,impact,and implementation outcomes.Fewer studies,assessing mainly performance,were identified for visceral leishmaniasis(n=9),filariasis and leptospirosis(each n=5),enteric fever and schistosomiasis(each n=3),dengue and leprosy(each n=2),and Chagas disease,human African trypanosomiasis,and cholera(each n=1).Reported sensitivity of rapid tests was variable depending on several factors.Overall,specificities were high(>80%),except for schistosomiasis and cholera.Impact and implementation outcomes,mainly acceptability and cost,followed by adoption,feasibility,and sustainability of rapid tests are being evaluated in the field.Challenges to implementing rapid tests range from cultural to technical and administrative issues.Conclusions:Rapid diagnostic tests for vector-borne and other diseases of poverty are being used in the urban context with demonstrated impact on case detection.However,most evidence comes from malaria rapid diagnostics,with variable results.While rapid tests for tuberculosis and visceral leishmaniasis require further implementation studies,more evidence on performance of current tests or development of new alternatives is needed for dengue,Chagas disease,filariasis,leptospirosis,enteric fever,human African trypanosomiasis,schistosomiasis and cholera.

Priorities and needs for research on urban interventions targeting vector-borne diseases: rapid review of scoping and systematic reviews

This paper highlights the critical importance of evidence on vector-borne diseases(VBD)prevention and control interventions in urban settings when assessing current and future needs,with a view to setting policy priorities that promote inclusive and equitable urban health services.Research should produce knowledge about policies and interventions that are intended to control and prevent VBDs at the population level and to reduce inequities.Such interventions include policy,program,and resource distribution approaches that address the social determinants of health and exert influence at organizational and system levels.