[Is mortality an objective indicator for measuring the impact of an epidemic?: The example of Covid-19 in Switzerland]

Measuring the health impact of an epidemic using appropriate indicators is necessarily complex. Mortality does not sum up all the issues, but at least it seems to be an objective indicator. There are, however, a number of different mortality indicators, which do not all convey the same message. During the Covid-19 epidemic in Switzerland, the mortality rate rose by 10.2% in 2020, while life expectancy fell by "only" 0.8%, or 8.3 months, a decline described as "modest" or "complete freefall" depending on when it was published. In reality, the population living in Switzerland in 2020 lost an average of "only" 2.4 days, as the epidemic did not last their entire lives. The use of such an indicator, in comparison with losses due to other factors, would enable us to better estimate the real impact of an epidemic.

[Malaria vaccines: a new tool for elimination?]

A malaria vaccine represents an essential complementary tool to curb the stagnation, or even increase, in malaria cases observed over the last decade due to the emergence of resistance to insecticides impregnated on mosquito nets, wars and internal conflicts, as well as global warming. In October 2021, WHO recommended the use of the RTS,S/ASO1 vaccine for children aged 5-17 months in areas of moderate to high transmission. In October 2023, a second vaccine received WHO approval for deployment in the same population, following demonstration of around 70 % efficacy in protecting young children against malaria for one year. Given their partial efficacy, however, these vaccines are not generally recommended for travelers to endemic countries.

[Dengue vaccines, a time for cautious optimism?]

Vaccine could take a central role in the strategy to reduce the burden of dengue. The development of an effective and safe vaccine must address various immunological challenges. Several vaccines are currently in development. To date, two live-attenuated vaccines have been deployed. Both have an effectiveness that varies depending on the serotypes. The deployment of the Dengvaxia vaccine, which began in 2015, was marked by a major safety alert leading to its use being restricted to previously dengue-seropositive people over 9 years old. The Qdenga vaccine is currently being deployed. There is for now insufficient data to ensure its safety in seronegative people. Some travelers, who have previously been infected with dengue, are a group for whom a vaccination recommendation applies.

A digital health algorithm to guide antibiotic prescription in pediatric outpatient care: a cluster randomized controlled trial

Excessive antibiotic use and antimicrobial resistance are major global public health threats. We developed ePOCT+, a digital clinical decision support algorithm in combination with C-reactive protein test, hemoglobin test, pulse oximeter and mentorship, to guide health-care providers in managing acutely sick children under 15 years old. To evaluate the impact of ePOCT+ compared to usual care, we conducted a cluster randomized controlled trial in Tanzanian primary care facilities. Over 11 months, 23,593 consultations were included from 20 ePOCT+ health facilities and 20,713 from 20 usual care facilities. The use of ePOCT+ in intervention facilities resulted in a reduction in the coprimary outcome of antibiotic prescription compared to usual care (23.2% versus 70.1%, adjusted difference -46.4%, 95% confidence interval (CI) -57.6 to -35.2). The coprimary outcome of day 7 clinical failure was noninferior in ePOCT+ facilities compared to usual care facilities (adjusted relative risk 0.97, 95% CI 0.85 to 1.10). There was no difference in the secondary safety outcomes of death and nonreferred secondary hospitalizations by day 7. Using ePOCT+ could help address the urgent problem of antimicrobial resistance by safely reducing antibiotic prescribing. Clinicaltrials.gov Identifier: NCT05144763.

Development of hybrid immunity during a period of high incidence of Omicron infections

BACKGROUND

Seroprevalence and the proportion of people with neutralizing activity (functional immunity) against SARS-CoV-2 variants were high in early 2022. In this prospective, population- based, multi-region cohort study, we assessed the development of functional and hybrid immunity (induced by vaccination and infection) in the general population during this period of high incidence of infections with Omicron variants.

METHODS

We randomly selected and assessed individuals aged ≥16 years from the general population in southern (n = 739) and north-eastern (n = 964) Switzerland in March 2022. We assessed them again in June/July 2022, supplemented with a random sample from western (n = 850) Switzerland. We measured SARS-CoV-2 specific IgG antibodies and SARS-CoV-2 neutralizing antibodies against three variants (ancestral strain, Delta, Omicron).

RESULTS

Seroprevalence remained stable from March 2022 (97.6%, n = 1894) to June/July 2022 (98.4%, n = 2553). In June/July, the percentage of individuals with neutralizing capacity against ancestral strain was 94.2%, against Delta 90.8% and against Omicron 84.9%, and 50.6% developed hybrid immunity. Individuals with hybrid immunity had highest median levels of anti-spike IgG antibodies titres [4518 World Health Organization units per millilitre (WHO U/mL)] compared with those with only vaccine- (4304 WHO U/mL) or infection- (269 WHO U/mL) induced immunity, and highest neutralization capacity against ancestral strain (hybrid: 99.8%, vaccinated: 98%, infected: 47.5%), Delta (hybrid: 99%, vaccinated: 92.2%, infected: 38.7%) and Omicron (hybrid: 96.4%, vaccinated: 79.5%, infected: 47.5%).

CONCLUSIONS

This first study on functional and hybrid immunity in the Swiss general population after Omicron waves showed that SARS-CoV-2 has become endemic. The high levels of antibodies and neutralization support the emerging recommendations of some countries where booster vaccinations are still strongly recommended for vulnerable persons but less so for the general population.

Seroprevalence trends of anti-SARS-CoV-2 antibodies and associated risk factors: a population-based study

PURPOSE

We aimed to assess the seroprevalence trends of SARS-CoV-2 antibodies in several Swiss cantons between May 2020 and September 2021 and investigate risk factors for seropositivity and their changes over time.

METHODS

We conducted repeated population-based serological studies in different Swiss regions using a common methodology. We defined three study periods: May-October 2020 (period 1, prior to vaccination), November 2020-mid-May 2021 (period 2, first months of the vaccination campaign), and mid-May-September 2021 (period 3, a large share of the population vaccinated). We measured anti-spike IgG. Participants provided information on sociodemographic and socioeconomic characteristics, health status, and adherence to preventive measures. We estimated seroprevalence with a Bayesian logistic regression model and the association between risk factors and seropositivity with Poisson models.

RESULTS

We included 13,291 participants aged 20 and older from 11 Swiss cantons. Seroprevalence was 3.7% (95% CI 2.1-4.9) in period 1, 16.2% (95% CI 14.4-17.5) in period 2, and 72.0% (95% CI 70.3-73.8) in period 3, with regional variations. In period 1, younger age (20-64) was the only factor associated with higher seropositivity. In period 3, being aged ≥ 65 years, with a high income, retired, overweight or obese or with other comorbidities, was associated with higher seropositivity. These associations disappeared after adjusting for vaccination status. Seropositivity was lower in participants with lower adherence to preventive measures, due to a lower vaccination uptake.

CONCLUSIONS

Seroprevalence sharply increased over time, also thanks to vaccination, with some regional variations. After the vaccination campaign, no differences between subgroups were observed.

[Dengue fever is knocking on the doors of Europe]

Dengue is a subject of major concern in global health because its incidence is increasing, and its geographical area continues to expand. On a global scale, the projections available point in the direction of an extension of the geographical areas of the Aedes vectors, partly in connection with the increase in temperatures and the modification of precipitation cycles in the context of the climate change. This expansion is expected at the borders of the areas of current spread with, however, a possible contraction in certain areas that are now endemic. In Europe, the threat of a dengue epidemic outbreak now exists. It is on this continent that the number of new exposures in immunologically naïve people is likely to be the greatest in the near future.

Association of plasma zinc levels with anti-SARS-CoV-2 IgG and IgA seropositivity in the general population: A case-control study

INTRODUCTION

Some micronutrients have key roles in immune defence, including mucosal defence mechanisms and immunoglobulin production. Altered micronutrient status has been linked with COVID-19 infection and disease severity. We assessed the associations of selected circulating micronutrients with anti-SARS-CoV-2 IgG and IgA seropositivity in the Swiss community using early pandemic data.

METHODS

Case-control study comparing the first PCR-confirmed COVID-19 symptomatic cases in the Vaud Canton (May to June 2020, n = 199) and controls (random population sample, n = 447), seronegative for IgG and IgA. The replication analysis included seropositive (n = 134) and seronegative (n = 152) close contacts from confirmed COVID-19 cases. Anti-SARS-CoV-2 IgG and IgA levels against the native trimeric spike protein were measured using the Luminex immunoassay. We measured plasma Zn, Se and Cu concentrations by ICP-MS, and 25-hydroxy-vitamin D₃ (25(OH)D₃) with LC-MS/MS and explored associations using multiple logistic regression.

RESULTS

The 932 participants (54.1% women) were aged 48.6 ± 20.2 years (±SD), BMI 25.0 ± 4.7 kg/m² with median C-Reactive Protein 1 mg/l. In logistic regressions, log₂(Zn) plasma levels were negatively associated with IgG seropositivity (OR [95% CI]: 0.196 [0.0831; 0.465], P < 0.001; replication analyses: 0.294 [0.0893; 0.968], P < 0.05). Results were similar for IgA. We found no association of Cu, Se, and 25(OH)D₃ with anti-SARS-CoV-2 IgG or IgA seropositivity.

CONCLUSION

Low plasma Zn levels were associated with higher anti-SARS-CoV-2 IgG and IgA seropositivity in a Swiss population when the initial viral variant was circulating, and no vaccination available. These results suggest that adequate Zn status may play an important role in protecting the general population against SARS-CoV-2 infection.

REGISTRY

CORONA IMMUNITAS:: ISRCTN18181860.

Clinical evaluation of BioFire® multiplex-PCR panel for acute undifferentiated febrile illnesses in travellers: a prospective multicenter study

BACKGROUND

Identifying the causes of Acute Undifferentiated Febrile Illness(AUFI) is key to improve the management of returning travellers with fever. We evaluated a BioFire®FilmArray® prototype panel of multiplex nucleic acid amplification tests(NAAT) targeting different relevant pathogens in travellers returning with fever.

METHODS

Prospective, multicenter study to evaluate a prototype panel in whole blood samples of adult international travellers presenting with AUFI in three European travel Clinics/Hospitals (November2017-November2019). We evaluated 15 target analytes: Plasmodium spp., P.falciparum, P.knowlesi, P.malariae, P.ovale, P.vivax, chikungunya virus, dengue virus, Zika virus, Anaplasma phagocytophilum, Borrelia spp., Leptospira spp., Orientia tsutsugamushi, Rickettsia spp., Salmonella spp. Results were compared with composite reference standards(CRS) for each target infection, including direct methods (smear microscopy, rapid diagnostic test(RDT), reference NAAT, blood cultures) and indirect methods(paired serology).

FINDINGS

Among 455 travellers with AUFI, 229 target infections were diagnosed; the prototype panel detected 143 (overall sensitivity and specificity of 62.5% and 99·8%, respectively). The panel identified all Plasmodium infections(n = 82). Sensitivity for dengue(n = 71) was 92·9%; 80·8% and 68·5% compared to RDT, NAAT and CRS. Compared to direct methods and CRS, respectively, the prototype panel detected 4/4 and 4/6 chikungunya, 2/2 and 4/29 Leptospira spp., 1/1 and 1/6 O.tsutsugamushi, 2/2 and 2/55 Rickettsia spp., but 0/2 and 0/10 Zika, 0/1 and 0/11 A.phagocytophylum, 0/3 Borrelia spp. diagnosed by serology and 1/7 Salmonella spp. diagnosed by blood cultures. 77/86 (89·5%) infections not detected by the panel were diagnosed by serology.

INTERPRETATION

The prototype panel allowed rapid and reliable diagnosis for malaria, dengue and chikungunya. Further improvements are needed to improve its sensitivity for Zika and important travel-related bacterial infections.

Prevalence of SARS-CoV-2 infection and associated risk factors among asylum seekers living in asylum centres: A cross-sectional serologic study in Canton of Vaud, Switzerland

Background

Understanding the factors influencing SARS-CoV-2 transmission in asylum seekers and refugees living in centres is crucial to determine targeted public health policies protecting these populations fairly and efficiently. In response, this study was designed to explore the pandemic's spread into asylum centres during the first wave of the pandemic in Switzerland. Specifically, it aimed to identify the risk factors associated with a positive anti-SARS-CoV-2 seroprevalence test after the first semi-confinement period (16 March to 27 April 2020) amongst asylum seekers and refugees living in centres.

Methods

This research is part of SérocoVID, a seroepidemiologic study of SARS-CoV-2 infection conducted in the canton of Vaud, Switzerland. Migrants living in two asylum centres, one known to have had an epidemic outbreak, were invited to participate in this study. Anti-SARS-CoV-2 IgG and IgA antibodies targeting the spike viral protein were measured in all participants using a Luminex immunoassay. Each participant also completed a questionnaire measuring socio-demographic characteristics, medical history (comorbidities, smoking status, BMI, flu-like symptoms), health literacy, public health recommendations (wearing a masque in a public area, social distancing and hands cleaning), behaviours and exposures (daily life activities, number of contacts weekly). The association of these independent variables with the serologic test result were estimated using a multivariable logistic regression model.

Findings

A total of 124 participants from the two asylum centres took part in the study (Centre 1, n = 82; Centre 2, n = 42). The mean participation rate was 36.7%. The seroprevalence in Centres 1 and 2 were 13% [95% CI 0.03, 0.14] and 50% [0.34, 0.65], respectively. Next, 40.63% of SARS-CoV-2 positive people never developed symptoms (asymptomatic cases), and no one had severe forms of the Covid-19 disease requiring hospitalisation. Participants report high compliance with public health measures, especially hygiene rules (96.3% of positive answers) and social distancing (88.7%). However, only 11.3% said they always wore a masque in public. After adjusting for individual characteristics, infection risk was lower amongst people with high health literacy (aOR 0.16, p = 0.007 [0.04, 0.60]) and smokers (aOR 0.20, p = 0.013 [0.06, 0.69]).

Conclusion

Despite the lack of severe complications of Covid-19 disease in this study, findings suggest that developing targeted public health measures, especially for the low health literacy population, would be necessary to limit the risk of outbreaks in asylum centres and improve this population's safety. Further investigations and qualitative approach are required to understand more finely how living conditions, risks and behaviours such as tobacco consumption, and the adoption of protective measures impact SARS-CoV-2 infection.

Assembling a global database of child pneumonia studies to inform WHO pneumonia management algorithm: Methodology and applications

Background

The existing World Health Organization (WHO) pneumonia case management guidelines rely on clinical symptoms and signs for identifying, classifying, and treating pneumonia in children up to 5 years old. We aimed to collate an individual patient-level data set from large, high-quality pre-existing studies on pneumonia in children to identify a set of signs and symptoms with greater validity in the diagnosis, prognosis, and possible treatment of childhood pneumonia for the improvement of current pneumonia case management guidelines.

Methods

Using data from a published systematic review and expert knowledge, we identified studies meeting our eligibility criteria and invited investigators to share individual-level patient data. We collected data on demographic information, general medical history, and current illness episode, including history, clinical presentation, chest radiograph findings when available, treatment, and outcome. Data were gathered separately from hospital-based and community-based cases. We performed a narrative synthesis to describe the final data set.

Results

Forty-one separate data sets were included in the Pneumonia Research Partnership to Assess WHO Recommendations (PREPARE) database, 26 of which were hospital-based and 15 were community-based. The PREPARE database includes 285 839 children with pneumonia (244 323 in the hospital and 41 516 in the community), with detailed descriptions of clinical presentation, clinical progression, and outcome. Of 9185 pneumonia-related deaths, 6836 (74%) occurred in children <1 year of age and 1317 (14%) in children aged 1-2 years. Of the 285 839 episodes, 280 998 occurred in children 0-59 months old, of which 129 584 (46%) were 2-11 months of age and 152 730 (54%) were males.

Conclusions

This data set could identify an improved specific, sensitive set of criteria for diagnosing clinical pneumonia and help identify sick children in need of referral to a higher level of care or a change of therapy. Field studies could be designed based on insights from PREPARE analyses to validate a potential revised pneumonia algorithm. The PREPARE methodology can also act as a model for disease database assembly.

Adherence to Coronavirus Disease 2019 Preventive Measures in a Representative Sample of the Population of the Canton of Vaud, Switzerland

Objectives: We quantified adherence to COVID-19 preventive measures and explored associated factors, after the first and during the second Swiss epidemic waves.

Methods: With an observational cohort study in a representative sample of individuals aged 15 years and more, we analysed the association between self-reported adherence to COVID-19 preventive measures (respect of simple hygiene rules; respect of social distancing rules; wearing a mask) and socio-demographic factors, the existence of a chronic disease, and the existence of a previous confirmed COVID-19 episode.

Results: Highest adherence was to simple hygiene rules, followed by social distancing rules and mask wearing, with a slight decrease for simple hygiene rules and a strong increase for mask wearing between visits. Men were significantly less likely to respect simple hygiene rules and wear a mask in public. Participants aged 65 years and more (versus 25–64 years) and those with at least one chronic disease (versus none) were two times more likely to respect social distancing rules and wear a mask.

Conclusion: Adherence to social distancing rules and mask wearing was rather poor, especially compared to other countries.

Clinical sign and biomarker-based algorithm to identify bacterial pneumonia among outpatients with lower respiratory tract infection in Tanzania

BACKGROUND

Inappropriate antibiotics use in lower respiratory tract infections (LRTI) is a major contributor to resistance. We aimed to design an algorithm based on clinical signs and host biomarkers to identify bacterial community-acquired pneumonia (CAP) among patients with LRTI.

METHODS

Participants with LRTI were selected in a prospective cohort of febrile (≥ 38 °C) adults presenting to outpatient clinics in Dar es Salaam. Participants underwent chest X-ray, multiplex PCR for respiratory pathogens, and measurements of 13 biomarkers. We evaluated the predictive accuracy of clinical signs and biomarkers using logistic regression and classification and regression tree analysis.

RESULTS

Of 110 patients with LRTI, 17 had bacterial CAP. Procalcitonin (PCT), interleukin-6 (IL-6) and soluble triggering receptor expressed by myeloid cells-1 (sTREM-1) showed an excellent predictive accuracy to identify bacterial CAP (AUROC 0.88, 95%CI 0.78-0.98; 0.84, 0.72-0.99; 0.83, 0.74-0.92, respectively). Combining respiratory rate with PCT or IL-6 significantly improved the model compared to respiratory rate alone (p = 0.006, p = 0.033, respectively). An algorithm with respiratory rate (≥ 32/min) and PCT (≥ 0.25 μg/L) had 94% sensitivity and 82% specificity.

CONCLUSIONS

PCT, IL-6 and sTREM-1 had an excellent predictive accuracy in differentiating bacterial CAP from other LRTIs. An algorithm combining respiratory rate and PCT displayed even better performance in this sub-Sahara African setting.

Prevalence of SARS-CoV-2 and associated risk factors among asylum seekers living in centres

Background

Understanding the factors influencing SARS-CoV-2 transmission in asylum seekers and refugees living in centres is crucial to determine targeted public health policies protecting these populations. We explored the pandemic's spread into asylum centres during the first wave of the pandemic (May-June 2020) in Switzerland and factors associated with the presence of SARS-CoV-2 antibodies.

Methods

This research is part of SérocoVID, a seroepidemiologic study of SARS-CoV-2 infection conducted in Canton of Vaud, Switzerland. All migrants living in two asylum centres were invited to participate. Anti-Spike IgG and IgA antibodies were measured in all participants. Each participant completed a questionnaire measuring socio-demographic characteristics, medical history, health literacy, public health recommendations, behaviours and exposures. The association of independent variables with serologic test result were estimated using a multivariable logistic regression model.

Results

The mean (SD) age of the 124 participants (23% women) was 33.7 (11.6) years (Centre 1, n = 82; Centre 2, n = 42). The mean participation rate was 37%. The seroprevalence in Centres 1 and 2 were 13% [95% CI 3-14%] and 50 [34-65%], respectively. Next, 41% of SARS-CoV-2 positive people never developed symptoms, and no one had developed severe Covid-19 disease. After adjusting for individual characteristics and centre, seropositivity was higher among people with low health literacy (aOR 6.2, p = 0.010 [1.6, 24.8]) and non-smokers (aOR 5.4, p = 0.013 [1.4- 20.3]). No other significant associations were found.

Conclusions

Findings suggest that developing targeted public health measures, especially for low health literacy people, would be necessary to limit the risk of outbreaks in asylum centres and improve this population's safety. Further investigations are required to understand better the negative association between tobacco consumption and SARS-CoV-2 infection.

Key messages

Asylum centres require specific public health measures to guarantee their population's safety and limit the virus spread. Asylum seekers and refugees with low health literacy seem particularly vulnerable during the Covid-19 pandemic.

Procalcitonin and lung ultrasonography point-of-care testing to determine antibiotic prescription in patients with lower respiratory tract infection in primary care: pragmatic cluster randomised trial

OBJECTIVE

To assess whether point-of care procalcitonin and lung ultrasonography can safely reduce unnecessary antibiotic treatment in patients with lower respiratory tract infections in primary care.

DESIGN

Three group, pragmatic cluster randomised controlled trial from September 2018 to March 2020.

SETTING

60 Swiss general practices.

PARTICIPANTS

One general practitioner per practice was included. General practitioners screen all patients with acute cough; patients with clinical pneumonia were included.

INTERVENTIONS

Randomisation in a 1:1:1 of general practitioners to either antibiotics guided by sequential procalcitonin and lung ultrasonography point-of-care tests (UltraPro; n=152), procalcitonin guided antibiotics (n=195), or usual care (n=122).

MAIN OUTCOMES

Primary outcome was proportion of patients in each group prescribed an antibiotic by day 28. Secondary outcomes included duration of restricted activities due to lower respiratory tract infection within 14 days.

RESULTS

60 general practitioners included 469 patients (median age 53 years (interquartile range 38-66); 278 (59%) were female). Probability of antibiotic prescription at day 28 was lower in the procalcitonin group than in the usual care group (0.40 v 0.70, cluster corrected difference -0.26 (95% confidence interval -0.41 to -0.10)). No significant difference was seen between UltraPro and procalcitonin groups (0.41 v 0.40, -0.03 (-0.17 to 0.12)). The median number of days with restricted activities by day 14 was 4 days in the procalcitonin group and 3 days in the usual care group (difference 1 day (95% confidence interval -0.23 to 2.32); hazard ratio 0.75 (95% confidence interval 0.58 to 0.97)), which did not prove non-inferiority.

CONCLUSIONS

Compared with usual care, point-of-care procalcitonin led to a 26% absolute reduction in the probability of 28 day antibiotic prescription without affecting patients' safety. Point-of-care lung ultrasonography did not further reduce antibiotic prescription, although a potential added value cannot be excluded, owing to the wide confidence intervals.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03191071.

Scoping future outbreaks: a scoping review on the outbreak prediction of the WHO Blueprint list of priority diseases

BACKGROUND

The WHO's Research and Development Blueprint priority list designates emerging diseases with the potential to generate public health emergencies for which insufficient preventive solutions exist. The list aims to reduce the time to the availability of resources that can avert public health crises. The current SARS-CoV-2 pandemic illustrates that an effective method of mitigating such crises is the pre-emptive prediction of outbreaks. This scoping review thus aimed to map and identify the evidence available to predict future outbreaks of the Blueprint diseases.

METHODS

We conducted a scoping review of PubMed, Embase and Web of Science related to the evidence predicting future outbreaks of Ebola and Marburg virus, Zika virus, Lassa fever, Nipah and Henipaviral disease, Rift Valley fever, Crimean-Congo haemorrhagic fever, Severe acute respiratory syndrome, Middle East respiratory syndrome and Disease X. Prediction methods, outbreak features predicted and implementation of predictions were evaluated. We conducted a narrative and quantitative evidence synthesis to highlight prediction methods that could be further investigated for the prevention of Blueprint diseases and COVID-19 outbreaks.

RESULTS

Out of 3959 articles identified, we included 58 articles based on inclusion criteria. 5 major prediction methods emerged; the most frequent being spatio-temporal risk maps predicting outbreak risk periods and locations through vector and climate data. Stochastic models were predominant. Rift Valley fever was the most predicted disease. Diseases with complex sociocultural factors such as Ebola were often predicted through multifactorial risk-based estimations. 10% of models were implemented by health authorities. No article predicted Disease X outbreaks.

CONCLUSIONS

Spatiotemporal models for diseases with strong climatic and vectorial components, as in River Valley fever prediction, may currently best reduce the time to the availability of resources. A wide literature gap exists in the prediction of zoonoses with complex sociocultural and ecological dynamics such as Ebola, COVID-19 and especially Disease X.

Anticipating the future: prognostic tools as a complementary strategy to improve care for patients with febrile illnesses in resource-limited settings

In low-income and middle-income countries, most patients with febrile illnesses present to peripheral levels of the health system where diagnostic capacity is very limited. In these contexts, accurate risk stratification can be particularly impactful, helping to guide allocation of scarce resources to ensure timely and tailored care. However, reporting of prognostic research is often imprecise and few prognostic tests or algorithms are translated into clinical practice.

Here, we review the often-conflated concepts of prognosis and diagnosis, with a focus on patients with febrile illnesses. Drawing on a recent global stakeholder consultation, we apply these concepts to propose three use-cases for prognostic tools in the management of febrile illnesses in resource-limited settings: (1) guiding referrals from the community to higher-level care; (2) informing resource allocation for patients admitted to hospital and (3) identifying patients who may benefit from closer follow-up post-hospital discharge. We explore the practical implications for new technologies and reflect on the challenges and knowledge gaps that must be addressed before this approach could be incorporated into routine care settings.

Our intention is that these use-cases, alongside other recent initiatives, will help to promote a harmonised yet contextualised approach for prognostic research in febrile illness. We argue that this is especially important given the heterogeneous settings in which care is often provided for patients with febrile illnesses living in low-income and middle-income countries.

Performance of RT-PCR on Saliva Specimens Compared With Nasopharyngeal Swabs for the Detection of SARS-CoV-2 in Children: A Prospective Comparative Clinical Trial

BACKGROUND

Saliva reverse transcriptase-Polymerase chain reaction (RT-PCR) is an attractive alternative for the detection of severe acute respiratory syndrome coronavirus 2 in adults with less known in children.

METHODS

Children with coronavirus disease 2019 symptoms were prospectively enrolled in a 1-month comparative clinical trial of saliva and nasopharyngeal (NP) RT-PCR. Detection rates and sensitivities of saliva and NP RT-PCR were compared as well as discordant NP and saliva RT-PCR findings including viral loads (VLs).

RESULTS

Of 405 patients enrolled, 397 patients had 2 tests performed. Mean age was 12.7 years (range, 1.2-17.9). Sensitivity of saliva was 85.2% (95% confidence interval: 78.2%-92.1%) when using NP as the standard; sensitivity of NP was 94.5% (89.8%-99.2%) when saliva was considered as the standard. For a NP RT-PCR VL threshold of ≥103 and ≥104 copies/mL, sensitivity of saliva increases to 88.7% and 95.2%, respectively. Sensitivity of saliva and NP swabs was, respectively, 89.5% and 95.3% in patient with symptoms less than 4 days (P = 0.249) and 70.0% and 95.0% in those with symptoms ≥4-7 days (P = 0.096). The 15 patients who had an isolated positive NP RT-PCR were younger (P = 0.034), had lower NP VL (median 5.6 × 103 vs. 3.9 × 107, P < 0.001), and could not drool saliva at the end of the sampling (P = 0.002). VLs were lower with saliva than with NP RT-PCR (median 8.7 cp/mL × 104; interquartile range 1.2 × 104-5.2 × 105; vs. median 4.0 × 107 cp/mL; interquartile range, 8.6 × 105-1 × 108; P < 0.001).

CONCLUSIONS

While RT-PCR testing on saliva performed more poorly in younger children and likely after longer duration of symptoms, saliva remains an attractive alternative to NP swabs in children.

Causes of fever in Tanzanian adults attending outpatient clinics: a prospective cohort study

OBJECTIVES

Exploring fever aetiologies improves patient management. Most febrile adults are outpatients, but all previous studies were conducted in inpatients. This study describes the spectrum of diseases in adults attending outpatient clinics in urban Tanzania.

METHODS

We recruited consecutive adults with temperature ≥38°C in a prospective cohort study. We collected medical history and performed a clinical examination. We performed 27 364 microbiological diagnostic tests (rapid tests, serologies, cultures and molecular analyses) for a large range of pathogens on blood and nasopharyngeal samples. We based our diagnosis on predefined clinical and microbiological criteria.

RESULTS

Of 519 individuals, 469 (89%) had a clinically or microbiologically documented infection and 128 (25%) were human immunodeficiency virus (HIV) -infected. We identified 643 diagnoses: 264 (41%) acute respiratory infections (36 (5.6%) pneumonia, 39 (6.1%) tuberculosis), 71 (11%) infections with another focus (31 (4.8%) gastrointestinal, 26 (4.0%) urogenital, 8 (1.2%) central nervous system) and 252 (39%) infections without focus (134 (21%) dengue, 30 (4.7%) malaria, 28 (4.4%) typhoid). Of the 519 individuals, 318 (61%), 179 (34%), 30 (6%) and 15 (3%), respectively, had a viral, bacterial, parasitic and fungal acute infection. HIV-infected individuals had more bacterial infections than HIV-negative (80/122 (66%) versus 100/391 (26%); p < 0.001). Patients with advanced HIV disease had a higher proportion of bacterial infections (55/76 (72%) if CD4 ≤200 cells/mm3 and 25/52 (48%) if CD4 >200 cells/mm3, p 0.02).

CONCLUSIONS

Viral diseases caused most febrile episodes in adults attending outpatient clinics except in HIV-infected patients. HIV status and a low CD4 level strongly determined the need for antibiotics. Systematic HIV screening is essential to appropriately manage febrile patients.

Blood virosphere in febrile Tanzanian children

Viral infections are the leading cause of childhood acute febrile illnesses motivating consultation in sub-Saharan Africa. The majority of causal viruses are never identified in low-resource clinical settings as such testing is either not part of routine screening or available diagnostic tools have limited ability to detect new/unexpected viral variants. An in-depth exploration of the blood virome is therefore necessary to clarify the potential viral origin of fever in children. Metagenomic next-generation sequencing is a powerful tool for such broad investigations, allowing the detection of RNA and DNA viral genomes. Here, we describe the blood virome of 816 febrile children (<5 years) presenting at outpatient departments in Dar es Salaam over one-year. We show that half of the patients (394/816) had at least one detected virus recognized as causes of human infection/disease (13.8% enteroviruses (enterovirus A, B, C, and rhinovirus A and C), 12% rotaviruses, 11% human herpesvirus type 6). Additionally, we report the detection of a large number of viruses (related to arthropod, vertebrate or mammalian viral species) not yet known to cause human infection/disease, highlighting those who should be on the radar, deserve specific attention in the febrile paediatric population and, more broadly, for surveillance of emerging pathogens.Trial registration: ClinicalTrials.gov identifier: NCT02225769.

Prevalence of SARS-CoV-2 in Household Members and Other Close Contacts of COVID-19 Cases: A Serologic Study in Canton of Vaud, Switzerland

Background

Research on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission within households and other close settings using serological testing is scarce.

Methods

We invited coronavirus disease 2019 (COVID-19) cases diagnosed between February 27 and April 1, 2020, in Canton of Vaud, Switzerland, to participate, along with household members and other close contacts. Anti-SARS-CoV-2 immunoglobulin G antibodies were measured using a Luminex immunoassay. We estimated factors associated with serological status using generalized estimating equations.

Results

Overall, 219 cases, 302 household members, and 69 other close contacts participated between May 4 and June 27, 2020. More than half of household members (57.2%; 95% CI, 49.7%-64.3%) had developed a serologic response to SARS-CoV-2, while 19.0% (95% CI, 10.0%-33.2%) of other close contacts were seropositive. After adjusting for individual and household characteristics, infection risk was higher in household members aged ≥65 years than in younger adults (adjusted odds ratio [aOR], 3.63; 95% CI, 1.05-12.60) and in those not strictly adhering to simple hygiene rules like hand washing (aOR, 1.80; 95% CI, 1.02-3.17). The risk was lower when more than 5 people outside home were met during semiconfinement, compared with none (aOR, 0.35; 95% CI, 0.16-0.74). Individual risk of household members to be seropositive was lower in large households (22% less per each additional person).

Conclusions

During semiconfinement, household members of a COVID-19 case were at very high risk of getting infected, 3 times more than close contacts outside home. This highlights the need to provide clear messages on protective measures applicable at home. For elderly couples, who were especially at risk, providing external support for daily basic activities is essential.

Epidemiology of sexually transmitted infections among female sex workers in Switzerland: a local, exploratory, cross-sectional study

Female sex workers are often considered highly vulnerable to sexually transmitted infections (STIs). However, data on STI epidemiology in female sex workers are lacking in Switzerland. Our main goal was to evaluate the prevalence of six STIs (human immunodeficiency virus [HIV], hepatitis B, hepatitis C, Chlamydia trachomatis, Neisseria gonorrhoeae and syphilis) among local female sex workers in Lausanne. A local, exploratory, cross-sectional study was conducted on a convenience sample of adult (&ge;18 years) Female sex workers in Lausanne, Switzerland, from 1 April 2015 to 31 December 2016. female sex workers who worked in street sex venues, massage parlours and brothels were approached for recruitment by a local non-governmental organisation. They were then invited to present at the Lausanne University Hospital, where they were offered a free STI screening and hepatitis A and B vaccination. We enrolled 96 female sex workers. They were predominantly undocumented immigrants (60%) from Africa and Eastern Europe with no health insurance; only one participant (1%) was Swiss born. During the study, 15 (16%; 95% confidence interval [CI] 9&ndash;23%) participants were newly confirmed to have an STI: six (6%; 95% CI 1&ndash;11%) had C. trachomatis, five (5%; 95% CI 0.6-9%) latent syphilis and four (4%; 95% CI 0.1&ndash;8%) hepatitis B (three with chronic active infection and one with past exposure). No human immunodeficiency virus (HIV) infections were newly diagnosed among the participants. Nineteen (20%) of the female sex workers were already vaccinated against hepatitis B, and 73 (76%) initiated vaccination against hepatitis A and hepatitis B during the study. Forty-four (46%) of the female sex workers required translation and assistance from social services.

Aetiology of fever in returning travellers and migrants: a systematic review and meta-analysis

BACKGROUND

Numerous publications focus on fever in returning travellers, but there is no known systematic review considering all diseases, or all tropical diseases causing fever. Such a review is necessary in order to develop appropriate practice guidelines.

OBJECTIVES

Primary objectives of this review were (i) to determine the aetiology of fever in travellers/migrants returning from (sub) tropical countries as well as the proportion of patients with specific diagnoses, and (ii) to assess the predictors for specific tropical diseases.

METHOD

Embase, MEDLINE and Cochrane Library were searched with terms combining fever and travel/migrants. All studies focusing on causes of fever in returning travellers and/or clinical and laboratory predictors of tropical diseases were included. Meta-analyses were performed on frequencies of etiological diagnoses.

RESULTS

10 064 studies were identified; 541 underwent full-text review; 30 met criteria for data extraction. Tropical infections accounted for 33% of fever diagnoses, with malaria causing 22%, dengue 5% and enteric fever 2%. Non-tropical infections accounted for 36% of febrile cases, with acute gastroenteritis causing 14% and respiratory tract infections 13%. Positive likelihood ratios demonstrated that splenomegaly, thrombocytopenia and hyperbilirubinemia were respectively 5-14, 3-11 and 5-7 times more likely in malaria than non-malaria patients. High variability of results between studies reflects heterogeneity in study design, regions visited, participants' characteristics, setting, laboratory investigations performed and diseases included.

CONCLUSION

Malaria accounted for one-fifth of febrile cases, highlighting the importance of rapid malaria testing in febrile returning travellers, followed by other rapid tests for common tropical diseases. High variability between studies highlights the need to harmonize study designs and to promote multi-centre studies investigating predictors of diseases, including of lower incidence, which may help to develop evidence-based guidelines. The use of clinical decision support algorithms by health workers which incorporate clinical predictors, could help standardize studies as well as improve quality of recommendations.

Citizen Responses to Government Restrictions in Switzerland During the COVID-19 Pandemic: Cross-Sectional Survey

Background

The success of government-recommended mitigation measures during the COVID-19 pandemic depends largely on information uptake and implementation by individual citizens.

Objective

Our aim was to assess citizens’ knowledge and perceptions about COVID-19 recommendations in the Canton of Vaud, Switzerland.

Methods

A cross-sectional electronic survey with open and closed questions was disseminated by community-based partners prior to the relaxation of government restrictions. Outcomes included citizen knowledge (9-question measure) and worry about the virus, perception of government measures, and recommendations for improvements. Comparisons used linear regression, controlling for age, sex, education, and health literacy. Free-text answers were analyzed thematically.

Results

Of 807 people who accessed the survey, 684 (85%) completed all questions and 479 (60%) gave free-text recommendations. Overall, 75% were female, the mean age was 48 years, and 93% had high health literacy. Knowledge scores were high, with a median score of 8 out of 9. Mean levels of worry about the COVID-19 pandemic were higher in women than men (55/100 versus 44/100, P<.001), and in respondents with lower health literacy (57/100 versus 52/100, P=.03). Self-reported adherence to recommendations was high (85%) and increased with age and worry (both P<.001). Respondents rated their own adherence higher than others (85% versus 61%, P<.001). Moreover, 34% of respondents reported having self-quarantined; this rose to 52% for those aged ≥75 years. Those who had self-quarantined reported higher levels of fear. Nearly half (49%) of respondents felt the government response had been adequate, though younger age and higher levels of worry were associated with considering the response to be insufficient (both P<.001). Analysis of open-text answers revealed 4 major themes: access to and use of masks, gloves, and hand sanitizer; government messaging; lockdown and lockdown exit plan communication; and testing for COVID-19.

Conclusions

Knowledge, adherence, and satisfaction regarding government recommendations and response were high in this sample, but many desired greater access to personal protective equipment. Those with lower health literacy and those who have been in self-isolation reported greater concerns about the pandemic.

Clinical Outcome of Febrile Tanzanian Children with Severe Malnutrition Using Anthropometry in Comparison to Clinical Signs

Children with malnutrition compared with those without are at higher risk of infection, with more severe outcomes. How clinicians assess nutritional risk factors in febrile children in primary care varies. We conducted a post hoc subgroup analysis of febrile children with severe malnutrition enrolled in a randomized, controlled trial in primary care centers in Tanzania. The clinical outcome of children with severe malnutrition defined by anthropometric measures and clinical signs was compared between two electronic clinical diagnostic algorithms: ePOCT, which uses weight-for-age and mid-upper arm circumference to identify and manage severe malnutrition, and ALMANACH, which uses the clinical signs of edema of both feet and visible severe wasting. Those identified as having severe malnutrition by the algorithms in each arm were prescribed antibiotics and referred to the hospital. From December 2014 to February 2016, 106 febrile children were enrolled and randomized in the parent study, and met the criteria to be included in the present analysis. ePOCT identified 56/57 children with severe malnutrition using anthropometric measures, whereas ALMANACH identified 2/49 children with severe malnutrition using clinical signs. The proportion of clinical failure, defined as the development of severe symptoms by day 7 or persisting symptoms at day 7 (per-protocol), was 1.8% (1/56) in the ePOCT arm versus 16.7% (8/48) in the Algorithm for the MANagement of Childhood illnesses arm (risk difference -14.9%, 95% CI -26.0%, -3.8%; risk ratio 0.11, 95% CI 0.01, 0.83). Using anthropometric measures to identify and manage febrile children with severe malnutrition may have resulted in better clinical outcomes than by using clinical signs alone.

Electronic clinical decision support algorithms incorporating point-of-care diagnostic tests in low-resource settings: a target product profile

Health workers in low-resource settings often lack the support and tools to follow evidence-based clinical recommendations for diagnosing, treating and managing sick patients. Digital technologies, by combining patient health information and point-of-care diagnostics with evidence-based clinical protocols, can help improve the quality of care and the rational use of resources, and save patient lives. A growing number of electronic clinical decision support algorithms (CDSAs) on mobile devices are being developed and piloted without evidence of safety or impact. Here, we present a target product profile (TPP) for CDSAs aimed at guiding preventive or curative consultations in low-resource settings. This document will help align developer and implementer processes and product specifications with the needs of end users, in terms of quality, safety, performance and operational functionality. To identify the characteristics of CDSAs, a multidisciplinary group of experts (academia, industry and policy makers) with expertise in diagnostic and CDSA development and implementation in low-income and middle-income countries were convened to discuss a draft TPP. The TPP was finalised through a Delphi process to facilitate consensus building. An agreement greater than 75% was reached for all 40 TPP characteristics. In general, experts were in overwhelming agreement that, given that CDSAs provide patient management recommendations, the underlying clinical algorithms should be human-interpretable and evidence-based. Whenever possible, the algorithm’s patient management output should take into account pretest disease probabilities and likelihood ratios of clinical and diagnostic predictors. In addition, validation processes should at a minimum show that CDSAs are implementing faithfully the evidence they are based on, and ideally the impact on patient health outcomes. In terms of operational needs, CDSAs should be designed to fit within clinic workflows and function in connectivity-challenged and high-volume settings. Data collected through the tool should conform to local patient privacy regulations and international data standards.

Diagnostic Performance of Conventional and Ultrasensitive Rapid Diagnostic Tests for Malaria in Febrile Outpatients in Tanzania

BACKGROUND

A novel ultrasensitive malaria rapid diagnostic test (us-RDT) has been developed for improved active Plasmodium falciparum infection detection. The usefulness of this us-RDT in clinical diagnosis and fever management has not been evaluated.

METHODS

Diagnostic performance of us-RDT was compared retrospectively to that of conventional RDT (co-RDT) in 3000 children and 515 adults presenting with fever to Tanzanian outpatient clinics. The parasite density was measured by an ultrasensitive qPCR (us-qPCR), and the HRP2 concentration was measured by an enzyme-linked immunosorbent assay.

RESULTS

us-RDT identified few additional P. falciparum-positive patients as compared to co-RDT (276 vs 265 parasite-positive patients detected), with only a marginally greater sensitivity (75% vs 73%), using us-qPCR as the gold standard (357 parasite-positive patients detected). The specificity of both RDTs was >99%. Five of 11 additional patients testing positive by us-RDT had negative results by us-qPCR. The HRP2 concentration was above the limit of detection for co-RDT (>3653 pg of HRP2 per mL of blood) in almost all infections (99% [236 of 239]) with a parasite density >100 parasites per µL of blood. At parasite densities <100 parasites/µL, the HRP2 concentration was above the limits of detection of us-RDT (>793 pg/mL) and co-RDT in 29 (25%) and 24 (20%) of 118 patients, respectively.

CONCLUSION

There is neither an advantage nor a risk of using us-RDT, rather than co-RDT, for clinical malaria diagnosis. In febrile patients, only a small proportion of infections are characterized by a parasite density or an HRP2 concentration in the range where use of us-RDT would confer a meaningful advantage over co-RDT.

Performance of prediction rules and guidelines in detecting serious bacterial infections among Tanzanian febrile children

Background

Health-workers in developing countries rely on clinical algorithms, such as the Integrated Management of Childhood Illnesses (IMCI), for the management of patients, including diagnosis of serious bacterial infections (SBI). The diagnostic accuracy of IMCI in detecting children with SBI is unknown. Prediction rules and guidelines for SBI from well-resourced countries at outpatient level may help to improve current guidelines; however, their diagnostic performance has not been evaluated in resource-limited countries, where clinical conditions, access to care, and diagnostic capacity differ. The aim of this study was to estimate the diagnostic accuracy of existing prediction rules and clinical guidelines in identifying children with SBI in a cohort of febrile children attending outpatient health facilities in Tanzania.

Methods

Structured literature review to identify available prediction rules and guidelines aimed at detecting SBI and retrospective, external validation on a dataset containing 1005 febrile Tanzanian children with acute infections. The reference standard, SBI, was established based on rigorous clinical and microbiological criteria.

Results

Four prediction rules and five guidelines, including IMCI, could be validated. All examined rules and guidelines had insufficient diagnostic accuracy for ruling-in or ruling-out SBI with positive and negative likelihood ratios ranging from 1.04–1.87 to 0.47–0.92, respectively. IMCI had a sensitivity of 36.7% (95% CI 29.4–44.6%) at a specificity of 70.3% (67.1–73.4%). Rules that use a combination of clinical and laboratory testing had better performance compared to rules and guidelines using only clinical and or laboratory elements.

Conclusions

Currently applied guidelines for managing children with febrile illness have insufficient diagnostic accuracy in detecting children with SBI. Revised clinical algorithms including simple point-of-care tests with improved accuracy for detecting SBI targeting in tropical resource-poor settings are needed. They should undergo careful external validation against clinical outcome before implementation, given the inherent limitations of gold standards for SBI.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4371-y) contains supplementary material, which is available to authorized users.

Procalcitonin and lung ultrasonography point-of-care testing to decide on antibiotic prescription in patients with lower respiratory tract infection in primary care: protocol of a pragmatic cluster randomized trial

Background

A minority of patients presenting with lower respiratory tract infection (LRTI) to their general practitioner (GP) have community-acquired pneumonia (CAP) and require antibiotic therapy. Identifying them is challenging, because of overlapping symptomatology and low diagnostic performance of chest X-ray.

Procalcitonin (PCT) can be safely used to decide on antibiotic prescription in patients with LRTI. Lung ultrasound (LUS) is effective in detecting lung consolidation in pneumonia and might compensate for the lack of specificity of PCT.

We hypothesize that combining PCT and LUS, available as point-of care tests (POCT), might reduce antibiotic prescription in LRTIs without impacting patient safety in the primary care setting.

Methods

This is a three-arm pragmatic cluster randomized controlled clinical trial. GPs are randomized either to PCT and LUS-guided antibiotic therapy or to PCT only-guided therapy or to usual care. Consecutive adult patients with an acute cough due to a respiratory infection will be screened and included if they present a clinical pneumonia as defined by European guidelines. Exclusion criteria are previous antibiotics for the current episode, working diagnosis of sinusitis, severe underlying lung disease, severe immunosuppression, hospital admission, pregnancy, inability to provide informed consent and unavailability of the GP. Patients will fill in a 28 day-symptom diary and will be contacted by phone on days 7 and 28. The primary outcome is the proportion of patients prescribed any antibiotic up to day 28. Secondary outcomes include clinical failure by day 7 (death, admission to hospital, absence of amelioration or worsening of relevant symptoms) and by day 28, duration of restricted daily activities, episode duration as defined by symptom score, number of medical visits, number of days with side effects due to antibiotics and a composite outcome combining death, admission to hospital and complications due to LRTI by day 28. An evaluation of the cost-effectiveness and of processes in the clinic using a mixed qualitative and quantitative approach will also be conducted.

Discussion

Our intervention targets only patients with clinically suspected CAP who have a higher pretest probability of definite pneumonia. The intervention will not substitute clinical assessment but completes it by introducing new easy-to-perform tests.

Trial registration

The study was registered on the 19th of June 2017 on the clinicaltrials.gov registry using reference number; NCT03191071.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0898-3) contains supplementary material, which is available to authorized users.

Detection of dicistroviruses RNA in blood of febrile Tanzanian children

Fever is the leading cause of paediatric outpatient consultations in Sub-Saharan Africa. Although most are suspected to be of viral origin, a putative causative pathogen is not identified in over a quarter of these febrile episodes. Using a de novo assembly sequencing approach, we report the detection (15.4%) of dicistroviruses (DicV) RNA in sera collected from 692 febrile Tanzanian children. In contrast, DicV RNA was only detected in 1/77 (1.3%) plasma samples from febrile Tanzanian adults, suggesting that children could represent the primary susceptible population. Estimated viral load by specific quantitative real-time RT–PCR assay ranged from < 1.32E3 to 1.44E7 viral RNA copies/mL serum. Three DicV full-length genomes were obtained, and a phylogenetic analyse on the capsid region showed the presence of two clusters representing tentative novel genus. Although DicV-positive cases were detected throughout the year, a significantly higher positivity rate was observed during the rainy season.

This study reveals that novel DicV RNA is frequently detected in the blood of Tanzanian children, paving the way for further investigations to determine if DicV possibly represent a new agent in humans.

Large-scale implementation of electronic Integrated Management of Childhood Illness (eIMCI) at the primary care level in Burkina Faso: a qualitative study on health worker perception of its medical content, usability and impact on antibiotic prescription and resistance

Background

Electronic clinical decision algorithms (eCDAs) that guide clinicians during patient management are being deployed in resource-limited settings to improve the quality of care and rational use of medicines (especially antimicrobials). Little is known on how local clinicians perceive the use and impact of these tools in their daily practice. This study investigates clinician insights on an eIMCI tool. Specifically, we report their views on its medical content, assess their knowledge on microbes, antimicrobials and the development of resistance.

Methods

This qualitative study was conducted in the frame of a large-scale implementation in Burkina Faso of an eIMCI tool developed by the Swiss NGO Terre des hommes. Twelve in-depth interviews and 2 focus-group discussions were conducted including 21 health workers from 10 primary care facilities. Emerging themes were identified using qualitative data analysis software.

Results

eIMCI users expressed a high level of satisfaction, slowness of the tablet was perceived as the major inconvenience limiting uptake. Several frequent illnesses were identified as missing in the algorithm along with guidance for fever without focus. When asked about existing types of microbes, 9 and 4 out of 21 participants could mention bacteria and virus respectively; only 5 correctly answered that antibiotics had no action on viral disease and 6 mentioned the risk of antibiotic resistance. Level of knowledge was higher in nurses than in less trained health workers. The tool was perceived as improving patient management and the rational use of antibiotics. Positive changes in health facility organisation were reported, such as task shifting and improved triage. eIMCI was also perceived as a learning tool, and users expressed a strong desire to expand the geographic and temporal scope of the intervention.

Conclusion

The use of eICMI was widely accepted and perceived as a powerful tool guiding daily practice. Findings suggest that it has positive effects on the health care system beyond the quality of consultation. To support large uptake and sustainability, better training of health workers in infectiology is essential and the medical content of eIMCI should be optimized to include frequent diseases and, for each of them, the appropriate management plan.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6692-6) contains supplementary material, which is available to authorized users.

Screening strategy for Chagas disease in a non-endemic country (Switzerland): a prospective evaluation

The WHO recommends screening of Latin American migrants for Chagas disease to reduce morbidity and mortality and increase the likelihood of eradicating the disease. The objective was to assess the feasibility and acceptability of a screening strategy in one Swiss canton. From February 2011 to September 2012, people attending six healthcare centres of different types were offered a rapid diagnostic test if they or their mother were of Latin American origin (or, at the blood donation centre, if they had travelled for &ge;1 year in Latin America). In addition, testing was offered during events where Latin Americans gathered. In total, 1,010 people were tested, mainly originating from Brazil (24%), Ecuador (13%) and Chile (10%). 54% were born in Latin America, 15% had a Latin American mother, and 29% were travellers. The prevalence of Chagas disease was 2.3% among migrants (15.5% in the community testing) and 0% among travellers. The prevalence was 18.0%, 0.8%, 0.5% and 0% among Bolivians, Ecuadorians, Brazilians and other countries respectively. Predictors for Chagas disease were: born in Latin America (OR = infinite, p &lt;0.001), Bolivian origin (OR = 95, 95% CI: 19&ndash;482, p &lt;0.001), being tested in the community (OR = 56, 95% CI: 14&ndash;218, p &lt;0.001), and age &gt;35 years OR = 3.4, 95% CI: 1.1&ndash;10.5, p = 0.03). The prevalence of Chagas disease was much higher in people attending social events than healthcare centres, suggesting that observations based only on health facility data underestimate the real prevalence of Chagas disease. Screening in the community was well accepted and should be promoted to reach the population at highest risk.

Dengue fever in Dar es Salaam, Tanzania: clinical features and outcome in populations of black and non-black racial category

BACKGROUND

Although the incidence of dengue across Africa is high, severe dengue is reported infrequently. We describe the clinical features and the outcome of dengue according to raceduring an outbreak in Dar es Salaam, Tanzania that occurred in both native and expatriate populations.

METHODS

Adults with confirmed dengue (NS1 and/or IgM on rapid diagnostic test and/or PCR positive) were included between December 2013 and July 2014 in outpatient clinics. Seven-day outcome was assessed by a visit or a call. Association between black race and clinical presentation, including warning signs, was assessed by logistic regression adjusted for age, malaria coinfection, secondary dengue and duration of symptoms at inclusion. The independent association between demographic and comorbidities characteristics of the patients and severe dengue was evaluated by multivariate logistic regression that included potential confounders.

RESULTS

After exclusion of 3 patients of mixed race, 431 patients with dengue (serotype 2, genotype Cosmopolitan) were included: 241 of black and 190 of non-black race. Black patients were younger (median age 30 versus 41 years; p < 0.001) and attended care after a slightly longer duration of symptoms (median of 2.9 versus 2.7 days; p = 0.01). Malaria coinfection was not significantly different between black (5%) and non-black (1.6%) patients (p = 0.06). The same proportion of patients in both group had secondary dengue (13 and 14%; p = 0.78). Among warning signs, only mucosal bleed was associated with race, black race being protective (adjusted OR 0.44; 95% CI 0.21-0.92). Overall, 20 patients (4.7%) presented with severe dengue. Non-black race (adjusted OR 3.9; 95% CI 1.3-12) and previously known diabetes (adjusted OR 43; 95% CI 5.2-361) were independently associated with severe dengue.

CONCLUSIONS

Although all patients were infected with the same dengue virus genotype, black race was independently protective against a severe course of dengue, suggesting the presence of protective genetic or environmental host factors among people of African ancestry. The milder clinical presentation of dengue in black patients might partly explain why dengue outbreaks are under-reported in Africa and often mistaken for malaria. These results highlight the need to introduce point-of-care tests, beside the one for malaria, to detect outbreaks and orientate diagnosis.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT01947075 , retrospectively registered on the 13 of September 2014.

Diagnostic tools for tackling febrile illness and enhancing patient management

Most patients with acute infectious diseases develop fever, which is frequently a reason to visit health facilities in resource-limited settings. The symptomatic overlap between febrile diseases impedes their diagnosis on clinical grounds. Therefore, the World Health Organization promotes an integrated management of febrile illness. Along this line, we present an overview of endemic and epidemic etiologies of fever and state-of-the-art diagnostic tools used in the field. It becomes evident that there is an urgent need for the development of novel technologies to fulfill end-users' requirements. This need can be met with point-of-care and near-patient diagnostic platforms, as well as e-Health clinical algorithms, which co-assess test results with key clinical elements and biosensors, assisting clinicians in patient triage and management, thus enhancing disease surveillance and outbreak alerts. This review gives an overview of diagnostic technologies featuring a platform based approach: (i) assay (nucleic acid amplification technologies are examined); (ii) cartridge (microfluidic technologies are presented); (iii) instrument (various detection technologies are discussed); and at the end proposes a way that such technologies can be interfaced with electronic clinical decision-making algorithms towards a broad and complete diagnostic ecosystem.

[Travel Apps: applications and websites of travel medicine]

Advancements in technology have led to the development of medical applications (Apps) and websites. Their use is especially relevant in the field of travel medicine, be it for travelers before their trip to get specific information on how to best prevent diseases and medical emergencies, or during their trip on what to do in case of health problem while abroad. These resources are also relevant for health professionals to prepare their clients before departure and know how to deal with medical problems they are not familiar with. We searched for apps and websites for the general public and health professionals in the field of travel medicine, based on the findings of an already published systematic review, updated and adapted to make it appropriate for local use in Switzerland.

Self-diagnosis of malaria by travellers: a cohort study on the use of malaria rapid diagnostic tests provided by a Swiss travel clinic

Background

The WHO recommends that all suspect malaria cases be tested before receiving treatment. Rapid diagnostic tests (RDT) for malaria can be performed reliably by community health workers with no formal medical background and thus, RDTs could also be provided to travellers for self-diagnosis during visits to endemic regions.

Methods

RDTs were proposed during pre-travel consultations to pre-defined categories of travellers. A training run on their own blood was performed and, if carried out correctly, the traveller was given a written procedure on how to perform the test and act on its result. The travellers were then proposed to buy a malaria RDT kit and were interviewed upon their return.

Results

From February 2012 to February 2017, 744 travellers were proposed RDTs and 692 performed the training run (one could not complete it due to a hand tremor). Among the 691 subjects included, 69% travelled to moderate- or low-risk areas of malaria, 18% to high-risk areas and 13% to mixed-risk areas. The two most frequent categories of travellers to whom RDTs were proposed were long-term travellers (69%) and those travelling to remote areas (57%). 543 travellers (79%) were interviewed upon return. During their trip, 17% (91/543) had a medical problem with fever and 12% (65/543) without fever. Among 91 febrile patients, 57% (52/91) performed an RDT, 22% (20/91) consulted immediately without using the test, and 21% (19/91) did neither. Four RDTs (4/52; 8%) were positive: 2 in low-risk and 2 in high-risk areas (0.7% attack rate of self-documented malaria). Two travellers could not perform the test correctly and attended a facility or took standby emergency treatment. Four travellers with negative results repeated the test after 24 h; all were still negative. Carrying RDTs made travellers feel more secure, especially when travelling with children.

Conclusions

1/6 travellers experienced fever and 4/5 of those reacted appropriately: more than half used RDTs and a quarter consulted immediately. Four travellers (including 2 from low-risk areas) diagnosed themselves with malaria and self-treated successfully. This strategy allows prompt treatment for malaria in high-risk groups and may avoid over-diagnosis (and subsequent inappropriate treatment) of malaria on-site.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-017-2079-2) contains supplementary material, which is available to authorized users.

Malaria prevention strategies and recommendations, from chemoprophylaxis to stand-by emergency treatment: a 10-year prospective study in a Swiss Travel Clinic

BACKGROUND

There are several possible malaria prevention strategies for travellers. In Switzerland, chemoprophylaxis (CP) is recommended for persons visiting areas highly endemic for malaria and stand-by emergency treatment (SBET) for areas with moderate to low risk.

OBJECTIVE

To describe the type of malaria prevention prescribed to travel clinic attendees with a specific focus on changes over time following adaptation of recommendations.

METHODS

All pre-travel first consultation data recorded between November 2002 and December 2012 were included. Country-specific malaria preventive recommendations provided and medicines prescribed over time were analysed.

RESULTS

In total, 64 858 client-trips were recorded. 91% of travellers planned to visit a malaria endemic country. Among those clients, 42% were prescribed an antimalarial medicine as CP only, 36% as SBET only, and 3% both. Between 2002 and 2012, there was a 16% drop of CP prescription ( P  < 0.001) and a 21% increase of SBET prescription ( P  < 0.001). Among travellers receiving CP, the proportion of those prescribed mefloquine dropped from 82% in 2002 to 46% in 2012 while those prescribed atovaquone-proguanil (AP) increased from 7% to 39%. For those prescribed SBET, the proportion dropped from 46% to 30% for AP and increased from 2% to 61% for artemether-lumefantrine. CP prescription for travellers to India fell from 62% to 5% and SBET prescription increased from 40% to 88% after the change of recommendation from CP to SBET in 2005 for this country. Comparatively, CP prescription for travellers to Senegal, for which no change of recommendation occurred, remained relatively stable between 88% in 2002 and 89% in 2012.

CONCLUSION

This study shows the considerable decline of antimalarial prescription for chemoprophylaxis that occurred over the 10-year period in favour of SBET.

A prospective multicentre study of healthcare provider preference in rapid HIV testing kits: Determine versus INSTI

Rapid HIV testing may circumvent the practical barriers to HIV testing in several settings. User preference of the testing kits available has been relatively underexplored. We examined healthcare provider (HCP) ratings of two validated rapid testing kits in clinical practice. From 1 July to 1 December 2012 we prospectively recruited HCPs (clinic nurses) from three outpatient clinics linked to Lausanne University Hospital, Lausanne, Switzerland. The HCPs had experience in taking blood samples but varying experience in rapid HIV testing. Participating HCPs performed rapid HIV testing using Determine™ Combo (DETE) or INSTI™ (INSTI), according to a predefined randomization sequence, and rated practical aspects of each test using a Likert scale. Seventeen HCPs of 23 approached (74%) were eligible and agreed to participate, performing a total of 336 HIV tests. Globally, the testing procedure was rated as easy or very easy by 97% (DETE) to 99% (INSTI) of tests performed. Among experienced HCPs, DETE was rated easier than INSTI for kit storage (p < 0.001) and blood collection ( P = 0.012) while INSTI was rated easier than DETE for blood application ( P = 0.001) and test interpretation ( P = 0.005). Among less experienced HCPs, both tests performed equally with the exception of test interpretation ( P < 0.001) and overall ease of use ( P = 0.05) in favour of INSTI. Of all HCPs, 94% stated they would recommend INSTI over DETE based on the time to result, ease of test interpretation and overall ease of use. Rapid HIV testing was considered easy to perform, even by inexperienced nursing staff. Whilst both tests were considered easy to use, the HCPs in this study preferred INSTI to DETE overall, due to rapid time to result, ease of test interpretation and general ease of use.

Increased Nasopharyngeal Density and Concurrent Carriage of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis Are Associated with Pneumonia in Febrile Children

Background

We assessed nasopharyngeal (NP) carriage of five pathogens in febrile children with and without acute respiratory infection (ARI) of the upper (URTI) or lower tract, attending health facilities in Tanzania.

Methods

NP swabs collected from children (N = 960) aged 2 months to 10 years, and with a temperature ≥38°C, were utilized to quantify bacterial density of S. pneumoniae (Sp), H. influenzae (Hi), M. catarrhalis (Mc), S. aureus (Sa), and N. meningitidis (Nm). We determined associations between presence of individual species, densities, or concurrent carriage of all species combination with respiratory diseases including clinical pneumonia, pneumonia with normal chest radiography (CXR) and endpoint pneumonia.

Results

Individual carriage, and NP density, of Sp, Hi, or Mc, but not Sa, or Nm, was significantly associated with febrile ARI and clinical pneumonia when compared to febrile non-ARI episodes. Density was also significantly increased in severe pneumonia when compared to mild URTI (Sp, p<0.002; Hi p<0.001; Mc, p = 0.014). Accordingly, concurrent carriage of Sp⁺, Hi⁺, and Mc⁺, in the absence of Sa^- and Nm^-, was significantly more prevalent in children with ARI (p = 0.03), or clinical pneumonia (p<0.001) than non-ARI, and in children with clinical pneumonia (p = 0.0007) than URTI. Furthermore, Sp⁺, Hi⁺, and Mc⁺ differentiated children with pneumonia with normal CXR, or endpoint pneumonia, from those with URTI, and non-ARI cases.

Conclusions

Concurrent NP carriage of Sp, Hi, and Mc was a predictor of clinical pneumonia and identified children with pneumonia with normal CXR and endpoint pneumonia from those with febrile URTI, or non-ARI episodes.

Performance of Health Workers Using an Electronic Algorithm for the Management of Childhood Illness in Tanzania: A Pilot Implementation Study

In low-resource settings, where qualified health workers (HWs) are scarce and childhood mortality high, rational antimicrobial prescription for childhood illnesses is a challenge. To assess whether smartphones running guidelines, as compared with paper support, improve consultation process and rational use of medicines for children, a pilot cluster-randomized controlled study was conducted in Tanzania. Nine primary health-care facilities (HFs) were randomized into three arms: 1) paper algorithm, 2) electronic algorithm on a smartphone, and 3) control. All HWs attending children aged 2-59 months for acute illness in intervention HFs were trained on a new clinical algorithm for management of childhood illness (ALMANACH) either on 1) paper or 2) electronic support; 4 months after training, consultations were observed. An expert consultation was the reference for classification and treatment. Main outcomes were proportion of children checked for danger signs, and antibiotics prescription rate. A total of 504 consultations (166, 171, and 167 in control, paper, and phone arms, respectively) were observed. The use of smartphones versus paper was associated with a significant increase in children checked for danger signs (41% versus 74%, P = 0.04). Antibiotic prescriptions rate dropped from 70% in the control to 26%, and 25% in paper and electronic arms. The HWs-expert agreement on pneumonia classification remained low (expert's pneumonia identified by HWs in 26%, 30%, and 39% of patients, respectively).Mobile technology in low-income countries is implementable and has a potential to improve HWs' performance. Additional point-of-care diagnostic tests are needed to ensure appropriate management. Improving the rational use of antimicrobial is a challenge that ALMANACH can help to take up.

[New approaches of malaria prevention for travelers]

Malaria is declining in many tropical countries. This reduction challenges our usual preventive strategies. In moderate to low risk areas, the Swiss guidelines recommend a stand-by emergency treatment. Controversies between experts are numerous though. Professionals at the Travel Clinic in Lausanne has explored shared-decision making through three clinical studies. The first showed that travelers visiting moderate to low risk malaria areas prefer a standby emergency treatment rather than chemoprophylaxis. The second study investigates the use of rapid diagnostic tests by travelers. The third focuses on the prospects of tropical telemedicine. Involving the traveler into the debate is a priority, until a vaccine becomes available.

Travel-related health risks in moderately and severely immunocompromised patients: a case-control study

BACKGROUND

The number of immunocompromised persons travelling to tropical countries is increasing. The hypothesis is that this population is at increased risk of travel-related health problems but there are few data to support it. The objective was to assess the risk of travel-related health problems in immunocompromised persons when compared with the general population of travellers.

METHODS

A retrospective matched case-control study was performed. Cases were moderately or severely immunocompromised persons travelling to tropical countries and controls were non-immunocompromised persons, matched for demographic and travel characteristics. All participants responded to a phone questionnaire, asking them about any health problem they may have encountered while travelling or during the month following their return. The primary outcome was the incidence of a significant clinical event defined as repatriation, hospitalization during the travel or during the month following the return if due to a travel-related health problem and medical consultations during the trip.

RESULTS

One hundred and sixteen moderately or severely immunocompromised cases [HIV infection (15), active cancer (25), splenectomized (20), solid organ transplant recipients (4) and use of systemic immunosuppressive medication (52)] and 116 controls were included. Incidence rates of significant clinical events were higher in immunocompromised travellers (9/116, 7.8%) than in controls (2/116, 1.7%) [OR = 4.8 , 95% CI 1.01-22.70; P = 0.048]. Most cases were related to infectious diseases (5/9, 55.5%), others were pulmonary embolism (2/9, 22%), inflammatory disease and trauma (1/9, 11.1% each). There was no significant difference between the two groups regarding common health problems.

CONCLUSION

Moderately and severely immunocompromised travellers are at increased risk of developing a serious health problem during or after a trip in a tropical country. They should be well informed about the specific risks they are particularly prone to. Travel medicine health professionals should favour effective preventive measures for immunocompromised travellers and envisage stand-by antibiotic treatment.