Evaluation of C-reactive protein and myxovirus resistance protein A to guide the rational use of antibiotics among acute febrile adult patients in Northwest Ethiopia

Performance evaluation of a combination Plasmodium dual-antigen CRP rapid diagnostic test in Lambaréné, Gabon

PURPOSE

The consequent use of malaria rapid diagnostic tests (RDTs) preceding a treatment decision has improved the global management of malaria. A combination RDT, including an inflammation marker to potentially guide antibiotic prescription, could improve the management of acute febrile illness (AFI).

METHODS

We performed a prospective, cross-sectional study in Gabon evaluating the STANDARD Malaria/CRP DUO (S-DUO) RDT. Participants aged 2 to 17 years with fever at presentation and/or a history of fever < 7 days were enrolled. Expert microscopy, SD Bioline Malaria Ag P.f/Pan test for malaria detection, and NycoCard CRP device for CRP were used as comparators. AFI cases were classified on a spectrum encompassing bacterial vs. non-bacterial infection.

RESULTS

415 participants with AFI were enrolled. S-DUO RDT sensitivity and specificity for malaria detection vs. microscopy were 99·1% (95·2-100%) and 72·7% (64·3-80·1%); and for CRP detection (20 mg/L and above) 86·9% (80-92%) and 87% (79·2-92·7%), respectively. The difference in CRP levels between bacterial infection (mean = 41·2 mg/L) and other causes of fever, measured from our study population using the Nycocard device, was statistically significant (p < 0·01); CRP precision-recall AUC to distinguish bacterial infection class vs. non-bacterial classifications was 0·79.

CONCLUSION

S-DUO RDT is suitable for malaria detection in moderate-to-high malaria transmission settings such as in Lambaréné; however, a CRP band detection limit > 40 mg/L is more adequate for indication of antibiotic prescription for AFI cases in Gabon.

Recent updates of interferon-derived myxovirus resistance protein A as a biomarker for acute viral infection

BACKGROUND

Antibiotic resistance (AMR) remains a global public health threat with a high burden in sub-Saharan countries. The overuse of antimicrobials in the clinical setting is the main factor for the spread of antibiotic resistance. Diagnostic uncertainty in differentiating between bacterial and viral infections is the major contributor to antimicrobial overuse. The available biomarkers lack specificity in guiding clinicians to make antibiotic decisions and only estimate bacterial infection.

MAIN BODY

Myxovirus resistance (Mx) proteins are a type of interferon (IFN)-inducible protein that belongs to the dynamin superfamily of large guanine triphosphates (GTPases) involved in broad antiviral responses. Myxovirus resistance protein A (MxA) is a host-derived biomarker with antiviral properties against various viruses. It is induced by IFN I and IFN III as part of the innate immune response. Its basal level is < 15 ng/ml and elevated levels are detectable 1-2 h after IFN induction and remain detectable in serum up to 10 days after viral infection. Increased levels in the blood are associated with viral infection and remain low during bacterial infections. This biomarker showed promising performance in diagnosing undifferentiated febrile patients with respiratory tract infections. In this review, we discuss the role of Mx proteins, specifically MxA, in diagnosing acute viral infections, including how they are induced and their potential as diagnostic tools.

METHODS

A comprehensive electronic search was conducted in Scopus and Medline (using the PubMed interface) regarding myxovirus resistance protein A as a biomarker for acute viral infection. In the search strategy, English language was used without date restriction. Manual search was also performed when appropriate.

CONCLUSIONS

Elevated MxA combined with other biomarkers, such as CRP and PCT, is a promising tool for identifying patients with viral infections. Therefore, incorporating MxA in the existing point of care formats help to improve the antibiotic stewardship programs and future randomized controlled trials are recommended to evaluate its utility in medical practice.

Developing a Tool for Differentiation Between Bacterial and Viral Respiratory Infections Using Myxovirus Resistance Protein A and C-Reactive Protein

INTRODUCTION

The aim was to assess the performance of a blood assay combining measurements of MxA (myxovirus resistance protein A) and CRP (C-reactive protein) to differentiate viral from bacterial respiratory infections.

METHODS

In a prospective study, MxA and CRP were measured in the blood by the AFIAS panel in adults admitted with respiratory infection. Patients were split into discovery and validation cohorts. Final diagnosis was adjudicated by a panel of experts. Microbiology-confirmed cases comprised the discovery cohort, and infections adjudicated as highly probable viral or bacterial comprised the validation cohort.

RESULTS

A total of 537 patients were analyzed: 136 patients were adjudicated with definitive viral infections and 131 patients with definitive bacterial infections. Using logistic regression analysis, an equation was developed to calculate the probability for bacterial infection using the absolute value of MxA and CRP. Calculated probability ≥ 0.5 and/or MxA to CRP ratio less than 2 applied as the diagnostic rule for bacterial infections. This rule provided 91.6% sensitivity and 90.4% negative predictive value for the diagnosis of bacterial infections. This diagnostic sensitivity was confirmed in the validation cohort. A MxA/CRP ratio less than 0.15 was associated with unfavorable outcome.

CONCLUSION

The calculation of the probability for bacterial infection using MxA and CRP may efficiently discriminate between viral and bacterial respiratory infections.

Detection of dengue virus infection in children presenting with fever in Hawassa, southern Ethiopia

Dengue fever is a mosquito-borne viral infection, with rising incidence globally. Eastern Ethiopia has had dengue fever outbreaks in recent years. However, the extent to which the infection contributes to hospital presentation among children with fever in southern Ethiopia is unknown. We examined 407 stored plasma samples collected to investigate the aetiology of fever in children aged at least 2 months and under 13 years presenting to the outpatient of the largest tertiary hospital in southern Ethiopia. We analyzed samples for dengue virus non-structural 1 antigen using enzyme-linked immunosorbent assay. The median (interquartile range) age of the 407 children examined was 20 (10-48) months, and 166 (40.8%) of the children were females. Of 407 samples analyzed, 9 (2.2%) were positive for dengue virus non-structural 1 antigen, of whom 2 were initially treated with antimalarial drugs despite having negative malaria microscopy, and 1 of the 8 patients had a persistent fever at the seventh day of follow-up time. The presence of active dengue virus infection in the study area highlights the need for studies at the community level as well as the integration of dengue diagnostics into fever-management strategies. Further research to characterize circulating strains is warranted.

Differences in diagnosis, management, and outcomes of acute febrile illness by health facility level in southern Ethiopia

We assessed the diagnosis, management and outcomes of acute febrile illness in a cohort of febrile children aged under 5 years presenting at one urban and two rural health centres and one tertiary hospital between 11 August 2019 and 01 November 2019. Pneumonia was diagnosed in 104 (30.8%) of 338 children at health centres and 128 (65.0%) of 197 at the hospital (p < 0.001). Malaria was detected in 33 (24.3%) of 136 children at the urban health centre, and in 55 (55.6%) of 99 and 7 (7.4%) of 95 children at the rural health centres compared to 11 (11.6%) of 95 at the hospital. Antibacterials were prescribed to 20 (11.5%) of 174 children without guidelines-specified indications (overprescribing) at health centres and in 7 (33.3%) of 21 children at the hospital (p = 0.013). Antimalarials were overprescribed to 13 (7.0%) of 185 children with negative malaria microscopy at the hospital. The fever resolved by day 7 in 326 (99.7%) of 327 children at health centres compared to 177 (93.2%) of 190 at the hospital (p < 0.001). These results suggest that additional guidance to health workers is needed to optimise the use of antimicrobials across all levels of health facilities.

Etiologies of acute undifferentiated febrile illness at the emergency ward of the University of Gondar Hospital, Ethiopia

OBJECTIVE

Causes of acute febrile illness (AFI) often remain undetermined in developing countries, due to overlap of symptoms and limited available diagnostics. We aimed to assess the etiology of AFI in adults in a referral hospital in northwest Ethiopia.

METHODS

While all participants were tested for malaria by rapid diagnostic test (RDT), microscopy was only done on physician's request. Dengue virus (DENV) infections were detected using an RDT and ELISAs and dengue, yellow fever and chikungunya cases were identified by PCR. Bacterial etiologies were investigated using blood culture and PCR.

RESULTS

The etiology of acute infection was identified for 20.5% of 200 patients enrolled. 11.0% tested positive for Plasmodium, while microscopy was only requested for half of the identified malaria cases. For 4.0% of the Plasmodium-infected patients, an acute or past DENV (co-)infection was detected. We found 7.5% acute and 13.0% past DENV - all serotype 3 - infections. Bacterial infections were observed in 4.5% of the patients.

CONCLUSION

Malaria is still a considerable etiology of AFI and dengue is underrecognized. There are areas where both diseases occur concomitantly, and the DENV-3 serotype spreads from Sudan to northern Ethiopia. As only 20.5% of the etiologies were identified, a broader testing platform is required.