Brief clinical and laboratory observation

Value of the C-reactive protein test in the differentiation of bacterial and viral pneumonia†

In the One Health context, Integrated Wildlife Monitoring (IWM) merges wildlife health monitoring (WHM) and host community monitoring to early detect emerging infections, record changes in disease dynamics, and assess the impact of interventions in complex multi-host and multi-pathogen networks. This study reports the deployment and results obtained from a nationwide IWM pilot test in eleven sites representing the habitat diversity of mainland Spain. In each study site, camera-trap networks and sampling of indicator species for antibody and biomarker analysis were used to generate information. The results allowed identifying differences in biodiversity and host community characteristics among the study sites, with a range of 8 to 19 relevant host species per point. The Eurasian wild boar (Sus scrofa) was the most connected and central species of the host communities, becoming a key target indicator species for IWM. A negative relationship between biodiversity and disease risk was detected, with a lower number and prevalence of circulating pathogens in the sites with more species in the community and larger network size. However, this overall trend was modified by specific host-community and environmental factors, such as the relative index of wild boar - red deer interactions or the proximity to urban habitats, suggesting that human-driven imbalances may favour pathogen circulation. The effort of incorporating wildlife population monitoring into the currently applied WHM programs to achieve effective IWM was also evaluated, allowing to identify population monitoring as the most time-consuming component, which should be improved in the future. This first nationwide application of IWM allowed to detect drivers and hotspots for disease transmission risk among wildlife, domestic animals, and humans, as well as identifying key target indicator species for monitoring. Moreover, anthropogenic effects such as artificially high wildlife densities and urbanisation were identified as risk factors for disease prevalence and interspecific transmission.

Point-of-care (POC) C-reactive protein (CRP) testing is employed in European primary care settings to differentiate viral from bacterial respiratory tract infections (RTIs) the latter, requiring referral for antibiotics. This service has yet to be trialled in Australian community pharmacy to support over-the-counter RTI management.

To evaluate the feasibility, based on clinical and operational outcomes, of POC CRP testing to support Western Australian community pharmacists’ management of RTIs.

Patients with RTI signs and symptoms were recruited from June–August 2019 at 5 community pharmacies. Trained pharmacists made recommendations based on participants’ POC CRP levels and routine clinical assessment. Participants completed questionnaires and telephone follow-ups on Days 3 (by pharmacists) and 5 (by researchers) post-testing. Service provision and uptake were assessed in 3 separate weekly tally sheets.

Clinical outcomes: CRP levels among the 131 participants recruited were: < 5 mg/L (bacterial infection unlikely; n = 60; 45.8%); 5–19 mg/L (bacterial infection possible if suggestive routine assessment; n = 52; 39.7%) and 20–100 mg/L (bacterial infection likely if suggestive routine assessment; n = 19; 14.5%). Pharmacists’ management included over-the-counter medicines (131, 100%), self-care advice (125, 95.4%) and immediate general practitioner (GP) referral (15, 11.5%). Sixty-five percent (76/117) of participants had recovered by Day 5. Operational outcomes: The services was provided in 21.2% of eligible RTI presentations, representing a service uptake rate of 28.1%. Post-CRP testing, 50.9% (58/114) of participants had changed perceptions regarding their need for antibiotics, with 14.3% (16/112) subsequently intending to seek a GP prescription. Consumer satisfaction was high (100%) and most participants (93.4%, 123/131) would utilise the service again.

POC CRP testing was a feasible and well-accepted strategy to facilitate community pharmacy as a triage point for RTI. Consumer confidence in the pharmacists’ advice, supported by CRP testing, potentially reduced unnecessary GP visits and antibiotic prescribing.

This study aimed to find a method to distinguish between bacterial and viral infection by measuring inflammatory markers in the early phase of the illness. We examined the activity of acute phase proteins, including C-reactive protein (CRP), serum amyloid A (SAA), and 2′-5′-oligoadenylate synthetase (2-5A synthetase), in sera obtained from children with bacterial and viral infections that were diagnosed by isolation of the pathogen or by positive serology. Increases in levels of CRP and SAA generally paralleled each other. In the acute stage of bacterial infections, CRP levels were moderately or highly increased and 2-5A synthetase levels were normal, whereas in viral infections, CRP levels were normal or slightly increased and 2-5A synthetase levels were increased. To better distinguish between bacterial and viral infection we used the ratio of CRP (mg/l) to 2-5A synthetase (pmol/dl) ×10 as the differential index. The values for this index in bacterial infections ranged from 3.9 to 50, and were higher than the values in viral infections, which ranged from 0 to 0.9. We propose that the measurement of both CRP and 2-5A synthetase during the acute phase of illness (within 5 days of onset) is of value to determine whether the infection is caused by a bacteria or virus.