C-reactive protein as an early biomarker for malaria infection and monitoring of malaria severity: a meta-analysis

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Association of uric acid levels with severity of Plasmodium infections: a systematic review and meta-analysis

Elevated uric acid (UA) levels have been reported in malaria patients and are particularly prominent in severe malaria cases. This study aims to synthesize the difference in UA levels between malaria patients and uninfected controls, and between patients with severe and non-severe malaria. A comprehensive literature search was carried out across databases such as Embase, MEDLINE, Ovid, PubMed, Scopus, ProQuest, and Google Scholar to identify relevant studies for inclusion. The methodological quality of the included studies was evaluated independently by two reviewers using the JBI critical appraisal tool for observational studies. A meta-analysis was performed to calculate the pooled effect sizes, expressed as Hedges' g, with 95% confidence intervals (CIs). The Hedges' g was pooled using the random-effects model. An initial search yielding a total of 1122 articles, and a final total of 19 studies being included in the review. Elevated UA levels were observed more prominently in malaria patients, especially those with severe manifestations, when compared to uninfected controls. The conducted meta-analysis demonstrated a significant elevation in UA levels in patients suffering from malaria as compared to uninfected controls (P < 0.01, Hedges's g = 1.40, 95% CI 0.84-1.95, I2 = 95.81, 16 studies). The conducted meta-analysis demonstrated a significant elevation in UA levels in patients suffering from severe malaria as compared to non-severe malaria (P < 0.01, Hedges's g = 3.45, 95% CI 1.06-5.83, I2 = 98.73, 6 studies). In summary, these findings provide valuable insights into the potential use of UA as a biomarker for malaria infection and determination of its severity. Further research is needed to validate these findings and to explore the underlying mechanisms that contribute to the elevation of UA levels during malaria infection.

A systematic review and meta-analysis of inflammatory biomarkers associated with malaria infection and disease severity

Inflammatory biomarkers; C-reactive protein (CRP), Interleukin 6 (IL-6), and tumor necrosis factor- alpha (TNF-α) play a very crucial role in disease pathogenesis. Studies conducted earlier showed the associativity of these biomarkers with malaria severity. Meta-analysis of individual biomarkers was done in many studies, while in a few others, all these candidates were estimated, but the findings were inconclusive. Therefore, a systematic review and meta-analyses were performed to evaluate differences in biomarkers mentioned above in complicated and uncomplicated malaria patients. Studies focussed on CRP, IL-6, and TNF-α with quantitative data on complicated and uncomplicated malaria patients were searched on PubMed, Scopus, and Google Scholar. The quality of the studies selected for this review was checked following Newcastle-Ottawa Scale guidelines. The standard mean difference and confidence interval of biomarkers in the targeted groups were calculated using the random effects model. Egger's test and funnel plot asymmetry were performed to assess the publication bias. Thirteen studies that qualified the inclusion criteria were considered for this meta-analysis. CRP levels were higher in complicated malaria patients than uncomplicated ones (P < 0.00001, pooled SMD: 0.90 mg/L, 95 % CI: 0.51 to 1.30 mg/L, I2: 80 %, six studies). IL-6 levels were elevated in complicated cases (P < 0.00001, pooled SMD: 0.89 pg/ml, 95 % CI: 0.66 to 1.12, I2: 99 %, four studies) and TNF-α also showed an increase in severe complicated patients (P < 0.00001, pooled SMD: 1.18 pg/ml, 95 % CI: 1 to 1.36, I2: 99 %, six studies). In most of the included studies, CRP, IL-6, and TNF-α were higher in complicated malaria patients. Nevertheless, the results of a few studies were not convincing. Due to the lack of specificity in all individual biomarkers, none had adequate diagnostic accuracy. Considering the role of pro-inflammatory cytokines in the CRP activation pathway in malaria progression, the combination of these biomarkers should be used in monitoring the disease severity.

A Randomized Trial to Assess the Impact of a Package of Diagnostic Tools and Diagnostic Algorithm on Antibiotic Prescriptions for the Management of Febrile Illnesses Among Children and Adolescents in Primary Health Facilities in Burkina Faso

BACKGROUND

Low- and middle-income countries face significant challenges in differentiating bacterial from viral causes of febrile illnesses, leading to inappropriate use of antibiotics. This trial aimed to evaluate the impact of an intervention package comprising diagnostic tests, a diagnostic algorithm, and a training-and-communication package on antibiotic prescriptions and clinical outcomes.

METHODS

Patients aged 6 months to 18 years with fever or history of fever within the past 7 days with no focus, or a suspected respiratory tract infection, arriving at 2 health facilities were randomized to either the intervention package or standard practice. The primary outcomes were the proportions of patients who recovered at day 7 (D7) and patients prescribed antibiotics at day 0.

RESULTS

Of 1718 patients randomized, 1681 (97.8%; intervention: 844; control: 837) completed follow-up: 99.5% recovered at D7 in the intervention arm versus 100% in standard practice (P = .135). Antibiotics were prescribed to 40.6% of patients in the intervention group versus 57.5% in the control arm (risk ratio: 29.3%; 95% CI: 21.8-36.0%; risk difference [RD]: -16.8%; 95% CI: -21.7% to -12.0%; P < .001), which translates to 1 additional antibiotic prescription saved every 6 (95% CI: 5-8) consultations. This reduction was significant regardless of test results for malaria, but was greater in patients without malaria (RD: -46.0%; -54.7% to -37.4%; P < .001), those with a respiratory diagnosis (RD: -38.2%; -43.8% to -32.6%; P < .001), and in children 6-59 months old (RD: -20.4%; -26.0% to -14.9%; P < .001). Except for the period July-September, the reduction was consistent across the other quarters (P < .001).

CONCLUSIONS

The implementation of the package can reduce inappropriate antibiotic prescription without compromising clinical outcomes.

CLINICAL TRIALS REGISTRATION

clinicaltrials.gov; NCT04081051.

Host biomarkers for early identification of severe imported Plasmodium falciparum malaria

BACKGROUND

Severe imported P. falciparum malaria is a source of morbi-mortality in non-endemic regions. WHO criteria don't accurately classify patients at risk of complications. There is a need to evaluate new tools such as biomarkers to better identify patients with severe imported malaria.

METHODS

A case-control study was conducted in Barcelona, from January 2011-January 2021. Adult patients with microbiologically confirmed P. falciparum malaria were classified according to WHO criteria. Patients with imported non-malarial fevers were included as controls. In each group, angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), soluble triggering receptor expressed on myeloid cells (sTREM-1), C-reactive protein (CRP) and platelets were measured and their concentrations were compared between groups. New groups were made with a modified WHO severity classification and biomarkers' performance was evaluated using multiple imputation models.

RESULTS

131 participants were included: 52 severe malaria, 30 uncomplicated malaria and 49 non-malarial fever cases. All biomarkers except sTREM-1 showed significant differences between groups. Using the modified WHO severity classification, Ang-2 and CRP presented the best AUROC; 0.79 (95%CI 0.64-0.94) and 0.80(95%CI 0.67-0.93). A model combining CRP and Ang-2 showed the best AUROC, of 0.84(95%CI 0.68-0.99), with the highest sensitivity and specificity: 84.6%(95%CI 58.9-98.1) and 77.4% (95%CI 65.9-87.7), respectively.

CONCLUSIONS

The combination of Ang-2 and CRP may be a reliable tool for the early identification of severe imported malaria. The use of a rapid prognostic test including the mentioned biomarkers could optimize imported malaria management, with the potential to decrease the rate of complications and hospitalizations in patients with imported malaria.

Expression of TRIM56 gene in SARS-CoV-2 variants and its relationship with progression of COVID-19

Aim

The present study aimed to determine a correlation between differential TRIM56 expression levels and severe infections of COVID-19 between the Alpha, Delta and Omicron BA.5 variants.

Materials & methods

This study was performed on 330 COVID-19 patients, including 142 with severe and 188 with mild infections, as well as 160 healthy controls. The levels of TRIM56 gene expression were determined using a qPCR.

Results

TRIM56 gene showed significantly lower mRNA expression in the severe and mild groups compared with healthy individuals. Our finding indicated the high and low reduction of TRIM56 mRNA expression in Delta and Omicron BA.5 variant, respectively.

Conclusion

Further research is needed to characterize the impact of TRIM proteins on the severity of COVID-19.

Procalcitonin as a Candidate Biomarker for Malarial Infection and Severe Malaria: A Meta-Analysis

Procalcitonin (PCT), as a marker of malaria severity, remains to be investigated. The present study collated and compared the levels of PCT between patients with severe malaria, uncomplicated malaria, and control participants to assess their role in predicting malaria infection and disease severity. The systematic review was registered at PROSPERO with registration number CRD42021297243. The search for relevant studies that reported PCT in patients with malaria was performed in PubMed, Scopus, and Web of Science. The following meta-analyses were conducted; (1) the pooled mean PCT levels in patients with severe and uncomplicated malaria, and (2) the pooled mean difference in PCT levels between patients with severe and uncomplicated malaria. Fifteen studies were included for qualitative and quantitative syntheses. The meta-analysis results show that the pooled mean PCT levels in patients with uncomplicated malaria were 3.92 ng/mL (95% CI: 2.26-5.58 ng/mL, I²: 96.5, five studies), whereas the pooled mean PCT levels in patients with severe malaria were 14.13 ng/mL (95% CI: 8.75-19.5 ng/mL, I²: 92.6, six studies). The meta-analysis showed that patients with severe malaria had an equal mean of PCT compared to those with uncomplicated malaria when the random-effects model was used (p: 0.055, weighted mean difference: 6.93, 95% CI: -0.16-14.02, I²: 84.6%, four studies). There were probable correlations between the level of parasitemia, immunity level, and possibly bacterial or other parasitic co-infection that could affect the PCT level among different clinical severities of malaria. Therefore, the PCT level alone does not seem to be a suitable biomarker to discriminate the severe/uncomplicated or infected/uninfected cases. Further studies should investigate the increased PCT levels in combination with other markers in association with malaria infection and severity.

Sickle cell anaemia and severe Plasmodium falciparum malaria: a secondary analysis of the Transfusion and Treatment of African Children Trial (TRACT)

BACKGROUND

Sickle cell anaemia (SCA) has historically been associated with high levels of childhood mortality in Africa. Although malaria has a major contribution to this mortality, to date, the clinical pathology of malaria among children with SCA has been poorly described. We aimed to explore the relationship between SCA and Plasmodium falciparum malaria in further detail by investigating the burden and severity of malaria infections among children recruited with severe anaemia to the TRACT trial of blood transfusion in Africa.

METHODS

This study is a post-hoc secondary analysis of the TRACT trial data, conducted after trial completion. TRACT was an open-label, multicentre, factorial, randomised controlled trial enrolling children aged 2 months to 12 years who presented with severe anaemia (haemoglobin <6·0 g/dL) to four hospitals in Africa. This secondary analysis is restricted to Uganda, where the birth prevalence of SCA is approximately 1% and malaria transmission is high. Children were classified as normal (HbAA), heterozygous (HbAS), or homozygous (HbSS; SCA) for the rs334 A→T sickle mutation in HBB following batch-genotyping by PCR at the end of the trial. To avoid confounding from SCA-specific medical interventions, we considered children with an existing diagnosis of SCA (known SCA) separately from those diagnosed at the end of the trial (unknown SCA). The outcomes considered in this secondary analysis were measures of P falciparum parasite burden, features of severe malaria, and mortality at day 28 in malaria-positive children.

FINDINGS

Between Sept 17, 2014, and May 15, 2017, 3944 children with severe anaemia were enrolled into the TRACT trial. 3483 children from Uganda were considered in this secondary analysis. Overall, 1038 (30%) of 3483 Ugandan children had SCA. 1815 (78%) of 2321 children without SCA (HbAA) tested positive for P falciparum malaria, whereas the prevalence was significantly lower in children with SCA (347 [33%] of 1038; p<0·0001). Concentrations of plasma P falciparum histidine-rich protein 2 (PfHRP2), a marker of the total burden of malaria parasites within an individual, were significantly lower in children with either known SCA (median 8 ng/mL; IQR 0-57) or unknown SCA (7 ng/mL; 0-50) than in HbAA children (346 ng/mL; 21-2121; p<0·0001). In contrast to HbAA children, few HbSS children presented with classic features of severe and complicated malaria, but both the frequency and severity of anaemia were higher in HbSS children. We found no evidence for increased mortality at day 28 in those with SCA compared with those without SCA overall (hazard ratios 1·07 [95% CI 0·31-3·76] for known SCA and 0·67 [0·15-2·90] for unknown SCA).

INTERPRETATION

The current study suggests that children with SCA are innately protected against classic severe malaria. However, it also shows that even low-level infections can precipitate severe anaemic crises that would likely prove fatal without rapid access to blood transfusion services.

FUNDING

UK Medical Research Council, Wellcome, and UK National Institute for Health and Care Research.

A systematic review and meta-analysis of blood interleukin-4 levels concerning malaria infection and severity

Background

Interleukin (IL)-4 had been linked to malaria severity, but the findings are controversial, and the evidence is inconsistent and imprecise. In the current investigation, data on IL-4 levels in patients with severe and uncomplicated malaria were compiled.

Methods

The systematic review was registered at PROSPERO (CRD42022323387). Searches for relevant articles on IL-4 levels in patients with severe malaria and studies that examined IL-4 levels in both uncomplicated malaria and healthy controls were performed in PubMed, Embase, and Scopus using the search strategy without limitation to publication years or language. The quality of all included studies was evaluated using The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: standards for reporting observational studies. Qualitative and quantitative data syntheses were performed. The random-effects model, which weights each study according to its between- and within-study variance, was used to pool the mean difference (MD) of individual studies. The degree of heterogeneity was determined using Cochran's Q and I² statistics. Additionally, meta-regression and subgroup analyses were perfomed to investigate possible sources of heterogeneity. The outliers were identified using the leave-one-out method and assessed publication bias using funnel plots, Egger’s test, and a contour-enhanced funnel plot.

Results

A total of 2300 studies were identified through database searches, and 36 were included for analyses. The meta-analysis results showed lower mean IL-4 levels in severe malaria (434 cases) than in uncomplicated malaria (611 cases) (P = 0.01, pooled MD: −3.36 pg/mL, 95% confidence intervals CI −5.55 to −1.16 pg/mL, I²: 98.15%, 11 studies). The meta-analysis results showed no difference in mean IL-4 levels between cerebral malaria (96 cases) and noncerebral severe malaria (108 cases) (P = 0.71, pooled MD: 0.86 pg/mL, 95% CI −3.60 to 5.32 pg/mL, I² 92.13%, four studies). Finally, no difference was found in mean IL-4 levels between uncomplicated malaria (635 cases) and healthy controls (674 cases) (P = 0.57, pooled MD: 0.79 pg/mL, 95% CI −1.92 to 3.50 pg/mL, I²: 99.89%, 11 studies).

Conclusion

The meta-analysis revealed lower IL-4 levels in patients with severe malaria than in those with uncomplicated malaria, though a trend toward comparable IL-4 levels between both groups was more likely because several sources of heterogeneities were observed. Based on the limited number of studies included in the meta-analysis, until additional investigations have been conducted, IL-4 consideration as an alternative prognostic factor for malaria severity is not warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04237-z.

Factors associated with prolonged hospital stay of imported malaria cases in Chengdu, China: a retrospective study

BACKGROUND

Although China has entered the post-malaria-elimination era, imported cases remain a public health concern in China.

METHODS

We retrospectively analyzed data from cases of imported malaria from January 2017 to December 2020 in Chengdu Public Health Clinical Center. We assessed potential clinical, epidemiological, geographical, and seasonal effects on duration of hospital stay. Cox proportional hazards model was used to identify predictive factors for prolonged hospital stay. Multivariate logistic regression was used to assess the potential risk factors associated with severe cases.

RESULTS

The highest number of imported cases of malaria were from the Democratic Republic of the Congo (23%, 34/150) and most patients (74%, 26/34) were infected by Plasmodium falciparum. The Edwards test indicated no significant seasonality in imported cases of malaria (χ² = 2.51, p = 0.28). Bacterial infection (adjusted hazard ratio [aHR] for discharge = 0.58, p = 0.01) and thrombocytopenia (aHR = 0.66, p = 0.02) were risk factors for prolonged hospital stay. The C-reactive protein (OR = 1.02, p = 0.01) and procalcitonin (OR = 1.03, p = 0.01) were risk factors for severe cases.

CONCLUSIONS

Bacterial infection and thrombocytopenia are risk factors for prolonged hospital stay among imported malaria cases. The C-reactive protein and procalcitonin level were risk factors for severe cases.

Malaria and Helminthic Co-Infection during Pregnancy in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Malaria and helminthic co-infection during pregnancy causes fetomaternal haemorrhage and foetal growth retardation. This study determined the pooled burden of pregnancy malaria and helminthic co-infection in sub-Saharan Africa. CINAHL, EMBASE, Google Scholar, Scopus, PubMed, and Web of Science databases were used to retrieve data from the literature, without restricting language and publication year. The Joanna Briggs Institute’s critical appraisal tool for prevalence studies was used for quality assessment. STATA Version 14.0 was used to conduct the meta-analysis. The I² statistics and Egger’s test were used to test heterogeneity and publication bias. The random-effects model was used to estimate the pooled prevalence at a 95% confidence interval (CI). The review protocol has been registered in PROSPERO, with the number CRD42019144812. In total, 24 studies (n = 14,087 participants) were identified in this study. The pooled analysis revealed that 20% of pregnant women were co-infected by malaria and helminths in sub-Saharan Africa. The pooled prevalence of malaria and helminths were 33% and 35%, respectively. The most prevalent helminths were Hookworm (48%), Ascaris lumbricoides (37%), and Trichuris trichiura (15%). Significantly higher malaria and helminthic co-infection during pregnancy were observed. Health systems in sub-Saharan Africa must implement home-grown innovative solutions to underpin context-specific policies for the early initiation of effective intermittent preventive therapy.