Prevalence of malaria and performance of a rapid diagnostic test for malaria in febrile children with sickle cell disease

Performance of an HRP-2 based (First Response®) and p-LDH-based (Optimal®) rapid diagnostic tests for diagnosis of malaria in paediatric sickle cell disease patients

BACKGROUND

Rapid diagnostic tests (RDTs) have been extensively evaluated and play an important role in malaria diagnosis. However, the accuracy of RDT for malaria diagnosis in patients with sickle cell disease (SCD) is unknown.

METHODS

We compared the performance of a histidine rich protein 2 (HRP-2) - based RDT (First Response®), and a lactate dehydrogenase (LDH) - based RDT (Optimal®) with routine microscopy as reference standard in 445 SCD children with an acute febrile illness in Accra, Ghana.

RESULTS

The overall sensitivity, specificity, positive and negative predictive values of the HRP-2 based RDT were, 100%, 95.7%, 73.8% and 100%, respectively. Comparable values for the LDH based RDT were, 91.7%, 99.5%, 95.7% and 99.0% respectively. A total of 423 results were true in both tests, one result was false in both tests, 16 results were false in the HRP-2 test only and 5 were false in the LDH test only (McNemar's test, p=0.03). At follow up, 73.7 % (28/38), 52.6 % (20/38), 48.6 % (17/35), and 13.2 % (5/38) of study participants were HRP-2 positive on days 14, 28, 35 and 42, respectively, compared to 0, 2.6 % (1/38), 2.9 % (1/35), and 2.6 % (1/38) for LDH.

CONCLUSION

The HRP2 based RDT fulfilled WHO criteria for malaria diagnosis in SCD patients and may provide diagnostic evidence for treatment to begin in cases where treatment would otherwise have begun presumptively based on symptoms, while LDH based RDT may be more suitable as a confirmatory test in low-parasitaemic sub-groups, such as SCD patients.

High value of rapid diagnostic tests to diagnose malaria within children: A systematic review and meta-analysis

Background

Children aged under five years accounted for 61% of all malaria deaths worldwide in 2017, and quicker differential diagnosis of malaria fever is vital for them. Rapid diagnostic tests (RDTs) are strips to detect

Plasmodium

specific antigens promptly and are helpful in resource-limited areas. Thus, our aim is to assess the diagnostic accuracy of RDTs for malaria in children against the gold standard.

Methods

MEDLINE, Web of Science, EMBASE, Cochrane Library, the China National Knowledge Infrastructure, Wanfang, and Sinomed databases were systematically searched on August 23, 2019. Studies that compared RDTs with microscopy or polymerase chain reaction in malaria diagnoses for children were eligible. Relevant data were extracted. The quality of studies was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies instrument. Meta-analyses were carried out to calculate the pooled estimates and 95% confidence intervals of sensitivity and specificity.

Results

51 articles were included. For diagnostic accuracy, the pooled estimates of the sensitivity and specificity of RDTs were 0.93 (95% confidence interval (CI) = 0.90, 0.95) and 0.93 (95% CI = 0.90, 0.96) respectively. Studies were highly heterogeneous, and subgroup analyses showed that the application of RDTs in high malaria transmission areas had higher sensitivity but lower specificity than those in low-to-moderate areas.

Conclusions

RDTs have high accuracy for malaria diagnosis in children, and this characteristic is more prominent in high transmission areas. As they also have the advantages of rapid-detection, are easy-to-use, and can be cost-effective, it is recommended that the wider usage of RDTs should be promoted, especially in resource-limited areas. Further research is required to assess their performance in WHO South-East Asia and Americas Region.