Reliability of rapid diagnostic tests in diagnosing pregnancy and infant-associated malaria in Nigeria

Accuracy of rapid diagnostic test to diagnose malaria in children under 5 years of age, a meta-analysis

OBJECTIVE

To assess the accuracy of the rapid diagnostic test for malaria diagnosis in children under 5 years of age.

METHODS

As of August 31, 2020, PubMed, Web of Science and Cochrane Library databases had been systematically searched. Relevant data were extracted and meta-analysis was carried out. A random effects model was used for subgroup analysis.

RESULTS

According to the inclusion criteria, a total of 26 studies were included in this meta-analysis. The pooled sensitivity and specificity were 0.92 (95% confidence interval 0.83-0.96) and 0.92 (0.86-0.95), the parasite-specific lactate dehydrogenase-based test were 0.96 (0.85-0.98) and 0.93 (0.86-0.95), the histidine-rich protein 2-based test were 0.94 (0.84-0.98) and 0.86 (0.77-0.91).

CONCLUSIONS

This meta-analysis showed that rapid diagnostic test had good accuracy in diagnosing malaria in children under 5 years of age. And the diagnostic performance of parasite-specific lactate dehydrogenase test was better than that of the histidine-rich protein 2 test.

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.

Malaria and HIV Infection among Febrile Patients in a Large Area of Southwestern Nigeria

Background: Malaria and HIV/AIDS are two major diseases that represent serious public health threats in Nigeria. They have been ascribed diseases of poverty, and therefore their distribution is expected to be overlapping.

Aim: The aim of this study was to determine the prevalence of malaria parasites and HIV among febrile patients in the Ikeja area of Lagos State, Nigeria.

Materials and Methods: The study was conducted on 300 patients attending medical consultation and referred to blood screening for malaria parasites at Reddington Hospital, Lagos State. Malaria parasites were identified microscopically, and HIV screening was carried out using rapid diagnostic tests (RDT).

Results: The prevalence of malaria and HIV was 98.7% and 3.7%, respectively. All HIV-positive individuals were also infected by malaria parasites. Mean parasitemia was significantly higher in HIV-positive individuals (16,507.9 ± 2,280.7 P/μL) than in HIV-negative subjects (3,252.505 ± 236.3 P/μL) (p <0.05).

Conclusions: Our results suggest that HIV-infected individuals are more susceptible to infection with malaria parasites. Prompt HIV management is necessary in malaria-endemic areas to reduce disease severity in case of coinfection with HIV.

Accuracy of One Step malaria rapid diagnostic test (RDT) in detecting Plasmodium falciparum placental malaria infection in women living in Yaoundé, Cameroon

Background

Plasmodium falciparum infected erythrocytes sequestering in placental tissue release Plasmodium lactate dehydrogenase (pLDH) and histidine-rich protein-II (HRP-II). These proteins can be detected in peripheral blood using monoclonal antibody-based rapid diagnostic tests (RDTs). Nevertheless, studies to evaluate the reliability of RDTs in detecting placental malaria compared with microscopy of placental tissue impression smear (PTIS) as the gold standard are scarce.

Methods

Between August 2013 and January 2015, Giemsa-stained blood smears for peripheral blood smear (Pbs), placental intervillous space (IVS) blood smear and placental tissue impression smear (PTIS)] were prepared from HIV-negative women during delivery at the Marie Reine Medical Health Centre in Yaoundé, Cameroon. RDTs with monoclonal antibodies specific to HRP-II (P.f) or pLDH (Pan) antigens were used to screen maternal peripheral blood samples.

Results

The prevalence of malaria was 16%, 7.5%, 11.5%, 8% and 13% for One Step malaria HRP-II and pLDH RDTs, peripheral blood smear, IVS blood and placental tissue impression smears, respectively. The proportion of women positive by One Step malaria pLDH RDT and Pbs increased with parasite density in PTIS, while One Step malaria HRP-II RDT detected high proportion of infected women even with low parasite density. Although the prevalence of malaria infection by both microscopy and RDTs decreased significantly with mother age (0.0008 ≤ p ≤ 0.025), parity seemed to have very little influence. The sensitivity of One Step malaria HRP-II and pLDH RDTs were 96.15% and 61.53%, respectively, compared to 80.76% for Pbs (p = 0.014 and 0.0029, respectively). The specificity of these RDTs was 96.49% and 100%, respectively, compared to 100% for Pbs (p ≥ 0.12). In addition, the positive predictive values were 80.64% and 100% for HRP-II and pLDH-based RDTs, respectively, compared to 100% for Pbs (p < 0.0001 and 1, respectively), while the negative predictive values were 99.40% and 94.48%, respectively, compared to 97.16% for Pbs (p ≥ 0.49). The combination of One Step malaria HRP-II RDT and Pbs showed the similar performance as that observed with One Step malaria HRP-II RDT only.

Conclusion

These results depict One Step malaria HRP-II RDT to be better in detecting placental P. falciparum infection in pregnant women compared to Giemsa-stained peripheral thick blood smear. This is important for better case management since microscopic examination of PTIS cannot be employed during pregnancy.