Table 1 Summary of findings

Population

Pregnant women

Settings

At delivery where both placental and peripheral material is available; mostly P. falciparum infections

Index test

Microscopic examination of placental or peripheral blood slide

Reference Test

Histological examination of placental biopsies

Type of test

Effect

[95% CI]

Participants

(studies)

Median prevalence

(range)

Implications of results

Quality and comments

Microscopy of placental blood

Sensitivity 54%

[40-67]

Specificity 97%

[95-98]

2153

(5)

24.4%

(18.4-35.5)

With a prevalence of 25%, 25 out of 100 pregnant women will develop PM; 12 and 14 patients will be missed by placental and peripheral microscopy.

Representative patient spectrum; uncertain if all tests blinded; withdrawals poorly Reported.

Microscopy of peripheral blood

Sensitivity 44%

[34-54]

Specificity 92%

[86-95]

4044

(8)

28.6%

(17.2-52.5)

With a prevalence of 25%, 6 patients will be false positive in peripheral microscopy, but treatment is not harmful and can act as prophylaxis during the rest of the pregnancy.

Representative patient spectrum; uncertain if all tests blinded; withdrawals poorly reported; 1 study did not report selection criteri; 1 did not report the execution of the reference test; risk of verification bias in study.

What is the diagnostic accuracy of RDTs and PCR to correctly identify PM confirmed by microscopy of placental blood?

Population

Pregnant women

Settings

At delivery where both placental- and peripheral blood is available; mostly P. falciparum infections

Index test

RDT or PCR with peripheral or placental blood

Reference Test

Microscopic examination of placental blood slide

Type of test/subgroups

Effect

[95% CI]

Participants

(studies)

Median

prevalence

(range)

Implications of results

Quality and comments

Microscopy of peripheral blood

Sensitivity

72%

[62-80]

Specificity

98%

[95-99]

16609

(26)

15.9%

(3.3-74.0)

Of 16 of 100 patients positive in placental blood, 4 would be missed in peripheral blood by microscopy.

Representative patient spectrum; 4 did not describe selection criteria; execution of index/reference test not reported in 13 tests

RDT of placental and peripheral blood

Peripheral and placental blood pooled together

Sensitivity

81%

[62-92]

Specificity

94%

[76-99]

3141

(5)

16.2%

(2.4-11 34.9)

Of 16 of 100 patients positive with placental blood microscopy, 3 would be missed in any type RDT. Of 11 of 100 patients positive with placental blood microscopy, 3 patients would be missed by RDTs with placental blood. With a prevalence of 16%, 5 patients will be false positive with RDTs compared to placental blood microscopy.

Representative patient spectrum; uncertain if all tests blinded; withdrawals and uninterpretable results poorly reported; execution of test not reported in 3/7 tests; 1 study did not report selection criteria.

only placental Blood

Sensitivity

76%

[44-92]

Specificity

95%

[87-99]

2124

(4)

11.20%

(2.4 -22.6)

PCR of placental and peripheral blood

all types of PCR

Sensitivity

86%

[65-95]

Specificity

77%

[71-82]

2608

(6)

18.5%

(1.7-34.9)

Of 18 of 100 patients that test positive in placental blood microscopy, 3 would be missed by PCR, but 19 would be false positive.

Representative patient spectrum; uncertain if all tests blinded; withdrawals and uninterpretable results poorly reported.

What is the diagnostic accuracy of RDTs and PCR to correctly identify microscopically confirmed peripheral malaria infection during pregnancy?

Population

Pregnant women

Settings

During pregnancy, placental examination not possible; mostly P. falciparum infections

Index test

RDT or PCR with peripheral blood

Reference Test

microscopic examination of peripheral blood slide

Type of test/subgroups

Effect [95% CI]

Participants (studies)

Median

prevalence

(range)

Implications of results

Quality and comments

RDT of peripheral blood

all types (pLDH and HRP2)

Sensitivity 81%

[55-93]

Specificity 94%

[82-98]

5340

(7)

17.60%

(1.3-51.3)

Of 18 of 100 patients positive in peripheral blood microscopy, 3 would be missed in any type RDT. Of 28 of 100 patients positive in peripheral blood microscopy, 2 patients would be missed in HRP2 RDTs.

Representative patient spectrum; uncertain if all tests blinded; withdrawals and uninterpretable results poorly reported; test execution not reported in 3/7 tests; 1 study did not report selection criteria.

only HRP2 based

Sensitivity

94%

[91-96]

Specificity 81%

[71-88]

28.10%

(17.6-51.3)

With a prevalence of 28%, 14 patients will be false positive with HRP2 RDTs compared to peripheral blood microscopy.

PCR of peripheral blood

all types of PCR

Sensitivity 94%

[86-84]

5741

(11)

19.0%

(5.3-51.3)

Of 19 of 100 patients that test positive in peripheral blood microscopy, only 1 would be missed by PCR, but 20 would be false positive compared to peripheral blood microscopy.

Representative patient spectrum; uncertain if all tests blinded; withdrawals and uninterpretable results poorly reported;