Unclear association between levels of Plasmodium falciparum lactate dehydrogenase (PfLDH) in saliva of malaria patients and blood parasitaemia: diagnostic implications?

Table 1 Sample quantification of PfLDH in saliva samples

Sample ID	Parasites/µl	OD	Concentration pg/ml
Positive blood sample	48,400	3.944	117,544.6
Saliva MSG 104	2560	0.055	Below detection limit
Saliva MSG 105	2160	0.087	Below detection limit
Saliva MSG 120	15,200	0.109	78.95249
Saliva MSG 041	38,800	0.1	69.472
Saliva MSG 035	32,320	0.101	70.46383
Saliva MSG 038	38,240	0.144	127.6701
Saliva MSG 078	32,400	0.145	129.3391
Saliva MSG 021	32,120	0.158	152.4354
Saliva MSG 116	40,300	0.131	107.3745
Saliva MSG 115	49,600	0.1480	134.4382
Saliva MSG 097	48,000	0.116	87.18796
Saliva MSG 042	53,600	0.146	131.0234
Saliva MSG 025	31,600	0.148	134.4382
Saliva MSG 106	4320	0.106	75.65383
Saliva MSG 026	2080	0.106	75.65383
Saliva MSG 124	1200	0.103	72.49367
Saliva MSG 147	6960	0.13	105.921
Saliva MSG 009	11,680	0.065	Below detection limit
Saliva MSG 104	2560	0.082	Below detection limit
Saliva MSG 015	39,600	0.074	Below detection limit
Negative saliva sample	–	0.053	N/A
Negative control (kit)	–	0.066	N/A

Blood sample with parasitaemia of 48,400 had a concentration of 117,544.6 pg/ml while saliva MSG 115 and MSG 097 with similar parasitaemia range had 134.4382 pg/ml and 87.18796 pg/ml, respectively. False negatives were present in samples with low, moderate as well as high parasitaemia MSG 104 and MSG 015, respectively. The ELISA results for saliva samples were generally weak positives compared to blood samples

ISSN: 1475-2875