Nucleic acid tests (NATs) have higher sensitivity and specificity but are not typically in use in Cameroon or other typhoid-endemic countries due to the complexity of the test design, cost and requirement for laboratory facilities compared to serological tests. There has been numerous scientific publication demonstrating S. Typhi and S. Paratyphi detection by PCR , real-time PCR and loop mediated isothermal amplification (LAMP) (Table 2) \cite{Kaur_2018,Fan2015,Nga2010,Tennant2015,Frickmann_2019,Francois2011})(complete ref) but none are currently in wide use and we were unable to find any laboratories in Cameroon offering molecular diagnosis of enteric fever.
Table 2: Molecular Detection of S. Typhi and S. Paratyphi (Including detection limits and any other useful information)
NAT
Bacteria
Target
Sample type
Duration numeric (minutes)
Detection Limit (Unit)
Detection Limit
Sensitivity %
Specificity %
Reference
RT-PCR
S. typhi
prg K
Blood
Not specified
Not reported
Not reported
83.33
73.68
Aldusogi & Enan, 2020.
Multiplex three colour RT-PCR
S. typhi, S. paratyphi A
STY0201,
Blood, Bone Marrow
~100 (PCR only)
copies/ml
250
42
100
Nga et al., 2010
Multiplex three colour RT-PCR
S. paratyphi A
SSPA2308
Blood
~100 (PCR only)
copies/ml
250
39
100
Nga et al., 2010
Multiplex three colour RT-PCR
S.typhi
STY0201
Bone Marrow
~100 (PCR only)
Not reported
Not reported
100
100
Nga et al., 2010
Multiplex three colour RT-PCR
S. paratyphi A
SSPA2308
Bone Marrow
~100 (PCR only)
Not reported
Not reported
100
100
Nga et al., 2010
RT-PCR
S.typhi
clyA
Blood
154 ± 15
cfu/ml
0.01
40
90
Tennat et al., 2015
RT-PCR
S. paratyphi A                  
clyA
Blood
154 ± 15
cfu/ml
0.01
40
90
Tennat et al., 2015
RT-PCR
S.typhi
clyA
Blood
154 ± 15
Not reported
Not reported
Not reported
96
Tennat et al., 2015
RT-PCR
S. paratyphi A
clyA
Blood
154 ± 15
Not reported
Not reported
Not reported
96
Multiplex PCR
S.typhi                   
rfb, tyv, vi, prt, H antigen typing, dT fermentation 
Blood culture isolates
30-60 (PCR only)
Not reported
Not reported
100
100
Levy et al., 2008
Multiplex PCR
S. paratyphi A
rfb, tyv, vi, prt, H antigen typing, dT fermentation 
Blood culture isolates
30-60 (PCR only)
Not reported
Not reported
100
100
Levy et al., 2009
Multiplex PCR
S. paratyphi B
rfb, tyv, vi, prt, H antigen typing, dT fermentation 
Blood culture isolates
30-60 (PCR only)
Not reported
Not reported
100
100
Levy et al., 2010
Multiplex PCR
S.typhi
fliC-d, tyv, prt, Via B
Bacterial strains
75 (PCR only)
Not reported
Not reported
Not Reported
Not Reported
Hirose et al., 2001
Multiplex PCR
S. paratyphi A
fliC-a, prt
Bacterial strains
75 (PCR only)
Not reported
Not reported
Not Reported
Not Reported
Hirose et al., 2002
PCR
S.typhi
STY0312, STY0313 to STY0316
Blood
210 (PCR only)
cfu/ml
4
95
Not Reported
Nagarajan et al., 2009
PCR
S. paratyphi A
SPA2476
Blood
210 (PCR only)
cfu/ml
4
95
Not Reported
Nagarajan et al., 2010
Nested PCR
S. typhi
fliC
Blood
617 (PCR only)
cfu/ml
0.01
100
97.3
Nandagopal et al., 2010
Nested PCR
S. typhi
H1-d
Blood
137 (PCR only)
Not reported
Not reported
92.8
Not Reported
Prakash et al., 2004
PCR
S. typhi
fliC-d
Blood
1445 (PCR only)
Not reported
Not reported
Not Reported
Not Reported
Munir et al., 2015
Blood culture PCR
S. typhi
fliC-d
Blood
Not specified
cfu/ml
0.75
NA
NA
zhou & pollard, 2010
Nested multiplex PCR
S. typhi
fliC, tviA, tviB
Blood
70 (PCR only)
cfu/ml
5
Not Reported
Not Reported
Prabagaran et al., 2017
PCR
S. typhi
STY1599
Blood
107 (PCR only)
Not reported
Not reported
89
Not Reported
Al-Emran et al., 2016
Multiplex PCR
S. typhi
invA, fliC
Blood
Not reported
Not reported
100
86.49
El-sayed et al., 2015
Nested PCR
S. typhi
fliC
Urine
117 (PCR only)
Not reported
Not reported
95.5
100
Kumar et al., 2012
Nested PCR
S. typhi
fliC
Blood
117 (PCR only)
Not reported
Not reported
90.9
100
Kumar et al., 2012
Nested PCR
S. typhi
fliC
Stool
117 (PCR only)
Not reported
Not reported
68.1
85
Kumar et al., 2012
Nested PCR
S. typhi
fliC
Blood
117 (PCR only)
Not reported
Not reported
Not Reported
100
Kumar et al., 2002
MIOD
S. typhi
STY2879
Blood
Not specified
cfu/ml
5
100
100
Kaur et al., 2018
 rtLAMP
S. typhi
STY1607,
 Blood
cfu/ml
3
100
100
Fan et al., 2015
 rtLAMP
S. typhi
STY1607,
 stool
cfu/ml
3
100
100
Fan et al., 2015
Blood culture multiplex PCR
S. typhi
STY0201, SSPA2308
Blood
53 55.5 (only PCR)
cfu/reaction
1
95
95
Pouzol et al., 2019
Blood culture multiplex PCR
S. paratyphi
SSPA2308
Blood
53 55.5 (only PCR)
cfu/reaction
1
95
95
Pouzol et al., 2020
LAMP
S. typhi
STBHUCCB_38510
Blood culture isolates
62 (LAMP only)
cfu/reaction
20
100
100
Abdullah et al., 2014
Magneto-DNA nanoparticle system
S. typhi
staG, SPA2472, sopB, sipC
Blood
210
cfu/ml
1
NA
NA
Park et al., 2016
Magneto-DNA nanoparticle system
S. paratyphi A
hsdR, sopB, sipC
Blood
210
cfu/ml
1
NA
NA
Park et al., 2016
SMOL
S. typhi
 STY2879
Blood culture isolates
Not specified
cfu/ml
5
100
100
Kaur et al., 2019
SMOL
S. paratyphi A
 SPA2539
Blood culture isolates
Not specified
cfu/ml
5
100
100
Kaur et al., 2019
Enrichment Broth Culture-Multiplex PCR
Samonella serovars
invA, spvC
Stool
92 (PCR only)
bacteria
200
Not Reported
Not Reported
Chiu & Ou, 1996
PCR
S. Typhi
dH flagellin gene of S typhi.
Blood
Not specified
pg/DNA
28
100
93.7
Chaudhry et al., 1997
Multiplex PCR
S. typhi
STY4220, stg, SSPAI, OmpC
Bacterial strains
130 (PCR only)
pg/DNA
1
100
100
Ngan et al., 2010
Multiplex PCR
S. typhi
STY4220, stg, SSPAI, OmpC
Bacterial strains
130 (PCR only)
pg/DNA
1
100
100
Ngan et al., 2010
Nested PCR
S. typhi
fliC
Blood
210 (PCR only)
Not reported
Not reported
84.5
Not reported
Hatta M et al., 2007
Nested PCR
S.typhi
fliC
Urine
210 (PCR only)
Not reported
Not reported
46.9
70
Hatta M et al., 2007
Nested PCR
S.typhi
fliC
Stool
210 (PCR only)
Not reported
Not reported
69.3
70
Hatta M et al., 2007
PCR
S.typhi
fliC
Blood
Not specified
pg/DNA
0.00891
Not reported
100
Massi Mn et al., 2003
Nested PCR
S.typhi
fliC
Blood
95 (PCR only)
Not reported
Not reported
Not reported
Not reported
Sankar S et al., 2014
PCR
Salmonella sp.
hilA
Blood
103 (PCR only)
cfu/ml
10
100
100
Sánchez-Jiménez MM et al., 2004
PCR
Salmonella sp.
hilA
Stool
103 (PCR only)
cfu/ml
400
97
100
Sánchez-Jiménez MM et al., 2004
Nested PCR
S.typhi
staA
Blood
117 (PCR only)
cfu/ml
30000
92.7
100
Pratap et al., 2013
Nested PCR
S.typhi
staA
Stool
117 (PCR only)
cfu/ml
30000
62.2
100
Pratap et al., 2013
Nested PCR
S.typhi
staA
Urine
117 (PCR only)
cfu/ml
30000
96.5
100
Pratap et al., 2013
Nested PCR
S.typhi
staA
Gall bladder stone
117 (PCR only)
Not reported
Not reported
73.9
100
Pratap et al., 2013
Nested PCR
S.typhi
staA
Gall bladder wall
117 (PCR only)
Not reported
Not reported
20.9
100
Pratap et al., 2013
Nested PCR
S.typhi
staA
Carcinoma gallbladder tissue
117 (PCR only)
Not reported
Not reported
78.3
100
Pratap et al., 2013
Nested PCR
S.typhi
staA
Bonemarrow specimen
117 (PCR only)
Not reported
Not reported
23.3
100
Pratap et al., 2013
RT-PCR
S.typhi
h1d
Blood
Not specified
copies/ml
3.9
100
100
Massi MN et al., 2005
Nested PCR
S.typhi
fliC
Blood
Not specified
Inaccessible
Inaccessible
88.7
100
Sultana S et al., 2012
Nested PCR
S.typhi
fliC
Blood
130 (PCR only)
Not reported
Not reported
100
35.8
Khan S et al., 2015
RT-PCR
S.typhi
clyA
Blood
Not specified
cfu/ml
0.01
40.1
91
Sharon M et al., 2015
Nested PCR
S.typhi
fliC
Blood
~175 (PCR only)
Not reported
Not reported
100
76.9
Khan S et al., 2012
LAMP
S.typhi
STBHUCCB_38510
Blood culture isolates
Not specified
cfu/reaction
20
100
100
Hagen et al., 2018
LAMP
S.typhi
STBHUCCB_38510
Blood culture isolates
Not specified
cfu/reaction
20
100
97.1
Hagen et al., 2018
LAMP
S.typhi
STBHUCCB_38510
Blood
Not specified
cfu/reaction
20
10
98.3
Hagen et al., 2018
LAMP
S.typhi
STBHUCCB_38510
Blood
Not specified
Not reported
Not reported
38
83.3
Hagen et al., 2018
LAMP
S.typhi
STBHUCCB_38510
Blood culture isolates
Not specified
Not reported
Not reported
Not reported
Not reported
Hagen et al., 2018
LAMP
S.typhi
STBHUCCB_38510
Blood culture isolates
Not specified
Not reported
Not reported
Not reported
Not reported
Hagen et al., 2018
TAC
S.typhi
Not reported
Blood
Not specified
Not reported
Not reported
Not reported
Not reported
Ahmed A et al., 2018
TAC
S.typhi
Not reported
Stool
Not specified
Not reported
Not reported
Not reported
Not reported
Ahmed A et al., 2018
PCR
S.typhi
Not reported
Not reported
Not specified
Not reported
Not reported
Not reported
100
Khan S et al., 2017
PCR
S.typhi
fliC-d
Blood cuture isolates
~70 (PCR only)
Not reported
Not reported
70
65
Thomas C et al., 2017
PCR
S.typhi
fliC-d
Blood cuture isolates
132 (PCR only)
copies/reaction
30000
NA
NA
Das S et al., 2016
RT-PCR
S.typhi
fliC-d
Blood cuture isolates
132 (PCR only)
copies/reaction
3
NA
NA
Das S et al., 2016
Nested PCR
S.typhi
fliC-d
Blood cuture isolates
132 (PCR only)
copies/reaction
3
NA
NA
Das S et al., 2016
RT-PCR
S.typhi
fliC-d
Blood
Not specified
Not reported
Not reported
91.4
100
Das S et al., 2016
Nested PCR
S.typhi
fliC-d
Blood
Not specified
Not reported
Not reported
81.5
100
Das S et al., 2016
Electrochemical DNA Biosensor
S.typhi
STM4497
Stool
Not specified
nM DNA
0.94
NA
NA
Savas S et al., 2018
PCR
S.typhi
STY0201
Blood cuture isolates
66 (PCR only)
Not reported
Not reported
100
97.2
Goay YX et al., 2016
PCR
S.typhi
STY0307
Blood cuture isolates
67 (PCR only)
pg/DNA
1.28
100
100
Goay YX et al., 2016
PCR
S.typhi
STY0322
Blood cuture isolates
68 (PCR only)
pg/DNA
32
100
100
Goay YX et al., 2016
PCR
S.typhi
STY0326
Blood cuture isolates
69 (PCR only)
pg/DNA
6.4
100
100
Goay YX et al., 2016
PCR
S.typhi
STY2020
Blood cuture isolates
70 (PCR only)
pg/DNA
6.4
100
100
Goay YX et al., 2016
PCR
S.typhi
STY2021
Blood cuture isolates
71 (PCR only)
pg/DNA
6.4
100
100
Goay YX et al., 2016
Metal nanoparticle assisted PCR
S.typhi
fliC
Blood culture isolates
Not specified
Not reported
Not reported
NA
NA
Rehman A et al.,2015