Goals for improved diagnostics for Cameroon

The most commonly used typhoid POC tests (Widal, Typhidot, Tubex, Test-It Typhoid, TPTest) require between 5µL and 1mL of blood, but have only moderate sensitivity and specificity. 23 Survey respondents agreed that an optimal next-generation typhoid RDT would use a capillary blood sample with a volume of ≤100µL, or a less invasive sample type, excluding urine and stool.12 28 However, survey respondents indicated that ≤1mL of venous blood was an acceptable minimum requirement due to the current difficulty in accurately diagnosing typhoid fever (table 3). The TPP allows for up to two sample processing steps as an RDT may require serum to be separated from whole blood, with at most five steps for the test of which no more than two should be timed,28 and a total hands on time of

Nucleic acid testing options for Enteric Fever   

PCR and preferably real-time PCR are the 'gold standard' method for NAT diagnostics due to their high sensitivity and specificity. However, they depend on equipment such as thermocyclers which are not commonly available in Cameroonian diagnostic laboratories, could be expensive and also slow . The discovery of isothermal methods of amplifying the nucleic acid target in the last two decades has revolutionized the NAT diagnostics by reducing the amplification time and bypassing the need for a thermocycler. Recombinase polymerase amplification (RPA) \cite{Piepenburg_2006} and LAMP \cite{Notomi2000} are the two most popular PCR alternatives that have seen a wide spread application, particularly in rapid, low-cost, point of care (POC) and near-POC diagnostics.  LAMP relies on a single polymerase  that amplifies DNA at 65C but has complex primer design requirements as well as using up to six primers compared to the two used for PCR. RPA depends on x enzymes including a polymerase, recombinase, single strand binding protein that amplify DNA at  37C.