BNCC Nucleic Acid Quality Control Solutions for *Rickettsia* and Related Pathogens

Fever, rash, eschar, thrombocytopenia, history of tick bites... underlying these clinical presentations could be infections caused by *Ehrlichia chaffeensis*, *Anaplasma phagocytophilum*, *Coxiella burnetii* (Q fever), *Orientia tsutsugamushi* (scrub typhus), *Rickettsia typhi* (murine typhus), or members of the spotted fever group (SFG) *Rickettsia*. As surveillance expands for tick-, rodent-, and mite-borne infectious diseases, an increasing number of laboratories are incorporating these pathogens into their nucleic acid testing panels.

However, this expansion raises a critical question:

Have quality control materials kept pace with the expanded testing menus?

Most of these pathogens are obligate intracellular organisms or are difficult to culture, and they often present a long serological window period; consequently, PCR has become a vital tool for early diagnosis and surveillance. Yet, challenges such as low viral/bacterial loads, nucleic acid extraction inhibition, aerosol contamination, and non-specific primer amplification can all lead to false-negative or false-positive results. Without reliable quality control materials, every test report lacks a necessary "benchmark."

Why is the use of quality control materials essential for testing these six types of pathogens?

·*Ehrlichia chaffeensis*: Causes human monocytic ehrlichiosis; tick-borne; early symptoms are non-specific.

·*Anaplasma phagocytophilum*: Causes human granulocytic anaplasmosis; presents with fever and leukopenia/thrombocytopenia; easily confused with other tick-borne diseases.

·*Coxiella burnetii*: Causes Q fever; transmitted via aerosols and animal contact; poses a high risk of laboratory-acquired infection.

·*Orientia tsutsugamushi*: Causes scrub typhus; characterized by eschar, lymphadenopathy, and fever; a key target for surveillance in southern regions.

·*Rickettsia typhi*: Causes endemic typhus (murine typhus); transmitted by rat fleas.

· *Spotted Fever Group (SFG) Rickettsia*: Causes spotted fever-like illnesses; comprises numerous species with a wide geographical distribution.

Nucleic acid testing for these pathogens often faces three key quality control challenges:

1. Low Viral/Bacterial Load: Early-stage samples often contain low concentrations of pathogen nucleic acid, posing a high risk of false-negative results.

2. Cross-Contamination: Contamination from aerosols or amplification products can easily lead to false-positive results.

3. Batch-to-Batch Variation: Results must remain comparable across different reagent batches, extraction methods, and testing platforms.

BNCC Product Portfolio: Precise coverage of 6 major core pathogens

Product Advantages:

1. Comprehensive Coverage: A single product series covering 6 major core pathogens

Covers *Rickettsia*, *Orientia*, *Coxiella*, *Ehrlichia*, *Anaplasma*, and the Spotted Fever Group; suitable for CDC surveillance, hospital differential diagnosis, and third-party testing menus.

2. Reliable Value Assignment: Absolute quantification via digital PCR

Utilizes digital PCR for value assignment, ensuring accurate target values ​​and controllable batch-to-batch CV; available in high and low concentration levels to meet various limit-of-detection (LOD) verification needs.

3. Flexible Customization

Customizable options for species- or group-specific targets, concentration levels, and packaging specifications; supports the creation of reference panels for reagent manufacturers and external quality assessment (EQA) programs.

4. Ready-to-Use Design

Simple to use, minimizing errors associated with manual preparation; ideal for routine quality control in high-throughput testing laboratories.