, main results integration of a rapid test into french guidelines in order to improve tetanus...

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MAIN RESULTS

INTEGRATION OF A RAPID TEST INTO FRENCH GUIDELINES IN ORDER TO IMPROVE TETANUS PROPHYLAXIS IN PATIENTS PRESENTING WITH

WOUNDS TO EMERGENCY DEPARTMENTS. D. Elkharrat, P. Espinoza, J. de la Coussaye, G. Potel, JL. Pourriat & MJ. Sanson-Le Pors for the French Tetanus Prophylaxis Group, University-Hospital Ambroise Paré, Boulogne, France.

INTRODUCTION AND MAGNITUDEOF THE PROBLEMIn emergency departments (ED) worldwide, tetanus prophylaxis (TP) is unscheduled and, in over 65% of cases, aimed at patients presenting with accidental wounds.

Medical compliance with TP guidelines is very low. Consequently, TP is mostly empirical mainly based on immunization history, of which patients are hardly aware. Until recently, the lack of a reliable test to predict in real time tetanus seroprotection of individuals, led to 30-40% of inadequate TP, 17-30% of which were excessive and 5-10% consisted of underimmunization. In the latter group, more than 50% had a conjunction of tetanus-prone wounds and nonprotective antibody titers. These figures are particularly meaningful since 1 500 000 persons present annually to French EDs with an indication for unscheduled TP.

The availability of a rapid, reliable test reflecting tetanus seroprotection has sharply increased TP accuracy.

PURPOSETO INCLUDE THE PERFORMANCES OF TETANOS QUICK STICK (TQS)- validated by 2 prospective french studies- into the current French Health Department TP Guidelines used for patients presenting with wounds to ED

METHODS

WHAT IS TETANOS QUICK STICK? IT IS RAPIDLY PREDICTIVE OF TETANUS IMMUNITY IN INDIVIDUALS

1. Tetanos Quick Stick (Gamma*) Detects specific antitoxins in blood

(> 0.2 IU/ml), serum and plasma (> 0.1 IU/ml).

- Principle: Tetanus toxoid conjugation in liquid/solid phases (figure 1).

- How to perform TQS (figure 2).

- Binary outcome: positive or negative (Photo)

C window : Control reagent

T window : Tetanus toxoid.

C

T

Well

Well : tetanus toxoid- dye conjugate

Positive test Negative test

migration

C

T

C

T

WellWell

Fig. 1. Principle of Tetanus Quick Stick

2. Serum antitoxin levels measurement by Elisa (Virotech*)- Specific IgG neutralizing tetanus toxins- Reading by optical density; outcome expressed in International Units per milliliter

- 0.1IU/ml is considered non protective, requires complete vaccination- 0.5 IU/ml is protective; no TP required- 0.1 et < 0.5, intermediate; tetanus toxoid booster is advised.

TWO LARGE SCALE STUDIES IN THE ED1 CENTER IN 2000 (STUDY I), 39 CENTERS IN 2001(STUDY II) ASSESSED RELIABILITY and FEASIBILITY of TQS in ED WORKING CONDITIONS

BOTH ARE CONCORDANCE STUDIESSAME INCLUSION CRITERIAREFERENCE: SERUM ANTITETANUS LEVELS (SAL) SAL PERFORMED IN THE SAME LABORATORY

 Inclusion of patients (Stage C)

Consecutive patients 24 h/7dWith fresh (< 24 h.) woundsAge > 15 yearsSeroprotection measured by both techniques After signing informed consent

Non inclusion: patients not interviewed, severe surgical wounds.

End points In theory

- TQS would read positive when SAL is > 0.1 IU/ml- TQS would be negative when SAL is 0.1 IU/ml- When doubtful for at least 1 reader, interpreted as negative

Main end point: a rate of false positives close to 0 was expected Other end points: rate of false negatives under 10% Study conduct

- Definitions: Sensitivity (Se) = true positives and Specificity (Sp) = true negatives- 1018 individuals in study I and 989 in study II were tested in a double blind fashion with TQS and SAL

Preliminary Statistical analysis was applied only to patients with TQS and SAL tests. Included and non included patients did not differ for demography and wound types

- -

-

:

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STUDY I STUDY IIDate 2000 2001Inclusions 1018 989Sex ratio (% M) 70,9 70,5Age [Min-Max] 39,2 [16-94] 43,5[15-96]

Sensitivity 82,8-90,4% 70-84%Specificity 97,3-100% 98-100%

EXPERT CONSENSUSSIX PHYSICIANS5 specialists of Emergency Medicine1 of Microbiology (who coordinated SAL all measurments)AN ALGORITHM WAS DESIGNEDAfter the 2 study coordinators were interviewed during 48 hours OBJECTIVEInsertion of TQS in the Health Ministry GuidelinesTo conduct in real time acurate TP in french EDs

CONCLUSIONS

TQS is reliable and easily performed by care providers.

It is currently the most specific and sensitive tool for predicting in real time tetanus protection of patients presenting in ED with wounds.

Its incorporation in European Guidelines would be useful in the better management of tetanus-prone wounds.

Fig. 2. Photo

Inclusion of TQS in a decisional algorithm of TP in Emergency Departments. FILL OUT FOR ALL PATIENTS WITH WOUNDS YES NO

*Carry a vaccination certificate ?. **Demographics : Born in an emerging country and implanted In France after age of 15 ? Age > 65 y (regardless of gender or country of birth)?

***Is the wound tetanus-prone? 1. Based on wound mechanism: Bite, scratch Burn Chronic wound Wound during gardening Deep puncture Difficult to clean foreign body May not be evaluated or unknown Other (specify) : ……………………… 2. Due to contact with soil: 3. Age of wound > 6 hours IF ONE RED BOX IS TICKED Perform TQS

IF TQS POSITIVE Patient IS IMMUNIZED. No Ig°. Vaccination follow up by primary care physician

IF TQS NEGATIVE ° Inject Ig and update AT vaccination°°