Post vaccination abscesses and deviations from correct vaccination practices

Two sisters aged five months and four years developed post vaccination abscesses after receiving DPT vaccine on 8 May 1996 in a Primary Health Care Center (PHCC) in the index City. Within two days after the vaccination, the younger sister, aged five months, developed oedema around the injection site in the right thigh extending to the abdomen. Her temperature was 40.8°C. She was pronounced dead on arrival to the hospital due to septicemia shock. The elder sister, aged four years, was hospitalized for incision and drainage of an abscess at the DPT vaccination site in the right gluteal region on 16 May 1996. The abscess recurred seven days later and was reincised. Of the 20 other children vaccinated at the PHCC on same day, 14 children were given DPT vaccine, and one of these developed a persistent intramuscular nodule at the vaccination site. No abscesses formed in the other 13 children, or in six who received other vaccines.

The nurse who vaccinated the two sisters in this PHCC routinely left a hypodermic needle inserted through the rubber septum of multidose (10 dose) DPT vaccine vials. She then used new syringes to withdraw individual DPT doses through the needle left in the septum. After loading the syringe, she placed a new needle on the syringe for vaccinating the child. This process would allow airborne microorganisms to contaminate the residual vaccine in the needle which could have been injected into the vaccine vial or extracted with next vaccine dose.

All children under five years of age who had incision and drainage for gluteal, thigh, shoulder, or cervical abscess treated in hospitals, PHCCs or dispensaries in the index city from May 1995 to July 1996 were identified from log books and corresponding medical records were reviewed.

Including the two sisters, we identified 11 thigh and gluteal abscesses in children aged five years or less (31 per 100,000 children). However only three abscesses (eight abscesses per 100,000 DPT vaccination ) followed DPT vaccination by less than one week. The remaining eight index city children had an interval from two weeks to 16 months between DPT vaccination and abscess appearance.

To identify the extent of the practice of keeping a needle inserted in the multidose vial, and other deviations from safe hygienic vaccination practice, we surveyed all 13 PHCCs in the index city and a sample of 14 PHCCs in the study area.

Nurses in all health centers in the index area routinely used saline soaked cotton swabs to clean the vaccination site. They did not wash their hands before picking up saline soaked cotton swabs. Of the vaccinating nurses, 0% washed her hands before administering a vaccine to the child and 30% left a needle inserted through the septum of the DPT vaccine vial (Table).

In the study area, the questionnaire on vaccination practices was modified and administered to the vaccinating nurses in selected centers. In addition, settling plates (blood agar) were left for one hour during a vaccination session to estimate the number of airborne microorganisms that could fall into the hub of the needle. We collected seven DPT vials which had a needle left inserted through the septum from the PHCCs in the study area and cultured the remaining solution in the vial and residual vaccine remaining inside the hub and needle.

From a sample of 20 nurses working in the 14 selected health centers, we observed that only 25% washed hands before administering vaccines, 90% used alcohol to disinfect the vaccination site, and 65% used alcohol to disinfect the vial septum. We found 50% of the nurses kept one needle inserted through the septum of multi-dose vials and extracted the doses from it (Table 1). Forty-five percent of nurses used one syringe with one needle for vial and vaccination, 20% of nurses used two needles for one syringe for vaccination. Of nurses who left needles in multidose vaccine vials, 55% learned this technique from a previous nurse and 25% from nursing school. We observed that only 55% of vaccination rooms had a sink for hand washing. The results from settling plates indicated that 8.6 organisms would contaminate the hub of a needle left in the vaccine vial per 100 hours of exposure to vaccination room air. No microorganisms were isolated from the remaining solution of seven DPT vials collected.

Having a needle inserted through the septum of a multi-dose vial can lead to the contamination of residual vaccine in the needle or vaccine vial contents by airborne microorganisms that fall into the hub of the needle. Although the bore of the needle is very small, the hub is larger and can act as a funnel to trap microorganisms. If the vaccine is refrigerated, multiplication of contaminating organisms is unlikely. However, vaccine vials are often left in an ice bath on the vaccination table. This assures a low temperature for the vaccine in the vial, but residual vaccine in the needle placed through the septum could be at room temperature. Post vaccination abscesses could also be related to unhygienic nurse practices such as not washing hands, not cleaning the site of injection.

DPT vaccine can produce a sterile abscess in one out of 116,000 doses[1]. Higher rates of post DPT abscesses or post DPT abscesses with clinical features of infection need addition epidemiologic investigation to identify and correct unsafe practices.

Vaccinations are only safe when the correct vaccine is properly administered with sterile equipment that is disposed of safely[2]. In Saudi Arabia vaccines are always administered with a disposable syringe and needle. Therefore the risk of infection comes from unhygienic techniques in vaccination practices such as keeping a needle inserted into the vial septum.

MOH requires that post vaccination reactions be reported. In addition to abscesses physicians should report cellulitis at vaccination sites and any antibiotic treatment of a post vaccination reaction. These reports will help identify and remedy defects in vaccination procedures.

Table. Vaccination hygiene in index and study areas, Saudi Arabia, 1996.