Incidence of needlestick injury among healthcare workers in western India

Needlestick injury (NSI) indicates to a penetrating wound with an instrument potentially contaminated with another person’s body fluid. According to the United States National Institute of Occupational Safety and Health, NSIs are caused by hypodermic needles, blood collection needles, intravenous (IV) stylets and needles used to connect parts of IV delivery systems1. Since NSI carries risk of transmitting blood-borne diseases, it needs to be monitored, documented and investigated. Healthcare workers (HCWs), which include doctors, nurses and phlebotomy technicians handling sharps such as scalpels, needles and venous catheters, are commonly at risk. HCWs handling biomedical waste are also at risk if proper segregation and disposal of sharps are not followed. Data from the Exposure Prevention Information Network (EPINet) system suggest that, on an average, hospital workers incur approximately 27 NSI per 100 beds per year2. For HCWs worldwide, the attributable fractions for percutaneous occupational exposure to human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) are 4.4, 39 and 37 per cent, respectively3. The estimated risk of seroconversion from a known positive source is approximately 0.3 per cent for HIV, 2 per cent for HCV and 6 per cent for HBV4. The risk increases to approximately 30 per cent for HBV, if the individual is not vaccinated. The American Centre for Disease Control has estimated an annual occurrence of 385,000 needlestick and sharp injuries among hospital-based HCWs5. However, this may not represent the actual number of needlestick injuries as they are grossly under-reported67. This represents missed opportunities for initiating post-exposure prophylaxis, early detection of seroconversion and implementation of preventive strategies. This study was conducted to estimate the incidence of voluntarily reported NSI among HCWs and to analyze the details with respect to such injuries. Based on the data obtained for this investigation, possibilities and measures to prevent NSI would be explored.

Material & Methods

This study was conducted at Bhabha Atomic Research Centre Hospital, Mumbai, a 390-bedded multispecialty hospital after procuring the ethical clearance from the Institutional Ethics Committee. HCWs of this healthcare setup include 164 medical officers, 90 resident doctors, 350 nurses, 220 technicians and subordinate staff and 210 cosmetic maintenance staff. The data of all the HCWs who reported NSI over the past three years, i.e., 2019-2021 was included in the study. As per the hospital protocol for NSI, HCWs were expected to step-wise follow immediate management, i.e., cleaning the wound with soap and water, which is to be followed by reporting of the event to the immediate superior and casualty. As per the NSI protocol of the hospital, the medical officer on duty fills out a questionnaire for all self-reporting HCWs. It includes demographic details, HCW’s work category, information regarding the type of injury, the source of injury (known/unknown), use of personal protective equipment (PPE) at the time of injury, immediate post-exposure measures taken such as washing of hands, assessement of hepatitis B vaccination status and HIV, HCV and HBV infection status of the HCW and the source. Details of injury, i.e. during a procedure, clean up or waste disposal, are recorded. The data of each NSI event are saved in Excel sheets for future reference and audit. The data from the past three years were used for this study. For those HCWs who were not vaccinated against HBV, the first dose of the vaccine was administered at the time of reporting of injury, which was recorded in the questionnaire. Anti-HBs (HBV surface antibodies) titres were measured for HCWs who suffered NSI from a known hepatitis B-positive source and if it was <10 IU/dl, hepatitis B immunoglobulin was administered.

Blood samples of HCW and the source (if known) were collected for HIV, HCV and HBV serum markers as per hospital NSI protocol. These tests were conducted by Monolisa fourth-generation ELISA assays (BIO-RAD, USA) which detect HBsAg antibodies, anti-HCV antibodies and antigens. GenUltra fourth-generation ELISA kit (BIO-RAD, USA) was used to detect HIV I and II antibodies and P24 antigen. HCWs were also tested for the same over one month to one year. Results of testing and compliance to the prescribed prophylactic antiretroviral therapy (ART) regimen, were recorded during the follow up of the HCWs.

Data thus obtained were analyzed under different headings to uncover various aspects of NSI. A descriptive analysis of all variables of the NSI events was carried out. We report the number, frequency and percentages for each of the categorical variables. The number of NSIs per year was divided by the corresponding number of occupied beds, and the mean NSI incidence rate per 100 occupied beds was calculated.

Results

Over three years (2019-2021), 56 cases of NSI were recorded, which included 40 female and 16 male HCWs. The average annual cases was 18.66, which corresponded to an incidence of 10.4/100 occupied beds per year. The details are given in Table. There were 25, 20 and 11 cases of NSI in the first, second and third years, respectively. The mean age of HCWs who suffered NSI was 32 yr. Maximum cases of NSI occurred between 20 and 40 yr age group, i.e., 41 out of 56 cases (73.2%). HCWs of study healthcare setup include 254 doctors (164 medical officers and 90 resident doctors), 350 nurses, 72 technicians (including 36 laboratory technicians, 4 trainee technicians, 20 dental technicians and 12 CSSD technicians) and 210 cosmetic maintenance staff. The work category of the 56 HCWs who suffered NSI were as follows: 21 doctors (37.5%), 15 nursing staff (26.8%), 7 phlebotomy technicians (12.5%), 7 housekeeping/subordinate staff (12.5%), 5 dental technicians (8.9%) and one central sterilizing department technician (1.8%). The sharp injuries involved hands, mainly the fingers of the HCWs in 54 cases (96.4%) and in 2 cases, these involved the feet. Appropriate PPE was donned by 37 (66%) HCWs. Of the 56 cases, 26 (46.4%) occurred in the wards, 13 (23.2%) took place in operation theatres, 7 (12.5%) in the phlebotomy room, 5 (8.9%) in dental laboratory, 2 (3.6%) cases each occurred in the outpatient department and sonography room and one (1.8%) in the emergency room.

Phlebotomy was the most common situation during which HCWs suffered NSI (35.7%), of which 55 per cent occurred post-procedure; 25 per cent due to recapping and 30 per cent during sharp disposal. The next common situations were conducting minor procedures such as hemoglucose test (done with Glucometer-by finger prick method to know capillary glucose level), IV cannula insertion and operative procedures, which contributed to 33.9 per cent. Other situations included the administration of injectable drugs (12.5%), stray sharps that were not disposed and were left behind inadvertently (8.9%) and during biomedical waste handling (5.4%). Two cases occurred due to sharps such as glass items accidentally getting dropped on feet. Forty cases (71.4%) of NSI occurred between 7 am and 3 pm, 11 cases (19.6%) between 3 pm and 11 pm and 5 cases (8.9%) between 11 pm and 7 am. Of the 40 cases of NSI occurring between 7 am and 3 pm, 18 cases (45%) occurred at the time of phlebotomy, either during the procedure or at post-procedure sharp disposal. This also represented 90 per cent of the total situations where injury had occurred at the time of phlebotomy.

Majority of the cases (83.9%) involved bored sharp equipment, mostly needles. In 16.1 per cent cases, the sharps involved were non-bored sharps such as suturing needles, scalpel blades and glass pieces.

Of the 56 HCWs, 64.2 per cent were completely vaccinated for hepatitis B, 12.5 per cent HCWs had incomplete vaccination, i.e. either one or two doses of vaccine were received and 23.2 per cent HCWs were not vaccinated or their vaccination status was not known. Post-vaccination antibody titres were available in 10.71 per cent HCWs. Baseline viral marker studies for HIV, HCV and HBV were negative for all HCWs. The source patient’s immune status for HIV, HCV and HBV was unknown in 16 cases and it was negative in the remaining 40 cases except for three cases, where it was positive for hepatitis B surface antigen. Of these three cases, two received hepatitis B immunoglobulin therapy as their vaccination status was unknown, and simultaneously, hepatitis B vaccination was also initiated. All three cases were followed up over six weeks, three months, six months and one year and were reported to be negative for hepatitis B surface antigen. The source patient’s immune status for HIV, HCV and HBV were unknown for 16 cases; HCWs in these cases were counselled and were started on post-exposure prophylaxis for HIV. For those not vaccinated or with unknown vaccination status for HBV, vaccination was initiated as per hospital NSI protocol. All cases were tested for HIV antibody and P24 antigen, HCV antigen and antibody and HBV surface antigen at the time of injury, at six weeks, three months and six months and one year by fourth-generation ELISA kits of BIORAD make (highly sensitive and specific assay). HCWs were monitored for symptoms and liver enzyme levels during this period.

Immediate washing of the site of injury with soap and water was done in all cases. A prophylactic ART regimen was prescribed for all the cases. Compliance with ART regimen was poor, 100 per cent cases had taken the immediate dose of ART; however, only 5.4 per cent cases had completed the regimen as prescribed. Follow up viral markers over one month to one year were negative in all cases.

Discussion

The incidence of NSI in the present study was 10.4/100 occupied beds per year. This was lower compared to 19.46/100 occupied beds per annum reported in the EPINet 2011 data8. A similar study from a tertiary care hospital in India reported an incidence of 8.9 per cent/100 beds per annum9. Rates of NSI in hospitals differ by country, use of safety devices and methodologies (including potential under-reporting) used. Studies have reported a wide range from 14.9 to 69.4 per cent of HCWs experiencing NSI, and 3.2-24.7 NSIs per 100 occupied hospital beds10. In a recent systematic review and meta-analysis, the prevalence of needlestick injuries (NSIs) (occurrence of at least one NSI within previous 12 months) was assessed in 87 studies conducted in 31 countries. Based on the results of the random effects method, the global prevalence of NSIs in all the 50,916 HCWs studied was 44.5 per cent (95% confidence interval: 35.7-53.2; I²=99.9%)11. As NSIs are often under-reported, healthcare institutions should not interpret low reporting rate as low injury rate12. The high incidence in our study despite various awareness programme is a result of better incident reporting and documentation. It is believed that only one out of three NSIs are reported in the US, while these injuries virtually go undocumented in many developing countries3. In the present study, 25 cases of NSI were reported in the first year, followed by 20 and 11 cases in the second and third years, respectively. Regular awareness and training programmes for HCWs were started during the study.

Among HCWs, doctors constituted the largest group that suffered NSI (37.5%), followed by nursing staff (26.8%). Studies from India have reported a wide range of 39-73.7 per cent of sharp injuries among doctors913, which could be due to the resident doctors in teaching hospitals being commonly involved in blood sample collection and clinical procedures as in the present study setup.

Notably the probability of ever having a NSI has been reported to be inversely related to the years of experience14. An Indian study from Ahmedabad by Shah et al12 mentioned that 61 per cent HCWs had less than five years of work experience; a few other studies from India reported similar findings915. The higher incidence of NSI in relatively younger HCWs may be due to lack of experience, handling more workload of patients under pressure situations and lack of awareness due to inadequate training with respect to preventive measures. In the present study, NSI was more frequently reported in female HCWs (71.4%) than their male counterpart (28.6%). Noticeably, while some studies reported NSI to be more common in male HCWs915; others reported it to be more in female HCWs10 indicating no definite prediction.

Phlebotomy was the most common situation during which HCWs suffered NSI. Of these, 55 per cent occurred post-procedure. In the study by Goel et al9, almost half of the NSIs occurred during blood sample collection and recapping. In the EPInet study, a little more than one third of the NSIs occurred during needle use, while 42 per cent occurred after the use of the needle and before its disposal16 as reported by other investigators. A higher number of NSIs have also been reported post-procedure in studies conducted at Vellore (recapping 8.5%, disposal 18.6%), Goa (recapping 6.3%, disposal 31.7%) and New Delhi (recapping 39%)151718. Importantly, recapping of needles is not recommended as per the Occupational Safety and Health Administration Guidelines19. However, findings in our study and those reported in literature indicate that hazard and occupational safety awareness among HCWs regarding sharp disposal methods are inadequate. As an increasing number and variety of needle devices with safety features are now available; careful selection and evaluation of such devices may be necessary for safe injection practices.

The second-most common situation where NSIs occurred was during minor procedures such as IV cannulation, hemoglucotest (HGT) measurement and operative procedures, which collectively contributed about a third of the cases. Other studies reported suturing as the most common procedure during which HCW suffered NSIs61520.

Out of 56 cases in our investigation, 47 (83.9) involved hollow bored sharp equipment, mostly needles. Studies by, Murlidhar et al15, in 2010 (71%); Askarian et al21, in 2007 (72.2%) and Ng et al22, in 2002 (62.2%) also reported NSI to be most commonly associated with hollow bore needles152122. Recoginizing this association is important, as hollow bore needles are associated with higher fluid content and pathogen load, with a higher risk of disease transmission15.

More than 70 per cent of cases of NSI in our study occurred during morning and early afternoon hours which could be due to the fact that majority of the procedures and investigations are undertaken during such time. Of the 40 cases of NSI that occurred between 7 am and 3 pm, 18 cases (45%) occurred at the time of phlebotomy, which represented 90 per cent of the total situations where injury had occurred at the time of phlebotomy while resident medical officers were on duties. We could not determine the number of NSI events that occurred among senior HCWs after they completed night duties.

Of the blood-borne diseases, hepatitis B is the most transmissible infection. However, it is is preventable by vaccination23. In developing countries, 40-65 per cent of hepatitis B infections in healthcare workers were attributable to percutaneous occupational exposure. By contrast, in developed countries, the attributable fraction was <10 per cent. This is because of immunization and post-exposure prophylaxis24. The anti-HBV vaccination coverage varies between 18 per cent in Africa to 77 per cent in Australia and New Zealand as estimated by WHO24. In our study, about two third of the HCWS were completely vaccinated against hepatitis B. Although hospital policy recommends voluntary vaccination of all HCWs against HBV, like in other studies13, about a fifth of the HCWs in our study, who suffered NSI were either not vaccinated or not sure about their vaccination status. This underlines the importance of launching HBV-vacination campaign across hospitals. Another concern emerging from this study was that less than a tenth of the HCWs, suffering NSI, completed the prescribed PEP as observed by other investigators6925. Fear of side effects, as well as poor awareness, could be factors leading to such poor compliance with PEP among HCWs.

This study was conducted in a multispecialty government hospital, where data regarding NSI events are documented at the time of injury in the Hospital Information System for self-reporting HCWs. This has allowed a standard reporting format, availability of data regarding all variables that were studied and prevented recall bias. This study has not described the impact of preventive measures such as the use of safety-engineered devices or determined the impact of specific types of safety devices used. Audit of NSI events over a longer period is necessary to determine the impact of various awareness programmes and preventive measures implemented in healthcare setting.

Inadequate awareness about preventive measures and inexperience among HCWs can contribute to increased occurrence of NSI. Hence, comprehensive training is needed about precautionary measures that could help prevent NSI. The study also emphasizes the need for hospital-wide active hepatitis B vaccination and documentation of anti-Hbs antibody levels among all HCWs. Counselling and supportive therapy should be implemented for better post-exposure prophylaxis compliance.