Background
The World Health Organization (WHO), International Labor Organization (ILO) and their allied organizations/institutions recognise the need for placing exposure to HIV as a workplace priority intervention. According to the WHO, the term ‘exposure to HIV’ is defined as ‘percutaneous injury (e.g. needle-stick; or cut with a sharp object) or the contact of mucous membrane or non-intact skin (e.g. exposed skin that is chapped, abraded or afflicted with dermatitis) with blood, tissue or other body fluids that are potentially infectious’ [
1]. Empirical evidence has shown that HCWs are among the most at risk groups for contracting the HIV virus through blood and body fluids from their workplace which may lead to AIDS – Acquired Immune Deficiency Syndrome [
2]. Apart from the chronic illness the HCW faces as a result of contracting HIV, the possibility of persistent recurrent nightmares and fear after one’s exposure to HIV cannot be underrated [
3]. Such exposures can have a negative impact on families and colleagues of the HCW [
4].
The risk of pathogen transmission from infected persons through an injury with a sharp object has been estimated to be 0.3% for HIV [
5]. Developing countries, especially those in sub-Saharan Africa (SSA) account for the highest prevalence of HIV-infected patients and that 90% of occupational exposure occur in these countries [
6‐
9]. Shortage of occupational safety facilities and HCWs’ sensitiveness to taking precautionary measures are among the reasons contributing to high frequency of occupational exposure in these countries [
10].
Ensuring that safety devices are in place and workplace safety practices are adhered to in order to help prevent acquisition of infection is greatly recommended [
11]. According to experts, safety devices and practices include: routinely using barriers such as gloves and goggles when anticipating contact with blood or body fluid; immediately washing hands and other skin surfaces after contact with blood or body fluid; carefully handling and disposing sharp instruments during and after use, and administering post-exposure prophylaxis [
1]. Post-exposure prophylaxis alone is said to reduce sero-conversion by 81% [
6].
The nature (including the source of infections) and the actual magnitude of the exposed HCWs, including the prevalence of exposure events and number of HCWs exposed is inadequately reported from most of sub-Saharan African countries and this is partly due to the lack of systematic studies [
1]. In Tanzania, documented information on the estimated risk of occupational exposure to HIV infection among HCWs is scarce and this means more systematic evidence is needed. Therefore, the main objective of this study was to estimate the risk of HIV acquisition after occupational exposure and examine HCWs practices for preventing occupational exposure to HIV infection at Tumbi and Dodoma Hospitals, Tanzania.
Dodoma is a government owned hospital with the bed capacity of 420 and serves 118,000 Patients per year as a regional referral hospital. Tumbi is a parastatal owned hospital with 253 beds and serves as a designated regional referral hospital to 300,000 patients per year. Both hospitals are located in urban areas and provide inpatient and outpatient services such as general OPD, care and treatment clinic (CTC), voluntary counselling and testing (VCT), reproductive and child health (RCH) and clinics for Tuberculosis and Leprosy, Diabetes, eye, dental, gynaecology and obstetrics, etc.
Discussion
A total of 58 cases of occupational exposure were recorded at 2 hospitals over a 6 year period. Of these, 52 were NSIs and the incidence of NSIs was 0.011 per HCW year. The follow up data on HIV status of exposed HCWs were not available as none of the HCW returned for a follow up test. Adequate handling of blood exposure accidents requires reporting of the accidents by the victims [
15]. Studies in other hospitals worldwide indicate that only half of occupational exposure accidents are actually reported [
8]. In this study the number of unreported incidents, HIV status after PEP initiation and compliance to prescribed PEP is not known. Thus the quality of data collected is questionable and there is the possibility that the risk of acquiring HIV infection from needle-stick injuries reported in this study is underestimated. Furthermore, this study did not estimate the prevalence of HIV in hospital patient population, and thus used hospital HIV prevalence reported in other hospitals in Tanzania [
16]. This possibly has led to over or underestimation of the risk of acquiring HIV infection due to occupational exposure.
When a HCW reports an exposure, sources are not routinely tested but assumed to be HIV positive for the purpose of PEP prescription. Exposed HCWs are scheduled for follow up appointments at 3 and 6 months subsequent to incident of occupational exposure to HIV. However, there is no mechanism in place to check whether HCWs took PEP as prescribed. Gaps in the documentation of the health service management data at the studied health facilities are reflected in Tables
1 and
2. The number of unreported accidental exposures is not known. Follow up data on the HIV status of the exposed HCWs after PEP or 3 months after the occupational exposure were not available mainly due to the fact that the exposed HCWs did not return for the second HIV test as per requirement. Therefore, we were not able to discern any incidence of acquisition of HIV infection due to occupational exposure. In all probabilities another factor relating to non-attendance of the required second HIV test might be “self-counselling” which frequently takes place, and this means that HCWs decide not to go for the second test because the overall risk involved is considered to be low.
Using the risks of sero-conversion after percutaneous exposure of 0.32% [
17], a presumed HIV prevalence of 24% among hospital patients in Tanzania [
16] and an incidence of 0.011 needle-stick injuries per HCW-years and taking into the account that all exposed HCWs were offered PEP, the estimated risk of HIV infection due to needle stick injury is 7 cases per 1,000,000 HCW-years. The calculation based on the assumption that all exposed HCWs complied with the prescribed PEP. However, it is not known how many, if any, actually took the PEP or completed the course. This means, the calculated risk may be underestimated and therefore should be interpreted with caution. If none of the exposed HCW took the prescribed PEP, the estimated risk would have been 8 cases per 1,000,000 HCW-years. If the number of needle-stick injuries doubled the estimate would have been 16 cases per 1,000,000 HCW-years. If the number of needle-stick injuries were four times the number recorded, the estimated risk of HIV transmission would have increased to 34 cases per 1,000,000 HCW-years. Nevertheless potential variability of degree of exposure (i.e. seriousness or severity of exposure, quantity of transmitted blood or contaminated material) was not taken into account. This might vary from one discipline to another, e.g. between internal medicine and surgery. Furthermore, because of lack of data, it was not clear whether multiple needle stick occurrences involved the same patient.
The most striking thing about the results from the present study is the very low number of incidents reported. Given the WHO calculation of 1/300,000 worldwide [
9], then one would expect a much higher risk for HCWs in sub Saharan Africa (SSA). Therefore the calculated risk of 7/1,000,000 HCW years is likely to be a gross underestimate. Poorly implemented surveillance of occupational exposure to HIV in the two Hospitals may explain this gross underestimation. Nevertheless, under reporting of blood and body fluid exposure is common because of a belief that most exposures are not significant [
18]. In contrary 91% of junior doctors in South Africa reported a needle-stick injury in the previous 12 months [
19]. However, occurrence of occupational exposure among interns is very common [
18] and these junior doctors were frequently motivated to report needle-stick injuries they encountered [
19].
The estimated risk of HCWs acquiring HIV infection following needle stick injury reported in the present study is lower than the incidence of HIV infection calculated in a study conducted in 1997 in Mwanza region [
14]. With an average of 5 percutaneous injuries per HCW per year, 20% HIV prevalence among patients and a transmission probability of 0.25%, the Mwanza study calculated the incidence of HIV infection through occupational exposure to be 0.27% or approximately 3 per 1000 HCWs per year [
14]. The present study estimated the risk of HIV infection using needle-stick injuries only, excluding other percutaneous injuries caused by sharp object or instrument. In addition implementation of universal precautions to infection at these health care facilities may explain the reduced risk of HIV transmission from the patient to the HCW and vice versa. The Mwanza study was conducted prior to implementation of universal precautions.
Prevention of HIV in healthcare settings requires preventive measures towards exposure to blood and blood products and the availability of PEP [
20]. However, the use of PEP should not be the primary means to prevent occupationally acquired HIV infection. In countries with a high incidence of percutaneous injuries and high prevalence of HIV, PEP use may become difficult because of the related high cost and toxicity of the drugs. An important tool to protect HCWs against occupational HIV infection is to follow standard universal precautions (e.g. use of PPE, and the use of safety devices such as retractable needles. These devices are a suitable and important tool in the reduction of needle stick injuries and improving medical staff’s health and safety [
13,
21].
Hygiene measures taken by Dodoma and Tumbi Hospitals to reduce the risk of infection were insufficient. Over 50% of the Hospital departments at the studied Hospitals did not have health and safety guidelines/instructions in place at all or in clearly visible places for quick reference. Lack of health and safety instructions were more frequently observed at the Dodoma Hospital than at Tumbi Hospital. At both Hospitals, measures for preventing occupational exposures to HIV infection are poorly implemented. A good example is the inappropriate use of gloves. This poor practice seems to have partly been contributed by lack of essential working facilities. Use of PPE such as boots, aprons and eye protective glasses depended on their availability and sometimes HCWs shared torn aprons. In some Hospital departments, the hand washing practice was hampered by lack of running tap water and towels. Lack of towels forced HCWs to dry their hands on the clothes they are wearing or hanging curtains.
Crucial to prevention of occupational exposure to infectious diseases is the handling of infectious materials. Instructions for handling infectious materials were not displayed in most of the hospital departments observed. Though plastic bags/containers/safety boxes for waste disposal were colour coded, approximately one-fifth of the hospital departments visited failed to adhere to the instructions pertaining to correlation between waste materials and the corresponding colour coded bag/container/safety box.
The present study has been able to identify specific needs and concerns for action in the current surveillance system of occupational exposure to HIV. More information is needed from all levels of healthcare especially, lower level facilities such as primary and secondary healthcare facilities. These facilities may be even more poorly supported with the necessary human resources, equipment etc. compared to tertiary hospitals. Information from the private sector is needed to add to the database as a necessity for advocacy and improvement.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
KOM: Principal investigator, conceived of the study, designed the study, collected data, statistical analysis and manuscript writing. GMM: designed study and manuscript writing. HMM: Participated in design of study and manuscript writing. HM: collected data and manuscript writing. EM: Have commented on the paper and provided valuable guidance for manuscript write up. All authors read and approved the final manuscript.