1.1 INTRODUCTION

Infection is one of the most important problems in health care services worldwide.  It constitutes one of the most important causes of morbidity and mortality associated with clinical, diagnostic and therapeutic procedures.1,2

Health care workers (HCWs) are at a high risk of needle stick injuries and blood-borne pathogens as they perform their clinical activities in a hospital.3  They are exposed to blood borne pathogens, such as human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV) viruses, from sharp injuries and contacts with blood and other body fluids.4,5  According to a WHO estimate, in the year 2002, sharp injuries resulted in 16,000 hepatitis C Virus, 66,000 hepatitis B virus and 10,000 HIV infections in health care workers worldwide.6  There is no immunization for HIV and hepatitis C.7  It becomes important to prevent infection by preventing exposure.  Recapping, disassembly, and inappropriate disposal increase the risk of needle stick injury.8,9  The incidence rate of these causative factors is higher in developing countries for the higher rate of injection with previously used syringes.10  Developing countries where the prevalence of HIV-infected patients is very high, record the highest needle stick injuries too.10  Needle stick injuries were also reported as the most common occupational health hazard in a Nigerian teaching hospital.11  The World Health Organization (WHO) estimates that about 2.5% of HIV cases among HCWs and 40% of hepatitis B and C cases among HCWs are the result of these exposures.12  Irrational and  unsafe injection practices are rife in developing countries.13  The practice of recapping needles has been identified as a contributor to incidence of needle stick injuries among HCWs.5, 14 It is believed that only one out of three needle stick injuries are reported in the US, while these injuries virtually go undocumented in many developing countries.15  Unsafe injections and the consequent transmission of blood borne pathogens are suspected to occur routinely in the developing world.16  It was estimated that each person in developing countries receives an average of 1.5 infections per annum. 16, 19 About 90-95% of injections are therapeutic, while 5-10% is given for immunization.17 It has been shown that between 70% and 99% of these injections are unnecessary, while at least 50% are unsafe in 14 of 19 countries in five developing world regions with data. 17, 18, 19, 20.

Hauri et al of the Department of Essential Health Technologies, WHO estimates 3.4 injections per person per year in developing countries.16, 18  In Nigeria, the annual mean was found to be 4.9 injections per year.21  Injection over use and unsafe practices account for a substantial burden of death and disability worldwide.16  Eighteen studies reported a convincing link between unsafe injections and the transmission of hepatitis B and C., HIV, Ebola and Lassa virus infections and malaria.19  Injuries from sharp devices have been associated with the transmission of more than 40 pathogens, including HBV, HCV, HIV, haemorrhagic fevers, malaria and tetanus, thereby increasing the risk and burden of infectious diseases.22, 23, 24, 25  Contaminated sharps such as needles, lancets, scalpels, broken glass, specimen tubes and other instruments, can transmit blood borne pathogens such as HIV, Hepatitis B (HBV) and Hepatitis C viruses (HCV).26  The circumstances leading to needle stick injuries depend partly on the type and design of the device and certain work practices.27  Also, the level of risk depends on the number of patients with that infection in the health care facility and the precautions the health care workers observe while dealing with these patients.27  It is documented that 10 – 25% injuries occurred while recapping a used needle.5  The recapping of needles has been prohibited under the Occupation Safety and Health Administration (OSHA) blood-borne pathogen standard.28

A data combined from more than 20 prospective studies worldwide of health care workers exposed to HIV infected blood through percutaneous injury revealed an average transmission rate of 0.3% per injury,4, 15, 27, 29 and after a mucous membrane exposure approximately 0.09.30  The commonest mode of transmission of HIV –contaminated blood to health care workers is via needle stick injury.27  The greater the size and depth of the blood inoculation, the greater the risk.4  Transmission through the conjunctiva and open lesions in the skin can also occur when in contact with HIV containing fluids.4

An increasing number and variety of needle devices with safety features are now available.  Needleless or protracted needle I.V. systems have decreased the incidence of needle – stick injuries by 62% - 88%.31Some of these injection devices are; Auto-disable syringe, manually retractable, automatically retractable, standard disposable and needle remover.31 

The World Health Organization defines a safe injection as one that is given using appropriate equipment, does not harm the recipient, does not expose the provider to any waste that is dangerous to the community.32 A safe injection is only given when there is no other suitable alternative. Developing countries, especially those in sub-Saharan Africa, that account for the highest prevalence of HIV-infected patients in the world also report the highest incidences of occupational exposure.12, 25, 33  HCV and HBV infections are generally considered endemic in sub-Saharan Africa.33

Occupational safety of HCWs is often neglected in low-income countries in spite of the greater risks associated with occupational exposure to blood, inadequate supply of personal protective equipment (PPE), and limited organizational support for safe practices.33

National data are unavailable for these blood borne infections in Ethiopia.  However, surveys in different parts of the country indicate the prevalence of HCV to be 0.9 to 5.8%34,35 and estimates for HBV range from 4.7% to 14.4%.35-39  According to projections for 2010, the prevalence of HIV/AIDS for Ethiopia is estimated at 2.8%.40  In a study on standard precautions carried out from February to May, 2010 in 10 hospitals and 20 health centres in two administrative regions of Ethiopia (Harare and Dire Dawa), projected estimates of HIV/AIDS prevalence for 2010 as 4.4% for Harare and 5.7% for Dire Dawa.40  The prevalence of HBS Ag in healthy blood donors in Kathmandu Valley has been reported to be about 1.67%.41  Sero-prevalence study suggests that the overall anti-HCV positivity in blood donors is about 0.3% in Nepal.42  The prevalence of HCV sero positivity in health blood donors has been reported to be about 0.2% in Nepal.43  The prevalence of HBS Ag in healthy blood donors in Saudi Arabia ranges from 2.7% to 9.8%.39-40  Sero-prevalence studies suggest that the overall anti HCV positivity is about 3.5 – 5%.43-45