|HIV in Pregnancy: A Review (UNAIDS, 1999, 67 p.)|
|SECTION C : INFECTION CONTROL MEASURES|
|Risks of needlestick injuries|
Needlestick injuries occur relatively commonly in obstetric practice and health workers should know their local policy for the appropriate management of injury. The most common form of injury occurs when re-sheathing needles. Injuries from hollow needles are more dangerous than those from solid surgical needles, as they are more likely to transfer blood.
Any such injury carries a risk of exposure to HIV, Hepatitis virus, and other pathogens. For Hepatitis B the risk of infection is between 5% (HBV-e Ag negative source patient) and 43% (HBV-e Ag positive source patient). The amount of blood required to transmit Hepatitis B is only 0.00004 ml, while a minimum of 0.1 ml is required for HIV transmission. All health care workers should have Hepatitis B vaccinations, in view of the high risk of accidental transmission, and high prevalence in many developing countries.
Estimates of the risk of HIV transmission from patient to health care worker vary from 0.23% to 0.5% per exposure384,396,397,398,399. The type of exposure and the stage of the HIV positive source patient affect the risk, since the viral load will be greater in the recently infected patient and in late stages of the disease. The estimated risk of transmission of HIV from a deep needlestick injury from an HIV-positive patient is 0.4%, and the estimated risk of transmission from a trans-cutaneous exposure is 0.05%.
There is evidence that the risk of infection is reduced by the use of post exposure prophylaxis with anti-retroviral drugs, by as much as 79%400. The management of needlestick injuries should be according to local guidelines and antiretroviral drugs should be used for significant injury, if available in the country. Recent guidelines have set out recommendations for the use of antiretrovirals in these cases 379, 401, 402, 403, 404, 405.
First aid treatment
First aid measures should be undertaken as soon as possible after injury. These should include decontamination of the exposure site as soon as possible, allowing a needlestick injury or cut to bleed, washing the area with chlorhexidine or other antiseptic and decontaminating exposed mucosa or conjunctivae by vigorous flushing with water.
Assessment of risk following exposure
A clinical assessment should be made about the level of risk following exposure. This is based upon the following factors:
A. THE NATURE OF THE INJURY:
Puncture: type of needle [hollow or
depth of penetration
Contamination of non intact skin
B. THE SOURCE OF EXPOSURE:
Blood, blood products, body fluids, amniotic fluid, semen and vaginal secretions are associated with transmission of HIV, while stool and urine are not
C. THE SOURCE PATIENT:
Clinical condition or available laboratory results such as viral load
Counselling and testing of the source patient
HIV testing should be offered to all source patients, with their informed consent. Where such consent is not available (for example in a comatose or anaesthetized patient), this consent should be obtained from a relative or senior medical staff member. Where the source patient does not wish to know the HIV result, it may be acceptable to offer to take blood for the test (for the protection of the health care worker), without disclosing the result to the source patient. In practice, very few patients refuse consent and most are extremely concerned about health worker risk.
Counselling and testing of the health worker
A baseline HIV test is required for the management of the health worker and in case of a later claim for compensation. If the health worker has not been immunized for Hepatitis B, a test for HBV should also be undertaken at this time.
Follow-up tests should be done at six weeks, three months and six months. PCR testing may provide an earlier result, if available, which can reduce the stress of waiting for many months for a test result for seroconversion.
The injured staff member should receive follow-up counselling at any stage during the six months that this is required. Counselling should include advice to practise safe sex, to avoid blood donation and to consider delaying pregnancy for six months, if this had been planned.
Post exposure prophylaxis
Post-exposure drug prophylaxis should take into account the type and source of the injury and is not recommended for superficial needlestick injuries or cutaneous exposure. For deeper injuries or lacerations, the use of post exposure prophylaxis should be considered, and treatment started as soon as possible after the injury, with the first dose of ZDV ideally taken within two hours402.
Combination therapy, such as ZDV and 3TC (lamivudine), is currently recommended402,403,404. The addition of a protease inhibitor is recommended for deep exposures in the guidelines of Canada and the USA402,403. Where viral drug resistance is less common, this may not be as necessary. The decision to use post exposure prophylaxis must be taken by the injured party, after discussion of the benefits and risks.