Public health priority: Routine.
PHU response time: If requested by CDB, begin investigating cases within 1 working day of request.
Case management: By treating doctor. PHUs do not follow up cases routinely. Follow up may be required when an unusual mode of transmission is suspected, or through appropriate AHS staff where partner notification is required.
Contact management: By the treating doctor. AHS specialist staff must assist if requested by the treating doctor or CDB.
To monitor the epidemiology of human immunodeficiency virus (HIV) infections in NSW and so inform the development of better prevention strategies.
Newly acquired HIV disease may be diagnosed in individuals aged 18 months or older at the time of blood sample collection. A diagnosis of newly acquired HIV infection excludes a diagnosis of HIV infection (unspecified).
A probable case requires laboratory suggestive and clinical evidence.
HIV seroconversion illness within the 12 months prior to blood sample collection.
A confirmed case requires definitive laboratory evidence only.
HIV infection (unspecified) is diagnosed in individuals aged 18 months or older at the time of blood sample collection, who do not have evidence of HIV acquisition in the previous 12 months. A diagnosis of HIV infection (unspecified) excludes a diagnosis of newly acquired HIV infection.
A probable case requires laboratory suggestive evidence only.
Detection of HIV by at least one of the following virologic assays (nucleic acid testing for proviral DNA; HIV p24 antigen, with neutralisation; virus isolation) in one blood sample only.
A confirmed case requires definitive laboratory evidence.
Detection of HIV by one of the following virologic assays (nucleic acid testing for proviral DNA; HIV p24 antigen, with neutralisation; virus isolation) in one blood sample (excluding cord blood) and no subsequent negative HIV virologic or antibody tests.
A confirmed case requires definitive laboratory evidence
Detection of HIV by at least two virologic assays (nucleic acid testing for proviral DNA; HIV p24 antigen, with neutralisation; virus isolation) on at least two separate blood samples (excluding cord blood).
A confirmed case requires laboratory evidence and clinical evidence.
Definitive diagnosis of HIV-1 infection.
A diagnosis of at least one of the following clinical conditions:
(Illnesses indicative of AIDS are defined in ANCA Bulletin 18: Definition of HIV infection and AIDS defining illnesses.)
HIV is to be notified directly to the Communicable Diseases Branch by HIV reference laboratories within one week of diagnosis of a new case. HIV reference laboratories are required to send a notification form with the HIV positive result to the treating doctor seeking information about the case, with instructions to return the form to CBD within 14 days. A copy of the form is simultaneously sent to CDB for entry onto the HIV/AIDS Database.
If CBD does not receive a completed notification form from the treating doctor within 28 days of receipt of the lab notification, CDB sends a follow up request to the treating doctor. If, within 14 days, there is no response to the follow up request a final reminder is sent. The case is then finalised until further information is obtained.
Follow up of a perinatal case is conducted through the NCHECR. The Australian Paediatric Surveillance Unit notify NCHECR of the perinatal case. If the treating doctor indicates that the HIV infected woman has children, copies of the Perinatal Exposure form are forwarded for completion by NCHECR.
AIDS is to be notified to PHU by medical practitioners and hospital CEOs on provisional clinical diagnosis. On completion of the AIDS notification form, the form is forwarded to the Public Health Unit, where it is entered onto the Notifiable Diseases Database (NDD). The PHU also forwards a copy to CDB for entry onto the HIV/AIDS Database.
All Public Health Units complete annual active surveillance for unreported cases of AIDS and deaths in a HIV infected person.
The human immunodeficiency virus (HIV) 1 or 2.
HIV is usually transmitted by contact with blood, semen, vaginal secretions or breast milk of an infected person. The virus must be introduced through broken skin, via the placenta or come in contact with mucous membranes for infection to occur. HIV may also be present in the cerebrospinal fluid, saliva, tears, pre-ejaculatory fluid, amniotic fluid, urine and bronchoalveolar fluid of infected persons. However transmission via exposure to these fluids has not been documented.
Routine social or community contact with an HIV infected person carries no risk of transmission. Only sexual exposure and exposure to blood, body fluids or tissues carry a risk.
Documented modes of transmission include:
The window period (which is the period between exposure and possible laboratory diagnosis) is variable, but the time from infection to the development of detectable antibodies is generally 30 to 90 days. The time from HIV infection to diagnosis of AIDS may be less than a year or longer than 10 years where no treatment is instituted.
The period of infectivity begins early after onset of HIV infection and extend throughout life. Infectiousness is high following initial infection, and is likely to increase as the immune system deteriorates, as characteristic clinical symptoms appear and in the presence of other sexually transmissible diseases.
HIV infection is biphasic. The initial phase, which may be so mild as to go unnoticed, occurs shortly after infection. This acute syndrome resolves spontaneously, and most cases remain asymptomatic for a period of some years. Eventually, however, a progressive immunodysfunction develops, associated with depletion of T4 (CD4+) lymphocytes, which predisposes these individuals to a number of opportunistic infections, tumours and other conditions.
Shortly after exposure, many persons experience a nonspecific illness that may resemble mononucleosis and usually resolves over 2 to 3 weeks. There is typically an abrupt onset, with the following non-specific symptoms (in descending order of frequency):
Most persons remain asymptomatic for years after initial infection; infection can only be determined by antibody or other laboratory testing. Subsequent HIV-related illness may present in a variety of ways such as:
PHU are not required to routinely follow up HIV or AIDS cases. PHUs may be required to investigate cases in special circumstances (see below).
The response to a notification will normally be carried by the case's health carers. Sexual Health Service (SHS) staff should assist if requested.
PHU are not required to routinely follow up HIV or AIDS cases. PHUs may be required to investigate cases if:
Clinicians are required to provide pre and post test counselling to patients seeking HIV tests. A range of educational services are available to people diagnosed with HIV through the AIDS Council of NSW and other agencies.
People with HIV infection must avoid exposing others to their body fluids and (under the Public Health Act) must not knowingly place others at risk of infection.
Health care workers who are HIV infected must not perform exposure-prone procedures.
Usually none. Where nosocomial transmission is suspected, then a review of the facility's infection control procedures will usually be required.
Contacts are people who have been exposed to the case's blood, semen, vaginal secretions, or breast milk. Follow up of contacts to determine their risk of infection is the responsibility of the case's treating doctor. The doctor may seek the assistance of the Area Health Service staff for this, in which case trained AHS must assist in contact tracing.
Contact investigation and treatment should be managed through a medical practitioner or AHS Sexual Health Service Specialists. Contacts should be assessed for risks for HIV, and whether post exposure prophylaxis is warranted.
The treating clinicians must provide counselling and education for contacts.
HIV-infected health care workers must not perform exposure prone procedures. The risk of transmission of HIV to patients of an infected HCW performing exposure-prone procedures must be assessed in accordance with NSW Health Department Circular 99/88. Health care workers should be aware of the need to comply with standard infection control precautions (Circular 2002/45).
Where iatrogenic infection is suspected, notify CDB immediately.
Where a case has donated blood or plasma while infectious, the blood bank and the CDB should be notified immediately.
If transfused blood or blood products are suspected as the possible source of infection, the blood bank and the CDB should be notified immediately.