Diseases Covered
Diseases covered under this Policy DirectivePertussis (Whooping Cough)
Measles, Mumps, Rubella
Varicella (Chickenpox)
Influenza
Hepatitis B
References
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Pertussis (Whooping Cough) Measles, Mumps, Rubella Varicella (Chickenpox) Influenza Hepatitis B References Pertussis (Whooping Cough)Pertussis is a highly infectious bacterial respiratory infection, spread by respiratory droplets (coughing, sneezing etc). The cough may persist for longer than 3 months and may be accompanied by vomiting. As the 'whooping' phenomena rarely occurs in adults, diagnosis usually follows a prolonged period of moderate to severe coughing. Pertussis is HIGHLY infectious during the first 3 weeks of illness.
Epidemiology
Pertussis epidemics occur every 3-4 years with notifications rates reaching a peak of 8,337 notifications in NSW in the 2000-2002 epidemic (a rate of 63.8 per person per year per 100,000 population). The highest rates of pertussis notifications are currently in the 35-59 year age group. In 2004/2005 NSW Health undertook a whole of high school based vaccination program to address the high notification rates in the 10-14 year age group The impact of pertussis on adults
The complications of pertussis include: pneumonia, fractured ribs, pneumothorax, inguinal hernia, aspiration, hearing loss, carotid artery dissection, urinary incontinence and prolapses; and seizures, encephalopathy and inter-cranial bleeding in the elderly.
Healthcare workers may need to take extended sick leave as symptoms may take more than 3 months to abate. Further, infected employees can transmit pertussis to household contacts, family and young babies in the community.
Patient groups at risk of exposure to pertussis non-immune employees
Neonates, premature infants and children less than 2 years of age
Pertussis infection in babies less than 6 months of age (too young to be fully immunised) can cause hypoxic encephalopathy resulting in brain damage, pneumonia and death. The mortality rate in hospitalised infants less than 6 months of age is 3.5% and six infants died from pertussis in NSW in 1997. Women presenting for perinatal care
Maternal antibodies do not protect neonates from pertussis. Mothers and babies exposed to pertussis require chemoprophylaxis (erythromycin), which can cause unpleasant side effects. There have been an increasing number of Reportable Incident Briefs relating to neonates exposed to Area employees suffering from pertussis, which have required both the exposed mothers and babies to be placed on antibiotics.
Measles, Mumps, RubellaMeasles
Measles is a serious highly infectious acute viral illness spread by respiratory droplets. It is infectious 3 to 5 days before the rash appears and for up to 4 days following this. Measles is often a severe disease complicated by otitis media and bronchopneumonia. Acute encephalitis occurs in between 2 and 10 per 100,000 cases. Measles encephalitis has a mortality of 10-15% and 15-40% of survivors of this complication have permanent brain damage. Subacute sclerosing panencephalitis (SSPE) is a late complication of measles and causes progressive brain damage and is always fatal Epidemiology
In the 24 years from 1976 to 2000, measles caused 98 deaths in Australia, exceeding the number of deaths caused by diphtheria (4), tetanus (53), pertussis (29) and poliomyelitis (4) combined (NHMRC, 2003, p182). In 2001 and 2002 in Australia there were 171 notified cases of measles and 105 hospitalisations (Brotherton et al, 2004, s27). The National Serological Survey conducted in 2002 showed that 1-6 year olds and adults aged 18- 35 are the most susceptible to measles infection (Gidding et al, 2001). Mumps
Mumps is a contagious virus spread by saliva that causes swollen glands and fever, but may be asymptomatic. Mumps can be infectious from 6 days prior to the swelling of the glands and causes orchitis (swelling of the testes) in up to 20% of cases in post-pubertal males. Permanent pancreatic damage may result from mumps. Nerve deafness is one of the most serious of the rare complications of the disease Epidemiology
In Australia, there have been 10 reported deaths from mumps between 1978 and 1997. In 2000, mumps was recorded as the underlying cause of death in 2 adults, both over 80 years of age. About 15% of mumps cases occur in adolescents and adults. In 2001 to 2002 in Australia there were 180 notifications of mumps with 85 hospitalisations (Brotherton et al, 2004, s37) Rubella
Rubella is a highly contagious virus spread by droplets that causes rash, fever, swollen glands. The disease is usually mild, however, it causes foetal damage known as congenital rubella syndrome (CRS) in up to 90% of babies of pregnant women infected during the first 8-10 weeks of pregnancy and in up to 20% by 16 weeks of gestation. Foetal defects include mental handicap, cataract, deafness, cardiac abnormalities, retardation of intrauterine growth and inflammatory lesions of the brain, liver, lungs and bone marrow (NHMRC, 2003, p251). Epidemiology
In Australia, 511 cases of rubella were notified in the period 2001-2001 with more cases in males than females and a shift in the age distribution to more cases in older age groups. Mass vaccination of schoolgirls and non-pregnant seronegative women since 1971 has reduced the incidence of rubella, but many adolescent and young adult males are susceptible to rubella as they have not received an MMR vaccine (Brotherton et al, 2004, s53). The impact of measles, mumps and rubella on adults
The complications of measles include otitis media (7%) and bronchopneumonia (6%). Acute encephalitis occurs in 2-10 per 10,000 reported cases and has a mortality of 10 to 15% and 15 to 40% of survivors of this complication have permanent brain damage (NHMRC, 2003, p182). The declining notification rates of both measles and rubella in children and higher proportions in adults have led to an increase in the median age of both notified and hospitalised cases since the Measles Control Campaign in 1998.
In 2002 the median age for notified cases was 22 years. Similarly, the median age of hospitalised cases was 24 years compared with a median of 6 years for the period 1993/94 and 1997/98 (Brotherton et al, 2004, s29).
Patient groups at risk of exposure to measles, mumps and rubella by non-immune employees Neonates, premature infants and children less than 2 yrs of age Complications from measles, mumps and rubella are more common and severe in this age group and children are not fully immunised until they have received two doses of MMR vaccine by 4 years of age Women presenting for peri-natal care
Maternal rubella infection in the first 8 to10 weeks of pregnancy results in foetal damage in up to 90 percent of affected pregnancies and multiple defects are common (congenital rubella syndrome). Foetal damage, whilst rare, has been reported up to 20 weeks. Foetal defects include mental handicap, cataract, deafness, cardiac abnormalities, retardation of intrauterine growth and inflammatory lesions of the brain, liver, lungs and bone marrow
Immunosuppressed patients
Immunosuppressed patients are highly susceptible to infectious diseases and often cannot be vaccinated as their immune response to the vaccine may be inadequate and there is a risk that some live vaccines may themselves cause progressive infection. Emergency Departments and Intensive Care Units
These potentially high volume patient clinical areas place both employees and patients at risk of transmission of infectious diseases. Measles has been transmitted from patient to employee in Emergency Departments in NSW in the recent past. Varicella (Chickenpox)Varicella is usually a mild disease in healthy children, but can be more severe in adults and fatal in immunosuppressed people of any age. The average incubation period is 14 to 15 days, with the appearance of a rash occurring after this period. Varicella is spread by coughing/ sneezing and through direct contact with the skin sores. Varicella is infectious from 48 hours prior to the appearance of a rash and until crusting of all lesions has occurred (which may be difficult to determine as lesions can occur inside the mouth and mucous membranes) (NHMRC, 2003, p278).
Epidemiology Varicella is not a notifiable condition in NSW. Whilst over 90 percent of the population have had varicella by the age of 15 years, it is a highly infectious disease in non-immune individuals. There were 19 deaths from varicella in Australia between 2001-2002 with 6 of those deaths occurring in the 25-59 year old age group. There were over 3,000 hospitalisations for varicella infection recorded between 2000 and 2002, with the highest rate of hospitalisation in the 0-4 years age group (Brotherton et al, 2004, s62).
Herpes Zoster or shingles is a sporadic disease caused by the reactivation of the latent varicella-zoster virus. Although herpes zoster can occur at any age, most cases occur after 50 years of age and incidence increases with age. There were 30 deaths in Australia in 2001-2002, 93 percent of these were in those aged 60 years or over (Brotherton et al, 2004, s65).
There are about 240 000 cases, 1500 hospitalisations and 7 deaths each year from varicella in Australia (NHMRC, 2003, p278). Although the risk of severe disease is greater in adolescents and adults, the greatest absolute number of hospitalisations are in children because disease incidence is far higher in childhood (Brotherton et al, 2004, s61).
The impact of varicella infection on adults
The complications of varicella infection include cerebellar ataxia, aseptic meningitis, transverse myelitis, thrombocytopenia, encephalitis, and pneumonia (NHMRC, 2003, p278) Patient groups at risk of exposure to varicella infection Neonates, premature infants and children less than 2 yrs of age
Severe neonatal varicella infection can result from perinatal maternal varicella. Infants with intrauterine exposure have a risk of developing herpes zoster in infancy Women presenting for peri-natal care
Maternal varicella infection can cause serious complications for both mother and baby. Congenital Varicella Syndrome results in malformations, skin scarring and other anomalies. The onset of varicella in pregnant women from 5 days before delivery to 2 days after delivery is estimated to result in severe varicella in 17 to 30 percent of their newborn infants.
Immunosuppressed patients
Immunosuppressed persons have a high risk of serious varicella infection and disseminated disease. Herpes zoster can be a serious illness in older adults and immunosupressed individuals and some may develop disseminated zoster with visceral, central nervous system and pulmonary involvement. (NHMRC, 2003, p278)
InfluenzaInfluenza is a virus transmitted through respiratory droplets, which can cause a wide spectrum of disease from asymptomatic infection; to respiratory illness with systemic features; to multi-system complications and death from primary or secondary bacterial pneumonia (NHMRC, 2003, p166-7).
Every 10 to 30 years, new subtypes of influenza A emerge through antigenic shift and cause pandemics in which a quarter or more of the population may be affected over a short period, with a high mortality rate. Attaining high rates of coverage of the normal seasonal influenza vaccine and the pneumococcal vaccine in identified cohorts and high-risk groups during the non-pandemic period was identified as a priority in the Australian Action Plan for Pandemic Influenza (2003).
Epidemiology
In most years, major or minor epidemics of Type A or Type B influenza occur, usually during the winter months. During epidemics the mortality rises, especially among the elderly and people with chronic diseases, and there is an increased morbidity and hospitalisation for pneumonia and exacerbation of chronic diseases (NHMRC, 2003, p167-8). In 2001-2002 in Australia there were 87 deaths recorded for influenza as the underlying cause, of which 84% were in persons 60 years or older and 13% were in persons aged 25-59 years (Brotherton et al, 2004, s24-25).
Rates for hospitalisation for influenza by age group are highest in infants less than one year (116 per 100,000 in 2001/2002) but length of hospital stay is highest in the over 60 years age group (Brotherton et al, 2004, s65).
High rates of influenza transmission occur during outbreaks in residential care facilities with up to 76% of residents and 42% of staff contracting influenza during the outbreaks. In NSW in September 2004, 13 outbreaks of influenza-like illness were reported from residential institutions in six of the 17 Health Service Areas in NSW, including 12 aged care facilities (ACFs) and one correctional centre. Annual vaccination of staff is demonstrated to reduce influenza transmission in residential facilities.
The impact of influenza on adults
In adults the onset of the illness is usually abrupt, following an incubation period of 1-3 days and includes symptoms of malaise, feverishness, chills, headache, anorexia, and myalgia, which can last for several weeks. Complications of influenza include acute bronchitis, croup, acute otitis media, pneumonia, cardiovascular complications including myocarditis and pericarditis, post-infectious encephalitis, Reye's syndrome, and various haematological abnormalities.
Patient groups at risk of complications of influenza Neonates, premature infants and children less than 2 years of age
The clinical features in infants and children are similar to those in adults but temperatures may be higher (and may include febrile convulsions) and otitis media and gastrointestinal manifestations are more prominent. Immunosuppressed patients
Secondary bacterial pneumonia is a frequent complication in immunosuppressed patients and those whose medical condition makes them vulnerable to the disease and they may die of pneumonia or cardiac decompensation. Cardio-thoracic and respiratory patients
Influenza causes increased morbidity in adults with coronary artery disease, congestive heart disease and chronic suppurative lung disease. Geriatric Patients
Geriatric patients have a greater risk of influenza infection in 'closed' environments such as hospitals and aged care facilities and of developing complications such as pneumonia and death from influenza infection. Clinical Areas that may place employees at risk of contracting and spreading influenza
Emergency Departments and Intensive Care Units
These potentially high volume patient clinical areas place both employees and patients at risk of transmission of infectious diseases. Concerns regarding the recent outbreaks of Highly Pathogenic Avian Influenza (HPAI) have prompted the World Health Organisation (WHO) to recommend that all health care workers, who may come into contact with a patient with HPAI, be vaccinated with the current Influenza vaccine to avoid simultaneous infection by human influenza and HPAI and the re-assortment of the virus's genes to create a pandemic influenza strain. Laboratories
Laboratory employees are at risk of contracting influenza from laboratory specimens and may be exposed to novel strains in the case of a re-assortment of the influenza virus. Hepatitis BHepatitis B is a blood borne virus transmitted by percutaneous or permucosal exposure to infective body fluids such as blood, semen, vaginal secretions and any other body fluid containing blood. Nosocomial exposure of health care workers is a major mode of transmission (Brotherton et al, 2004, s18).
Epidemiology
HBV is the most readily transmitted of the blood borne viruses, and since the early 1970s when testing for HBV commenced, there have been many published reports of clusters of patients infected with HBV by HBV infected HCWs. There have also been multiple reports of transmission of HBV from infectious patients to non-immune HCWs. Transmission of HBV has been shown to occur in the healthcare setting primarily via injuries sustained during the performance of exposure prone procedures (EPPs) which enable either patient exposure to the blood of an infectious HCW or HCW exposure to the blood of an infectious patient. Transmission has also been documented in association with the performance of invasive procedures, other than those which are exposure prone, and sharps injury; and despite modification of EPP practice to minimize the risk of injury and subsequent exposure (Health and Welfare Canada, 1992; Heptonstall J, 1991, Lettau A L et al, 1986). In Australia, between January 2001 and December 2002, there were 837 acute hepatitis B notifications with more than 60% of these occurring in the 25-59 year age group (Brotherton et al, 2004, s19-20). Acute hepatitis B infection leads to chronic infection and carrier status in some people and prevalence rates of hepatitis B infection in Australia range from 0.1 to 0.2% in the Caucasian population and to greater than 10% in some Aboriginal populations. First generation immigrants usually retain the carrier rate of their country of origin (NHMRC, 2003, p167-8).
The impact of Hepatitis B on adults
Acute infection with hepatitis B virus, may produce a range of conditions from subclinical infection to acute hepatitis with jaundice and rarely fulminant hepatitis. The risk of an acute infection becoming chronic varies inversely with age: chronic HBV infection occurs in about 90% of infants infected at birth and about 1-10% of people infected as adults.
Of those chronically infected with HBV, 15-40% develop cirrhosis of the liver and/or hepatocellular carcinoma. (Brotherton et al, 2004, s18).
Patient groups at risk of exposure to hepatitis non-immune employees
All patients and health care workers who are exposed to blood and other body fluids and are non-immune to hepatitis B are at risk of exposure in health care settings. HBV is currently the only blood borne virus for which a vaccine is available. Successful HBV vaccination prevents a person from acquiring HBV, thus eliminating the possibility that they may become infected and transmit the infection to others. It is strongly recommended that all non-immune HCWs who may be exposed to HBV in the course of their work be vaccinated against HBV for their own protection.
ReferencesBrotherton J, McIntyre P, Puech M, Wang H, Gidding H, Hull B, Lawrence G, MacIntyre R, Wood N, Armstrong D. Vaccine Preventable Diseases and Vaccination Coverage in Australia, 2001 to 2002. Communicable Diseases Intelligence 2004; 28: Suppl2: 1-116. Commonwealth of Australia. 2003. Australian Action Plan for Influenza. Gidding HF, Gilbert GL. Measles Immunity in young Australian adults. Commun Dis Intell 2001; 35:133-6. Health and Welfare Canada. Nosocomial hepatitis B associated with orthopaedic surgery - Nova Scotia. Can Commun Dis Rep 1992;18:89-90 Heptonstall J. Outbreaks of hepatitis B virus infection associated with infected surgical staff. Commun Dis Rep (UK) 1991; 1R81-5 Lettau A L et al. Transmission of hepatitis B with resultant restriction of surgical practice. JAMA 1986; 255:934-7 National Health and Medical Research Council. The Australian Immunisation Handbook, 8th Edition, 2003. Commonwealth of Australia This web page is managed and authorised by AIDS & Infectious Diseases of Centre for Health Protection of the NSW Department of Health. Last updated: 31 March, 2009
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