Infectious Disease Report - May 2008
Communicable Disease Report, May 2008
Table 1 shows reports of communicable diseases received through to the end of May 2008 in NSW by Area Health Service. To check the latest reports for a particular disease, scroll down the table to the disease of interest, and click on the column headed "NSW data".
Measles continues
To the end of May, 34 cases of measles have been reported in NSW in 2008 compared with 4 for all of 2007. The majority of cases have been reported from public health units in the Sydney area.
In May 2008, 14 cases of measles were notified through Public Health Units in NSW. Of these, two cases were associated with overseas travel, nine were associated with a cluster in Sydney South West (SSW), and for the remaining three cases the source of infection was not identified. The cases ranged in age from seven months to 36 years of age, nine were male and five female. Over half the cases had not received measles immunisation.
In the cluster of nine cases identified in SSW in May, the initial case had attended an emergency department but was not diagnosed with measles at the time. Two siblings of this case (thought to be fully vaccinated against measles) also presented to the same Emergency Department five days later with fever, cough and rash (consistent with measles). The cluster had three generations of transmission:
- Generation 1: the initial case and the initial case's siblings (who were likely infected at the same time from an unknown source),
- Generation 2: four of their emergency department contacts and one of their school contacts
- Generation 3: one of the emergency department contact's work colleagues (resident in Sydney West). In early June a tenth case was identified in a family member of the school contact.
Public health units across Sydney continue to investigate this outbreak and have conducted clinics for contacts of the cases to offer vaccination and provide information.
Measles is highly preventable through immunisation. Children and young adults born during or since 1966 who have never had measles should have 2 doses of MMR vaccine. For more information see measles fact sheet
Tuberculosis
In May 2008 NSW Health was notified of a case of tuberculosis in a young man. The man had been in year 12 at a school in the Strathfield area when he developed a cough and fever in October 2007. He was diagnosed with TB in December while overseas and commenced on treatment, but the diagnosis was not reported to NSW Health until he returned to Australia some months later.
TB is caused by infection with the bacteria (Mycobacterium tuberculosis) that are passed from person to person via the air mainly after coughing. Prolonged exposure is usually required before infection occurs. In most people infection remains latent, causing no symptoms (latent infection cannot spread to other people). A few people (about 10%) progress to active TB disease in the following weeks to years. When disease occurs, symptoms may include cough, fever, weight loss and night sweats. People with latent infection can be identified by demonstrating a reaction to a tuberculin skin test, and can be given preventive antibiotic treatment that substantially reduces their risk of developing TB disease.
Sydney South West AHS contacted the school administration and with their assistance identified 45 students and 5 teachers who may have been in close contact with the case. Affected students and teachers have been contacted to arrange tuberculin skin tests to screen for possible latent TB infection. Parents of some students in year 11 with less contact with the case have been informed through a letter. Initial tuberculin skin test results from the case's closest contacts (ie, those in his household) suggest that he was unlikely to be very infectious while at school. No other students or staff are thought to be at risk of infection. The investigation continues. For further information see tuberculosis fact sheet
Enterics
In May 2008, NSW public health units investigated 46 outbreaks of gastroenteritis including 42 where person-to-person spread was implicated and four suspected to be food borne. The NSW Food Authority inspected commercial premises associated with these suspected outbreaks.
Among the four outbreaks suspected to be foodborne, Chinese banquet style meals from two different restaurants were implicated in two and 12 people were affected. The other two were large outbreaks affecting approximately 100 people and were likely caused by preformed bacterial toxins in foods (Clostridium perfringens and Bacillus cereus).
Among the 42 suspected person-to-person outbreaks a total of 662 people were affected. Nine occurred in child care centres and affected 85 people, 20 occurred in aged care facilities and affected 361 people, 12 occurred in hospital and affected 139 people, and 1 occurred in a school and 77 students were reported absent. Viral gastroenteritis was the suspected cause in all outbreaks. Norovirus is the most commonly reported cause of diarrhoeal outbreaks in aged care facilities in NSW, and rotavirus is a common cause of viral gastroenteritis outbreaks in childcare centres. Control depends on early recognition that an outbreak is occurring, exclusion (or isolation) of infectious cases, careful hand-washing, care with food preparation, and environmental cleaning. For more information see
- viral gastroenteritis
- gastroenteritis in children
- and guidelines on managing outbreaks in institutional settings