Tuberculosis in New Zealand, 1992-2001: a resurgence

Abstract

Objective: To describe the recent epidemiology and clinical features of paediatric tuberculosis (TB) in New Zealand (NZ). Methods: A retrospective review was conducted of clinical, laboratory, and radiology records of children ,16 years old diagnosed with TB between January 1992 and June 2001 in nine NZ health districts. Results: A total of 274 patients ,16 years old were identified; the average annual TB rate was 4.8 per 100 000. Rates rose over time reaching a peak of 10.1 in 1999. Rates were highest in under-5 year olds, at 6.2 per 100 000, and varied by ethnicity: African 575.2, Pacific Island 15.2, Maori 6.4, Asian 5.6, and European 0.6. Seventy two cases (26%) were foreign born. Thirty six per cent of cases were not detected until they presented with symptoms and of these 44% had no known TB contact. Most cases were identified by contact tracing (48%) or immigrant screening (11%); 43% were part of outbreaks. Miliary TB or meningitis occurred in 8% of patients, two of whom died. Drug resistance was found in 7% of culture positive cases and no HIV co-infection was found. Conclusions: A resurgence of TB occurred among children in NZ between 1992 and 2001 predominantly involving non-European and immigrant groups. Despite established contact tracing and immigrant screening programmes, many cases were part of outbreaks, remained unidentified until symptoms arose, or had no known TB contact. These findings point to an unrecognised burden of adult disease, ongoing community transmission, and missed opportunities for prevention. Further study is required to confirm these hypotheses.

The epidemiology of tuberculosis in children in Australia, 2003–2012

“…Our findings suggest that recent immigration has had a greater influence on the burden of TB in children than transmission within Australia. In most cases (56%), the reported country of birth was outside Australia, and this proportion was higher than the corresponding figures for New Zealand, the United States and western Europe, where 26%–31% of patients with TB were born outside the respective country 16 , 17 , 19 . The notification rate of 9.57 per 100 000 overseas‐born children per year is lower than the rate of 35–37 per 100 000 overseas‐born children reported for the United Kingdom (1999–2006) and the Netherlands (1993–2012) 15 , 20 .…”

“…In most cases (56%), the reported country of birth was outside Australia, and this proportion was higher than the corresponding figures for New Zealand, the United States and western Europe, where 26%e31% of patients with TB were born outside the respective country. 16,17,19 The notification rate of 9.57 per 100 000 overseas-born children per year is lower than the rate of 35e37 per 100 000 overseasborn children reported for the United Kingdom (1999e2006) and the Netherlands (1993e2012). 15,20 This difference may reflect the fact that there was no pre-migration screening in those countries during the reported periods, so that all cases were detected and notified after arrival.…”

“…Current opportunities for prevention that are supported by our findings include contact investigations. While BCG status was not reported for the cases we analysed, BCG vaccination of young children before they travel for extended periods to high‐incidence countries could play a greater role 15 , 19 , 25 . Opportunities for prevention in at‐risk children are often missed 15 …”

“…The higher notification rate for Indigenous than for non‐Indigenous Australian‐born children is similar to the pattern reported for the general population 6 , 26 . In New Zealand, higher rates of TB were found in children of Pacific Island and Maori background than for other locally born children 19 . An active program for diagnosing and treating LTBI in Indigenous people by contact, community, school and prison screening is one strategy used in some areas to better prevent and to ultimately eliminate TB 27 .…”

Burden of tuberculosis in indigenous peoples globally: a systematic review [Review article]

“…5 Although the most recent data suggest that TB rates have declined among the Maori and Pacific Islanders in the past 15 years, 5 earlier data reveal lower incidence rates among the indigenous population than currently observed. 92,93 …”