Appendix 4: Direct laboratory notification of communicable diseases flowcharts

Part of the Communicable Disease Control Manual

Appendix updated in January 2021. A description of changes can be found at Updates to the Communicable Disease Control Manual.


This appendix covers the following diseases.

Section C – infectious diseases notifiable to the medical officer of health without identifying information of patient or deceased person

Diseases notifiable to the medical officer of health (other than notifiable infectious diseases)

Section C – infectious diseases notifiable to the medical officer of health without identifying information of patient or deceased person

Acquired immunodeficiency syndrome (AIDS)

AIDS is a clinical syndrome. No action is required by laboratories.

Gonorrhoeal infection

Specimen: first void urine; swab from vagina, cervix, uretha; swab from throat, rectum, conjunctiva[1]; blood culture, aspirated fluid, tissue. Send for NAAT[1] and culture. If N. gonorrhoeae DNA detected or N. gonorrhoeae isolated, report result to the medical officer of health. Click to enlarge

Note:

  1. It is recommended that culture negative, reactive NAAT results on specimens from extra-genital sites be confirmed by supplementary testing, using a different nucleic acid target, before reporting depending on the test method used.

Human immunodeficiency virus (HIV) infection

Specimin: serum – serological testing; plasma – qualitative or quantitative NAAT. For adults and children over 18 months, sent for reactive HIV point of care test, for HIV antibody or p24 antigen/antibody screening EIA. If repeatedly reactive, sent for western blot assay or antibody differentiation immunoassay, and HIV NAAT[1]. If indeterminate or negative western blot/antibody differentiation immunoassay, refer HIV NAAT. If specific HIV-1 or HIV-2 antibodies detected on assay, or following HIV NAAT, report result to the medical officer of health[2]. For children under 18 months, send for HIV NAAT, if positive, confirm on second specimin from different date. Report result to the medical officer of health[2]. For both groups, reported results will then be passed on to the AEG to process. Click to enlarge

Note:

  1. Whether positive or negative, the result of the first NAAT/viral load test performed must be notified for surveillance purposes. Subsequent new positive results on an individual for whom all previous results have been negative, also require notification. Subsequent results (positive or negative) on the same individual do not require notification. (Note: All subsequent results may be requested separately for other purposes, such as cascade of care monitoring, but this would not be done through the e-notification system.)
  2. Any known cases previously diagnosed in New Zealand and having a viral load test, will be filtered by the AEG.

Syphilis

Specimins (all ages, including neonatal/infant/child): serum or CSF for serological testing; tissue specimin or body fluid, eg, placenta and umbilical cord, amniotic fluid, neonatal nasal discharge, CSF, mucocutaneous ulcers – genital or oral (NAAT, direct fluorescent antibody [DFA]). In the context of congenital syphilis, this should be from a normally sterile specimin, eg, CSF, placental tissue. Sent for T. pallidum EIA (enzyme IgG immunoassay) (specific treponemal antibody test); specific treponemal antibody test (TPPA, TPHA, FTA-ABS, IgM immunoassay); NAAT; DFA. If T. pallidum EIA reactive, send for non-specific treponemal test (RPR, VDRL) as well as specific. If non-specific treponemal test reactive (serum or CSF) at any titre, report result to the medical officer of health, and comment if your records show there has been a fourfold or greater increase within the past 2 years. Following specific treponemal antibody test, send for different specific treponemal antibody test, report result to medical officer of health. For NAAT, on detection of T. pallidum DNA, report result to medical officer of health. For DFA, if T. pallidum visualised, report result to the medical officer of health. Click to enlarge

Diseases notifiable to the medical officer of health (other than notifiable infectious diseases)

Cysticercosis

  • Cysticercosis is caused by the larval stage of T. solium after ingestion of eggs (rather than encysted larvae) from contaminated food, water or via faecal-oral autoinoculation.
  • Stool examinations can be performed; however, eggs are typically not found, since the majority of people diagnosed with cysticercosis do not have a viable T. solium tapeworm in their intestines.
  • Serology is available through reference laboratories for patients with suggestive radiological findings. Occasionally, the diagnosis of extraneural cysticercosis is made by finding a larval scolex in an excisional biopsy of a skin or muscle lesion.

Specimen: serum or CSF for antibody detection, tissue. Sent for serology and histological examination. On detection of T.solium antibodies or larval scolex, report to the medical officer of health.

Taeniasis

  • Taeniasis (adult tapeworm infection) occurs after the ingestion of inadequately cooked pork containing encysted T. solium larvae.

Specimin[1]: usually faeces. Sent for direct microscopy. On detection of Taenia eggs or proglottids[1], report to the medical officer of health.

Note:

  1. If cysticercosis is also suspected, possible use of serology should be discussed with the clinical microbiologist.
  2. It is not possible to differentiate the eggs of T. solium from the beef tapeworm T. saginata. Identification to species level requires examination of proglottid segments passed in the stool.

Trichinosis

Specimin: usually muscle biopsy[1], serum[2] for antibody detection. Sent for histology and serology. On detection of larvae in muscle or of Trichinella antibodies, report result to the medical officer of health. Click to enlarge

Note:

  1. Muscle biopsy for histology collected at least 10 days and ideally ~4 weeks after infection.
  2. Eosinophilia is supportive but not diagnostic.
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