The Microbiology Laboratory is Accredited Center of Veneto Region for diagnosis of Rare Infectious Diseases (https://www.malattierare.gov.it/)

Hansen’s disease (Leprosy)

The leprosy or Hansen’s disease is a chronic infectious disease caused by Mycobacterium leprae affecting mainly the skin and peripheral nerves. It is a rod-shaped, acid-alcohol resistant (BAAR) micro-organism that may not be cultivated in vitro. In vivo, the bacterium is able to develop a strict intracellular parasitism, mainly in macrophages and Schwann cells of peripheral nerves.

In Italy the leprosy is among rare diseases with exemption code RA0010.

Generally the diagnosis is clinical, supported by proof of etiologic agent in nasal swab and skin smears performed in “cold zones” (ear lobes, elbows and knees) and in biopsy with Ziehl-Neelsen staining and polymerase chain reaction (PCR) procedure.

The serologic tests (Immunoglobulin IgM anti-PGL-1 antibody research) are useful to provide for the relapses during therapy, but also to highlight possible sub-clinical cases among contacts.

 Lyme disease or borreliosis

The Lyme borreliosis (or Lyme disease) is a bacterial infection acquired as a result of tick bite, common in wooded areas of Europe, Asia, North America and occasionally North Africa. The etiologic agent is a spirochete of the kind Borrelia, identified in a tick (Ixodes scapularis) in 1982 by researcher Willy Burgdorfer, from which the name Borrelia burgdorferi derived.

In Italy the disease was reported in the regions of Friuli Venezia Giulia, Veneto, Trentino Alto Adige, Liguria and Toscana. Since 1982, due to initial low number of reported cases, the Lyme borreliosis was included in the list of rare infectious diseases, with exemption code RA0030.

The laboratory diagnosis is based on detection of specific antibodies directed against Borrelia burgdorferi. In case of tick bite before carrying out serologic investigations is necessary to wait 4-6 weeks, time needed to allow the production of specific antibodies. In case of neurological involvement is necessary to carry out the serology both on serum and on cerebrospinal fluid.

The research of Borrelia with molecular biology procedures by PCR (Polymerase Chain Reaction) may be performed in all biological liquids as additional test of serologic investigation.

 Whipple’s disease

The Whipple’s disease is a rare infectious disease caused by the bacterium Tropheryma whipplei. Its characteristic feature is the accumulation of lipidic and lycoproteic matter in mucosa of small intestine and lymphatic tissue.

It is mainly a gastrointestinal malabsorption disease but can affect more organs (systemic), as heart, lungs, eyes, skin and, in severe cases, even the central nervous system (CNS).

In Italy the Whipple’s disease is included among rare diseases with exemption code RA0020.

The diagnosis is based on histologic confirmation of macrophages PAS+, especially in duodenal mucosa or enlarged lymph nodes. The diagnostic confirmation is given by molecular research with RealTime PCR of specific DNA sequences, on various matrices, as stool, saliva, blood and cerebrospinal fluid (in suspicion of central nervous system involvement).

For initial screening the samples to analyze are stool, blood and saliva: if there is a suspicion of localized infection, the investigation may be carried out on cerebrospinal fluid (CSF) or other cavitary liquids. Only if PCR Level 1 has positive outcome an in-depth analysis is proceeded (PCR Level 2)