The National Reference Laboratory of Respiratory Infections is focused on viral and bacterial agents of respiratory infection as well as bacteria that may be either commensal in the upper respiratory tract and be the cause of severe systemic infection. This laboratory includes the Laboratory of influenza virus, the Laboratory of tuberculosis, the Laboratory of Neisseria meningitidis and the Laboratory of bacterial agents of respiratory infection dedicated to bacteria as Haemophilus influenza and Corynebacterium diphtheria.
Laboratory of influenza virus
Influenza is a respiratory disease caused by influenza virus, responsible for an excess mortality and morbidity during annual epidemics, as well as for pandemics, which may came to cause the loss of millions of human lives. One of the main characteristics of the influenza virus is its extensive antigenic variability that allows it to evade the immune response of the host. Influenza diagnosis is complex due to the unspecific clinical features presented which are common respiratory infections caused by other pathogenic agents.
The National Influenza Reference Laboratory (LNRVG) is, since 1953, a member of the WHO network of laboratories. It is responsible for the epidemiological surveillance of Influenza, in collaboration with the Epidemiology Department of INSA, and has as one of its main objectives the identification and characterisation of influenza viruses circulating as well as the detection of emerging viruses with pandemic potential. To accomplish with its reference and surveillance activities, along with the laboratory diagnosis, the LNRVG carries out the antigenic characterisation (isolation in cell cultures or embryonated chicken eggs), as well as the molecular analysis of influenza viruses (phylogenetic analysis, mutation and aminoacid substitution verification). The LNRVG also carries out human serology studies to evaluate the immune response conferred by vaccination or by natural infection with influenza virus.
The LNRVG coordinates the National Laboratory Network for the Diagnosis of A(H1N1)2009 Influenza Infection which currently carries out the laboratory surveillance of Acute Respiratory Infections.
- Raquel Guiomar – Head of the laboratory
- Pedro Pechirra
- Paulo Gonçalves
- Patrícia Conde
National Reference Laboratory for Bacterial Respiratory Infections
Haemophilus influenzae (Hi) are responsible for a number of human diseases ranging from chronic infections to meningitis. It is known until now six serotypes (a-f), but most of the isolates are non-encapsulated (NC). In the nineties, meningitis affected mostly young children and in more than 95% of the cases HI serotype b was the responsible for the infection. A Hi serotype b (Hib) vaccine was developed and introduced in the National Vaccination Plan (NVP) to children less than five years old, in 2000. HI invasive infections dramatically decreased as a consequence of the use of the vaccine, but the remaining cases are now mostly due to non-b type and NC Hi strains.
Once diagnosed an invasive infection, the accurate antibiotic treatment should be established with most rapidity. Until the beginning of the seventies, all HI isolates were susceptible to ampicillin, until the first resistant strain was described. However, in the seventies, the first resistant strain to this antibiotic was described. Since then one or more resistance mechanisms have been associated to this resistance. Molecular studies in the pre-vaccine era have shown that there were few clones involved in the type b form of the disease, although NC strains presented a marked genetic and phenotypic diversity.
The National Reference Laboratory for Bacterial Respiratory Infections, of the Infectious Disease Department, of the Portuguese National Institute of Health, is mostly dedicated to study of this infection. The responsible for the Laboratory is the national microbiologist for invasive HI disease, for ECDC, We are conducting surveillance, as well as research studies, in the epidemiology of the disease after the introduction of the vaccine in the NVP, in the Portuguese population. Antibiotic resistance is another challenge, since the bacteria are capable of acquire resistance mechanisms in a way that will “bypass” the effect of antibiotic.
The responsible for the Laboratory is also the national microbiologist for Diphtheria and related infections, for ECDC. Although we haven’t had any notified case of Diphtheria in last years we should be aware of this severe infection because in countries like Latvia and in the former Russian Federation there are still cases of this infection. Also some sporadic cases were detected in other European countries. In this context we are the reference laboratory to this rare disease and will aim to collaborate with clinicians to deal with this infection, in case it is detected in our country.
Haemophilus influenzae: Gram Staining and colony aspect on Chocolate Agar