[Laboratory diagnosis of influenza H1N1 2009 at the Central Virology Laboratory in Israel during the first 12 weeks of the pandemic].

BACKGROUND

Diagnosis of new emerging viruses in Israel is the responsibility of the Ministry of Health's Central Virology Laboratory (CVL). In April 2009, following the emergence of influenza H1N1 2009 virus in Mexico and the WHO declaration of pandemia, the Israeli preparedness plan was launched.

AIMS

Development and application of a diagnostic test for H1N1 2009, diagnosis of cases in an outbreak setting and data analysis.

METHODS AND RESULTS

In the absence of a validated test to detect the new strain of H1N1 2009, an RT-PCR amplification of a highly conserved matrix (M) gene of influenza A virus was employed. All positive PCR products were sequenced and compared to sequences in the GenBank. At a later stage, a specific kit provided by the WHO was used. Further improvements were introduced including "in-house" developed assays. Arrangements were made to allow around-the-clock testing of hundreds of samples without compromising other laboratory services. Between April 27th and mid July, 2809 samples were tested of which 1082 (38.5%) were positive. Most of the cases were found in the central part of Israel and around Jerusalem. The highest morbidity was in the 20-29 years age group, with the highest rate of positive cases in the 10-19 years age group. More males than females were ill.

CONCLUSIONS

When a large outbreak of a novel infectious agent occurs, a supreme quality laboratory is essential. The Israel CVL made possible an early and prompt identification of H1N1 2009 from the outset and has met its ongoing challenges with a high degree of success.