Introduction: A new Influenza A virus H1N1 appeared in March-April 2009, and thousands of cases are being reported worldwide. In the initial months, several imported cases were reported in many European countries, while some countries reported local chains of transmission. We describe the first cluster of in-country transmission of the new Influenza A H1N1 which occurred in Italy, involving 3 patients.
Case presentation: Patient 1, a 11-year-old male child developed fever, cough, and general malaise 4 days after returning from a travel to Mexico. Some days later, the 69-year-old grandfather (patient 2), who did not travel to Mexico, and the 33-month-old brother (patient 3) of patient 1 developed mild influenza symptoms. PCR tests resulted positive for Influenza A, and sequence analysis confirmed infection with the Influenza A (H1N1) strain for all three patients. Some problems were experienced in the administration of chemoprophylaxis and therapy in the patient 3. The chemoprophylaxis policies in other family members are described, too.
Conclusion: Some interesting facts emerge from the analysis of this cluster. The transmission of Influenza A H1N1 virus seems to be dependent on strict contacts. Patient 2 and patient 3 did not take the chemoprophylaxis properly. The problems in the administration of chemoprophylaxis and therapy to patient 3 suggest that in infants specific individual-based strategies for assuring the correct administration are advisable.