Seroprotection after hepatitis a vaccination in patients with drug-induced immunosuppression.

BACKGROUND: Increasing numbers of travelers using immunosuppressive drugs visit hepatitis A endemic countries. Data on protection rates after hepatitis A vaccination in this group are scarce. METHODS: In this retrospective study, records of subjects with hepatitis A serology taken after vaccination were searched for in travel clinic databases. Relation between immunosuppressive drug use, age, gender, and time between vaccination and serology was evaluated. RESULTS: Seroprotection rates within 4 weeks after primary vaccination (50%) are lower than after 4 weeks (64%). After the complete series of two vaccinations seroprotection rates reach 95% although success depends on the immunosuppressive drug being used. Subjects under anti-TNF alpha treatment have significantly lower seroprotection rates than subjects using classical immunosuppressive drugs after the second vaccination. There is no influence of age or gender on seroprotection rates. CONCLUSIONS: Last-minute vaccination in subjects using immunosuppressive medication is not reliable, only 60% of our subjects had a protective antibody level after a single vaccination. When serology was done within 4 weeks after a single vaccination, seroprotection rates were only 50%, after 4 weeks this number rose to 64%. When persons visit a travel clinic in time for a complete vaccination series, satisfactory seroprotection rates can be reached. Seroprotection rate depends on the drug being used, persons using anti-TNF alpha are less protected.

Transmission of H7N7 avian influenza A virus to human beings during a large outbreak in commercial poultry farms in the Netherlands.

BACKGROUND: An outbreak of highly pathogenic avian influenza A virus subtype H7N7 started at the end of February, 2003, in commercial poultry farms in the Netherlands. Although the risk of transmission of these viruses to humans was initially thought to be low, an outbreak investigation was launched to assess the extent of transmission of influenza A virus subtype H7N7 from chickens to humans. METHODS: All workers in poultry farms, poultry farmers, and their families were asked to report signs of conjunctivitis or influenza-like illness. People with complaints were tested for influenza virus type A subtype H7 (A/H7) infection and completed a health questionnaire about type of symptoms, duration of illness, and possible exposures to infected poultry. FINDINGS: 453 people had health complaints--349 reported conjunctivitis, 90 had influenza-like illness, and 67 had other complaints. We detected A/H7 in conjunctival samples from 78 (26.4%) people with conjunctivitis only, in five (9.4%) with influenza-like illness and conjunctivitis, in two (5.4%) with influenza-like illness only, and in four (6%) who reported other symptoms. Most positive samples had been collected within 5 days of symptom onset. A/H7 infection was confirmed in three contacts (of 83 tested), one of whom developed influenza-like illness. Six people had influenza A/H3N2 infection. After 19 people had been diagnosed with the infection, all workers received mandatory influenza virus vaccination and prophylactic treatment with oseltamivir. More than half (56%) of A/H7 infections reported here arose before the vaccination and treatment programme. INTERPRETATION: We noted an unexpectedly high number of transmissions of avian influenza A virus subtype H7N7 to people directly involved in handling infected poultry, and we noted evidence for person-to-person transmission. Our data emphasise the importance of adequate surveillance, outbreak preparedness, and pandemic planning.