Focus on Infectious Diseases

Research Corner

Probable Person-to-Person Transmission of Avian Influenza A (H5N1)

K Ungchusak, P Auewarakul, S Dowell, R Kitphati, W Auwanit, P Puthavathana, et al;

Background: During 2004, a highly pat hogenic avian influenza A (H5N1) virus caused poultry disease in eight Asian countries and infected at least 44 persons, killing 32; most of these persons had had close contact with poultry. No evidence of efficient person-to-person transmission has yet been reported. We investigated possible person-to-person transmission in a family cluster of the disease in Thailand. Methods: For each of the three involved pat ients, we reviewed the circumstances and timing of exposures to poultry and to other ill persons. Field teams isolated and treated the surviving pat ient, instituted active surveillance for disease and prophylaxis among exposed contacts, and culled the remaining poultry surrounding the affected village. Specimens from family members were tested by viral culture, micro neutralization serologic analysis, immunohistochemical assay, reverse-transcriptase-polymerase-chain-reaction (RT-PCR) analysis, and genetic sequencing. Results: The index pat ient became ill three to four days after her last exposure to dying household chickens. Her mother came from a distant city to care for her in the hospital, had no recognized exposure to poultry, and died from pneumonia after providing 16 to 18 hours of unprotected nursing care. The aunt also provided unprotected nursing care; she had fever five days after the mother first had fever, followed by pneumonia seven days later. Autopsy tissue from the mother and nasopharyngeal and throat swabs from the aunt were positive for influenza A (H5N1) by RT-PCR. No additional chains of transmission were identified, and sequencing of the viral genes identified no change in the receptor-binding site of hemagglutinin or other key features of the virus. The sequences of all eight viral gene segments clustered closely with other H5N1 sequences from recent avian isolates in Thailand. Conclusions: Disease in the mother and aunt probably resulted from person-to-person transmission of this lethal avian influenza virus during unprotected exposure to the critically ill index pat ient.

NEJM , Vol 352 No. 4: 333-340 January 27, 2005

Drug use and risk of bloodborne infections: A survey of female prisoners in British Columbia.

Elwood Martin R., Gold F., Murphy W., Remple V., Berkowitz J., Money D.

Background : Clinicians working in a women's prison in British Columbia observed hepatitis C sero-conversion among inmates, prompting this study to determine: the characteristics of women who do and do not report illicit drug use in prison; patterns of drug use inside prison; factors associated with illicit drug use that might contribute to bloodborne transmission inside prison. Methods: A cross-sectional observational data set was created using an anonymous 61-item self-administered survey. Results: Eighty-three percent (104/126) of eligible inmates participated. Seventy-four percent (77/104) reported their current prison sentence was related to illicit drug use and 25% (26/104) reported their ethnicity as Aboriginal. Ninety-three percent (97/104) reported a prior history of illicit drug use, of whom 70% (68/97) reported a history of injection drug use. Thirty-six percent (37/104) reported illicit drug use in prison, and 21% (22/104) reported injection drug use in prison. Fifty-two percent (54/104) reported hepatitis C sero-positivity, and 8% (8/104) reported HIV sero-positivity. Of the 22 women who reported prison injection drug use, 91% (20/22) reported hepatitis C infection and 86% (19/22) reported injecting with shared needles inside prison, with or without bleach cleaning. Women were more likely to report illicit drug use in prison if they had had illegal sources of income prior to incarceration (p=0.0081, OR 3.19), had previously injected drugs (p=0.036, OR 2.97), and had first injected drugs at a friend's house (p=0.066, OR 2.70). Interpretation: The majority of women reporting prison injection drug use also reported hepatitis C sero-positivity and shared needle use. Canadian prisons are risk situations for transmission of bloodborne pathogens, and provide opportunities for harm reduction strategies.

Can J Public Health 2005; 96 (2): 97-101.