HIV-1-prevalence in fatalities from Hamburg, Germany

Postmortem bacteriology in forensic pathology: diagnostic value and interpretation

The proof of a pathogenetic germ can be of evidential value for the medico-legal expertise concerning etiopathogenetic conclusions towards a causal relationship between infection and fatal outcome. In specific cases the forensic pathologist may be confronted with the decision whether cultures for postmortem bacteriological investigations should be obtained at autopsy. The present review surveys the value and practicability of postmortem bacteriological cultures in the light of the literature. The most promising media for postmortem bacteriological cultures are spleen and heart blood. In contrast, postmortem lung culture results are often unreliable due to frequently false positive results. The collection of specimens from at least two different sampling sites should be the standard procedure in cases where an underlying (potentially fatal) infection is presumed. Multiple postmortem cultures from different sampling sites raise the probability to identify the etiologic agent of antemortem infection. A careful correlation of culture results from different anatomical sampling sites with autopsy and histological findings is essential for the differentiation between vitally acquired infection and postmortem contamination. Various factors (e.g. the time interval between death and sampling of specimens, agonal spread of microorganisms or preceding antibiotic therapy prior to death) may limit the diagnostic utility of postmortem culture results. Contamination of specimens may, e.g. originate from inadequate sampling techniques, use of unsuitable transport media or postmortem growth of bacteria. The number of contaminated postmortem cultures increases when bowel manipulation or evisceration occurs prior to sampling and is depending on the anatomy of the sampling site. Polymicrobial growth can be considered contamination in the majority of cases. For the medico-legal expertise a thorough histological examination of inner organs and tissues is needed; the histological section has to represent the sampling site for culture. The presence of an underlying infection can be proven when postmortem bacteriological cultures yield a primary infectious pathogen and a cellular response in the affected tissue can be detected on the histopathological level. Postmortem bacteriology can be regarded as a reliable diagnostic tool for postmortem quality control of preceding diagnostic and therapeutic procedures and can serve as an additional indicator of nosocomial infections within a specific hospital environment. From the medico-legal point of view, a more widespread application of this valuable investigative procedure, that adds to diminish the number of otherwise unresolved deaths in forensic autopsy practice, is desirable.

Prevalence of HIV and hepatitis C markers among a cadaver population in Milan

AIMS

To examine the distribution of serological markers for HIV and hepatitis C virus (HCV) infection in a medicolegal population; to compare prevalence of HIV and HCV markers and cause of death; and to evaluate the risk of potential infection to personnel involved in medicolegal incidents and procedures.

METHODS

Blood samples were collected at necropsy from 328 males and 69 females, aged 16 to 50 years at time of death, and tested for antibodies to HIV and HCV. The individuals were classified according to cause of death and whether there was known antemortem risk of infection.

RESULTS

Overall, 134 subjects gave positive test results: 20 for anti-HIV, 69 for anti-HCV, and 45 for both. By cause of death, the total number of positives (and negatives) with the pairs of figures referring, respectively, to patients with and without known antemortem risks were: natural causes 3 (1), 8 (32); AIDS 2 (0), 0 (0); homicide 0 (2), 5 (24); suicide 3 (0), 9 (69); road traffic accidents 1 (0), 9 (81); other accidents 2 (3), 1 (12); drug overdose 74 (17), 7 (9); unknown causes 3 (2), 7 (11).

CONCLUSIONS

The cases tested represented a predominantly young male population with a high prevalence of serological markers for HIV and HCV infection. The distribution of HIV and HCV positivity varied with the cause of death, probably reflecting the known association between high risk behaviour and infection. However, a substantial number of cases with no known risks also had markers for HIV and HCV, suggesting that there is a large unrecognised pool of potential infection in medicolegal practice.