Non-West Nile virus-associated mortality in a population of American crows (Corvus brachyrhynchos): a gross and histopathologic study.

The American crow (Corvus brachyrhynchos) is a common urban and rural inhabitant of the Northeast and Midwest United States that is commonly infected with West Nile virus (WNV). The current study was initiated to determine non-WNV-associated causes of mortality in the American crow. All animals (40/40) tested negative for WNV infection via polymerase chain reaction and had no evidence of infection based on immunohistochemistry. Common gross necropsy findings included external trauma (6/40), hepatosplenomegaly (6/40), poxviral dermatitis (5/40), and pneumonia (3/40). Common histologic findings included endoparasitism (32/40), multifocal hepatic and splenic necrosis (7/40), pigment accumulation in the spleen (5/40), and disseminated bacterial infection (3/40). The most significant and debilitating diseases included fungal pneumonia and poxvirus-associated lesions. The present report increases the knowledge of diseases present in the American crow population.

The epidemiological transition in an overseas territory: disease mapping in French Polynesia.

During the last 200 years in French Polynesia the people have experienced several dramatic changes in the pathological scene. First the discovery of Tahiti and the surrounding islands at the end of the eighteenth century caused the spread of diseases previously unknown, usually in the form of epidemic outbreaks. In contrast, from the 1860s to soon after the end of the Second World War, health amelioration in French Polynesia was slowly occurring. This constituted a first epidemiological transition in which infectious disease mortality was sharply reduced. The distribution of vaccines, hygiene education and legislation stemmed the long period of some 100 years of demographic disaster and at last the population was able to increase. However for a long time infectious or parasitic diseases remained the main causes of morbidity and mortality. Only from the end of the 1950s has the situation evolved to the present state where morbidity and mortality of the circulatory system and cancer are similar in prevalence to industrialized countries. Diachronistic mapping of some of the most noteworthy diseases is presented to illustrate this last and most important phase of the epidemiological transition.

Hemolytic complement and its components in Syrian hamsters: a study of five strains uninfected and infected with Brugia pahangi.

Complement profiles were tested in outbred (LVG) Syrian hamsters (Mesocricetus auratus) and compared to the MHA, LHC, PD4, and CB inbred strains. The total C and C component concentrations in the sera varied among the strains and were in the following ranges in untreated animals (in CH50 units per ml): total C, 140-260 (undetectable in PD4 and CB); Cl, 14,000-25,000; C2, 200-800 (except PD 4 and CB); C3, 40,000 and 80,000; C4, 2,000-2,800 (except PD4 and CB); C4, 40,000-80,000; C6, 3,600-6,000 (undetectable in PD4 and CB); C7, 50,000-350,000; C8, 10,000-30,000; C9, 30,000-60,000. The PD4 and CB strains had undetectable total C and C6, and their exact C2 and C4 levels could not be determined, but were lower than in the other strains. The MHA strain had the highest total C levels, but had significantly lower (1/3 or less) C7 levels than the other strains of hamsters. Infection of hamsters with the filarid nematode Brugia pahangi for four to five months produced moderate decreases in the total C and C3 levels, but varied changes in other C components. Six infected and three uninfected animals died during the experiment from spontaneous enteritis and weight loss.