Ecology and Geography of Plague Transmission Areas in Northeastern Brazil

Abstract

Plague in Brazil is poorly known and now rarely seen, so studies of its ecology are difficult. We used ecological niche models of historical (1966-present) records of human plague cases across northeastern Brazil to assess hypotheses regarding environmental correlates of plague occurrences across the region. Results indicate that the apparently focal distribution of plague in northeastern Brazil is indeed discontinuous, and that the causes of the discontinuity are not necessarily only related to elevation—rather, a diversity of environmental dimensions correlate to presence of plague foci in the region. Perhaps most interesting is that suitable areas for plague show marked seasonal variation in photosynthetic mass, with peaks in April and May, suggesting links to particular land cover types. Next steps in this line of research will require more detailed and specific examination of reservoir ecology and natural history.

Genetic diversity of Yersinia pestis in Brazil

“…They have different epidemiological characteristics and patterns of disease manifestations in the human population. The foci have alternating periods of high incidence followed by other periods of low incidence or even the absence of cases (Baltazard, 2004;Giles et al, 2011). The presence of similar genotypes separated by long geographical and temporal distances as in the A 2 and B 2 subgroups remains to be explained.…”

Seroprevalence and spatial distribution dynamics of Yersinia pestis antibodies in dogs and cats from plague foci in the State of Ceará, Northeastern Brazil

“…These results agree with those of Baltazard 29 , who considered that the geographical massifs of Ibiapaba, Baturité, Machado, Uruburetama, Pedra Branca and Matas constitute a single focus. Giles et al 30 confirmed that plague is focal in northeast Brazil, with a discontinuous distribution. These studies showed that those foci depend on a broad set of conditions, and are not necessarily correlated with their elevation, but likely to the presence of the hairy-tailed bolo mouse, Necromys lasiurus, which is the primary plague host in these foci, and is responsible for epizootics.…”

Bubonic Plague: a brief history of changes to current situation in Brazil

“…First the Porto city, in Portugal, was attacked by the disease, after that, some neighbors' countries of the South America, like Paraguay and Argentina, and, finally, Santos, in São Paulo coast, where, for the first time in history, the disease landed in national field, in October of 1899 [12,17].…”

“…Since that time, all of the foci entered a period of relative inactivity, with few or no human cases [17], concentrated in Bahia, being the last register, in this state, in Feira de Santana city, in 2000. After a silent period of four years, the Ceará registered the last case of the country in Pedra Branca city, in 2005 [19].…”