The Eco-epidemiology of Pacific Coast Tick Fever in California

Rickettsia philipii (type strain “Rickettsia 364D”), the etiologic agent of Pacific Coast tick fever (PCTF), is transmitted to people by the Pacific Coast tick, Dermacentor occidentalis. Following the first confirmed human case of PCTF in 2008, 13 additional human cases have been reported in California, more than half of which were pediatric cases. The most common features of PCTF are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four case-patients required hospitalization and four had multiple eschars. Findings presented here implicate the nymphal or larval stages of D. occidentalis as the primary vectors of R. philipii to people. Peak transmission risk from ticks to people occurs in late summer. Rickettsia philipii DNA was detected in D. occidentalis ticks from 15 of 37 California counties. Similarly, non-pathogenic Rickettsia rhipicephali DNA was detected in D. occidentalis in 29 of 38 counties with an average prevalence of 12.0% in adult ticks. In total, 5,601 ticks tested from 2009 through 2015 yielded an overall R. philipii infection prevalence of 2.1% in adults, 0.9% in nymphs and a minimum infection prevalence of 0.4% in larval pools. Although most human cases of PCTF have been reported from northern California, acarological surveillance suggests that R. philipii may occur throughout the distribution range of D. occidentalis.     

Interrelations between mangrove ecosystem,local economy and social sustainability in Caeté Estuary,North Brazil

Various types of subsistence and commercialextraction of mangrove products areidentified on the North Braziliancoast. Of 2500 households in 21 ruralcommunities (about 13.000 people) near theCaeté estuary, 83% derive subsistenceincome, and 68% cash income through use ofmangrove resources. The mangrove crab (Ucides cordatus) is collected and sold by42% of households, and constitutes a mainincome source for 38%. Includingprocessing and trading occupations, overhalf of the investigated population dependon the mangrove crab for financialincome. Mangrove fishery occupies the lowerrural income groups in the fisheriessector. About 30% of householdsengage in commercial fishing in or near themangrove. Illegal commercial andsubsistence use of mangrove wood and barkmaintains a considerable number of ruralhouseholds. In the context ofwidespread rural poverty in coastal NorthBrazil, it is important for mangrovemanagement to take into account subsistenceproduction, which has a centralsocio-economic function for the rural poorwho live close to the mangroves.Socio-economic priorities in mangrovevillages were, in order of importance,educational quality, occupational options,medical care, the low level of mangroveproduct prices, access to electricity andlocal leadership quality.