Toxoplasmaand other protozoan infections of economic importance in New Zealand

Abstract

Of the protozoans infecting domesticated animals and humans in New Zealand, it is undoubtedly the apicomplexans that are most important. These include Toxoplasma, Sarcocystis, Eimeria, Cryptosporidium, and Neospora species. All have the potential to cause both clinical disease in animals and subclinical losses of production and, in some industries, they necessitate the use of costly preventive measures. Some are also potentially important to human health and others to the acceptability of meat products. There have been very few attempts to estimate the economic significance of infections with these parasites in this country and it is difficult to do so. In this paper, I review the biology and prevalence of these infections in New Zealand, attempt to estimate the significance of at least some of them, and discuss the problems associated with doing so.

Advances in New Zealand mammalogy 1990–2000: House cat

“…Both feral and farm cats carry Toxoplasma gondii and transmit it to sheep, but which are the more important is unknown (Charleston 1994). No Toxoplasma oocysts were found in 63 scats collected from feral cats on farmland in the Hawkes Bay (Langham & Charleston 1990), but five of 508 faecal samples from domestic cats (0.98%, all under six months old) showed infection (McKenna & Charleston 1980).…”

“…Human toxoplasmosis is also common in 1999 1997 1998 1998 1998 1998 1999 1998 Downloaded by [Southern Illinois University] at 03:04 03 December 2014 New Zealand, and generally not a problem for normal healthy people. The main concern is the risk of congenital infection of the foetus in women who become infected with toxoplasmosis for the first time while pregnant (Charleston 1994;Thompson 1995). However, the risks of contracting toxoplasmosis from domestic cats are considered to be more than offset by the benefits that they provide to the seriously ill, lonely or elderly, for whom animals provide much needed affection (Thompson 1995).…”

“…are another group of protozoan parasites of cats of economic importance in New Zealand, because they give rise to macroscopically visible sarcosysts in meat that has to be trimmed from carcasses at the meatworks (Langham & Charleston 1990;Charleston 1994). Sarcocvstis hirsuta can be transmitted to cattle by cats, and S. gigantea and 5. medusiformis can be transmitted to sheep, but are at most mildly pathogenic (Langham & Charleston 1990;Charleston 1994). Signs of Sarcocystis are not very abundant (found in three (4.8%) of the 63 scats analysed from Hawkes Bay farmland: Langham & Charleston 1990).…”

Oesophageal sarcocystosis observed at slaughter provides a reliable and efficient proximate measure of Toxoplasma gondii seroprevalence in sheep

“…Consequently, a reduced lambing rate associated with toxoplasmosis is responsible for substantial economic losses to sheep producers. For example, the New Zealand sheep industry was estimated to have lost at least NZ$14 million to T. gondii infection in 1992, equivalent to NZ$24 million in 2019. However, this dollar figure could be much larger, with more than a fourfold increase in lamb prices from 1998 to 2019…”

Imunodetecção de Toxoplasma gondii em tecido placentário de cabras naturalmente infectadas

“…As infecções por T. gondii vêm sendo relatadas em vários países do mundo, por meio do diagnóstico nos fetos abortados (Charleston, 1994), como na região da Múrcia/Espanha, em cabras e ovelhas (Navarro et al, 2009); em cabras (Caldeira et al, 2011;Pescador et al, 2007); na Jordânia, em cabras e ovelhas (Abu-Dalbouh et al, 2012); ovelhas, na Turquia (Atmaca et al, 2012); e, na Argentina, cabras (Ungaza et al, 2014).…”