Seroquel buy on line Toxoplasmosis

What is toxoplasmosis?

Toxoplasmosis is an infection caused by the protozoan parasite Toxoplasma gondii. While symptoms in humans are usually mild, if a pregnant woman becomes infected, it can have severe implications for both her and her baby. Infections in livestock animals such as sheep can cause abortion of lambs and lower birth weights. Infected cows , however, tend to be more resistant to the disease.1

What is the lifecycle of Toxoplasma gondii?

The only definitive hosts of Toxoplasma, where the parasite reaches sexual maturity, are animals of the family Felidae. In the UK, this is primarily domestic cats. Unsporulated oocysts  are shed in the cat’s faeces where they can then survive in the environment for over 18 months.2 Between 1-5 days, oocysts produce spores and become infective.

Intermediate hosts pick up the oocysts by eating contaminated soil, water or plant material. These intermediate hosts can be any warm-blooded animal, but are often animals like wild birds, rodents or livestock. Once in the secondary host, the oocysts quickly develop into tachyzoites – the fast-growing life stage. They then spread quickly through the animal’s blood stream. These tachyzoites concentrate in neural tissues, such as the eyes and brain, and muscle tissues.

At this stage, the immune response is greatest in a healthy animal or person, and symptoms may be experienced. If the immune system is compromised, then the disease can be extremely dangerous and potentially fatal.3 The parasite can also be transferred to a foetus in a pregnant female. This can have damaging effects on the development and health of the foetus. For information on why pregnant women should avoid lambing and so reduce risks, read our article here.

Once in the tissues of the host, the tachyzoites develop into cysts containing bradyzoites – the slow-growing life stage. In this form, they are generally quiescent and, as they are surrounded by a glycan-rich cyst wall4, the immune response is low.

The parasite is only able to then pass back into the definitive host by consumption. This usually happens when cats catch and eat rodents and wild birds, or eat raw, infected meat. Once in the cat, the Toxoplasma undergoes sexual maturation and releases oocytes, restarting the cycle.

How can humans get Toxoplasmosis?

Humans can catch toxoplasmosis through eating improperly cooked meat.
People can catch toxoplasmosis through eating improperly cooked meat.
  • Eating undercooked meat from infected animals
  • Blood transfusion or organ transfusion from an infected person
  • Drinking water contaminated with infected cat faeces
  • Consuming contaminated environmental samples, e.g. when cleaning a cat litter box or unwashed vegetables from the garden
  • Through the placenta from mother to foetus

How common is toxoplasmosis?

Toxoplasmosis affects between 30 – 50%5 of all people in the world. Consequently, it is the most prevalent latent infection in humans, greater even than latent tuberculosis which effects around a quarter of the human population. An estimated 90% of sheep flocks in the UK have been exposed to toxoplasmosis, but pig and cattle populations both have infection rates at <2%.6

The most common source of human infection is from eating of inadequately cooked, infected meat7. Cooking meat at high temperatures and maintaining strict hygiene can certainly reduce or even eliminate Toxoplasma infection. Making sure all fresh produce is thoroughly cleaned before eating can reduce any environmental contamination.

In livestock, the best way to prevent infection is to maintain strict biosecurity measures between flocks and ensure that any active outbreaks are contained. One of the main ways sheep can contract infections is by eating hay that has been contaminated with cat faeces. As a result, keeping an eye on where cats are living in relation to feed stocks can be crucial.

References

  1. Esteban-Redondo, I. & Innes, E. A. Comp. Immunol. Microbiol. Infect. Dis. http://powerguard.quibblecontent.co.uk/residential/ 20, 191–196 (1997).
  2. Lélu, M. et al. Appl. Environ. Microbiol. order accutane online australia 78, 5127–5132 (2012).
  3. Weiss, L. M. & Kim, K. Front. Biosci. J. Virtual Libr. http://wemswimmingandlifestylecentre.org.uk/index.php?rest_route=/ 5, D391–D405 (2000).
  4. Kim, K., Trends Parasitol. 31, 610–612 (2015).
  5. Flegr, J., Prandota, J., Sovičková, M. & Israili, Z. H. Toxoplasmosis – A Global Threat. Correlation of Latent Toxoplasmosis with Specific Disease Burden in a Set of 88 Countries. PLoS ONE 9, (2014).
  6. Dubey, J. P. Toxoplasmosis in pigs–the last 20 years. Vet. Parasitol. 164, 89–103 (2009).
  7. Cook, A. J. et al. Sources of toxoplasma infection in pregnant women: European multicentre case-control study. European Research Network on Congenital Toxoplasmosis. BMJ 321, 142–147 (2000).