Tuesday, June 5, 2012


Aromas float through the yard in seasonal waves. Each fall there is a night you can smell the crisp air tip into winter. Spring rains chase the scent of wet creosote I remember from growing up in Arizona (or maybe I’m imagining things). If the early summer has a lot of rain, the humid air in Ephemerata Gardens has a tropical odor of sweet flowers and rotten fruit.

Once the summer heats up, sometimes the driveway smells faintly of shit. The white gravel is too big to cover the cat poop of the same size, and the decomposing leaf litter in the concrete courtyard is too thin to hide anything. Cats also use the dirt under the roses as a litter box. Roaming chickens add to the pungent sulpherous odor. Flies are happy with the situation, snacking on fresh stool. The neighbor’s dog loves to eat cat scat. The sun cures feces in a few days, but there is a constant flow of fresh excreta.

The human body recoils from the stench. It is an emanation of dangerous living garbage, polluted matter potentially loaded with the viral spores of the brain parasite Toxoplasma gondii. A cousin to malaria, the pathogen infects host mammals like rats and humans through feline feces and undercooked meat. It can be lethal to people with compromised immune systems. Because the parasite can cause fetal brain damage, encephalitis, and miscarriages, pregnant women are warned not to change litter boxes or garden in potentially contaminated soil. Surprisingly, epidemiologists estimate that 40% of the world’s population, or 2.5 billion people, are hosts to T. gondii (Boulter 2007: 35). And its patchy landscapes are growing as the parasite reaches new host populations in the Pacific Ocean.

In 2005, researchers began finding a “Type X” strain of T. gondii in dead sea otters and other aquatic mammals. They suggested that the parasite’s egg-like oocysts are reaching the sea through freshwater runoff from the densely populated coast. Once in the water, mussels, oysters, and anchovies ingest the oocysts, and are in turn eaten by mammals that contract often-lethal infections (Conrad et. al 2005). With the help of Californians who flush cat feces or have trained cats to use toilets, the parasite may also find its way into the ocean after moving through municipal sewage treatment plants that are not equipped to kill the oocysts.

While news coverage of T. gondii’s devious urbanization have been cast in catastrophic terms as another threat to oceans, media attention to the parasite's manipulation of human behavior has a playful sci-fi, Body Snatchers flavor. Behavioral ecologists have shown that the pathogen alters risk avoidance in infected rats, making them curious about the smell of cat urine instead of running the other way (Zimmer 2000: 92-4). So what does it do to us? US researchers link the pathogen’s manipulation of dopamine levels to schizophrenia (Torrey & Yolken 2003). Scientists in the Czech Republic and Turkey suggest that infected people are more prone to car accidents, and much like cell phones and text messaging, “latent toxoplasmosis of drivers should be taken into account while developing strategies to prevent traffic accidents” (Yereli, Balcioglu, & Özbilgin 2006). More controversially, Czech researchers correlated toxoplasmosis with behavioral changes that differ in men and women. Australian epidemiologist Nicky Boulter sums up their research with what feels like a list of outrageous bio-determinist claims:
Infected men have lower IQs, achieve a lower level of education and have shorter attention spans. They are also more likely to break rules and take risks, be more independent, more anti-social, suspicious, jealous and morose, and are deemed to be less attractive to women. On the other hand, infected women tend to be more outgoing, friendly, more promiscuous, and are considered more attractive to men compared with noninfected controls. In short, it can make men behave like “alley cats” and women behave like “sex kittens”! (2007: 36)
Pushing this logic of parasitic agency further into netherworlds of quack science, Kevin D. Lafferty hypothesizes that the pathogen’s alteration of individual personalities – neuroticism and macho sex roles in particular – must alter “aggregate personality at the population level” (2006: 1). He then goes on to compare culture formations at national scales in correlation with differential rates of toxoplasmosis infection. For example, 12% of Americans carry T. gondii vs. 66% of Brazilians, so this must explain something about machismo in Brazil. By number crunching and jettisoning a good deal of contradictory data on Asia, he concludes, “the effect of T. gondii on culture could be broader than postulated here” (5). Science writer Carl Zimmer picked up Lafferty’s dubious findings on his blog, extrapolating wildly: “What about other parasites? Do viruses, intestinal worms, and other pathogens that can linger in the body for decades have their own influence on human personality? How much is the national spirit the spirit of a nation’s parasites?” (2006). Blogger comments ranged from outrage at another form of scientific racism to speculation that the parasite “is responsible for the condition known as ‘being a cat lover’” by recoding ‘child’ as ‘feline’ in the crazy cat person’s virus-addled brain. Cast as the vector for crazy cat person syndrome, cat poop will never be the same! We handle it with fear and awe as the mobile home of parasites.

Feline shit became known as ordinary sublime matter, the “divine materials in manure” a source of death and life alike (Logsdon 2010:153). In 2009, microbiologist Laura Knoll began experimenting with a potential malaria vaccine with the premise that purposefully inoculating human hosts with T. gondii might provide immunity to its more lethal cousin malaria. She was inspired by the fact that “Toxoplasma is on the category B list of bioterrorism agents” (University of Wisconsin-Madison 2009). This year in Tanzania, working through the Red Cross, Knoll administered the first experimental rounds of malaria vaccines with oocysts isolated and prepared from infected cats’ feces (risking side effects of schizophrenia and bad driving).

Meanwhile, back in California, a Type X pandemic hits the Pacific seaboard. Somehow the Los Angeles water supply’s oocyst load spikes, sending over a hundred thousand people to hospitals and doctors with flu-like symptoms at first feared to be a swine flu epidemic. Since shit, soil, and meat are Toxo’s vectors, the outbreak is proving easy to isolate unlike SARS and other diseases accidentally transported by airplane. Presumably, Southern Californians are now immune to malaria but more cat-like in their behavior.

In San Francisco and Toronto, curbside cat and dog poop pickup are in full swing. The programs divert pet feces from the landfill to methane digesters that generate electricity when the gas is burned off, in the process effectively isolating Toxoplasma from other urban waste streams. Back in our driveway, cat shit decomposes into dirt loaded with oocysts. The spores can live up to two years, dreaming of mammal brain landscapes to inhabit. We buy more gravel so the cats can bury their stench. I finally spread three-year-old mulch from our pine kitty litter composter in the front rose garden, right where the cats have pooped for years. The roses had been getting yellow leaves with brown dots and falling off. Kitty litter mulch solved the problem, loaded with "divine" microbes that produce antibiotics to keep plant pathogens in check (Logsdon 2010:153).

In the coldest stretch of winter the buds open white and red, spilling their lemony scent.


Boulter, Nicky. “Alley Cats & Sex Kittens.” Australasian Science (January/February 2007),  35-27, http://www.control.com.au/bi2007/281parasites.pdf (accessed March 23, 2010).

Conrad, P.A., M.A. Miller, C. Kreuder, E.R. James, J. Mazet, H. Dabritz, D.A. Jessup, Frances Gulland, and M.E. Grigg, “Transmission of Toxoplasma: Clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment,” International Journal for Parasitology 35 (2005) 1155–1168.

Lafferty, Kevin D. “Can the Common Brain Parasite, Toxoplasma gondii, Influence Human
Culture?” Proceedings of the Royal Society B (2006), http://www.werc.usgs.gov/chis/pdfs/
Lafferty06toxoPRSLB.pdf (accessed January 13, 2010).

Logsdon, Gene. Holy Shit: Managing Manure to Save Mankind. White River Junction, VT: Chelsea Green Publishing, 2010.

Torrey, EF, and RH Yolken. “Toxoplasma Gondii and Schizophrenia.” Emerging Infectious
Diseases (2003), http://www.cdc.gov/ncidod/EID/vol9no11/03-0143.htm (accessed January
23, 2010).

University of Wisconsin-Madison, School of Medicine and Public Health. August 11, 2009. http://www.med.wisc.edu/news-events/cats-provide-unusual-source-for-potential-malaria-vaccine/1320

Yereli, K., I. Balcioglu, and A. Özbilgin. “Is Toxoplasma Gondii a Potential Risk for Traffic
Acciedents in Turkey?” Forensic Science International 163, no. 1 (2006), http://www.ncbi.
nlm.nih.gov/pubmed/16332418 (accessed March 23, 2010).

Zimmer, Carl. Parasite Rex: Inside the Bizarre World of Nature’s Most Dangerous Creatures.
New York: Touchstone Books, 2000.

–––––. “A Nation of Neurotics? Blame the Puppet Masters?” The Loom: A Blog About Life, Past and Future, posted August 1, 2006, http://scienceblogs.com/loom/2006/08/01/a_nation_of_
cowards_blame_the.php (accessed March 4, 2009).

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