"A kiss is not a kiss if it is inflicted instead of offered". . .

as is the case with one local species of assassin bug called the Western Conenose, Triatoma protracta. This 3/4-inch, brown-black nocturnal insect, whose wings form a distinctive "X" when folded over the abdomen, also goes by the name of the "kissing bug" or, as it is known in Latin America, "vinchuca."

The kissing bug label comes from the insect's ability to steal a blood meal by painlessly piercing the lips, eyelids or ears of a sleeping human victim. The real problem is that during the feeding process, the bug injects its saliva into the victim, which can result in anaphylactic shock to persons sensitive to the bite. In rare cases, an individual might contract Chagas disease, a form of African sleeping sickness, which is caused by a one-celled organism carried by 40 percent of the bugs in some areas of southern California.

They are like giant mosquitoes in that they are hunting you, prey on you while you sleep and carry diseases as well as a kind of venom. Unlike mosquitoes they are clumsy fliers so they tend to land nearby and sneak up on foot. They are remarkably light for their size and have a feathery touch. That, and the painless piercing, allow them to feed on you without alerting you that you are being consumed.

Living among them here in the hills has trained me to their ways. I can hear them land and will react to that sound instantly, without conscious thought. I know their hiding preferences and seek them out in and around buildings. I know their active periods of the day and year and go on heightened alert at those times. This may sound like a lot of bother, a time and consciousness consuming irritation, but I do it on auto-pilot without much effort.

The effects of Chagas Disease are debilitating.

After an acute infection characterized by swollen eyelids, those infected usually feel better. But the parasite [Trypanosoma cruzi] remains active inside them, in a chronic phase of infection, quietly invading cells and stimulating the immune system. As a result, people can develop heart and gastrointestinal problems months or years after being infected. Some 30,000 people die each year from Chagas disease, according to the World Health Organization, but the number of people who are carrying latent infections is unknown.

There is a newly discovered symptom of Trypanosoma cruzi infection.

“We now know that Chagas patients may have trouble seeing at night,” . . .

In previous research, Levin and colleagues showed that the immune systems of patients infected by T. cruzi generate antibodies that attack the parasite but also cause damage to heart cells. Levin suspected “molecular mimicry” as the cause of the misguided attack. Molecular mimicry occurs when a molecule that is part of an infectious agent resembles a molecule native to the body. Eventually, the immune system begins to mistake the native molecule for the invader. Levin's investigations revealed that an intra-cellular T. cruzi protein resembles the beta1-adrenergic receptor on the surface of heart cells, a finding that helped explain why Chagas patients develop certain heart problems.

Now, it turns out, molecular mimicry can also upset the delicate machinery inside retinal cells. Levin and his team found that antibodies geared to attack T. cruzi also block rhodopsin, a molecule that converts light into electrical impulses sent to the brain. “Rhodopsin takes light and transforms it - that's its function,” said Levin. . .

Levin said that Chagas patients' vision problems are caused exclusively by the antibodies that block rhodopsin, and not by inflammation. “In the hearts of Chagas patients, we see scarring because there is a complex reaction that causes inflammation,” he said. “But there are no such scars in the eyes of Chagas patients with reduced vision.”

“No one knew about the night blindness, so we don't know, for instance, if Chagas patients have more accidents at night,” Levin added. “That's one of many ideas to explore now. The research also points out that we need new drugs or vaccines to stop the parasite, and at a social level, it stresses the need to improve living conditions of Chagas patients, particularly those living in rural areas.”

I wish them good speed in finding some way to stop T. cruzi. The bugs around here don't carry it - I've never heard of anyone getting Chagas this far north - but that may change if the climate changes, or just due to increased population density as central America continues to move north. There's no way to get rid of the bugs since they live in the wild too, so vaccines or medications will always be needed.