It is a warm night. The community sleeps despite the mosquito bites. But it's not only for the buzzers that it's feeding time. Other conspicuous bugs also wake up to look for sustenance. They creep out of crevices, out of junk accumulated under beds, from behind pictures on the wall. They move slowly until they reach cots, beds, and hammocks. Once they have located the source of food - the inhabitants of the house, be they human or domestic animals - they prepare to attach their long proboscis with which they suck blood.
In nature, many animals have adapted to the consumption of blood as food, although myths and legends have attributed this characteristic to groups of animals such as bats, of which only a small part feed on the blood of other mammals. In this case, the eaters are insects known as "snout bugs", precisely because of the long "beak" they use to obtain blood from small mammals or humans.
They feed infrequently so when they do they are voracious. They take their time and their bellies swell as they fill up; they gather reserves for the next few days or weeks they will spend in hiding digesting the food. The next morning the only trace of their nightly passage will be a large swelling and a hardened red area.
The snout bug is an insect that originally inhabits wild areas. Hidden among vegetation, it feeds on the blood of wild animals such as armadillos, armadillos, rats, and bats. However, with the establishment of ranches and the growth of towns and cities, their areas of distribution have been invaded and in turn, the bugs have invaded human dwellings, where they find sustenance very easily.
Although blood loss from the bites can lead to anemia problems in young children, this is not the only reason to stay alert and chase bedbugs away from the house. These bugs are the vectors of another curious organism, Trypanosoma cruzi, which produces a disease that, if not controlled in its early stages, leads to death. This is Chagas disease, named after the Brazilian physician Carlos Chagas, who discovered T. cruzi, the parasite that causes the disease, at the beginning of the 20th century.
Contrary to what one might think, bedbugs do not introduce the Trypanosoma through saliva, it is found in the feces that the insect sheds while eating, and when the person scratches themselves, as a reaction to the aggression suffered, they introduce the feces into the wound.
Trypanosomiasis circulates in the bloodstream for up to three months and this stage is known as the acute phase of the disease. After the acute phase, it settles in the cells of some visceral tissues, mainly the colon, esophagus, and heart. The time it remains there without causing apparent symptoms, in an incubation period, ranges from 5 to 20 years, during which time it develops a deep inflammation that causes megacolon, megaesophagus, neurological problems, or irreversible damage to the heart leading to infarction.
Furthermore, Chagas disease is transmitted through blood transfusions from infected donors. In this regard, the National Blood Transfusion Center had reported that up to 3.5% of the blood bags handled there are contaminated with the parasite.
The behavior of Chagas disease
According to the World Health Organization, 25% of the total population of Central and South America is at risk of contracting the infection. There are one million cases each year and more than 45,000 people die in the same period. Of the 16 million people infected, 2 to 3 million already present the complications of the chronic stage and, in about 3 million, the Trypanosoma is still in the incubation period.
Although there is no consistent epidemiological follow-up of Chagas disease in Mexico, it is estimated that about 28 million people are at risk, mainly in rural areas where marginalization and lack of health services are the norms. However, it has been reported that in some urban or suburban areas of the cities of Oaxaca and Cuernavaca the prevalence of the infection is high.
The distribution of the disease is related to the distribution of the bedbug, which covers three-quarters of the southern region, in semiarid areas below 1,800 meters above sea level. Nonetheless, research to define specific risk areas in each state began years ago and for some specialists in the field, Chagas is the most important parasitological disease in Mexico.
Control of Chagas disease
The parasite induces an autoimmune reaction, so the possibility of finding a vaccine is remote since instead of attacking the Trypanosoma, it would attack the cells themselves. Furthermore, Chagas disease is not recognized by the country's health authorities, so it is not possible to organize fumigation campaigns in high-risk areas. In conclusion, the only weapon available is education for prevention.
What to do?
First of all, it is urgent to promote educational programs that provide the population with tools to learn about the existence of the problem. In rural and even in urban communities, people are not aware of the risk involved in the presence of bedbugs in their homes or in the countryside. In fact, in some places, they are considered pets, and in others, they are considered aphrodisiacs.
It is difficult for people to associate two events (the bite and the onset of the disease) so far apart in time. For the time being, habits such as the following would be of great help: constant checking of places where bedbugs hide, the use of non-toxic insecticides, the use of bed covers, and going to the doctor immediately after a bite with the characteristics described above.
Finally, there are some research institutions that carry out small campaigns to raise awareness on the one hand and to collect information on the bedbug and its distribution on the other. Supporting and participating in these small efforts is a great help.