Blog 31

Blog 31: 11/12/08-11/14/08

For the rest of this week, I was mostly on brigades. It was a pretty educational experience; we learned about Paludismo (malaria), dengue fever, and chagas, which are epidemiological problems in rural areas around Puerto. The diseases are spread through insect vectors; chagas is spread through a type of beetle called
Chinche (rhodnius prolixus), while dengue and malaria are spread through certain species of mosquito. The brigades were pretty tough, physically because the weather was really hot and humid, and there were tons of bugs everywhere. Rural areas (mostly located in the hills), are NOT easy places to live due to the terrain, weather, and sanitation. We went to people's houses in the these rural areas with entomologists employed by Oaxaca's health system.

I give these guys a lot of props because their job is not easy. They have to go to people's houses in many different areas and districts to look for the presence of mosquitos and chinche, as well as certain conditions favorable to their colonization. The entomologists do their work in this crazy hot weather in full uniform (hardhat, full sleeved shirts, khakis, and thick vest). Many times they have to goto houses located in the middle of rural jungle-forests, and other very hard to reach places. They also have to make sure people infected with any of these diseases comply with the treatments given to them. Definitely not easy work.

During the brigades we were able to ride in the beds of pick-up trucks, which was a really awesome. It probably wasn't the safest thing in the world. lol. It felt like a roller coaster ride, and I would do it again if I could. The entomologists need the All-Wheel drive trucks for the mountainous terrain of these rural areas.

We did our first bridage, the Chagas brigade, on Wednesday. We went to a rural, jungle hill region of Puerto, where Chagas was a problem. We inspected a few local houses to see if there were Chinche or an environment conducive to Chinche. The first house we saw was really dirty and a mess; also, it was completely open to the outside jungle. There were chickens, roosters, and dogs walking in and out of rooms. The furniture was a mess, and there were things sloppily piled into corners. Messy conditions are perfect for Chinche beetles because they prefer to hide under anything they can find. Also, the beetles don't attack people or animals when they're awake, they generally wait till people sleep and come out at night when they can feed without being noticed. When the Chinche does feed on a human it defecates into the cavity that it fed from. It's the feces of the Chinche that contains the Chagas parasite. When people itch or scratch the bite (usually a 3cm lesion), they spread the feces into their bloodstream, which is how the parasite enters the body.

I don't blame these people for the conditions of their houses because it's a result of their economic condition. Their houses are really old or poorly made; there's a lack of windows and the floors are made of dirt. New furniture and amenities are probably too expensive for most of these people, and they must do with whatever they have or whatever they can find. It's really unfortunate. The entomologists main advice for prevention of Chagas is to keep things washed and orderly because even though these people are poor, they can keep their houses clean. Education and awareness are really the best method of prevention because most of these people don't know about the disease or how it's spread. The main problem with Chagas is that the symptoms (maybe they'll feel some headaches or eye pain earlier on) don't surface until 15-25 years after infection. If it isn't treated within 6 months of infection, it cannot be cured. Many people within the rural population die of Chagas (causes heart failure, strokes etc.) in their 50s-60s, and usually didn't know that they were bitten 25 years earlier. The disease can be diagnosed through a microscopy of a blood sample, where the parasite can be seen.

The Dengue and Malaria brigades that took place on Thursday and Friday were pretty fun. Again, we had to get to secluded houses in rural country side hills via pick-up truck. Due to the fact the that main vector of transmission for both these diseases is mosquitos, cleanliness of the house isn't the main factor as a conducive environment. Instead there is a great focus on puddles, empty containers that can carry water, and wells. Any stagnant water, or areas where water can collect or stagnate after rains, will most likely be a breeding ground for mosquitos. This was a big problem in the first house we went to. The yard had wells and water bowls for chickens, all of which had mosquito larvae. Mosquito life-cycle is on average 11 days, however it can be much shorter with increased amounts of heat (5-6 days). Due to their short life-cycles, they can reproduce quick, and in containers as small as bottle caps. An important prevention technique is to remove containers and keep the yard orderly and clean. Regularly changing drinking water for chickens is also important. Wells or water basins should contain larvae killing chemicals, and the chemicals should be changed every 8 days to be effective (In the case of this house, the chemicals weren't changed for over 30 days...not good). The best way to prevent the incidence and prevalence of Paludismo and Dengue is to find ways to control mosquito population, which can only be done through educating the local population. There aren't enough men employed by the health system to clean up Puerto's districts, so all the work must be done by the local populations; therefore, compliance to health system guidelines is the real limiting factor in these rural areas.

There are two different species of mosquito that are of concern in the area. The Anopheles species carries Paludismo, while the A. aegypti species carries Dengue. You can distinguish between the two species by looking at the larvae. Anapheles larvae are suspended on the surface of a liquid horizontally (they lack a respiratory siphon), as apposed to the A. Aegypti larvae which are suspended vertically (they have a respiratory siphon). Also, the A. aegypti has a pair of striped legs, which distinguishes it from other mosquitos. The prevention for these two mosquitos are the same, which is cleaning up any stagnant water that could serve as a place of reproduction.

Dengue fever is caused by a blood-born virus that is transferred by a mosquito vector from an infected person to another. The entomologists were saying that A. aegypti are now being born with dengue already in them... SCARY stuff. Being that dengue is caused by a virus, it's untreatable, and you have to hope your immune system can fight it off. There are two forms of dengue, classic and hemorrhaging. The most dangerous form, Hemorrhaging dengue, is characterized by a bleeding from the eyes, nose, and internally; it has a high rate of mortality. Classic is a lesser form characterized by a fever and sensitivity to light (hemorrhaging also has this symptom). The virus causes bleeding by attacking platelets, which prevents the body from being able to clot (indicated by a platelet count lower than 100,000). Victims are usually hospitalized and can receive blood transfusions to compensate for the blood loss.

Paludismo, or Malaria, is caused by a parasite (Plasmodium vivax) that is transferred from one person to another via mosquito vector. The parasites multiply within and killing red blood cells, ultimately resulting in anemia. Symptoms include fever, shivering, and vomiting. Both sicknesses, Dengue and Malaria, can be detected by blood sample microscopy.

The first line of prevention, set up by the system of health, is the appointment of community volunteers. The community volunteers are respected members of the community who are appointed to take blood samples of everyone who has a fever or exhibits any symptoms of sickness. The blood sample is then sent to a Centro De Salud so it can be examined for Malaria, Chagas, or Dengue. My group met with Luis, a volunteer, who has been collecting blood samples for his community for over 30 years. He has this box full of slides and small needlelike devices meant to prick the skin. The Centros restock his supplies every so often. After pricking the skin, he collects a drop of blood and smears it on the slide. People whose samples are taken are then logged onto small charts or records. He's also given medications to distribute to people diagnosed with Malaria (Chloroquina and Primaquina). Community volunteers are extremely effective because they're trusted by their community and are easily accessible. Also, they're given pretty sweet benefits, such as free basic health care, and 50% off of surgeries.

I think that Oaxaca's system of health is doing a great job in fighting these diseases. By focusing on prevention and putting more effort into involving the local communities, they're able to prevent further incidence and prevalence. Prevention is definitely the most effective technique, especially considering the lack of resources and funding that the state can provide for those who are victimized by these diseases. Medication for Malaria and Chagas is expensive, and the state of Oaxaca simply can't provide enough for everyone to be treated. I think the main issue is compliance, due to the culture surrounding these areas. Unfortunately, in these rural areas the women do all the work and it's up to them to clean up all the stagnant water, yards, and houses. The men are extremely lazy and unconcerned of the situation, which is attributed to their machismo attitudes. One entomologist made the joke, that if there's a scorpion on the same hammock that a man is lying on, he's so lazy that he'll tell his wife to get the antidote because he's too lazy to move out of the way or to kill it. Being that women already have so much work to do, it's hard to believe that they make much more time for prevention efforts.

I learned a lot about these rural communities. Epidemiologically, they have more problems with communicable disease than other populations, due to their low socioeconomic status. It's really important to educate and increase awareness in these areas in order to fight the prevalence of diseases such as Malaria, Dengue, and Chagas. Salud Oaxaca's medical entomologists increase awareness by inspections and assessments of local living conditions and pest populations. I admire these men because they genuinely want to help these people improve their quality of life; it's the only explanation for why they would work in such harsh conditions and travel to isolated areas in order to deliver health care. They love the people they serve, and the people trust and love the, which is an essential quality for doctors to have as well. Luis, the community volunteer we met, with was telling us that the local people carry a deep respect for these entomologists and their work. I'm simply amazed at the level of dedication and selflessness that exists within these men!
I'll keep everyone posted more often about my adventures through Puerto! Salamz.