Assignment 11: Key Determinants

Problem Definition: There has been an increasing incidence of both classic dengue and dengue hemorrhagic fever among the adult population in Venezuela during the last two decades.


Key Determinants:


Biological:

• Individual Factors: Age, Gender, Genetic Background and Underlying Diseases: 

The host’s immune response, determined by individual factors like age, gender, genetic background and underlying diseases, plays a role in the clinical expression of DF/DHF. In Venezuela the incidence of DF has been the highest among 10 to 14 year old children, peaking in 2007 (570/100,000) On the other side, DHF highest incidence rates were observed among infants, peaking again in 2007 (62.9/100,000).

• Introduction of New and More Complex Secondary Vectors:

The number of countries with more than one viral stereotype circulating has steadily increased, favoring the occurrence of more cases of secondary infection and consequently and increase in the risk of DHF. Also, a potential additional risk is the introduction in the region of Ae. albopictus, an efficient dengue vector in Southeast Asia. Unlike Ae. aegypti, Ae. albopictus is not obligatorily anthropophilic and sometimes displaces the former from its habitat. This vector has been detected in several Latin American countries (Mexico, Honduras, Guatemala, Nicaragua, Panama, Cuba, Dominican Republic, Trinidad & Tobago, Brazil, and Bolivia); but thus far its presence has not been associated unequivocally with the increase in dengue transmission.


Social and Cultural:

• Mosquito Control is Virtually Non-Existing in the Society:

Mosquito control measures are practically non-existent in the society. In regular endemic periods, people do not take primary preventions to avoid the mosquito bite in the first place, such as using mosquito nets or lighting up citronella candles at home. Emphasis over the past 25 years has been placed on ultra-low-volume space sprays of insecticide for adult mosquito control, but this has been shown to be ineffective in controlling Ae. aegypti.

• Increased in Air Tavel

The increased travel of people by jet airplane favors the movement of dengue virus between endemic areas and other areas free of disease due to people's arrival during the disease incubation period (viremic period can be long and virus can be detected in blood from two days before initial symptoms until eight days after) and subsequent risk of infection of local mosquitoes and development of epidemics. An illustration of the increased human air travel is seen in the great number of Latin American airlines that emerged in this period of time and the increasing number of flights towards tropical areas.

Environmental:

• Population Growth

In the last 20 years, the urban population in Venezuela has more than doubled, and as a consequence, the incorporation of more land for food production and the negative impact of haphazard deforestation have created the conditions for the emergence of vector-borne diseases like dengue.

• Inadequate and Unplanned Urbanization:

The constant migrations from rural to urban areas have resulted in large, crowded human populations living in urban centres in substandard housing with inadequate water, sewer and waste management systems, creating ideal conditions for increased transmission of mosquito-borne infectious diseases.

• Trash Accumulation and Poor Urban Sanitation

The main urban centers, especially the city of Caracas, lack the appropriate urban sanitation infrastructures and the accumulation of trash is growing problem. Most of the consumer goods are packaged in non-biodegradable plastic or cellophane materials, which are discarded into the environment where they collect rain-water and provide ideal larval habitats for the vector mosquito.

• Global Warming

Increasing incidence of dengue in the Region might be be related to climatic changes that favor larval habitats for the mosquito vector, like increases in the amount of rainfall, higher sea-surface temperature, and increases in weekly minimum temperature. Although the association between climatic changes and the explosion of dengue in the Americas remains controversial; in April 2007, the Intergovernmental Panel on Climate Change concluded that global warming and climate change would cause an upsurge in dengue and other tropical diseases.


Economic:

• Decreased Access to Healthcare

Complications in cases of classic dengue that lead to an increasing incidence of DHF are related to the misdiagnosis and mistreatment of the disease when the first symptoms appear. This is the most common in low socio-economic status classes that have a more limited access to healthcare.

Political:

• Deterioration of the Public Health Infrastructure

The public health infrastructure required to deal with epidemic vector- borne infectious diseases has deteriorated during the past 20 years. Limited financial and human resources, and competing priorities for those resources, have resulted in a ‘crisis mentality’ among public health officials. The emphasis has thus been on implementing emergency control measures in response to epidemics rather than on developing programmes to prevent epidemic transmission. This approach has been particularly detrimental to dengue prevention and control because surveillance in Venezuela is very poor; the passive surveillance systems relied on to detect increased transmission are dependent upon reports by local physicians, who often have a low index of suspicion and do not consider dengue in their differential diagnosis of dengue-like illness. As a result, the epidemic has often reached or passed peak transmission before it is detected and emergency control measures are implemented too late to have any impact on the course of the epidemic.


References:
Javier Torres and Julio Castro; El Impacto Económico y Sanitario del dengue en América Latina http://www.scielosp.org/pdf/csp/v23s1/04.pdf


Duane J. Gubler; Epidemic Dengue/Dengue Hemorrhagic Fever: A Global Public Health Problem in the 21st Century; http://203.90.70.117/PDS_DOCS/B0776.pdf


José Luis San Martin; The Epidemiology of Dengue in the Americas Over the Last Three Decades: A Worrisome Reality; http://new.paho.org/hq/dmdocuments/2010/Jan%202010%20AJTMH%20Dengue%20BZ%20GD%20AB%20OS%20JSL%20OB%20MGG.pdf

Assignment 10: Data and magnitude Measurement

Since I couldn’t find enough data, I’ve decided to change my problem definition.

New Problem Definition: The rising incidence and prevalence of dengue in Latin America during the last two decades.

Dengue incidence and prevalence are rising in endemic areas of the tropical and subtropical regions. On the basis of mathematical model estimates, approximately 50 million infections occur each year. In the past, the burden of the disease has fallen on countries in South-East Asia and the Western Pacific regions, but a dramatic increase of cases has been reported in the Latin America during the last decade.

The World Health Organization (WHO), and its regional body in the Americas, the Pan American Health Organization (PAHO), keeps the dengue infection records for the 35 nations and 9 sub-regions of the territory. They carry an active surveillance through which they measure the number of cases reported on each country during each epidemiological week.

The total classic dengue fever cases reported in the Region were 1,033,417 (16.4/100,000) during the 80s, 2,725,405 (35.9/100,000) during the 90s, and 4,759,007 (71.5/100,000) during 2000–7. Similarly, the number of dengue hemorrhagic fever (DHF) cases increased over time from 13,398 (0.2/100,000) during the 80s, to 58,419 (0.8/100,000) during the 90s, to 111,724 (1.7/100,000) during 2000–7. The DHF cases as a percentage of total dengue cases also increased from 1.3% to 2.1% to 2.4%. Epidemic cycles were observed every 3–5 years with an increased frequency of DHF cases and fatalities caused by dengue during epidemic years. From 1980 through1987, 242 deaths were reported (1.8% of all DHF cases) compared with 1,391 deaths during 2000–7 (1.2% of all DHF cases).

The number of countries with an average incidence greater than 100/100,000 increased from 5 during the 80s to 7 during the 90s, and then to 15 during 2000–7. During the 27-year study period, Brazil reported the majority of dengue cases (54.5%) and Venezuela reported the highest number of DHF cases (35.1%) during the same period. In general, reported cases of both forms of dengue increased over time in all of the countries of the region, with the exception of those in the Hispanic Caribbean.

These data constitutes a direct indicator for the rising incidence and prevalence of dengue in the Region. I couldn’t find any indirect indicators for measuring dengue prevalence and incidence, but this is pretty strong data (even though it does not consider all the number of cases which are not reporter to the local public health institutions), but they do represent the general tendency considered for this study.

Sources:

Martín, José Luis: The Epidemiology of Dengue in the Americas Over the Last Three Decades: A Worrisome Reality; http://new.paho.org/hq/dmdocuments/2010/Jan%202010%20AJTMH%20Dengue%20BZ%20GD%20AB%20OS%20JSL%20OB%20MGG.pdf

World Health Organization, Dengue Alerts, http://new.paho.org/hq/index.php?option=com_moreinfo&moduleid=1011&Itemid=363

World Health Organization, Descripción de la situación epidemiologica actual del dengue en las Amèricas; http://new.paho.org/hq/index.php?option=com_content&task=view&id=4494&Itemid=2481

Assignment 9: Dengue Fever as a Public Health Problem

Dengue fever is a virus-caused disease that has been one of the most important resurgent tropical diseases in Latin America for the last two decades, where countries have experienced marked increases in the incidence of both classic dengue and dengue hemorrhagic fever.

The virus is spread by mosquitoes, specially by the mosquito Aedes aegypti, commonly known as patas blancas, because of the white markings on its legs. Its clinical diagnosis is relatively ambiguous, and lab tests are required in order to be sure that a case is dengue, because its initial symptoms are very similar to those of a common cold (fever, headache, fatigue, joints and muscles aches). This tends to lead to complications as people mis-diagnose the disease for common cold and take aspirin to treat it. Aspirin has anticoagulant effects that can increase the bleeding so that the classic dengue fever becomes an hemorrhagic fever that cannot be treated with regular antibiotics.

I want to do my research paper on how can public health institutions work to prevent the high incidence of dengue and develop/communicate more efficient and accessible diagnosis/treatment strategies for classical dengue fever, as to reduce the incidence of dengue hemorrhagic fever. As a background information, it will be necessary to study the major risk factors for the occurrence of dengue in the region and local societal/economical factors pertinent for the design of a preventive, diagnostic and treatment strategy for the localized region.

I'd like to frame this problem in my hometown, Caracas, during the last twenty years, because it is a problem that I have seen growing during my whole life. A lot of the people in my inner circle of friends and family have had dengue at some point of their lives, and I clearly remember the 2005 epidemic, when my mom wouldn't let us leave the house without mosquito repellent, Citronella candles where more coveted than gold and relatives where continuously looking for O- blood donors that could help for the treatment of those who had the hemorrhagic fever.

So, for the problem definition, it would be something around: The growing incidence of dengue hemorrhagic fever in Caracas during 1990-2010 as a consequence of the lack of an effective preventive, diagnostic and treatment structure for the classical dengue fever.

Assignment 8: On Human Rights

Human Rights are defined as the undeniable fundamental rights to which a person is entitled simply because of being human. For this reason, Human Rights are universal, applicable everywhere and to everyone. They are conceived in the Universal Declaration of Human Rights, which every nation has signed in order to make sure that local and international laws, as well as public policy, agree with these principles.

As dignified human beings, one of these fundamental rights is the right to an appropriate standard of living and health. This right not only assures the wellbeing of the people, in terms of guaranteeing conditions that can satisfy the most basic needs, like food, clothing, housing, and social services; but it also assures the wellbeing of the society in a macro-level, as these conditions allow the individuals to carry on better lives that allow them to be more productive in the society.

In this sense, the right to health is considered a fundamental right entitled under Article 25 of this declaration. It is a fundamental and universal right because health is a critical determinant for the kind of life we can carry on, and ultimately, the access to healthcare defines if we whether live or die. This article has a second clause that entitles pregnant women and children, of all social, economical and cultural backgrounds, require special care and assistance because they are vulnerable individuals that require specialized care and attention. Pregnant women have limited physical capacities and need to care for themselves and the child in their womb, and children aren't just capable of taking care of themselves, which is why they have the right to get this special care that sets hem aside from men.

In the Editorial that we read on maternal mortality and human rights we can see how progress in reducing maternal mortality has been slow across the nations in the last ten years, especially in developing and unstable countries were the material and human resources are limited and the State lacks an appropriate health infrastructure that can attend everyone equally, promptly and effectively.

In a case in Brazil, a woman died because her local health agency mis-diagnosed the symptoms and failed to deliver adequate obstetric care; and the case was brought up to the Committee on the Elimination of Discrimination against Women, alleging that the State had failed in providing this woman with appropriate care. As a result, the Committee established that governments have a human rights obligation to guarantee women of all racial and economic backgrounds timely and non-discriminatory access to appropriate maternal health services. In the case of countries outsourcing services to private health-care institutions, these states remain directly responsible for these institutions, so that they must regulate and monitor them in order to make sure that they are fairly providing the services that all sectors of the society deserve as a right.

Assignment 7: Contagion

Contagion is a thriller about the outbreak of a deadly virus and how our modern society attempts to deal with it as it evolves as a pandemic levels. The movie starts with the death of "Patient Zero", and it progresses as the disease spreads to a pandemic, showing what medical researchers, public health offices and government agencies do in order to identify the disease and develop a vaccine to stop its spread.

Analyzing the movie from a public health approach was very interesting; it showed how all of the areas of public health that we have studied in class relate to each other. For example, an epidemiology study is carried to trace back the origin of the outbreak, and the development of bio-weapons is thought to be linked to this origin at some point. Risk communication and policy are carried by public offices to contain the spread of the virus, while at the same time surveillance and clinical trials are being carried out in order to develop an effective vaccine.

In epidemiology, an outbreak is defined as the occurrence of infection with a particular disease in a small, localized group, such as the population of a village. The term is used more broadly to refer to an epidemic or pandemic as it spreads more rapidly. Outbreak investigation seeks for the origin of the virus in order to stop its spread, as we saw in the movie when the WHO epidemiologist is sent to the village in China. Isolation refers to the separation of cases for a disease's period of communicability in order to minimize the risk of transmission of the infectious agents to those who might be susceptible, like what they did with Mitch in the movie, being the husband of the first person who died from the virus. As the outbreak develops into an epidemic, absolute restrictions are enforced, and this is what we called a quarantine, which is what happened in the movie when a military quarantine was imposed, preventing everyone from leaving Chicago.

Public Health agencies in the movie could have been better prepared to deal with the outbreak if they had conducted a better risk communication strategy and enforced social order more effectively in order to stop the riots through which the spread of the disease actually increased. The riots could have also been avoided if the authorities had had a more effective and fair food supply systems, which could have been done by having preparedness plans in collaboration with local communities, so that the sources are large and close enough for when the emergency happens.

Assignment 6: Climate Change and Public Health

Climate change is an issue that keeps on getting more complex and present in our daily lives. Ten years ago talking about climate change was like talking about the apocalypse: something that was eventually going to come but not in our lifetimes. However, strong rains, heat and cold waves, hurricanes, earthquakes and tsunamis are becoming more and more common on the news, and the effects of this nature forces have widely changed the lives of millions of people's and the economical and social structures of many countries.

In 2009 I happened to be in L'Aquila, Italy, when an earthquake of a 6.0 magnitude in the Richer scale destroyed the old medieval town in the rural outskirts of the state of Abruzzo. My family and I were spending the Easter Holidays at my grandmother's house that Spring, and we had the misfortune of living through this natural disaster that completely destroyed the town's historical center and the surrounding villages. Luckily, my grandmother's house remained standing, and we were able to evacuate quickly; but still, the trembling and the images of the walls cracking and my family screaming and running is something that I won't ever forget. I'm writing about this because I noticed in the chart that one of the effects of natural disasters from the public health approach has to do with mental health.

As the years have passed and I have returned to L'Aquila and seen how the city has been progressively reconstructed, I can tell that the effects of the earthquake are still in people's minds and hearts. Those days right after the disaster were horrible, people were very upset, about losing their houses, their city, and some of their friends and family members; and the media didn't make it easier by being alarmist and emotional by telling personal stories on the disaster. I lived through the mental breakdown and the delicate emotional state in which people in the refugee camps and coastline hotels were, and being in Italy didn't help the cause because society there is even more culturally dramatic. For about months, the earthquake was the only thing my grandmother could talk about, and she always ended up crying when telling the story over and over again. I know about marriages that ended because of the tensions and pressures that this issue had over some couples.

Public health institutions could have made this situation better if they had monitored, diagnosed and dealt with the issue of the mental effects. Media content could have been regulated not to be so alarmist, recreation programs for kids in the refugee camps could have been held to distract them from these dramas and psychological help could have been offered in the refugee camps and the coastline hotels were people who had lost their homes where staying for free.

Another example of an essential service of public health professionals in order to deal with climate change events would have been preparation and prevention. Even though an earthquake can't be predicted, Italy is in a seismic zone and people and hospitals should have been better prepared in both material and mental resources for an issue this big.

Regarding to what are public health institutions in my hometown doing in order to prepare people for climate change I sadly need to answer that nothing. If a natural disaster as strong as L'Aquila's earthquake hits us, it would be the end of Caracas because with do not have strong firefighter bodies or a proper civil society structure strong enough to deal with the great material, social, economical and mental damages. 

These last couple of years heavy rains have been a huge problem that have caused the displacement of many families who lived in slums and other improper structures that have been literally washed away, and they still have not been placed in other homes. In fact, we didn't even have the resources to set up refugee camps, so these misplaced persons have been staying in government offices that have been closed in order to provide them with a roof.

Assignment 5: The 10 Greatest Public Health Achievments

During the past century, life expectancy and wealth not only increased notably in the US, but all around the world. In the early 1900s life expectancy in the modern Western democracies was around 40 years old, and nowadays it is almost the double. This amazing rise in living standards in just a hundred years was due to the great advancements in Public Health, especially in sanitation, water filtration and vaccine development.

The first decade of the 21st century had different, and still notable, achievements in Public Health, which are discussed in this article by the CDC. These achievements can be summarized in vaccine preventable diseases, prevention and control of infectious diseases, smoking bans, healthier mothers and babies, motor vehicle safety, cardiovascular disease preventions, safer workplaces, lead poisoning prevention and public health preparedness and response.

The context in which societies are living is what determines what it is needed to make their lives healthier and better. As we can see, in earlier centuries the greatest health related problems were due to the lack of sanitation and medical resources; but after the 20th century, most of the health problems we're facing have to do with the new ways and habits that we have been able to incorporate in our lives because of the growth of wealth and technological advances that we were able to achieve as soon as we were free from our previous problems. Take for example health problems derived from smoking; injuries from car accidents or firearms; the easier spread of epidemics, due to globalization and modern means of transportation that make traveling easier; heart problems, diabetes and obesity, due to the change in our diets because of the increasing sugars and carbs with all the new "industrialized food system"; childhood lead poisoning due to industrial pollution; and even the fear of bioterrorism, and our ability to respond to it, are some of the biggest health problems we now face.

For this reason, I consider that the greatest health achievements of the next ten years will have to deal with these great problems we have created in the last ten years: environment degradation, increasing incidence of carcinogens in our daily lives, hard access to natural and healthy foods and the development of biological weapons. In my opinion, solving these problems will have to do both with policy and advocacy (environmental laws, food regulations, and national security) and technological/medical advances (development of sustainable agriculture that can produce enough resources for the increasing population, alternate methods that can reduce the incidence of carcinogens, and development of vaccines for the new diseases).