Brian Altonen, MPH, MS

PART IV

The 3D Maps

In terms of physiographically-induced diseases–diseases caused primarily by the physical nature of the surrounding environment–a number of illnesses follow specific regional patterns at the national level.  Some of these have patterns that can be linked to the Pacific Northwest, others not.  These patterns are often related to topographic and ecological features, but they can also be human ecologically based.  In many of the kinds of diseases, maladies, medical problems, and socially defined health conditions that strike the Pacific Northwest, both natural and human geography play a role in defining where they occur.

First, there are diseases that of course completely physiographic in terms of distribution, due almost entirely to topographic, climatic and ecologic causes.  For these diseases, people who are taken ill are a product of the relationship between man and nature.  They are not required to be present as a part of that diseases natural ecological rhythms and behaviors, but when they are present and are taken ill, such diseases are the consequence of the diseases natural ecology.

Then there are those diseases that are primarily related to natural ecological settings, but do require some steps be taken on behalf of people in order for the disease to develop and its causes continue to exist and survive.  Such diseases include those that are a consequence of poor living conditions, poor sanitation, poverty, all the consequences mostly of just people and their impacts on the surrounding environment.  These diseases are what we call human ecological in origin.

A third type of disease that displays itself in places is that which is dependent upon a combination of physical or natural history features to have or develop a potential for existence, but which depend almost completely on people’s behaviors and emotional, psychological and moral beliefs to exist.  These diseases would not exist without people, and cannot exist anywhere that people are not present.  These diseases are  purely of human behavioral origins.  They are somatic and human in nature, not environmental and ecological in nature.

.

Chicago Illness

Œ

(these are links to video maps)

The teaching video for Chicago Illness demonstrates the meaning of a title assigned to a disease–and the impacts of a place–Chicago–on our view of this illness.  Chicago Illness is a true diagnosis with its own ICD.  It is a microorganism induced condition that exists due to the ecology of the pathogen responsible for it, which has some biological and/or ecological limitations to its distribution.  The biological limitations pertain to the natural history of the causative organism.  The ecological limitations pertain to the locations where the pathogen is most plentiful as a surviving organism, capable of taking advantage of people every now and then.

In this case we find the Chicago Illness requires both the natural ecology aspects of the region in which it survives, brought about by the Great Lakes, in combination with human population features.  This condition thrived best in human ecological settings, namely urban areas, where climate patterns and opportunities for growing are in its favor.  The natural features give reason as to its cause; the human ecological features of this setting provide us with adequate reasons for its continuation–the availability of many more potential victims.

Unlike Chicago illness, not all diseases bear names that tell us about their expected ecology and spatial distribution.  The various forms of intestinal worm and tick diseases for example have their places of origin associated with their common names, but not their present spatial distribution.  Examples of this include African eye disease, Guinea worm, Chinese fluke, etc.  Most of these today bear distributions that go well beyond these political borders.

The same is true for some of the diseases within the United States.  For example, the California Tick is not only present in California, nor are the bacterial diseases named after California as a place of discovery born mostly by California.  The Lyme disease, named for its origins in Lyme, Connecticut, has as its origins some place in Sweden dating back a half century earlier.  Yet the West Nile fever, brought in by mosquitoes from Egypt, exists naturally along the Hudson River valley, yet it wasn’t renamed in the same manner due to its initial spatial distribution.

The best way to identify a regional disease pattern is simple–search for a concentration of cases that erupt in large numbers around a fairly small, isolated area.  Some disease maps for the United States clearly demonstrate regional disease patterns.  In the case of Rhinosporidiosis for example, there are two very well-defined sections of the U.S. where large numbers of cases prevailed according to a multiyear study.  The reasons these two regions existed do not include latitude.  Soil chemistry is typically the first concept to come to mind, however the distinct geographic differences may also make these two regions chemically different in terms of soil content as well.  The following is the isolated case pattern for this condition.

Γ     Π

Coccidiomycosis is soil-dependent and has two distinct endemic regions in the Americas.  These regions demonstrate some latitude-related distribution features as well, resulting in a natural break in the disease ecology noted between the north and south hemisphere afflicted regions.

Θ

The above diseases are primarily axenotic in nature.  According to Russian geographers Pavlovsky and Voronov, this means that biological life processes of other non-pathogenic organisms, hosts, vectors or victims, do no play a role in the spread of this disease.  For each soil appears to play some role in harboring the organism, but local climate, topography and hydrological features seem to impact distributions more so than just soil.

There are also metaxenotic or zoonotic diseases, diseases which have animal or organism ecological requirements in combination with mankind or people related requirements.  In the following illustration of Lyme disease distribution in the Northeastern U.S., we see how topographic features alone like the Adirondack and Appalachian mountains serve as barriers to its migration too far inland, away from the eastern shores and onto the Great Plains. The first illustrates its numbers distribution, the second its relative independent prevalence.

Λ1     Λ2

 

When ecological diseases rely upon man for the cases and nature as the mans to develop case clusters, aggregates and ultimately epidemics, the cases are ecologically dependent in both natural and human ecological settings.  Lyme disease for example can exist anywhere in theory, but it tends to prevail in regions where topography and natural history define its best areas for occupancy, without any involvement of people, not officially becoming a disease however until it infects man.  For these diseases, the concepts of regionalism as it relates to disease patterns–like ‘the Lyme Disease region’–needs to fit well together make sense.

Another useful example of the notion of regional diseases pertains to outbreaks.  Anytime a rare disease has an outbreak and is entered into the database, this data become available for mapping and can be developed for spatial analysis using GIS.  Outbreaks can then be compared in terms of certain characteristics of their regions.  These outbreaks are short-lived, but may return or recur a year later.   Asiatic Cholera provides an example of this sort of disease behavior.

Ξ

 

California is a hot spot for particular diseases due to its combined population density and unique combined maritime-forested-range-desert settings, within a fairly isolated but immigratible and zoomigratible, neotropical to subtropical latitude setting.  The clearest demonstration of this feature is the map demonstrating the ability of El Tor Cholera to produce outbreaks next to the coastline of Southern California.  We expect Cholera in general to show migration patterns that favor routes crossing the Gulf of Mexico region, in part due to the dietary patterns of the Mexico portion of this route and the combined climate-topographic and epidemiological histories of this part of Middle America (a demonstrated tendency for Vibrio to reside naturally in the Mississippi Delta ecological setting and in association with the barrier coast settings of Galveston area for examples).  As shown by numerous studies of vibrio ecology, other places along the shores of the United States do exist where vibrio can reside naturally, but very few of these have all the requirements needed to become a cholera nidus or become cholera endemic.

G

We find that the tendency for vibrio (V. cholera/comma and other species like parahaemolytica) to reside all along West Coast brackish and salt water settings makes it possible for California to become a hot spot for Vibrio cholera El Tor outbreaks.

Ê

But this combined topographic, climatic, ecological behavior of the west coast doesn’t just relate to the salt water Vibrio species.  We also see the ability of this setting to influence bacterial and fungal disease ecological disease patterns, and even pedological (soil-based) behaviors that demonstrate a reduced need for human geographic requirements.  In the following example of a Seattle outbreak of a California bacterial disease, the following was seen (sorry about the fuzzy image):

Œ

Occupational Disease

Certain occupational disease patterns demonstrate the role of natural ecology and topography quite well when mapped.  Occupational diseases linked to natural resource linked occupations like mining, forestry, certain forms of crop production, all have tendencies to demonstrate regionalism.  Allergic bronchitis is a side effect of inhaling sawdust and other fresh cut wood related particulates and fibers.  In the Pacific Northwest, the development of a chronic form of allergic bronchitis was found to be common to certain loggers due to the chemistry of liverworts found growing on the tree trunks being cut  (esp. frullania, with the sequiterpene lactones frullaniosides, as per a 1989 study).

Mapped examples of this include:

• Coal Miner’s Lung, which happens where coal mining is the primary business.
• Maple Bark Lung, incidentally found more in southern settings, not in maple rich ecological settings.
• Bagassosis, which has a peak in the southwestern coastal region, where products from the fields in the eastern parts of the state are shipped in closer to transportation and manufacturing settings for preparation of food products from the related grain crops.
• Farmer’s Lung, which exists where dense dairy farm settings exist
• Farmer’s Liver Fluke.

A very unique occupational disease of the west coast, lacking a link to the Natural Resource industries, pertains to international commerce.  California is often on the news regarding illegal drug activities and importation of cocaine from Columbia for example.  The tropical birds importation industry is another such illegal activity with major fencing operations taking place in California seaports.  The tropical birds industry has attached to it Psittacosis, a lung condition developed by inhaling guano (powdered, dried fecal material).  Historically, the lung conditions related to guano inhalation were related to the industry as a whole, but now are more linked to legal and illegal bird trade.  The two capital towns or cities for this legal/illegal trade are demonstrated by the following map produced as part of a study of Occupational Allergic Bronchitis. (This map is unique in that it also demonstrates scanning techniques; one of my first such products and so has some shakiness, and is a bit slow.)

§

Ethnicity and Region

When people come into this country, they have the potential of bringing diseases,  disease-causing habits and disease related lifestyles with them.  This is not so much a condemnation of their different lifestyles, just a mention of how and why disease is and can be closely linked to certain immigration practices, legal or illegal.

φ

One of the more diffuse disease patterns related to ethnicity, although less the case as the generations pass, pertains to sickle cell disease, in particular the carriers of Sickle Cell.  The distribution of this condition was originally managed naturally due to its ability to increase the lifespan of sickle cell carriers in malaria ridden countries.  In the United States, its distribution into this country has a history that is deeply attached to slavery prior to the Civil War, and former slave families following the war.  Unlike the other African/African-American diseases with links to African slave trade and immigration, such as yaws, cardiomyopathy, loasis and African Tapeworm, we do not see the link for malaria importation today appearing anything like the continued carriage of sickle cell.

ð

Poverty and Region

The impacts of poverty on disease are difficult to define.  All regions have areas of poverty for the most part.  One can define a particular large area of the US as impoverished, like the heart of Appalachia, the early 1900s shacks still standing in the Adirondacks, the poorest families surviving in the outskirts of dilapidated and ghetto-ridden intercity regions.

Quite often, we can break these sections into smaller parts, some relatively rich and others very poor.  In the Pacific Northwest, there are poor backwoods towns and hamlets as well as borderland urban settings rich in low income to barely subsistent families.  This is especially true in part of the Northwest where strips of land with rich communities lie immediately adjacent to strips of poor communities, a feature common to the larger urban settings.  This means that the study of regionalism and poverty is less a study of regionalism and more a study of socieconomic status and inequity.  There are those immediate impacts that poverty can have regarding health, intermediate effects that occur due to poverty-linked suffering and life experiences lasting more than several months, and the long term, chronic impacts of a lifestyle limited by poverty.   The development of cases amongst the more susceptible poor people may even make it possible for other less vulnerable social settings to now become infected.

The following diseases have ICDs that demonstrate these regional and/or small area poverty related behaviors.

• Fetal Exposure to Narcotics/Narcotics Use during Pregnancy
• Fetal Exposure to Nicotine/Smoking during Pregnancy
• Crack Baby syndrome
• Beriberi in children less than 3 years old
• Desertion of Newborn (n), IP
• Shaken Baby Syndrome
• Battered Child Syndrome

Those diseases we are so strongly working to immunize children against for example enter the country this way.  When we look at where these diseases have happened in the past, and then merge this data together, we get some very important insights into how and why these almost preventable disease patterns could perhaps never be fully preventable when global disease patterns and human behaviors are taken into consideration.  The following fairly lengthy map video demonstrates this fact.

Ð

During the late 199os, a concern Portland epidemiologists had pertained to the possible spread of Hanta Virus to the city.  This was due to the drought suffered that year south of Oregon, resulting in rodent migration northward from Arizona and neighboring states into the Pacific Northwest.

HV

.

Exclusions

Mapping disease is also helpful when it comes to seeing what diseases and conditions are rare to absent from a region.  Many such exclusions may be expected, due to various natural ecology related and topographic reasons, such as the anticipated scarcity of coal miner’s lung in the Pacific Northwest.

It is important to note for example that the following fairly common diseases are rare to the Pacific Northwest:

Rabies (IP)

Other diseases or diagnoses we anticipate being common to the Pacific Northwest but are in fact rare, and not peaking in this part of the country.  We can in part state this is due to the lower population density, but for diagnoses where numbers of people and population density do not really matter, such is still not the case for some diagnoses.

The following map with its peaks in Yellow Fever suggest that the introduction of this disease seems to favor a north-to-south route from Canada (and the Great Lakes if we view regions further east) and a west-to-east into the country’s interior route via the Columbia River.

Ÿ

Altitude sickness for example is a condition we’d expect to see peaking in the Pacific Northwest due to its Coastal range and proximity to the west face of the Rocky Mountains.  This diagnosis however instead has its peaks located where major international airports exist.

Å

Family history and genetics can also impact distribution of certain diseases.  The young adult onset of blindness due to retinopathy is typically not a condition demonstrating herding or grouping like distributions, implying that it is clustered in a region due to continued distribution of this condition to new children.  Likewise, it is not expected to see other genetically linked disease phenomena to show some sort of strong clustering, unless culture has an impact on hos and to whom the disease is spread.  Such is the case for the following condition, which in the following map video is compared with two other congenital or genetically linked conditions lacking this clustering:

Ψ 

Exceptions

Exceptions to the rule are perhaps the most important reasons for mapping ICDs.  An Independent Prevalence (IP) map of the country depicts Ratbite fever as infrequent to rare to the Pacific Northwest.  This means that ongoing monitoring of the status of this disease in urban settings (metropolitan districts) has some value to monitoring the health patterns and an important part of the population health of this region.

RF-IB

The bubonic plague has a history of relationships with Prairie Dog communities in the Midwest, and domestic and wild animal settings back east.  Its lack of high amounts of IP in the Pacific Northwest enables it to be monitored as well.  This reduction in Northwest presence for the plague also demonstrates a possible large area cause for the poor distribution of this condition into northwestern states–the effects of the Rocky Mountains as a barrier–thereby implying the need for population rich related regions to assist in this diffusion process (i.e. from south the north).

þ

We are often concerned about the in-migration of foreign-born diseases.  Sometimes these in-migrations are of highly contagious diseases, other times they are of diseases that others suffered back home, but are usually unable to spread within the new social and domestic-workplace settings.

Ø

A classic example of this related to the Pacific Northwest is the Mexican disease Chiclero’s Ulcer.  This is a fungal condition typically of an occupational nature — chiclero’s or the gatherers of chicle latex catch it.

ñ

Another Mexican disease is Pinta (older name Pinto).  The main features to note for Pinta are its possible in-migration routes or routes of entry and diffusion by transportation routes, its tendency to adhere to population density and type I (linear, and sequential, rather than hierarchical) diffusion patterns, and the development of a spike far from the southern Mexico-US border, reasons for which have yet to be identified.

The next part in this series provides examples of diseases with Far West and Pacific Northwest behaviors, and what it is about the Pacific Northwest that defines it as a unique epidemiological and public or community health region.. [Link to next page]

.