The Healthiest and Wormiest Ancestral Puebloans

50 Pages·2017·5.54 MB·English

by  Karl Reinhard

University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln
Karl Reinhard Papers/Publications Natural Resources, School of
2008
Parasite Pathoecology of Salmon Pueblo and Other
Chacoan Great Houses: The Healthiest and
Wormiest Ancestral Puebloans
Karl Reinhard
University of Nebraska-Lincoln, [email protected]
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Parasitology Commons
Reinhard, Karl, "Parasite Pathoecology of Salmon Pueblo and Other Chacoan Great Houses: The Healthiest and Wormiest Ancestral
Puebloans" (2008).Karl Reinhard Papers/Publications. 25.
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Published in: Chaco’s Northern Prodigies: Salmon, Aztec, and the Ascendancy of the Middle San Juan Region
after AD 1100, edited by Paul F. Reed (Salt Lake City: The University of Utah Press, 2008), pp. 86-95 & 389-427.
Copyright © 2008 The University of Utah Press.
5
Parasite Pathoecology of Salmon Pueblo
and Other Chacoan Great Houses
The Healthiest and Wormiest Ancestral Puebloans
J.
KARL REINHARD
ARCHAEOPARASITOLOGY AND
affected parasitism at Antelope House and Salmon
PATHOECOLOGY IN THE SOUTHWEST
Ruin is another application ofp athoecology.
Two fields of paleopathological investigation orig Ancestral Pueblo communities have long been
inated in the Southwest. Archaeoparasitology is the focus of archaeoparasitology. Samuels (196S)
the study of ancient parasite infection (Reinhard developed the methods for helminth (parasitic
1990, 1992b). It includes comparisons between worm) egg recovery with coprolites from Mesa
time periods of single societies as well as compari Verde. Subsequently, Stiger (1977) provided the
sons of parasitism between different, contempora first intersite comparison analysis for sites on Mesa
neous cultures. For example, Fry (1980) compared Verde. Fry and his colleagues conducted the first re
Fremont and Anasazi parasitism, and also Archaic gional comparisons ofp arasitism, focusing on Can
hunter-gatherer and ancestral Pueblo parasit yon de Chelly and Glen Canyon (Fry 1977; Fry and
ism. All of these studies fall into the definition of Hal1197S, 1986). Fry (1977) also presented the first
archaeoparasitology. cross-cultural analysis ofA rchaic, ancestral Pueblo,
By contrast, pathoecology is the reconstruction and Fremont sites, and pioneered the comparison
ofr elationships among behavior, environment, and of parasitism among populations practicing differ
disease organisms in the development of illness ent subsistence strategies. Building on this previous
(Martinson et al. 2003; ReinhardandBuikstra2003; work, I have analyzed the diversity of helminths
Reinhardet al. 2003; Santoro et al. 2003).1his field that parasitized ancestral Pueblo peoples (Rein
developed from the need for fine-grained analysis hard 1985a, 1985b, 198sc, 1990; Reinhard et al.
ofp rehistoric ecological and behavioral conditions 1987). By 1985, archaeoparsitologists had identi
to assess factors that affected disease. Pathoecologi fied eight species of helminth that infected ances
cal interpretation depends on archaeological infor tral Puebloans (Figure S.I).
mation regarding parasitism, community size, trade Aidan Cockburn's insight into the origins of
patterns, water sourceS, subsistence practices, envi disease influenced the development of pathoecol
ronment, medicinal use, and many other topics. Al ogy in the archaeoparasitology of ancestral Pueblo
though the term is new, pathoecology developed sites. Cockburn (1967, 1971) argued that the evolu
over several decades. I view EI-Naijar et al.'s (1976) tion of infectious diseases followed human evo
study of ancestral Pueblo anemia as the first patho lution and the development of human cultures.
ecology study. Perhaps the most advanced exam Inspired by Cockburn, Reinhard (198Sa) compared
ple ofp athoecology is Stodder and Martin's (1992) the parasitic state of Colorado Plateau Archaic
multifactorial perspective on ancestral Pueblo dis peoples to ancestral Pueblo an sites. He verified
ease. My study (Reinhard 1996) of the factors that Cockburn's hypothesis that occasional infections
86
Parasite Pathoecology
~
I
stercoralis
n=3(0.6%)
Strongylate worm
n=7(1.4%)
FIGURE 5.1. Diagram showing the wide spectrum of parasites that infected ancestral Puebloans.
in hunter-gatherers became major health hazards vermicularis) prevalence in coprolites (Reinhard
in agricultural populations. Reinhard (1988) pre 1988). The pinworm was chosen as an indicator of
sented anumberofpathoecological findings regard general infectious disease because it is transferred
ing the development ofp arasitic disease in ancestral by person-to-person and by environmental con
Puebloans relative to earli~r hunter-gatherers. Para tamination (Figure 5.3).
sitism was limited in hunter-gatherers due to small Over millions of years of mutual evolution
band size, band mobility, diffuse regional popula with hominids and modern humans, pinworms
tions, and the presence of natural anti-helminthics have evolved multiple routes of infection, includ
(worm poisons) in hunter-gatherer diets. Hunter ing anal-oral, hand-to-hand, and airborne routes.
gatherer parasitism was promoted by the consump Pinworms are exceptionally remarkable among
tion of uncooked meat and insects. Parasitism human parasites because the female worm wrig
was promoted in ancestral Puebloan communi gles out of the anus of her host at night to scatter
ties by contaminated water sources, concentrated her eggs. Once outside of the intestine, she dis
populations, a more sedentary lifestyle, crowded perses eggs by two different mechanisms. Two
(apartment-style) living conditions, establishment types of eggs are produced in two parts of the pin
oflarge latrines, activities centered on water (agri worm uterus: light and heavy. Heavy eggs are laid
culture), and activities that expanded wetlands (in on the perianal folds with an irritant excretion.
eluding irrigation ofa ll types). The resulting itching (pruritis) and nocturnal host
By the 1990S, Reinhard (1992a) had identi scratching transfers the infective eggs to the host
fied wide variation in parasitism among ancestral fingers. Other eggs are distributed by aerosol when
Pueblo villages (Figure 5.2). At some settlements, the female's desiccated body bursts, which releases
parasitism was controlled, but others were over thousands of light eggs into the air. Ultimately,
whelmed by their pathogens. This topic was ex these light eggs contaminate the environment,
plored with a comparison of pinworm (Enterobius settling on food, in water, and throughout the
J.
KARL REINHARD
-----
I
I I
,
L-
I
I
i
Colorado
Utah
,
1- __
•
, 21%
•
. , New
Mexico
I
FIGURE 5.2. Map showing variation in percentages of pinworm parasitism among ancestral
Pueblo villages.
t
Eggs are transferred by direct
contact between humans and by
Inhalation ot eggs in air currents. ""
Noctural egg-laying
results in retrointection
as some eggs hatch and
larvae enter the same
host used by the mother
worm.
FIGURE 5.3. Diagram showing modes of pinworm transmission to human hosts.
habitation. How long these eggs remain infective perinanal region, and the larvae wriggle back into
depends on warmth and humidity. In general, even the host. Hand-to-hand transfer of the eggs occurs
in arid environments, human habitations have an when humans interact upon waking. Autoinfec
elevated humidity. Thus, several infection routes tion occurs when humans eat food contaminated
result from the pinworms' nocturnal excursions. with the eggs from their own hands. Airborne in
Retroinfection occurs when the eggs hatch on the fection occurs when humans inhale the eggs, or
88
Parasite Pathoecology
30
Q)
u •
-c Canyon de Chelly
Q) •
..
co Chaco Canyon
> 20
Q)
a..
..
E
• Inscription House
•
0
10
-C • Salmon Ruin
a..
at
01---~~---P--.-~~-.--~--~~---t
40 50 70 80 90
0/0 Porotic Hyperostosis Prevalence
FIGURE 5.4. Graph comparing pinworm parasitism with porotic hyperostosis prevalence for several southwestern
locales. The chart shows that the prevalence ofp inworm parasitism covaried with porotic hyperostosis prevalence at
ancestral Pueblo sites where both coprolites and skdetons were studied (Reinhard 1992.a).
when the air dissemination of eggs results in the sance, but reflects a serious health risk, particu
contamination off ood and water. Ofc ourse, other larly when one considers that other pathogens are
pathogens follow the same hand-to-hand, hand spread by the same means.
to-mouth, and aerosol routes as pinworm infec Reinhard (1992a) showed that the prevalence of
tion. Therefore, high rates of pinworm prevalence pinworm parasitism covaried with porotic hyper
suggest high rates of infection by other pathogens ostosis prevalence at ancestral Pueblo sites where
that are passed through the same modes of infec both coprolite and skeletons were studied (Figure
tion (see Figure 5.1). 5.4). Porotic hyperostosis is an indicator of gen
Some ancestral Pueblo communities were ex eral skeletal pathology that has been used to assess
tremely parasitized. In fact, some sites have the maternal-infant health. The fact that these indica
highest levels of pinworm infection recorded for tors of disease had a positive, statistically signifi
ancient or modern peoples. In a modern clini cant correlation underscores the use of pinworms
cal setting, only 5 percent of feces from pinworm as a general gauge of ancestral Pueblo disease state
infected people are positive for pinworm eggs. The (Reinhard 1992a).
percentages of coprolites positive for pinworm Pinworms are not very pathogenic but are a
from several sites far exceed this level. For example, good proxy for the infectious disease environment
~9 percent of the coprolites from Antelope House, (Reinhard 1996). Rates of pinworm infection at
19 percent of those from Inscription House, and ancestral Pueblo and Fremont culture sites were ex
21 percent of those from Chaco Canyon sites were plored by Hugot and his colleagues (1999). They
positive for pinworm eggs. This indicates that pin found that sites in rockshelters without walled
worm parasitism was unavoidable, and that in all villages (some Glen Canyon sites) had the lowest
probability people had heavy infections. In such levels ofp arasitism. Such sites had pinworm preva
populations, pinworm infection is not just a nui- lence comparable to hunter-gatherers. Next, village
J.
KARL REINHARD
sites outside of rockshelters had intermediate levels persal capability and the ability to find hosts when
of parasitism. Finally, walled villages built within needed. Also, they must possess attributes enabling
rockshelters had the highest prevalence of pin them to survive in the external environment. Fea
worm (see Figure S.4). tures of the host have less effect on survival and re
If we look at data from the Chacoan realm, we production of these parasites.
find that Chacoan great houses are anomalous: Nidicolous parasites live in the host's immedi
they include both the wormiest and healthiest ate environment: in beds, walls, granaries, caves,
sites. Salmon Pueblo has among the lowest prev rockshelters, and under floors. Fleas, mites, bed
alence values (7 percent). In contrast, Pueblo Bo bugs, triatomiid bugs, and the diseases transmitted
nito and Pueblo Alto in Chaco Canyon are among by these bugs are examples of nidicolous parasites.
the highest (21 percent). Clearly, the pathoecology They depend upon the host not only for food but
of great houses was defined by factors other than for creation of their habitat.
size. Puebloans living in great houses adapted their Permanent parasites live on or in the host ex
use of the structures in ways that either promoted cept when dispersing between hosts. These in
or limited parasitism. The remainder of this chap clude most protozoa, roundworms, flukes, and
ter explores the factors that could have limited tapeworms. They are completely dependent upon
parasitism at Salmon relative to other great house their host for food and all other environmental
communities. requirements.
CHACOAN GREAT HOUSES FACTORS OUTSIDE GREAT
AS NIDI FOR INFECTION HOUSE ENVIRONMENTS
Realizing that for parasitic disease to occur, all fac Ttater Source, Giardiasis,
tors related to the survival and reproduction of the and Amoebic Dysentery
parasite must be present, Pavlovsky (1966) com Water sources in desert environments are foci for
bined ecological factors into a predictive tool for in human activity and can therefore become nidi. As
fection. These can include vectors, reservoir hosts, long as they are plentiful and flowing, and popu
humans, and favorable external environments. He lations are not too concentrated around them,
defined a nidus as that portion of a natural geo water sources are not necessarily a pathoecological
graphic landscape that contains a community con factor in the spread of parasitism. However, when
sisting of a pathogen, vectors, reservoir hosts, and water sources are few in number and stagnant, and
recipient hosts, and that possesses an environment when populations aggregate around them, these
in which the pathogen can circulate. He further sources often becomes contaminated, providing a
found that pathogens possessed nidallty: the ten nidus and becoming significant pathoecological
dency of an infectious agent to occur in distinct problems.
nidi, such as being associated with particular geo Giardia lamblia has been found in ancestral
graphic, climatic, or ecological conditions. Thus, a Pueblo coprolites (Gon'ralves et al. 2002). This par
nidus is a focus of infection. For humans, a nidus asite is not highly pathogenic in most adults. In fact;
can be as confined as a single room accessed by ro most infected people show no symptoms. How
dents carrying plague-infected fleas, or as large as ever, when G. lamblia becomes established in stag
an entire community and its agricultural use-area, nant water sources, it becomes a problem. It is most
as is the case for the transmission of hookworms. perilous to pregnant women and their babies. Dis
Various types of parasites circulate in nidi. ease in mothers and children is due to poor mater
Temporary parasites, which live in the external en nal nutrition caused by malabsorption, resulting in
vironment and come to the host only to feed, in intrauterine growth retardation. G. lamblia causes
clude mosquitoes, chiggers, ticks, and leeches. In malabsorption when the intestinal villi become
these species, every individual must have good dis- blunted and the function of intestinal mucous di-
Parasite Pathoecology
minishes (Carden ~d MacLeod 1988). Clinical the large bowel or ileum. Amoebas can cause nodu
symptoms include cramps, watery diarrhea, nausea, lar granuloma formation, colitis, and diarrhea. The
vomiting, and sometimes fever. Among pregnant disease can become systemic and eventually an ul
women who exhibit symptoms, G. lamblia causes cerative disease of the large intestine, liver, lung,
malabsorption and dehydration at a period when brain, or other organs. Amoebiasis can be symp
there is a need for accentuated nutritional require tomatic or even fatal during pregnancy (Abioye
ments. Such women fall into a negative nutritional 1973; Lee 1929; Lewis and Antia 1969; Rivera 1972).
balance, as demonstrated by Carden and MacLeod Deaths that occur are due to a rapid onset of pro
(1988), who summarized the effects of G. lamblia fuse diarrhea with dehydration and severe ane
on the fetus and newborn. With protracted ma mia. Premature delivery results from colitis, diar
ternal infections, normal fetal development is im rhea, dehydration, ketosis, or shock (MacLeod and
peded. With asymptomatic maternal infections, Carden 1988). Weigel et al. (1996) found that high
low birth weight and infant anemia are common E. histolytica load in asymptomatic infections was
(De Morais and Suzuki 1997). Generally, infants associated with decreased maternal serum hemo
become infected after three months of age. Islam globin and hematocrit levels, and iron-deficiency
et al. (1988) found that some immunity is conveyed anemia. Among women who had severe prob
from, mother to infant, but this immunity is not ef lems (spontaneous abortion, stillbirth, low-birth
fective in infected infants. Immunity to G. lamblia weight babies), there was a fourfold increase in the
increases with age (Shettyet al. 1992). Thus, the pa prevalence of amoebiasis relative to normal births
thology caused by G. lamblia is most significant in (Czeizel et al. 1966). In infected but asymptomatic
infants and toddlers (Hjelt et al. 1992). mothers, Weigel et al: (1996) found increased indi
The epidemiology of giardiasis is well known cators of diminished intrauterine growth. Despite
(Taus et al. 1998; Hjelt et al. 1992; Harter et al. immunity conveyed by antibodies passed through
1982). Sullivan et al. (199 I) showed that giardiasis is the placenta and in milk, infants can become in
highly prevalent in children with chronic diarrhea fected. When this happens, infants exhibit fever
and malnutrition, and that giardiasis does not re with severe watery, sometimes bloody, diarrhea.
spond to standard therapeutic measures. Children Colitis, appendicitis, intestinal ruptqre, and peri
who have low iron or vitamin BI2levels have more tonitis result in a high mortality among infected in
severe giardiasis symptoms (Awasthi and Pande fants (MacLeod and Carden 1988).
1997; Olivares et al. 2002). Subadults in the age The Pueblo III occupation ofA ntelope House,
range of9 months to II years are most susceptible to at Canyon de Chelly in Arizona, is the best
infection, though infections can occur at 3 months documented case of an ancestral Pueblo village
of age. In developing nations, 91 percent of infants that suffered declining health due to water source
of infected mothers become infected by 6 months nidi. Morris (1986) describes the pathoecological
of age. Of infected infants, 86 percent have diar conditions that led to water contamination. To
rhea. Infected people tend to live in dwellings with wards the end of the occupation, drought affected
dirt floors, simple latrines, groundwater drinking the region. As more distant water sources dried up,
sources, and close contact with dogs. These aspects the population ofA ntelope House and Canyon de
of life were common at ancestral Pueblo villages Chelly burgeoned. The increased population and
(Reinhard 1996). In addition, person-to-person decreased water resulted in contamination. Gon
transmission of G. lamblia is common (Birkhead ~alves et al. (2003) found both E. histolytica and
and Vogt 1989; Black et al. 1977( Keystone et al. G.lamblia in Antelope House coprolites. El-Naijar
1978). The parasite Entamoeba histolytica also af (1986; EI-Naijar et al. 1976) found increased skel
flicted ancient Pueblo groups (Gon~alves et al. etal evidence ofs ystemic disease during the Pueblo
2002). Relative to G.lamblia, E. histolytica causes III occupation of Canyon de Chelly relative to
more dramatic pathology, creating ulcerations in other time periods. Thus, there is a relationship
91
J.
KARL REINHARD
between environmental stress, increased parasit cate human hosts and burrow through the skin.
ism, and skeletal indicators of morbidity in mother Also,A. duodenale can achieve transmammary and
and infants. transplacental infection. Thus, fetuses and infants
For Chaco an great houses, coprolites from can be infected without ever coming in contact
Salmon Ruin were tested for G. lamblia with nega with contaminated soil.
tive results (Wilson et al. 2006). The absence ofg i Hookworm causes specific problems in preg
ardiasis at Salmon is logical given the presence of a nancy. One of the most common causes of death
flowing water source (the San Juan River) within in labor in the developing world is cardiac failure
200 m of the community. Given these conditions, from severe anemia attributed to hookworm infec
there was little chance for contamination. No copr tion (Cintron Villaronga 1967). As many as 90 per
olites from Chacoan great houses have been tested cent of pregnant women are infected in endemic
for E. histolytica. areas (Ananthakrishnan et al. 1997; Navitskyetal.
1998). Crompton and Whitehead (1993) present
Irrigation, Hygiene, and Hookworm calculations comparing effects of hookworms on
Hookworm has been found in coprolites from An a nonpregnant woman versus a pregnant woman.
telope House and Pueblo Bonito, but at no other The model predicts that hookworms more rapidly
ancestral Pueblo. Hookworm is the greatest para deplete stored iron, with a rapid effect on red cell
sitic threat to the mother, fetus, and infant. Iron density per milliliter of blood in pregnant women.
deficiency anemia resulting from intestinal blood Macleod (1988) verified this model from the clin
loss is the major consequence of hookworm infec ical perspective. Each worm consumes 0.27 mlof
tion (Variyam and Banwell 1982; Ali et al. 1990). blood per day, and only 20 weeks after initial in~
Treatment for this type of anemia is administra fection, hypochromic, macrocytic anemia can
tion of iron supplements. According to Gilman develop. The minor symptoms of infection are
(1982), development of hookworm-induced iron indistinguishable from complaints of pregnancy
deficiency anemia is dependent on the intensity of (epigastric pain, heartburn, and so on). However,
infection, the species of hookworm, and the ability with moderate infections there is low-grade fever,
of the host to resist infection and to maintain ad fatigue dyspnea, heart palpitations, flow murmurs,
equate stores of iron. loss of blood is caused by di and anemia. In heavy infections, constipation or
rect ingestion ofr ed blood cells and by tissue trauma diarrhea, jaundice, emaciation, cardiac failure, or
produced by worm attachment and feeding. pre-eclampsia occur. If a woman survives labor, she
The species that causes the more serious pa cannot recover as easily from post-partum hemor
thology and that has been identified in ancient rhage, which can contribute to maternal death.
New World remains is Ancylostoma duodenale Hookworms also have a negative impact on fe
(Allison et al. 1974). This is a fascinating, human tuses and infants (MacLeod 1988). Abortion, still
specific parasite that has evolved several infection birth, and premature labor are associated with
modes and adaptations. Perhaps the most remark severe hookworm infection. Women infected with
able aspect of A. duodenale is its hypobiotic abil hookworm give birth to low-birth-weight infants
ity. Hypobiosis occurs when a parasite suspends it (a 2 percent hematocrit drop in the mother corre
development in host tissues in a way that prevents lates to a 100 gram decline in birth weight). Because
a strong immunologic response. A. duodenale can of transplacental migration, infants are infected at
go into hypobiosis in winter and come out of hy birth. Severe and sometimes fatal hemorrhage oc
pobiosis in summer. This is a significant adapta curs in infants less than four months ofa ge. Chaud
tion because the females can lay their eggs in the hary and Jayaswal (1984) first described an anemic
season that is optimal for larval survival. The larvae infant resulting from transplacental migration. In
hatch within a few days, exit the feces, and develop a survey of hundreds of transplacental-infected in
through three larval stages as free-living soil nema fants in China, Yu et al. (1995) defined the symp
todes. Subsequently, as third-stage larvae, they 10- toms of transplacental infection, which include
92
Parasite Pathoecology
bloody s~ools, melena, anorexia, listlessness, and village location that aggravated pinworm infec
edema. A. duodenale was the species implicated in tion. Although pinworm prevalence was highest
these types of infection. Transplacental migration in walled villages built within rockshelters, it is
is not rare. Nwosu (1981) documented that 10 per important to note that no thoroughly studied an
cent of 316 Nigerian newborns (four to five weeks cestral Pueblo site has been found to be pinworm
old) were infected with A. duodenale. Transmam free. Related cultures also were infected. The earli
mary infections from mother to infant also occur, est Basketmaker II coprolites from Bighorn Cave
with similar health results (MacLeod 1988). Stud (Grand Gulch, Utah) have a prevalence of 25 per
ies of many groups from around the world link cent. Later, the diffuse populations of ancestral
hookworm disease, especially from A. duodenale, Pueblo and Fremont in the Glen Canyon area were
to severe iron deficiency and anemia in children infected. Even the Sinagua inhabitants of Elden
(Albonico 1998; Stoltzfus et al. 1998). Pueblo were infected (Hevly et al. 1979). The in
Hookworm infection is dependent on mois fections resulted from air humidified by human ac
ture, shade, and warmth. The Colorado Plateau is tivity and contaminated with floating eggs within
normally too dry to promote infection, and in his confined spaces.
toric times hookworm was unknown. Thus, the Although pinworm infection tends to he as
discovery in Anasazi sites of hookworm eggs and ymptomatic, a high prevalence of heavy infections
another parasite with a similar infection mode, can result in severe pathology, including secondary
Strongyloides stercoralis, was surprising (Reinhard bacterial infections in juveniles. However, to my
1985C; Reinhard et al. 1987). Clearly, ancestral mind the real relevance ofp inworm relates to other
. Puebloans created microenvironment nidi where diseases that are also airborne transferred. For the
parasite larvae could hatch and mature in moist, ancestral Pueblos, tuberculosis was the other air
warm, and shaded soil. Puebloans also spent time borne disease. Among the most poignant epidemi
in these nidi, where they spread eggs and became ological descriptions of the tuberculosis threat to
infected by larvae. It is very likely that irrigated Pueblos, is applicable to pinworms as well, is pro
fields were hookworm and S. stercoralis nidi. vided by Fink (1985), who examined details ofA na
Studies of hand and foot washing in Bengal sazi life such as communal living, lack ofknowledge
show that the larvae can be washed offe asily within ofg erm theory, and cramped living conditions that
a few minutes ofc oming into contact with the skin. promoted infectious diseases.
The infection occurred in defecation grounds, and The San Juan period at Salmon Pueblo is enig
washing was prescribed by religious rules (Nawa matic in the context of pinworm prevalence at
linski et al. 1978). We do not know if ancestral other sites. Only 7 percent of 112 coprolites stud
Puebloans had similar rules, but it is very likely that ied contained pinworm eggs-approximately one
hookworms could penetrate the skin of Puebloan fifth the prevalence recorded for other Pueblo III
farmers as they worked in irrigated fields. If the sites, including Pueblo Alto and Pueblo Bonito.
division oflabor resulted in men working more in A probable explanation for this relates to Paul
irrigated fields, it may be that they were more often Reed's (2006c) finding that the Sanjuan residents
infected than women. of Salmon used primarily the second-floor rooms
for human activities. Air conditions in the lowest
INTERNAL GREAT HOUSE FACTORS rooms, and those closest to the windowless rear
Apartments, Plazas, Kivas, wall, would have been more likely to increase pin
and Second-Floor Living worm infection. Such rooms would have had the
Pat Horne (1985) attributed the remarkable pin most stagnant and humid air, promoting airborne
worm prevalence among ancestral Pueblos to infection with pathogens. Use ofh earths in second
crowded, apartment-style living conditions. As floor rooms would have produced a much less hu
noted above, Hugot et al. (1999) elaborated this mid environment, and any rooms opening towards
theme by detailing the aspects of architecture and the large Salmon plaza would have been healthier
93
J.
KARL REINHARD
with ventilation from the dry, relatively breezy air the scolex. As the they progress downward along
outside the pueblo. the length of the tapeworm, their ovaries and tes
Subterranean rooms such as kivas would have tes mature, fertilization occurs, and eggs mature.
provided the primary vector for transmitting air When a proglottid is filled with mature eggs, it is
borne disease. In kivas, the air would have been said to be gravid. In some tapeworms, such as those
humid, and the air flow around the ventilator would that infect humans who eat undercooked fish,
have been sufficient to transmit particles around the the eggs are laid through gravid proglottid geni
room, but not to remove infectious particles from tal pores. In other species, such as those that infect
the structure. This would explain, in part, why Bas humans who eat undercooked beef, entire gravid
ketmaker groups, who lived in pithouses with litde proglottids break off of the tapeworm. These pro
or no circulation, developed a high prevalence of glottids are pardy motile and squirm their way out
infection. After Basketmaker times, however, kivas of the host body.
would have been the most likely subterranean nidi Hymenolepis lays eggs through genital pores,
of pinworm dissemination. One way to test this and these eggs are infective when they pass into the
hypothesis is through analysis and comparison of environment. Although they have been found in
sediment samples from kiva, living room, and mill Canyon de Chelly coprolites, they have not been
ing room floors. found in Chacoan great houses.
By far the healthiest place to work and live at
Salmon was outside, in the plaza and on rooftops. CONCLUSION
Sunlight would have desiccated and radiated patho The Chacoan great houses provided many poten
gens, thereby reducing the number of infectious tial nidi for temporary, permanent, and nidiculous
airborne contaminants, and the clean air moving parasites. Great house inhabitants created or elim
across the plaza would have provided people with inated nidi through different activities and prac
alternate, healthy air. Humidity also was undoubt tices. Although there is was no way to completely
edly much lower in these open spaces compared to eliminate the transmission of permanent parasites,
confinedrooms and kivas. some aspects of life at Salmon retiuced the preva
lence of pinworm relative to other great houses.
Sanitation and Hymenolepidid A lower population density, among other factors,
Tapeworm Injection would have accomplished this.
With regard to tapeworms, there' are two main The absence of fecal-borne parasitism indi
types of hosts. The definitive host is the animal cates that nidi of fecal exposure were eliminated at
in which tapeworms accomplish sexual reproduc Salmon Ruin through the use of specific rooms as
tion, whereas intermediate hosts are infected with latrines, an effective way of stopping the spread of
nonsexual stages. Usually, tapeworm infections in parasites such as Giardia laMia.
humans occur through ingestion of infected inter Nidi external to Salmon Ruin where hook
mediate hosts. worm and S. stercoralis transmission could have
The most common tapeworm (Hymenolepis taken place did not exist. This was probably due
nana) found in ancestral Puebloan coprolites took to a different type of irrigation (perhaps using the
a different infectious pathway. This tiny tapeworm free-flowing San Juan River) and gardening relative
evolved the ability to use an intestinal villus as its to that of Pueblo Alto and Pueblo Bonito, where
intermediate host. The larvae emerge and become hookworms did infect humans.
adults in the intestinal lumen, thus using humans as In the future, more extensive analysis of ances
both their definitive and intermediate hosts. tral Pueblo coprolites should be conducted using a
Tapeworms have two methods of laying eggs. variety ofr esearch methods. Some sites, such as An
The tapeworm's anterior end, the scolex, attaches telope House, are currendy the focus of molecular,
to the intestinal wall. Proglottids are the sexually immunological, and microscopic analysis. Other
reproducing tapeworm organs that develop from sites, such as those in Glen Canyon, were studied
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