- Here it is more proof. Chagas is spreading in the US
not just being brought into the US but it is here. I don't use
the term "AUTOCHTHONOUS" ...
- I prefer to use 'local infections' which seems to really
state it well. So, the virus is HERE, in reservoir now, and is spread
via the vector (kissing bug species) which are also in the US. As
I stated last week, if we do not stop this spread and growing reservoir
NOW, we will have a public health crisis in 7-10 years in parts of the
US. Central, South America and Mexico are in crisis now with regard to
Chagas. The genie is out of the bottle there. Health officials in the
US have refused to believe people like me, Dr. Cosman and Frosty Wooldrige.
They must start to listen because Chagas has everything in the US that
it has in Mexico, etc: a small animal reservoir, vectoring, and plenty
of Chagas-infected people coming in everyday by the thousands. A perfect receipe
for another public health crisis.
- TRYPANOSOMIASIS, AUTOCHTHONOUS - USA (LOUISIANA)
- A ProMED-mail post
- ProMED-mail is a program of the
- International Society for Infectious Diseases
- Autochthonous Transmission Of The Chagas Disease In Louisiana
- Date: 14 Mar 2007
- From ProMED-mail
- Source: Dorn PL et al. Emerg Infect Dis, April 2007 [edited]
- Autochthonous transmission of the Chagas disease parasite,
_Trypanosoma cruzi_, was detected in a [74-year-old female] patient in
rural New Orleans, Louisiana [in July 2006]. The patient had positive test
results from 2 serologic tests and hemoculture; 56 percent of 18 _Triatoma
sanguisuga_ collected from the house of the patient were positive for __T.
cruzi__ by PCR.
- Only 5 autochthonous cases of infection with the Chagas
disease parasite have been reported in the United States: 3 in infants
in Texas (2,3), 1 in an infant in Tennessee (4), and 1 in a 56-year-old
woman in California (5). The most important triatomine species in the United
States for Chagas disease transmission are _Triatoma sanguisuga_
- [for photo see: http://www.rso.cornell.edu/bugclub/images/Triatoma%20sanguisuga.jpg
- - Mod.JW],
- whose broad range extends across the southeast and reaches
Maryland and Texas, and _T. gerstaekeri_, found in Texas and New Mexico
(6). There is an active sylvan cycle in the United States; __T. cruzi__
has been identified directly or by serologic analysis in >18 species
of mammals (7), including raccoons, opossums, armadillos, foxes, skunks,
dogs, wood rats, squirrels, and nonhuman primates (housed in outdoor research
facilities). In Louisiana, __T. cruzi__ infection has been identified in
28.8 percent and 1.1 percent of armadillos (8,9), 37.5 percent of opossums
(9), 4.7 percent of rural dogs (10) and rarely in nonhuman primates (11,
P.L. Dorn et al., unpub. data). The lack of human cases is usually attributed
to not having a suitable habitat for the bugs in most US homes, a preference
for animal hosts, and delayed defecation of triatomines found in the United
States compared with those found in Latin America (12).
- The Study
- In June 2006, a 74-year-old woman residing in a house
in rural New Orleans was bothered by a considerable number (more than 50)
of insect bites. The woman observed many bugs in the house and showed them
to a fumigator, who identified them as triatomines. An internet search
showed the potential for transmission of Chagas disease, and the woman
sought help from a local health sciences center.
- The assertion that the patient contacted _T. cruzi_ in
Louisiana is strongly supported by limited travel history to disease-endemic
areas and stays mostly in improved housing (risk for Chagas disease transmission
is associated with longer residence in disease-endemic areas), lack of
other risk factors, and large numbers of infected __T. sanguisuga__ in
the house. No periorbital swelling was reported. However, the streaks on
her nightgown consistent with triatomine feces indicate exposure, and the
parasite could have been introduced into any of her numerous bite wounds.
- The residents had not previously noticed large numbers
of _T. sanguisuga_ in the house. However, Hurricane Katrina had hit the
area 9 months earlier, and increases in domestic infestation with triatomines
have been previously reported after a hurricane (15). Anecdotally, the
armadillo population increased substantially in the months after Hurricane
Katrina, and one can speculate that these hosts supported a larger bug
population, who later sought other bloodmeal sources as the armadillo population
returned to pre-storm levels. Follow-up studies of local _T. sanguisuga_
ecology and animal reservoirs are planned.
- 1. Morel CM, Lazdins J. Chagas disease. Nat Rev Microbiol.
- 2. Woody NC, Woody HB. American trypanosomiasis (Chagas'
- 1st indigenous case in the United States. JAMA. 1955;159:676-7.
- 3. Ochs DE, Hnilica VS, Moser DR, Smith JH, Kirchhoff
- diagnosis of autochthonous acute chagasic myocarditis
- chain reaction amplification of a species-specific DNA
- Trypanosoma cruzi. Am J Trop Med Hyg. 1996;54:526-9.
- 4. Herwaldt BL, Grijalva MJ, Newsome AL, McGhee CR, Powell
- DG, et al. Use of polymerase chain reaction to diagnose
- reported US case of autochthonous transmission of Trypanosoma
- in Tennessee, 1998. J Infect Dis. 2000;181:395-9.
- 5. Schiffler RJ, Mansur GP, Navin TR, Limpakarnjanarat
- Chagas' disease (American trypanosomiasis) in California.
- 6. Lent H, Wygodzinsky P. Revision of the Triatominae
- Reduviidae) and their significance as vectors of Chagas
- Bulletin of the American Museum of Natural History. 1979;163:123-520.
- 7. John DT, Hoppe KL. Trypanosoma cruzi from wild raccoons
- Oklahoma. Am J Vet Res. 1986;47:1056-9.
- 8. Yaeger RG. The prevalence of Trypanosoma cruzi infection
- armadillos collected at a site near New Orleans, Louisiana.
Am J Trop
- Med Hyg. 1988;38:323-6.
- 9. Barr SC, Brown CC, Dennis VA, Klei TR. The lesions
- of Trypanosoma cruzi in opossums and armadillos from
- Louisiana. J Parasitol. 1991;77:624-7.
- 10. Barr SC, Dennis VA, Klei TR. Serologic and blood
- of Trypanosoma cruzi infection in four canine populations
- Louisiana. Am J Vet Res. 1991;52:570-3.
- 11. Seibold HR, Wolf RH. American trypanosomiasis (Chagas'
- in Hylobates pileatus. Laboratory and Animal Care. 1970;20:514-7.
- 12. Zeledon R. Epidemiology, modes of transmission and
- hosts of Chagas' disease. In: In Elliot K, O'Connor M,
- GF, editors. Trypanosomiasis and leishmaniasis with special
- to Chagas' disease. Amsterdam: Associated Scientific
- 1974. p. 51-85.
- 13. Yabsley MJ, Norton TM, Powell MR, Davidson WR. Molecular
- serologic evidence of tick-borne ehrlichiae in three
- lemurs from St. Catherines Island, Georgia, USA. J Zoo
- 14. Dorn PL, Engelke D, Rodas A, Rosales R, Melgar S,
Brahney B, et
- al. Utility of the polymerase chain reaction in detection
- Trypanosoma cruzi in Guatemalan Chagas' disease vectors.
Am J Trop
- Med Hyg. 1999;60:740-5.
- 15. Guzman-Tapia Y, Ramirez-Sierra MJ, Escobedo-Ortegon
- E. Effect of Hurricane Isidore on Triatoma dimidiata
- Chagas disease transmission risk in the Yucatan Peninsula
- Am J Trop Med Hyg. 2005;73:1019-25.
- It is highly plausible that the patient was indeed infected
in Louisiana, and even a single case like this demonstrates that there
must be an animal reservoir of _Trypanosoma cruzi_ in the locality. Previous
work (cited above in the references) has demonstrated _T. cruzi_ in Louisiana
armadillos, possums and dogs. It should be noted that transmission to humans
requires bites by infected triatomid bugs, which usually live in cracks
in house walls. It is a typical disease of poverty and poor living conditions.
Further studies of the animal reservoir and vector are needed. - Mod.EP
- Patricia A. Doyle DVM, PhD
- Bus Admin, Tropical Agricultural Economics
- Univ of West Indies
- Please visit my "Emerging Diseases" message
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- Zhan le Devlesa tai sastimasa
- Go with God and in Good Health