Chagas Infection
Spreading In Louisiana

From Patricia Doyle, PhD

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.
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:
- 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. 2003;1:14-5.
2. Woody NC, Woody HB. American trypanosomiasis (Chagas' disease);
1st indigenous case in the United States. JAMA. 1955;159:676-7.
3. Ochs DE, Hnilica VS, Moser DR, Smith JH, Kirchhoff LV. Postmortem
diagnosis of autochthonous acute chagasic myocarditis by polymerase
chain reaction amplification of a species-specific DNA sequence of
Trypanosoma cruzi. Am J Trop Med Hyg. 1996;54:526-9.
4. Herwaldt BL, Grijalva MJ, Newsome AL, McGhee CR, Powell MR, Nemec
DG, et al. Use of polymerase chain reaction to diagnose the fifth
reported US case of autochthonous transmission of Trypanosoma cruzi,
in Tennessee, 1998. J Infect Dis. 2000;181:395-9.
5. Schiffler RJ, Mansur GP, Navin TR, Limpakarnjanarat K. Indigenous
Chagas' disease (American trypanosomiasis) in California. JAMA. 1984;251:2983
6. Lent H, Wygodzinsky P. Revision of the Triatominae (Hemiptera,
Reduviidae) and their significance as vectors of Chagas disease.
Bulletin of the American Museum of Natural History. 1979;163:123-520.
7. John DT, Hoppe KL. Trypanosoma cruzi from wild raccoons in
Oklahoma. Am J Vet Res. 1986;47:1056-9.
8. Yaeger RG. The prevalence of Trypanosoma cruzi infection in
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 and prevalence
of Trypanosoma cruzi in opossums and armadillos from southern
Louisiana. J Parasitol. 1991;77:624-7.
10. Barr SC, Dennis VA, Klei TR. Serologic and blood culture survey
of Trypanosoma cruzi infection in four canine populations of southern
Louisiana. Am J Vet Res. 1991;52:570-3.
11. Seibold HR, Wolf RH. American trypanosomiasis (Chagas' disease)
in Hylobates pileatus. Laboratory and Animal Care. 1970;20:514-7.
12. Zeledon R. Epidemiology, modes of transmission and reservoir
hosts of Chagas' disease. In: In Elliot K, O'Connor M, Wolstenholme
GF, editors. Trypanosomiasis and leishmaniasis with special reference
to Chagas' disease. Amsterdam: Associated Scientific Publishers;
1974. p. 51-85.
13. Yabsley MJ, Norton TM, Powell MR, Davidson WR. Molecular and
serologic evidence of tick-borne ehrlichiae in three species of
lemurs from St. Catherines Island, Georgia, USA. J Zoo Wildl Med.
14. Dorn PL, Engelke D, Rodas A, Rosales R, Melgar S, Brahney B, et
al. Utility of the polymerase chain reaction in detection of
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 J, Dumonteil
E. Effect of Hurricane Isidore on Triatoma dimidiata distribution and
Chagas disease transmission risk in the Yucatan Peninsula of Mexico.
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
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