The ac ute p hase o f Chagas’ dise ase is characterized by high parasitemia levels in which the blood parasites may easily be detected by microscopic observation. However, most acute infections remain undiagnosed and clinical disease may only become apparent many years later during the chronic phase of disease in which some patients may develop c a rd i a c , d i g e s ti ve a n d /o r n e u ro l o g i c a l pathology3. During the chronic phase, blood p a ra s i t e s a re n o t d e t e c t a b l e b y d i re c t parasitological methods, but evidence for infection may be obtained by serological means. More recently, the presence of parasite DNA in pe riphe ral b lo o d in patie nts with c hro nic infection has been demonstrated by PCR2 14.
The mechanisms underlying the development of pathological disorders in chagasic patients are poorly understood. The infecting strain as well as autoimmune factors have been shown to be involved in the pathological process10 11. In Ecuador, the existence of chagasic endemic regions is well documented4 5 with a new foci with evidence of transmission recently reported1. Although in Ecuador cardiomyopathy has been asso c iate d with Chagas’ dise ase8, little is
known in relation to digestive pathology. We herein report two cases with severe digestive pathology suggestive of Chagas’ disease, in which circulating T. cruzi DNA was demonstrated by PCR.
CASE REPORTS
Ca se 1. A 65-year-old man living in the province of Esmeraldas (northwestern area of Ecuador) but born in an area highly endemic for Chagas (province of Loja, southwestern re gio n) , so ught me dic al assistanc e due to chronic constipation. His chief complaint was abdominal pain and no bowel movements for the last two weeks. Physical examination revealed abdominal distension and tenderness. Rectal examination revealed the presence of a fecaloma. Hematological and biochemical blood tests were all within normal limits. Radiological s tu die s o f th e a b do m e n c o n firm e d th e presence of a large amount of fecal material in th e re c to s ig m o ida l re g io n a lo n g w ith pronounced achalasia of esophagus. (Figure 1A). Oesophago-gastroduodenoscopy revealed th e p re se n c e o f e so p h a ge c ta sis, wh ile a c o lo no sc o py sho we d do lic ho me gac o lo n. Histopathological studies on biopsies taken fro m th e e s o p h a g u s a n d c o lo n s h o w e d n e uro n a l le s io n s in th e e s o p h a ge a l a n d intestinal mesenteric plexuses. A diagnosis of dolichomegaesophagus and megacolon was made.
Ca se 2. A 63-year-old woman born and permanent resident of the province of Morona Santiago (southeastern Ecuador), sought medical
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SEVERE DIGESTIVE PATHOLOGY ASSOCIATED WITH
CHRONIC CHAGAS’ DISEASE IN ECUADOR:
REPORT OF TWO CASES
Angel G. Guevara, José W. Eras, Marcelo Recalde, Luis Vinueza,
Philip J. Cooper, Ali Ouaissi and Ronald H. Guderian
DNA extra cted from periphera l blood of two Ecua doria n pa tients showing severe d i ge sti ve pa th o lo gy w a s a m pli f i e d b y th e po lym e ra se c h a i n r e a c ti o n u si n g a
Trypanosoma cruzi specific oligonucleotide primers derived from the prima ry sequence of a cDNA encoding for a 24 kDa excretory/secretory protein. The positive PCR results together with the clinica l findings confirmed tha t both pa tients ha d a digestive pa thology due to Cha ga s’ disea se. This pa thology could be more frequent tha n previously described in the cha ga sic endemic regions of Andea n countries.
Key-words: Cha ga s' disea se. T. cruzi. PCR. Mega esopha gus. Mega colon. Ecua dor.
Department of Clinic al Investigations, Department of Family Practice, Department of Surgery, Hospital Vozandes-Quito, Vozandes-Quito, Ecuador and Parasitology Laboratory, CJF INSERM No 96-04, Faculty of Medicine, Montpellier, France.
Ad d r e ss to :Dr. Ange l Gustavo Gue vara. Lab o rato r y o f Clinical Investigations. Hospital Vozandes-Quito, Villalengua 267 y 10 de Agosto, Casilla 17-17-691, Quito, Ecuador. Fax: ++ 593-2-269.234.
Recebido para publicação em 19/11/96.
Revista da Socieda de Bra sileira de Medicina Tropica l 30(5):389-392, set-out, 1997.
Rela to de Ca so. Gueva ra AG, Era s JW, Reca lde M, Vinueza L, Cooper PJ, Oua issi A, Guderia n RH. Severe digestive pa thology a ssocia ted with chronic Cha ga s’ disea se in Ecua dor: report of two ca ses. Revista da Socieda de Bra sileira de Medicina Tropica l 30:389-392, set-out, 1997.
390
help due to chronic constipation and abdominal pain. Physical examination revealed a painful distended abdomen. Radiological studies showed the presence of a megacolon associated with dolichome gacolon (Figure 1B ). On hospital admission, the patient was dyspneic due to abdominal distension. An emergency laparotomy was done which revealed an extremely dilated colon, in particular the sigmoid, occupying the whole abdominal cavity. A fecaloma was found in the rectum. A sigmoidectomy and colostomy was performed. Histopathological studies on the tissue s sho we d ganglio nar c e lls with d e g e n e ra t i v e c h a n g e s . A d i a g n o s i s o f dolichomegacolon was made.
Dia gnosis of T. cruzi Infection. Serology. Since the histo patho lo gical studie s sho we d nonspecific changes, and since megaviscera can be associated with Chagas’ disease, sera from both patients were tested for anti-T. cruzi antibodies. ELISA tests were performed using as antigens an epimastigote crude extract and a re c o mb in a n t T. c r u z i s p e c ific a n tige n (rTc24)8. A strong positive reaction against both antigens was seen with sera from both patients. DNA preparation and Tc24-based polymerase c hain re ac tio n. Antib o die s against rTc 24 reflect the presence of an active T. cruziinfection o r an unsuc c e ssful tre atme nt9, while tho se directed against crude lysate indicate exposure
Figure 1A - Cha ga sic mega esopha gus showing stenosis
typica l of a cha la sia (ca se 1). Figura 1B - Cha ga sic mega colon with enla rgement of thesigmoid.
to the parasite. To confirm the possible existence of a T. cruziinfection, a PCR assay6was performed as fo llo ws: 5ml o f ve no us b lo o d fro m b o th patients were collected with EDTA. 200µl of each sample were brought up to 400µl with PCR grade wate r and mixe d with the same volume of 2X lysis buffer (20mM EDTA, 20mM
b lo o d sample se ro lo gic ally ne gative fo r T. cruzi from a endemic area was used, while a pGEX-2T plasmid containing the Tc24 cDNA was use d as the po sitive c o ntro l. Fo r PCR assay, 5µl of purified DNA templates were adde d in a final vo lume o f 50-µl re ac tio n containing 100 pmol of Tc24-specific primers: T1 5´ GACGGCAAGAACGCCAAGGAC 3´ and T2 5´ TCACGCGCTCTCCGGCACGTTGTC 3´, a n d 2 . 5 u n its o f Ta q D NA p o lym e ra s e (Promega, Madison, WI, USA). After 35 cycles at 94oC (1 min, denaturation), 60oC (1 min, annealing) and 72oC (2 min, elongation), the amplifie d pro duc ts we re analyze d b y 1% agarose gel electrophoresis and visualized by ethidium bromide staining. Both samples were positive for T. cruzi(Figure 2) as shown by the presence of amplified DNA.
DISCUSSION
This report definitively demonstrated the pre se nce o f dige stive patho lo gy asso ciate d with Chagas’ disease in Ecuador. The positive PCR re sults c o nfirme d that the parasite T. cruzi was still present in both patients. In Latin America, there is evidence suggesting geographic differences in the prevalence of megaviscera in Chagas’ disease7. In chagasic endemic regions
in Brazil, Argentina and Chile, the prevalence of megaviscera is high, while in the Andean S o u th a n d Ce n tra l Am e ri c a n c o u n tri e s megaviscera are absent or very rare. Digestive pathology with probable chagasic etiology has been reported in Mexico while in Venezuela only changes in esophageal motility has been shown in T. cruzi infected patients12. The cases we report here emphazise that digestive pathology associated with T. c ru z i infection may not be as rare as previously thought.
It is of interest that the patients in this study came from different geographical endemic regions in Ecuador; Morona Santiago province located in the eastern side of the Andes and Lo ja pro vinc e lo c ate d o n the we ste rn side . Recently, additional cases from other provinces, Pastaza and El Oro have been documented (R. Guderian, unpublished observations) supporting the no tio n that dige stive patho lo gy due to American trypanosomiasis may be underestimated in Ecuador.
Antiparasitic treatment of chronic cases with severe pathology is still controversial. Surgical inte rve ntio n is re c o mme nde d in c hagasic patients with complicated megaviscera10. In the two case s de scribe d in this re port, both patients showed complications such as fecaloma. Surgery was done in case 2 with a satisfactory result. In case 1, clinical treatment was sufficient to improve esophageal function.
Control strategies for Chagas’ disease currently rely on reduction of transmission by insecticide spraying. Ho we ve r, asympto matic c hro nic cases constitute a potential risk of transfusion-associated transmission of T. cruziand reactivation of the disease in immunodepressed T. c ru z i infected individuals. Thus, in co-infections with HIV, the classical clinical manifestations of the disease may become altered, as neurological disturb anc e s suc h as me ningo e nc e phalitis have been observed13. More detailed surveys to determine seropositivity, quality of blood p ro du c ts a n d th e ir de riva tive s u s e d fo r transfusion, and consequent pathology due to Chagas’ disease are still required in Ecuador to define the epidemiology of this disease.
RESUMO
DNA o b tid o d o sa n gu e pe rifé ric o d e d o is pa cientes equa toria nos, que a presenta va m severa pa tologia digestiva , foi a mplifica do pela “polymera se cha in rea ction” (PCR) utiliza ndo os oligonucleotídoes Rela to de Ca so. Gueva ra AG, Era s JW, Reca lde M, Vinueza L, Cooper PJ, Oua issi A, Guderia n RH. Severe digestive pa thology a ssocia ted with chronic Cha ga s’ disea se in Ecua dor: report of two ca ses. Revista da Socieda de Bra sileira de Medicina Tropica l 30:389-392, set-out, 1997.
391
específicos do Trypanosoma cruzi,deriva dos de uma seqüência primá ria de cDNA codifica do de 24 kDa proteína excretória /secretória . Os resulta dos positivos da PCR junto com os a cha dos clínicos confirma m q u e o s d o is pa c ie n te s tin h a m u m a pa to lo gia d ige stiva d e o rige m c h a gá sic a . Esta pa to lo gia
p o d e r i a se r m a i s f r e q ü e n te q u e a d e sc r i ta previa mente na s regiões endêmica s cha gá sica s da s cida des dos Andes.
Pa la vra s-cha ves: Doença de Cha ga s. T. cruzi. PCR. Mega esôfa go. Mega cólon. Ecua dor.
Rela to de Ca so. Gueva ra AG, Era s JW, Reca lde M, Vinueza L, Cooper PJ, Oua issi A, Guderia n RH. Severe digestive pa thology a ssocia ted with chronic Cha ga s’ disea se in Ecua dor: report of two ca ses. Revista da Socieda de Bra sileira de Medicina Tropica l 30:389-392, set-out, 1997.
392
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