1 8 5 Revista da Sociedade Br asileir a de Medicina Tr opical 3 8 ( 2 ) :1 8 5 -1 8 7 , mar-abr, 2 0 0 5
RELATO DE CASO/CASE REPORT
1 . Unidade de Pro to zo o lo gia do Instituto de Pato lo gia Tro pic al e Saúde Públic a da Universidade Federal de Go iás, Go iânia, GO. 2 . Labo rató rio de Artro po do lo gia Médic a e Veterinária do Instituto de Pato lo gia Tro pic al e Saúde Públic a da Universidade Federal de Go iás, Go iânia, GO.
Órgão financ iado r: CNPq
Addr e ss to: Dr. Marc o Tulio A. Garc ia-Zapata. Caixa Po stal 1 2 .9 1 1 , Seto r Leste, Vila No va, 7 4 6 4 3 -9 7 0 Go iânia, GO, B rasil. Fax: 5 5 6 2 5 2 1 -1 8 3 9
e-mail: zapata@ iptsp.ufg.br
Rec ebido para public aç ão em 8 /1 0 /2 0 0 3 Ac eito em 1 6 /1 1 /2 0 0 4
Human pseudomyiasis caused by
Eristalis ten ax
( Linnaeus) ( Diptera: Syrphidae) in Goiás
Pseudomiíase humana causada por
Erista lis tena x
( Linnaeus) ( Diptera: Syrphidae) em Goiás
Marco Tulio A. Garcia-Zapata
1, Edson Sidião de Souza Júnior
1,
Fernando Freitas Fernandes
2and Sônia F.O. Santos
1ABSTRACT
Th e o b je c ti ve o f th e p re se n t wo rk wa s to re gi ste r th e f i rst p ro ve n c a se s o f h u m a n p se u d o m yi a si s d u e to Eristalis tenax i n Go i á s Sta te , Bra zi l, u n d e rsc o ri n g th e i r c li n i c a l m a n i f e sta ti o n s a n d d i re c t re la ti o n sh i p wi th h ygi e n e . Th e ta x o n o m i c i d e n ti f i c a ti o n o f th e i n sta rs wa s d o n e a c c o rd i n g to th e d e sc ri p ti o n s a n d k e ys p re se n te d b y Ja m e s ( 1 9 4 7 ) , Ha rtle y ( 1 9 6 1 ) a n d Gu i m a rã e s & Pa p a ve ro ( 1 9 9 9 ) . Two c a se s we re o b se rve d . In b o th c a se s th e re wa s n o e vi d e n c e o f a p p a re n t m e n ta l d i stu rb a n c e . Th e c li n i c a l p i c tu re o f th e se c a se s wa s se lf li m i te d . Th e wa te r su p p ly, se we r syste m , so c i o e c o n o m i c le ve l a n d h a b i ts o f th e su sp e c t sp e c i e s o f th e f li e s a re c ri te ri a th a t sh o u ld b e i n ve sti ga te d .
Ke y-words: Di p te ra . Syrp h i d a e . Eristalis tenax. Pse u d o m yi a si s.
RESUMO
O p re se n te tra b a lh o vi sa re gi stra r o s p ri m e i ro s c a so s e vi d e n c i a d o s d e p se u d o m i í a se s h u m a n o s p o r Eristalis tenax n o e sta d o d e Go i á s, Bra si l, d e sta c a n d o su a s m a n i f e sta ç õ e s c lí n i c a s e su a s re la ç õ e s d i re ta s c o m o s h á b i to s h i gi ê n i c o s. A i d e n ti f i c a ç ã o ta x o n ô m i c a d a s la rva s f o i re a li za d a c o m b a se n a s d e sc ri ç õ e s e c h a ve s a p re se n ta d a s p o r Ja m e s ( 1 9 4 7 ) , Ha rtle y ( 1961) e Gu i m a rã e s & Pa pa ve ro ( 1999) . Ob se rva ra m - se do i s c a so s. Em a m b o s n ã o ha vi a e vi dê n c i a de pe rtu b a ç õ e s m e n ta i s c la ra s. O q u a d ro c lí n i c o d e a m b o s o s c a so s e ra m e sm o li m i ta d o . O a b a ste c i m e n to d e á gu a , o n í ve l só c i o -e c o n ô m i c o -e o h á b i to d a s -e sp é c i -e s d a s m o sc a s sã o c ri té ri o s q u -e d -e v-e m s-e r c o n si d -e ra d o s n a i n v-e sti ga ç ã o .
Pal avr as-chave s: Di p te ra . Syrp h i d a e . Eristalis tenax. Pse u d o m i í a se s.
Gastrointestinal myiasis caused by the co sm o po lita n dro ne fly Erista lis tena x ( Diptera: Syrphidae) is classified as pseudomyiasis, given the biology of the fly and that it occurs in an accidental manner. Its presence, in the surface of the digestive tract is responsible for the pathologic physiology, in general of lesser gravity than that caused by the obligatory or facultative parasites6.
The genus Erista lis ( Linnaeus) was designated commonly as Tu b i f e ra ( Me ige n) , and so m e r e se ar c he r s have also denominated it Erista lo m yia. The simple observation of the f a m i ly r a t - t a i le d m a ggo t ( lo n g r e s pir a to r y s iph o n ) characteristic in larvae instars has incited some researchers to the diagnosis of E. te na x. Though, this is not a pathognomonic
c harac teristic , or exc lusive to this spec ies or its genus. Thus, many inc orrec t rec ords and inac c urate desc riptions result from this extrapolation3.
The larvas of E. te n a x are extremely resistant to adverse c onditions of pressure, heat and salinity5. They live in water
po lluted by fec es, sewage, liquid exc rements and o rganic materials in dec omposition, inc luding c arc asses. Oc c asionally they c an be found in relatively c lean water3, however, the
oc c urrenc e of E. te n a x larvae in stagnated waters indic ates a high degree of pollution1.
1 8 6
Ga r cia - Za pa ta MT e t al
number of eggs or larvae ingested, with the affec ted organ and the fly spec ies4.
The present work aims to register the first proven cases of gastrointestinal human pseudomyiasis in Goiás State, Brazil, underscoring their clinical manifestations and direct relationship with the hygiene habits that were responsible for initiating the dynamic process of the pathologic physiology by ingesting waters or fruits contaminated with larvae of this fly.
In this paper, the taxonomic identification of the instars was ac c omplished in the Laboratory of Medic al and Veterinary Arthropodology ( LAMV) at the Institute of Tropical Pathology and Public Health ( IPTSP) , based on the descriptions and keys presented by James3
, Hartley2 and Guimarães & Papavero1.
CASE REPORTS
Case 1 . Female patient, 11 months of age, natural and resident in the municipality of Goiânia-GO. The mother refers that after having ingested a great amount of mangos and guavas that had fallen under a tree and were in a state of decomposition, in a small farm near to where she lives, the child presented intense pasty diarrhea associated with abdominal pain and presence of four larval instars in the diaper. Later, the child’s diaper with feces containing the larvae was shown to the pediatrician during a medical consultation. This material was forwarded to the LAMV for diagnosis and appropriate handling of this pathology. The specimens were washed in distilled water, then fixed in 70% ethanol and subsequently identified as pre-pupae of E. te na x ( Figure 1).
Case 2 . Male patient, 2 7 years of age, natural and resident in the municipal district of Rio Verde-GO and a traveling salesman.
The frequent route of his trips was to São Paulo-SP, Recife-PE, and cities of the Goiás state interior. In the last four months he presented a non-mucosanguineous pasty diarrhea, associated
to colic, nausea, insomnia and weakness, that intensified, especially the diarrhea, until elimination of the larva. In the period he manifested neither fever nor vomits. The larva was detected by the patient himself after a diarrhea episode, the sample was conserved in 70% alcohol and directed by a diagnosis center of the Unified Health System ( SUS) network laboratories in Goiânia-GO for analysis in this LAMV. The larva was identified as third instar E. tena x ( Figure 2) .
Fi gu r e 1 - Pr e -pu pae of Eristalis tenax r e por te d i n case 1 .
In both c ases there was no evidenc e of apparent mental disturbanc e.
DISCUSSION
In c ase 1 , the patient’s age, without due supervision by an adult explains the non disc rimination of the foodstuffs ingested, given the diffic ulties in selec ting adequate fruit. It is believed that the transformation of mature larvae into pre-pupae oc c urred externally, due to the permanenc e of these in direc t c ontac t with the fec es and diaper material, during the period between defec ation and forwarding for exam under a stereosc opic mic rosc ope at the LAMV.
In c ase 2 , the patient did not prac tive appropriate hygiene habits, nor was c onc erned about the origin of foodstuffs and water c onsumed during his trips, whic h would explain the ac c idental origin of this infestation. The c linic al pic ture of both c ases was self limited, the gastrointestinal signs and symptoms c eased after spontaneous elimination of the larvae. The wate r supply, se we r syste m, so c io e c o no mic le ve l together with the habits of the suspec t spec ies of the flies are fac tors or c riteria that should be c onsidered in the evaluation of this pathology. Furthermore, in other countries, the ingestion of food or water c ontaminated by eggs or larvae has been c onsidered to be the main sourc e of infestation by E. te n a x4.
ACKNOWLEDGEMENTS
Th e a u th o r s th a n k P r o f. Mi gu e l Al í p i o Vi e i r a (i n m e m o ri a m) for referral to LAMV of the first c linic al c ase in Goiás and biologic al samples for respec tive spec ific diagnosis.
Fi gu r e 2 - Thi r d-stage l ar va of Eristalis tenax r e por te d i n case 2 .
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1 8 7 Revista da Sociedade Br asileir a de Medicina Tr opical 3 8 ( 2 ) :1 8 5 -1 8 7 , mar-abr, 2 0 0 5
REFERENCES
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