CLINICAL MICROBIOLOGY REVIEWS, Apr. 1992, p. 120-129 Vol. 5, No. 2 0893-8512/92/020120-10$02.00/0 Copyright ©O 1992, American Society for Microbiology Intestinal JOHN H. CROSSt U.S. Naval Medical Research Unit No. 2, Manila, Philippines

INTRODUCTION ...... DESCRIPTION OF THE PARASITE. HISTORY ...... 120 LIFE CYCLE OF THE PARASITE... .121 CLINICAL PICTURE...... 1IA symptoms ... Pathology ...... 124 Diagnosis...... 125 Treatment ...... 126 EPIDEMIOLOGY...... 127 Distribution and Prevalence...... 127 Transmission ...... 128 Control .129 REFERENCES. 129

INTRODUCTION widest part of the stichosome, 28 to 36 p.m at the vulva, and 29 to 47 pum postvulva. The vulva is located behind the Although more than 250 Capillaria species have been esophagus, is salient, and is without a flap. The anus is found in fish, amphibians, reptiles, birds, and mammals, subterminal. Figures 1 and 2 illustrate male and female only 4 species have been found in humans: Capillaria worms, respectively, showing some of the features men- C. hepatica, aerophila (Eucoleus aerophilus), C. plica, and tioned above. The female uterus contains numerous thick- C. Reports of human infections with C. philippinensis. shelled eggs (Fig. 2), thin-shelled eggs with or without C. and are rare, reports hepatica, aerophila, C. plica but of embryos (Fig. 2), or larvae (Fig. 3). Eggs found in feces are C. philippinensis infections are increasing and appear to be peanut shaped with a striated shell and inconspicuous flat- spreading geographically. C. philippinensis has been in- tened bipolar plugs, and they measure 36 to 45 by 20 pum volved in epidemics and has been responsible for the death of people in the Philippine Islands and Thailand. (Fig. 4). HISTORY DESCRIPTION OF THE PARASITE Although a number of Capillaria species are known to are related to Trichuris and Trichinella Capillarids closely inhabit the intestinal tract of lower animals, human intestinal species; all are members of the superfamily Trichinelloidea. capillariasis was unknown until Chitwood et al. presented The group is characterized by having a filamentous thin the initial case report at the First International Congress of anterior end and a slightly thicker, and sometimes shorter, Parasitology in Rome in 1964. The patient was a 29-year-old posterior end. The esophagus consists of a short muscular male schoolteacher from Northern Luzon in the Philippines. portion surrounded by rows of secretory cells called sti- He had an intractable for 3 weeks prior to admission chocytes. The entire esophageal structure is called a sticho- to the Philippine General Hospital, Manila. He suffered from some. The male worms may or may not have a single chronic recurrent and sheathed spicule. In the female, the vulva is located at the alcoholism, ascites, emaciation, junction of the anterior and posterior ends. cachexia and died a week after hospitalization. At autopsy, a large number of worms were recovered from the intestines, Chitwood et al. (6) described C. philippinensis in speci- but the parasite was not identified to species at the time. mens collected at autopsy from the first person known to have the infection and in material obtained from several In late 1966, a Catholic missionary priest in Tagudin Ilocos Sur, Central Luzon, notified authorities of an unusually large subsequent autopsies. Additional specimens were examined number of deaths due to a chronic gastroenteritis that had by other investigators, and the initial findings were con- been occurring since 1965 in a village called Pudoc West. firmed. The parasite is very small: males range in length from This village is approximately 150 km south of the area where 1.5 to 3.9 mm and in width from 3 to 5 ,um at the head, 23 to the first case was seen. Upon investigation the Philippine 28 ,um at the stichosome, and 18 ,um at the cloaca. The male Department of Health established that C. philippinensis was spicule is 230 to 300 ,um long, and the unspined spicular responsible for the illnesses. The parasitosis soon spread to sheath may extend to 440 p.m. The anus is subterminal, and other villages and towns, and by the end of 1967, more than the tail has ventrolateral expansions containing two pairs of 1,000 people had become infected and 77 had died. papillae. Females are much longer than males, 2.3 to 5.3 The people in the village of Pudoc West were superstitious mm, with widths of 5 to 8 p.m at the head, 25 p.m at the and believed that they were all destined to die of the mysterious disease because of a curse placed on them by a t Present address: Department of Preventive Medicine and Bio- mystical river god. Against the advice of the public health metrics, Uniformed Services University of the Health Sciences, authorities now working in the area, they hired two witch 4301 Jones Bridge Road, Bethesda, MD 20814-4799. doctors to exorcise the village. The witch doctors were 120 VOL. 5, 1992 121

SC

S p

FIG. 1. Adult male C. philippinensis indicating spicule (Sp), extended spicular sheath (Ss), and stichocyte (Sc). Magnification, x32.

retained until one of them died of intestinal capillariasis. parasitosis. Clinical management and treatment regimens Other beliefs and superstitions emerged during the epidemic were established, pathophysiologic studies were done, and until a cure and means of transmission were established (15). epidemiologic information was gathered. One of the most A few years after the Pudoc West outbreak, it was complex challenges, however, was to determine the means determined that during 1963 to 1965 a number of people had of transmission of the parasite and its life cycle. First, died of a chronic gastroenteritis in the area of Northern attempts were made to determine possible reservoir hosts Luzon where the first patient lived. In 1965, the disease began to be seen in Pudoc West, and in the ensuing years for adult and larval stages of the parasite. The Ilocano infections were found in villages along the western and populations of Northern Luzon have unique dietary habits, northern coasts of Central and Northern Luzon. unlike those of other Filipino populations. These eating habits were considered when searching for a source of infection. More than 150,000 specimens of animal life were LIFE CYCLE OF THE PARASITE examined, and although adult Capillana worms were found, Since C. philippinensis was a new human parasite, it was none were C. philippinensis. Capillaria larvae were also essential to obtain knowledge about every aspect of the found, but species determination was not possible (15).

SC , 4e.. Vu Eg, I UT it,. (r? Tk Lv

FIG. 2. Adult female C. philippinensis indicating stichocyte (Sc), salient vulva (Vu), uterus (Ut), eggs (Eg) in the uterus, and thin-shelled eggs with larvae (Lv). Magnification, x32. 122 CROSS CLIN. MICROBIOL. REV.

Lv

Vu

FIG. 3. Adult female C. philippinensis indicating salient vulva (Vu) and uterus filled with larvae (Lv). Magnification, x 160.

Massive stool surveys were undertaken to detect asymp- after 3 weeks (Fig. 5). Several species of fish in the Philip- tomatic infections and to determine whether a relationship pines (8, 10) and other species in Thailand (4) were found to existed between C. philippinensis and other intestinal para- be susceptible to infection. In further studies, one species of sites. More than 7,000 stool samples from 23 village popu- fish (Hypseleotris bipartita) was found naturally infected lations were examined, but there was no correlation between with the larval stage of the parasite, which was recovered C. philippinensis infection and other parasitic infections. from the intestine. Most people (94%) had 1 and, more often, 2 to as many as 10 Larvae from fish were subsequently fed to monkeys different parasites by a single stool examination. Only 2% (Macaca spp.), and patent infections developed (8). Mon- were passing C. philippinensis eggs, compared with 83% keys tolerated the infections well and never manifested passing eggs (12). symptoms. A few of these infections remained patent for as While the above studies were under way, investigations long as 14 months. Three to four months after being given 30 were conducted to establish the life cycle in the laboratory. to 50 larvae from fish, some monkeys were killed and 10,000 At that time the life histories of only a few Capillaria species to 30,000 worms were recovered from their intestines. This were known. Some species had a direct egg-to-egg cycle confirmed the suspicion that autoinfection was part of the whereas others had indirect cycles involving an intermediate life cycle because large numbers of worms in all stages of host. Eggs isolated from patients were found to embryonate development were found at autopsy. In addition, female at ambient temperatures in 5 to 10 days. The eggs were given worms are larviparous. orally to all types of animals, even human volunteers, but did Many other laboratory and wild animals were experimen- not hatch (9). The experiments continued, and eventually tally infected with larvae from fish. Some wild rats (Rattus eggs were found to hatch in the intestines of freshwater and spp.) and multimammate rats (Mastomys natalensis) devel- brackish-water fish from the lagoons in the endemic area. oped transient infections, but Mongolian gerbils (Meriones The eggs hatched within a few hours after ingestion, and the unguiculatus) developed patent infections and died of over- larvae increased in size from 130-150 ,um to 250-300 ,um whelming infections after 6 to 7 weeks. A series of experi-

FIG. 4. Two eggs of C. philippinensis, two-cell stage. Note the flattened bipolar plugs and striations in the eggshell; they measure 36 to 45 by 20 p.m. Magnification, x 160. VOL. S, 1992 INTESTINAL CAPILLARIASIS 123

4

Autointecton FIG. 5. Larva of C philippinensis from the intestines of a fish. Note the formation of stichocytes in the anterior end. Magnification, xlOO. ments were subsequently carried out with the gerbil, and the unique life cycle of C. philippinensis was determined. When larvae from fish were administered by stomach tube to gerbils, the larvae developed into adult males and females 3 weeks 4 in 10 to 11 days and female worms started to release first-stage larvae in 13 to 14 days. These larvae developed into adult males and females in 22 to 24 days, and the second-generation females began to release thick-shelled unembryonated eggs, which passed in the feces in 25 to 35 days postinfection. Most female worms at this time were oviparous, but a few female worms always produced larvae, FIG. 6. Proposed life cycle of C. philippinensis based on exper- an event that led to autoinfections and hyperinfections. In imental infection in Mongolian gerbils. Reprinted from reference 14 other studies only two larvae from fish were fed to gerbils, with permission of the publisher. and on two occasions 2,520 and 5,353 worms in all stages were recovered from gerbils that died after 46 and 47 days. Other studies were done by administering three larvae from Symptoms fish, and 852 to 5,253 worms were recovered (10). It was also established that female worms could switch from oviparous The first patients seen in the endemic area with intestinal to larviparous reproduction when transferred from a capillariasis had been suffering from abdominal pain, a necropsied infected gerbil to a clean gerbil. The larvae gurgling stomach (borborygmus), and intermittent diarrhea developed into adults and produced eggs that passed in the for several weeks. They eventually had 8 to 10 voluminous feces. stools daily and lost a considerable amount of body weight. In studies in Thailand (3) and Taiwan (11), fish-eating birds Some suffered from malaise, anorexia, and vomiting. Studies were infected with larvae from fish or were fed infected fish. by Whalen et al. (25) reported physical findings of muscle It is now believed that fish-eating birds are natural hosts and wasting and weakness, borborygmus, distant heart sounds, that the cycle is a fish-bird life cycle. However, humans can hypotension, gallop rhythm, pulsus alterans, abdominal dis- become infected when they eat the tiny fish that are usually tention and tenderness, , and hyporeflexia. There was consumed by birds. One bird has been found naturally no hepatosplenomegaly or jaundice. Laboratory findings infected with the parasite in the Philippines. The proposed showed severe protein-losing enteropathy, malabsorption of life cycle is presented in Fig. 6. fats and sugars, decreased excretion of xylose, and low levels of potassium, sodium, calcium, carotene, and total protein in serum. There were usually high levels of immu- CLINICAL PICTURE noglobulin E (IgE) and diminished levels IgG, IgM, and IgA; several months after treatment, however, all immunoglobu- Few intestinal infections actually cause disease lin levels returned to normal (21). Patients ill for more than that leads to death in their host. Most parasites live unmo- several months without treatment usually died either of the lested in the gut and at the same time do little to disturb their irreversible effects of the electrolyte loss resulting in heart environment and the gracious host. C. philippinensis, how- failure or of septicemia due to a secondary bacterial infec- ever, is different; it always causes illness as far as we know, tion. and, if the infection remains untreated, it leads to death. On Patients seen in the endemic areas at present usually have numerous occasions we detected individuals passing eggs in mild symptoms of borborygmus, abdominal pain, diarrhea, their stools during surveys. Most were asymptomatic and and edema. After treatment, the symptoms disappear in a would not report to the hospital for recommended treatment few days to a week and eggs and other stages of the parasite when told of their infections. Invariably, they developed are no longer present in the stools. It is important that symptoms as the worm population built up, and they then symptoms are recognized early and treatment initiated. One reported for treatment (17). of the last patients to die of the infection had been misdiag- 124 CROSS CLIN. MICROBIOL. REV.

FIG. 7. Human intestinal tissue at autopsy showing multiple histologic sections of C. philippinensis. Female worms with eggs in the uterus are visible. Magnification, x63. nosed at several hospitals as simply having gastroenteritis. Most pathologic changes were found in the small intestine, By the time the correct diagnosis was made, it was too late especially the jejunum. Numerous C. philippinensis worms to alter the course of his infection. in all stages were found in the lumen (Fig. 7 through 9) and in the intestinal mucosa (Fig. 10 and 11). In 1 liter of bowel Pathology fluid from one autopsy an estimated 200,000 worms were Fewer than 15 autopsies have been done on Filipinos who recovered. Although most worms are found in the jejunum, died of intestinal capillariasis (5, 18). Their bodies were some are found throughout the digestive tract, probably as a emaciated, dehydrated, and pale. Serous fluid was found in result of postmortem migration. The parasite was found once the peritoneal and pleural cavities. The heart weights were in extraintestinal tissue, in a section of liver (18). within normal limits with minimal pericardial fat. The lungs Histologic findings were fatty metamorphosis of the liver were congested. Bacteria (Micrococcus pyogenes [since and vacuolization of the cytoplasm of renal proximal convo- renamed Streptococcus pyogenes] and Klebsiella pneumo- luted tubular lining cells. Hemoglobin pigments were also niae) were cultured from the lungs of two patients. The found in the tubules of some patients. Vacuolization of splenic white pulp was conspicuous because of prominent myocardial cells and concentrations of lipochrome pigment malpighian corpuscles, and the livers were yellowish. The in the myocardium were also seen. In the intestines, the kidneys were reduced in weight, and there was cerebral crypts of Lieberkuhn were atrophied and often contained vascular congestion. parasites (Fig. 10 and 11) and cellular debris. The intestine

FIG. 8. First-stage larva of C. philippinensis recovered from the human intestine at autopsy. Magnification, x 160. VOL. 5, 1992 INTESTINAL CAPILLARIASIS 125

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W.h FIG. 9. Third-stage larva of C. philippinensis recovered from the human intestine at autopsy. Magnification, x63. also showed flattened denuded villi and dilated mucosal tinal mucosa may account in part for the malabsorption with glands, and the lamina propria was infiltrated with plasma loss of fluids, protein, and electrolytes (23). cells, lymphocytes, macrophages, and neutrophils. Electron micrographs of biopsied jejunal tissue showed Diagnosis loss of adhesion specialization and widespread separation of epithelial cells. In gerbil tissue taken at necropsy and studied Patients presenting with borborygmus, abdominal pain, by electron microscopy, the following changes were seen: (i) diarrhea, and weight loss are usually passing eggs (Fig. 4), microulcers in the epithelium (Fig. 12), (ii) compressive larvae (Fig. 8 and 9), and/or adult worms (Fig. 1 through 3) degeneration and mechanical compression of cells, and (iii) in their feces. Larvae found in the feces are in all stages of homogeneous material at the anterior end of the worm (Fig. development and are difficult to identify as C. philippinensis 13). These ulcerative and degenerative lesions in the intes- (Fig. 8 and 9), but adult males and females have character-

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FIG. 10. Female C. philippinensis (Cp) in crypts (Cr) of human intestinal tissue at autopsy. Note the larva (Lv) in the uterus. Magnification, x63. x 126 CROSS CLIN. MICROBIOL. REV.

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istic features (Fig. 1 through 3). An inexperienced observer unreliable (2, 16) and not necessary since eggs and worms may confuse the eggs with those of T. trichiura, which are are usually found in stool specimens. larger (50 to 54 by 22 to 23 ,um) and barrel shaped, with prominent mucoid bipolar plugs. Figure 14 shows C. philip- Treatment pinensis and T. tnichiura eggs for comparison. Multiple stools may have to be examined in some patients. The In the early days of the Philippine epidemic, all available parasite may also be found in material obtained by small- anthelminthic agents were given to infected persons; how- intestinal aspiration or biopsy. If intestinal capillariasis is ever, thiabendazole in dosages of 25 mg/kg/day or 1 g/day for suspected but not parasitologically confirmed, the patient 30 days eventually became the drug of choice. Most patients should be given an anthelminthic agent. The parasite usually responded well, but there were side effects and many re- passes in the feces for a few days following treatment. lapses. In the second and third years of the epidemic, there Serologic tests have been evaluated but are considered were more relapse cases than new infections (22). One

FIG. 12. Electron-microscopic view of a cross-section of C. philippinensis obtained from gerbil jejunum. Note the cuticular pore (CP) of the worm and dissolution of the plasma membrane and cytoplasmic organelles of the epithelial cell (arrow) opposite the cuticular pore. Magnification, x 12,500. Reprinted from reference 23 with permission of the publisher. VOL. S, 1992 INTESTINAL CAPILLARIASIS 127

FIG. 13. Electron-microscopic view of the penetrating site of the parasite (P) in gerbil jejunal epithelium. Note the electron-dense homogeneous material (arrow) at the anterior end of the parasite in connection with two large vesicles (V) at both sides of the worm. The basal lamina (BL) below the oral tip of the nematode appears deteriorated. Epithelial cells (EC) at the right side are compressed with increased compactness of the cytoplasmic organelles. A lym- phocyte (L) is seen between the cells. Magnification, x 7,500. Reprinted from reference 23 with permission of the publisher.

patient had 15 relapses in a 12-year period (1). Patients with severe disease are given electrolyte replacement therapy, an antidiarrheal agent, and a high-protein diet. at 400 mg/day in two divided doses for 20 days soon replaced thiabendazole. In patients with relapses the drug was given for 30 days and there were few subse- quent relapses. is presently the drug of choice in a dose similar to that for mebendazole, but is administered only for 10 days. Treatment for less than 10 days has resulted in relapses in some patients. It is believed that relapses result from the inability of thiabendazole and mebendazole to affect the larval stages. The adults are affected, and as the larvae mature, they are susceptible to the drugs. Albenda- zole, on the other hand, appears to act on the larvae as well as the adults. After therapy with most drugs the parasites are not found in the feces after 4 days. If treatment stops at this time, the parasite and eggs will reappear after 20 to 30 days.

EPIDEMIOLOGY Distribution and Prevalence From 1967 to the end of 1990, 1,884 confirmed cases of intestinal capillariasis were documented and 110 people died (Fig. 15). Through the years, twice as many males, mostly middle-aged, as females have become infected (Fig. 16). A few infections were reported elsewhere, and in the early 1980s a new endemic area was identified in Southern Leyte

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FIG. 14. Eggs of C. philippinensis (Cp) compared with an egg of T. trichiura (Tt). Magnification, x 160. 128 CROSS CLIN. MICROBIOL. REV.

1100 1037 Northern Luzon, Philippines U 1000 February 1967 - December 1990 Cl) 500 4 400 291 Cases C) 300- F11 200 | Deaths Z 100 IL 90- 80 74 0 65 70 - 5566 I 60- co 50- 41 40- 3 D 30- Z 20 10 121968 10- 96 26 0 LI L[HUH WII 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 YEAR FIG. 15. Intestinal capillariasis cases (total, 1,884) and deaths (total, 110) recorded in Northern Luzon in the Philippines from 1967 through 1990. in the Central Philippines. In a preliminary stool survey, 14% Iran and Taiwan have each had one case (7), and Egyptian of 362 specimens contained C. philippinensis eggs, larvae, workers have documented two cases (19). and adults (13). As far as we know, intestinal capillariasis was first re- Transmission ported from Bacarra, Ilocos Norte, in the Philippines. The first epidemic occurred in Pudoc West in Ilocos Sur, and The eating habits of people are responsible for the trans- infections were subsequently seen in persons from provinces mission of human C. philippinensis. Populations in the up and down the Philippine coast along the South China Sea. Philippines where intestinal capillariasis occurs have unique A focus of infection was found near a U.S. Naval Base in eating habits in that they prefer to eat a variety of foods Zambalas (24), and the subsequent epidemic occurred in uncooked. The Ilocanos of Northern Luzon relish raw Southern Leyte. Only sporadic cases are seen today in animal organs, and intestinal juices from animals are used to Northern Luzon. season rice and other foodstuffs. They also eat raw crabs, Capillariasis philippinensis was first recognized in Thai- snails, clams, shrimp, squid, goat, and water buffalo meat land in 1973 (20), and additional cases were reported there- and a variety of small freshwater and brackish-water fish after. The disease seems to be widespread in Thailand, with abundant in lagoons along the coast. The fish are too small to cases being seen at many medical centers in the north and eviscerate and so are eaten whole. The people especially like northwest and around Bangkok. No effort is being made to to eat female bagsit (Hypseleotris bipartita) (Fig. 17) when document the infections, however. An epidemic is known to filled with roe. Thai populations also enjoy eating small have occurred in 1981; more than 100 persons acquired the freshwater fish and crabs uncooked. In other countries disease and 9 died of the parasitosis (15). reporting the infections, consumption of raw fish has been C. philippinensis infections are now being seen in Japan, associated with most infections. with three cases reported, followed recently by a fourth (la). Since a number of species of freshwater fish have been experimentally infected with C. philippinensis and some fish in the Philippines were found naturally infected with larval forms of the parasite (15), it is believed that the means of 350- 18% Northem Luzon, Philippines February 1967 - December 1990 X 300- LU 14% U 1334 Males (70%) 250-| E 550 Females (30%) C°) = LLL11% . MpII-, LL 200 10% 0

4 100 4% FIG. 17. Bagsit (H. bipartita), a fish often eaten uncooked, especially when gravid, by Ilocano populations of Northern Luzon AGE GROUP 1-9 10-19 20.29 30.39 40.49 50-59 60.69 70-79 80-89 in the Philippines. The fish is usually only 2 to 3 in. (5.1 to 7.6 cm) COMBINED 7%o 14% 23% 19% 17% 12%h 6% 1% 1% in length. This species was found naturally infected. When these fish FIG. 16. Intestinal capillariasis cases (1,884) reported in North- were fed to Mongolian gerbils, patent infections developed and the ern Luzon in the Philippines by age and sex from 1967 through 1990. gerbils died. VOL. 5, 1992 INTESTINAL CAPILLARIASIS 129

transmission of capillariasis philippinensis is by eating un- intestinal capillariasis. II. Pathological features. Acta Med. cooked fish. The parasite has not been found in any area Philipp. 4:84-91. where the populations do not eat raw fish. 6. Chitwood, M. B., C. Valasquez, and N. G. Salazar. 1968. now Capillaria philippinensis sp. n. (Nematoda: Trichinellida) from Several species of fish-eating birds have been exper- intestine of man in the Philippines. J. Parasitol. 54:368-371. imentally infected with the parasite (3, 11), and one bird 7. Cross, J. H. 1990. Intestinal capillariasis. Parasitol. Today (Ixobrychus spp.) has been found naturally infected in the 6:26-28. Philippines. Birds, especially migratory fish-eating birds, are 8. Cross, J. H., T. C. Banzon, M. D. Clarke, V. Basaca-Sevilla, considered potential natural hosts, and their migratory hab- R. H. Watten, and J. J. Dizon. 1972. Studies on the experimental its are considered responsible for dissemination of the par- transmission of Capillaria philippinensis in monkeys. Trans. R. asite to widely separated parts of the world (7). Bird drop- Soc. Trop. Med. Hyg. 66:819-827. pings along the flyways could easily disperse the eggs into 9. Cross, J. H., T. C. Banzon, K. D. Murrell, R. H. Watten, and water bodies, where fish become infected. Birds, as well as J. H. Dizon. 1970. A new epidemic diarrheal disease caused by the such fish would become in- nematode, Capillariaphilippinensis. Ind. Trop. Health 7:124-131. humans, eating subsequently 10. Cross, J. H., T. C. Banzon, and C. M. Singson. 1978. Further fected. studies on Capillaniaphilippinensis: development of the parasite in the Mongolian gerbil. J. Parasitol. 64:208-213. Control 11. Cross, J. H., and V. Basaca-Sevilla. 1983. Experimental trans- mission of Capillania philippinensis to birds. Trans. R. Soc. Sanitation in rural areas of the Philippines and Thailand is Trop. Med. Hyg. 77:511-514. considered poor. There is indiscriminate defecation, and 12. Cross, J. H., and V. Basaca-Sevilla. 1984. Biomedical surveys in although indoor toilet facilities may be available, they may the Philippines. NAMRU-2 SP47:1-117. not be fully used. During the epidemic in Pudoc West in the 13. Cross, J. H., and V. Basaca-Sevilla. 1986. Intestinal capillaria- Philippines, bed sheets soiled with feces from patients were sis-current concepts, laboratory diagnosis and treatment. washed in the thus into the Asian J. Clin. Sci. 7:63-67. usually lagoons, depositing eggs 14. Cross, J. H., and V. Basaca-Sevilla. 1989. Intestinal capillariasis. water and exposing the fish to infection. This practice may Prog. Clin. Parasitol. 1:105-119. be the reason for more than 200 cases of intestinal capillar- 15. Cross, J. H., and M. Bhaibulaya. 1983. Intestinal capillariasis in iasis occurring in the village. Drinking water comes from the Philippines and Thailand, pp. 103-136. In N. Croll and J. H. wells and other natural sources and is rarely boiled or Cross (ed.), Human ecology and infectious diseases. Academic chemically treated. The people like to eat animals raw, and Press, Inc., New York. when asked why they do it, they explain that their ancestors 16. Cross, J. H., and J. C. H. Chi. 1978. The ELISA test in the did it, that it is a habit, and that in their opinion raw food is detection of antibodies to some parasitic diseases in Asia, p. more nutritious. 178-182. In Current concepts in the diagnosis and treatment of Control of this parasitosis is simple; it consists of not parasitic and other tropical diseases in Southeast Asia. Proc. raw to 18th SEAMEO TROPMED Semin., Kuala Lumpur, 2 to 5 eating fish. This habit is difficult end when it has been August 1977. practiced for generations. Educational programs warning of 17. Detels, R., L. Gutman, J. Jaramillo, E. Zerrudo, T. Banzon, J. the dangers associated with eating raw fish have been of little Valera, K. D. Murrell, J. H. Cross, and J. J. Dizon. 1969. An help. Cooking the fish for a short time would be sufficient to epidemic of human intestinal capillariasis: a study in a barrio in kill larvae in the intestines, but most people prefer the fish North Luzon. Am. J. Trop. Med. Hyg. 18:676-682. raw. Early diagnosis and treatment are recommended to 18. Fresh, J. W., J. H. Cross, V. Reyes, G. E. Whalen, C. V. prevent serious disease and death. Early treatment with Uylangco, and J. J. Dizon. 1972. Necropsy findings in intestinal mebendazole or albendazole has been very effective, and capillariasis. Am. J. Trop. Med. Hyg. 21:169-173. deaths are now rare. 19. Mansour, N. S., M. H. Anis, and E. M. Mikhail. 1990. Human Infections continue to be reported sporadically in the intestinal capillariasis in Egypt. Trans. R. Soc. Med. Hyg. and in the will 84:114. Philippines Thailand, and the future disease 20. Pradatsundarasar, A., K. Pecharanond, C. Chintanawongs, and P. very probably continue to be reported from Japan and Egypt Ungthavorn. 1973. The first case of intestinal capillariasis in and possibly other areas of the world. Thailand. Southeast Asian J. Trop. Med. Public Health 4:131-134. 21. Rosenberg, E. B., G. E. Whalen, H. Bennich, and S. G. 0. REFERENCES Johansson. 1970. Increased circulating IgE in a new parasitic 1. Alcantara, A. K., C. V. Uylangco, and J. H. Cross. 1985. An disease-human intestinal capillariasis. N. Engl. J. Med. 283: obstinate case of intestinal capillariasis. Southeast Asian J. 1148-1149. Trop. Med. Public Health 16:410-413. 22. Singson, C. N. 1974. Recurrences in human intestinal capillari- la.Ando, K. 1991. Personal communication. asis. Philipp. J. Microbiol. Infect. Dis. 3:7-13. 2. Banzon, T. C., R. M. Lewert, and M. G. Yogore. 1975. Serology 23. Sun, S. C., J. H. Cross, H. S. Berg, S. L. Kau, C. 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