Isospora infection in a homosexual man

A case of Isospora belli in a homosexual male is described. The procedures used for recovery and staining the cyst stages of Isospora are included.

Infectious diarrhea. Pathogenesis and risk factors

Our understanding of the pathogenesis of infectious, especially bacterial, diarrhea has increased dramatically. New etiologic agents, mechanisms, and diseases have become known. For example, Escherichia coli serogroup O157 is now known to cause acute hemorrhagic colitis. Also, E. coli serogroups that produce Shiga toxin are recognized as etiologic agents in the hemolytic-uremic syndrome. The production of bacterial diarrhea has two major facets, bacterial-mucosal interaction and the induction of intestinal fluid loss by enterotoxins. Bacterial-mucosal interaction can be described in stages: (1) adherence to epithelial cell microvilli, which is often promoted by or associated with pili; (2) close adherence (enteroadherence), usually by classic enteropathogenic E. coli, to mucosal epithelial cells lacking microvilli; and (3) mucosal invasion, as with Shigella and Salmonella infections. Further large strides in understanding infectious diarrhea are likely with the cloning of virulence genes if additional host-specific animal pathogens become available for study.

Cryptosporidiosis in Philippine children

Cryptosporidiosis, a newly recognized parasitosis of humans is being identified with increased frequency in immunocompromised and more recently in immunocompetent persons with gastroenteritis and or diarrhea. It has been found in the Philippines for the first time in children seen at the San Lazaro Hospital in Manila. A total of 735 stool specimens from adults and children with diarrhea were examined by the Ziehl-Neelson and Kinyoun acid-fast methods and 2.9% of the children 6 to 20 months of age were found passing Cryptosporidium oocysts. This parasitic infection should be considered in the differential diagnosis of cases of diarrhea in both immunodeficient and immunocompetent persons.

Travelers' diarrhea. NIH Consensus Development Conference

Diarrhea is the major health problem in travelers to developing countries. Travel to high-risk areas in Latin America, Africa, the Middle East, and Asia is associated with diarrhea rates of 20% to 50%. The syndrome is caused by an infection acquired by ingesting fecally contaminated food or beverages. Escherichia coli, a common species of enteric bacteria, is the leading pathogen, although a host of other bacteria, viruses, and protozoa have been implicated in some cases. Prudent dietary and hygienic practices should be followed, and they will prevent some, but not all, diarrhea. Antimicrobial agents are not recommended for prevention of TD. Such widespread usage in millions of travelers would cause many side effects, including some severe ones, while preventing a disease that has had no reported mortality. Instead of universal antimicrobial prophylaxis, a more sensible approach is rapid institution of effective treatment that can shorten the disease to 30 hours or less in most people. For mild diarrhea, an antimotility drug such as diphenoxylate or loperamide could be taken. Alternatively, bismuth subsalicylate, which works somewhat slower, can be used. For more severe diarrhea, an antimicrobial drug may be used for treatment, and trimethoprim-sulfamethoxazole, trimethoprim alone, and doxycycline are among the choices. These drugs could be carried by the traveler for use in the event of illness. Oral rehydration should be instituted when necessary. The millions of Americans who travel annually to developing countries and their physicians must be warned of the potential risks of prophylactic antimicrobial drugs, with the attendant side effects in otherwise healthy individuals, and should be informed of the alternative method of prompt, effective treatment of diarrhea.

Cryptosporidiosis in hospital personnel. Evidence for person-to-person transmission

An intern responsible for the care of a patient with chronic cryptosporidiosis developed acute diarrhea and serologic evidence of cryptosporidium infection. Sera from 26 hospital personnel exposed to the patient and 18 personnel with no exposure were examined with an indirect immunofluorescent antibody procedure for the presence of antibodies to Cryptosporidium. Eight (31%) exposed personnel--5 nurses, 2 house officers, and 1 student--had positive antibody titers (1:10 or more). The frequency of positivity in the nurse-housestaff-student group (8 of 18, 45%) was significantly greater (p less than 0.05) than that in the attending physicians and respiratory therapists (0 of 8). The former group had significantly more exposure to the patient's feces than did the latter group (p less than 0.01). Three of eighteen control personnel (17%) had positive cryptosporidium antibody titers. These findings suggest that Cryptosporidium may be transmitted from person to person in the hospital environment and that serologic evidence of infection is common among hospital personnel.

Gastrointestinal diseases of foals

Few foals escape gastrointestinal disease during the first weeks of life. Diarrhea is an extremely common problem; fortunately, however, it is usually mild and self-limiting. When it is not, the underlying cause is often an infectious agent, such as rotavirus or Salmonella spp. Our understanding of many of the infectious agents causing neonatal diarrhea is far from complete. Gastric and duodenal ulcers are a less common disease of neonatal foals. There has been an apparent increase in the incidence of ulcer disease in foals during the past few years. The most effective way of decreasing serious gastrointestinal disease in foals is through the use of good management practices. Environmental and dietary stress must be minimized, and good hygienic practices should be followed. Unfortunately, the needs of the neonate are often ignored, while attention is focused on the mare during the breeding season.

Intestinal parasites and bacteria in Aboriginal children in South West Australia

In a study of intestinal parasites in 697 Aboriginal children under the age of 6 years in South-west Australia, Giardia lamblia was recorded in 26% and Hymenolepis nana in 13.9%. G. lamblia infections occurred above 4 months of age, and H. nana infections above 18 months of age. There was a close correlation between infection with these two species (chi 2, P less than 0.001). Campylobacter jejuni, the predominant bacterial species recorded, was isolated in 2.3%, and was related to bowel symptoms in one child. G. lamblia was more prevalent in the country areas than in the Perth metropolitan area (chi 2, P less than 0.05. H. nana was more prevalent in children whose weight was below the third percentile (chi 2, P less than 0.02), and in those with diarrhoea (chi 2, P less than 0.01). There were strong correlations between low weight (below third percentile), a history of recent diarrhoea, and discharging ears.

Cryptosporidiosis in immunocompetent children

Cryptosporidial oocysts were identified by modified Ziehl-Neelsen stain in the stools of seven (3.2%) of 213 children with acute or chronic diarrhoea and one (0.9%) of 112 controls. All children with cryptosporidia were immunocompetent. Four of the index cases had a short illness (3-14 days) with watery diarrhoea, vomiting (2), and abdominal pain (2). Two index cases had chronic diarrhoea for over four months and failure to thrive. Both had a small intestinal enteropathy; one had cryptosporidial oocysts in stool specimens two months apart and the other had cryptosporidial schizonts attached to the jejunal mucosa. One index case had a colitis of indeterminate cause. Four of the index cases had recently travelled abroad. There had been an outbreak of gastroenteritis in the family of one of the index cases, and three affected sisters and an asymptomatic brother had oocysts in their stools. Cryptosporidial infestation seems to be associated with acute gastroenteritis and sometimes with chronic diarrhoea and small bowel damage in immunocompetent children.

Isospora belli in a patient with acquired immunodeficiency syndrome

Isospora belli is a cause of protracted diarrhea in immunocompromised patients. Acquired immunodeficiency syndrome (AIDS), seen mostly in homosexual men and narcotic addicts, predisposes affected persons to a number of opportunistic infections. As Isospora belli has been reported only once in this group, we report Isospora belli in an AIDS patient with chronic diarrhea.

Enteric coccidiosis among patients with the acquired immunodeficiency syndrome

Ten patients were identified at Jackson Memorial hospital/University of Miami Hospitals and Clinics with enteric coccidial infection due to Cryptosporidium spp. or Isospora belli. All had the acquired immunodeficiency syndrome as manifested by Kaposi's sarcoma or multiple opportunistic infections, or both. They presented with profuse diarrhea associated with weakness, anorexia, and weight loss. Routine examinations of stools for eggs and parasites as performed by the hospital laboratory were negative in all patients. Sugar flotation and modified acid fast techniques were used in the Tropical Disease Laboratory to identify oocysts of Cryptosporidium spp. in stools of seven patients. Malabsorption, characterized by a low 5-hour D-xylose and positive fecal fat, was observed in 6/6 of these patients. In three other patients Isospora belli oocysts were identified in stool specimens or via a duodenal string test. Spiramycin was the only drug found to be effective in treating patients with cryptosporidiosis. Patients with Isospora belli responded to a prolonged course of trimethoprim-sulfamethoxazole.

Intestinal parasites in pediatric patients with diarrhoeal diseases in Bangkok

Stool examinations of 147 pediatric patients with diarrhoeal disease were carried out at Siriraj Hospital, Bangkok by using the direct-smear technique. Stool of 27 patients (18.4%) were positive for intestinal parasites. Children under one year of age were free of intestinal helminths and protozoa. Parasites were equally prevalent in males and females and without any age group predilection. The prevalence of intestinal parasites were Entamoeba histolytica 6.8%, Giardia lamblia 6.1%, others were Ascaris lumbricoides, hookworm, Trichuris trichiura and Balantidium coli. Although the incidence of parasitism was not high as to be the main causatic agent of pediatric diarrhoea, the intestinal parasites may increase susceptibility to infection with other intestinal pathogens. The diagnosis of intestinal parasitoses can be determined by a simple direct faecal-smear technique and so that specific therapy can be instituted without delay in management of parasite-related diarrhoeas.

Coccidiosis associated with post-weaning diarrhoea in beef calves in a dry tropical region

The roles of helminths and coccidia in post-weaning diarrhoea in beef calves in the dry tropics were investigated. Diarrhoea occurred approximately one month after weaning in both anthelmintic treated and untreated calves. The highest numbers of coccidial oocysts were seen 29 days after weaning and 3 necropsies confirmed Eimeria zuernii coccidiosis. In the absence of wet overcrowded conditions, disease may have been precipitated by environmental interactions leading to suppression of host immunity. Other Eimeria identified were E. bukidnonensis, E. wyomingensis, E. bovis, E. auburnensis, E. cylindrica, E. ellipsoidalis and E. subspherica. The last 5 species are believed not to have been previously documented in Australia. The presence of E. canadensis was strongly suspected.

Bovine coccidiosis: protective effects of low-level infection and coccidiostat treatments in calves

Twenty coccidia-free Holstein bull calves were allotted to groups to study effects of treatment with lasalocid and decoquinate on subsequent resistance to coccidiosis (Eimeria spp infections). Calves fed medicated rations of either drug at dosages of 50 mg/kg of feed (approx 1.2 mg/kg of body weight) had significantly fewer oocysts (P less than 0.01) than did nontreated controls regardless of other procedures used. Treated calves premunized with 2,000 oocysts/day for 5 days and later challenge inoculated with 200,000 oocysts did not develop diarrhea, unless the drugs were withdrawn from feed. Animals premunized (2,000 oocysts/day for 5 days) in absence of drug were no more resistant to the challenge inoculation than nonpremunized animals. These results indicated that lasalocid and decoquinate were efficacious coccidiostats and protected calves as long as they were administered. Cessation of drug treatment usually resulted in appearance of oocysts in feces and diarrhea. Premunization alone cannot be expected to prevent coccidiosis when animals are exposed to large numbers of oocysts.

Parasitic, bacterial, and viral enteric pathogens associated with diarrhea in the Central African Republic

A total of 1,197 diarrheic children less than 15 years old were investigated for parasitic, bacterial, and viral enteropathogens from March 1981 through February 1982 in the Central African Republic. One or more pathogens were identified from 49.4% of the patients. Rotavirus was the most frequently identified pathogen among children less than 18 months old. Enteropathogenic Escherichia coli was the second most frequently isolated pathogen (12.1%) in children less than 2 years of age. Campylobacter jejuni was also isolated frequently from diarrheic children less than 5 years of age (10.9%). Entamoeba histolytica was identified in very young children and was found to be the most frequent enteropathogen associated with diarrhea in children over the age of 2 years. Enterotoxigenic Escherichia coli was rarely isolated (ca. 2%). There was a peak in the incidence of rotavirus during the dry season and in the incidence of Campylobacter jejuni during the rainy season.

Occurrence of Giardia lamblia in children in day care centers

We prospectively evaluated excretion of Giardia lamblia in children in day care centers in Houston by conducting two prevalence studies of 600 children enrolled in 30 DCC, day care centers, and an 18-month longitudinal study in 82 children in one center. In the two prevalence surveys, Giardia cysts were identified in 72 (21%) and 67 (26%) children, respectively, who provided stool specimens. Trophozoites were found in 15 (4%) and 8 (3%), respectively. There was no correlation between the frequency of recent diarrheal episodes and the finding of Giardia. Stool specimens containing cysts were significantly (P less than 0.0001) more frequent in the 13- to 30-month-old children than in children younger than 12 months. Children attending day care centers for more than 3 months were more likely to be excreting Giardia than those attending for less than 3 months. In the longitudinal study, cysts were detected in stool specimens from 27 (33%) of the 82 children at least once during the survey. Twelve children had Giardia cysts in weekly stool specimens for a mean of 6.2 +/- 1.2 months and trophozoites for 3.3 +/- 1.2 months. The number of enteric symptoms observed in children and the classification of nutritional status based on monthly height and weekly weight measurements did not differ significantly when infected and noninfected children were compared. Asymptomatic Giardia excretion in children younger than 36 months is common and appears to be well tolerated.

Cryptosporidiosis in homosexual men

Between April 1982 and June 1983, cryptosporidiosis was diagnosed in six homosexual men. Four patients with the acquired immunodeficiency syndrome had lymphopenia, cutaneous anergy, and profoundly impaired cellular immunity; their cryptosporidiosis was severe, unremitting, and refractory to all therapy. Two patients without other opportunistic infections or Kaposi's sarcoma had moderately impaired cellular immunity but not lymphopenia or anergy; their enteric illness was self-limited. Cryptosporidium recently had been recognized as a human pathogen that is transmitted through fecal-oral contamination. The severity of human cryptosporidiosis appears to be determined primarily by immunocompetence of the patient. These six homosexual men, with different degrees of immunologic impairment, had two clinically divergent forms of cryptosporidiosis. Their cases raise questions about human transmission of Cryptosporidium and the prognostic significance of this disease in patients who are at high risk for developing the acquired immunodeficiency syndrome.

Fatal cryptosporidiosis complicating Kaposi's sarcoma in an immunocompromised man

Fatal cryptosporidiosis in a bisexual immunosuppressed man with disseminated Kaposi's sarcoma and intractable diarrhea is described. Cryptosporidium sp. was isolated from the stool antemortem by Sheather's floation technique. This parasite should be considered in immunosuppressed hosts with chronic diarrhea when routine methods fail to demonstrate etiologic agent. Since this organism is already infectious when passed, stool precautions should be maintained.

A controlled study of endemic sporadic diarrhoea among adult residents of southern Brazil

The aetiology of sporadic summer diarrhoea and enterotoxin (LT) antibody titres was studied among 43 adult patients in southern Brazil who had an acute, untreated diarrhoeal illness and 43 age- and sex-matched controls from the same area. A potential pathogen was identified in 33 of 34 patients and in 17 of 43 controls (p less than 0.01). 10 Shigella, one invasive Escherichia coli, one Salmonella and one Entamoeba histolytica were identified in 17 patients with inflammatory diarrhoea (faecal polymorphonuclear neutrophil leucocytes (PMN) present). In the other four only enterotoxigenic strains of E. coli were identified. Among 26 patients with non-inflammatory (no faecal PMN) diarrhoea, heat-stable (ST) toxin-producing coliforms were the most common pathogens isolated (27%). Heat-labile (LT) toxin-producing coliforms or serological rises to LT were seen in five patients, Strongyloides larvae in five, Giardia lamblia trophozoites in four and an LT-producing Salmonella in one. No pathogen was found in 10 patients with non-inflammatory diarrhoea. Among 43 controls, 11 LT coliforms, two Shigella and two Strongyloides larvae were found. 40 of 41 controls had detectable serum anti-LT antibody. A single ST-producing E. coli was found in one other control. No pathogen was identified in 26 controls. No rotaviruses or Norwalk-like viral agents were seen by direct or immune electron microscopy of stool filtrates. While LT-producing E. coli are frequently associated with endemic summer childhood diarrhoea in southern Brazil and are recognized causes of travellers' diarrhoea, this study shows that they are often carried asymptomatically by adults living in this region.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental studies on the interaction between infections of Ostertagia leptospicularis and other bovine Ostertagia species

Experimental infections of calves were carried out with either isolates of predominantly Ostertagia ostertagi, pure O. leptospicularis or a mixed isolate of equal numbers of both these species. The total worms established on day 21 for the mixed species from a total inoculum of 100 000 infective larvae, was 1.2 times greater than from 100 000 larvae of the O. ostertagi isolate and 3.3 times that of the pure O. leptospicularis isolate. The increased establishment in the mixed inoculum referred to both O. ostertagi and O. leptospicularis (days 17 and 21). These differences were both highly significant (P less than 0.01). The severity of the pathological changes was also greater in the mixed infections. It is suggested that these findings must be taken into account when control measures involving alternate grazing of sheep and cattle are being employed.

[Parasitologic, bacteriologic and virological studies of feces in diarrhea in 212 non-hospitalized children in Dakar. Application of the concept of mass opportunistic infections]

A total of 212 stools specimens from diarrhoeal children were analyzed for the detection of pathogenic agents (parasites, bacteria and rotavirus). There were only 80 negatives specimens. In the 132 positive ones, a total of 192 pathogenic agents (81 parasites, 76 bacteria and 35 rotavirus) were found. There results are very similar to those obtained in the hospitalized children. The etiology of this African intestinal polymicrobism must be searched by comparison to the European monomicrobism . In the low conditions of hygiene and nutrition, the concept of "Herd infection" is discussed. In conclusion, specific pathogen agents must be considered as "opportunist pathogen agents of the unfortunate human collectivities ".

Human cryptosporidiosis: spectrum of disease. Report of six cases and review of the literature

Although once regarded exclusively as an animal parasite, Cryptosporidium has emerged during the last decade as a cause of diarrhea in humans. Of the 43 cases of human cryptosporidiosis reported, 27 patients in whom either humoral or cell-mediated immune defects were present had chronic protracted diarrhea that was almost invariably unresponsive to therapy and culminated in death. In contrast, 16 patients with intact immune systems had either self-limited disease or were asymptomatic. Animal exposure was almost exclusively recorded in the latter group. During the last six months at University of Texas M. D. Anderson Hospital and Tumor Institute, Houston, gastrointestinal (GI) tract cryptosporidiosis developed in six homosexual men with acquired immune deficiency syndrome (AIDS). The diagnosis of cryptosporidiosis was established histologically in five patients. In four, cryptosporidial oocysts were detected in the stool. In addition to extensive GI tract cryptosporidiosis, two patients had biliary tract involvement. Multiple chemotherapeutic agents failed to control the disease, and five patients eventually died. Cryptosporidiosis should be considered in the differential diagnosis of diarrhea, in animal handlers or in the severely compromised patient, especially one with AIDS, who has chronic protracted diarrhea.

Strongyloidiasis. When to suspect the wily nematode

Strongyloidiasis is a tenacious soil-transmitted nematode infestation endemic in the south-eastern United States. Thirty-three cases were diagnosed in a series of 1,290 stool examinations in 971 patients at Veterans Administration Medical Center, Mountain Home, Tennessee. Most patients had a concurrent major illness, such as chronic lung disease, serious bacterial infection, or cancer. A minority presented with gastrointestinal symptoms alone. Skin rash was uncommon. Eosinophilia, IgE elevation, and skin anergy were common. Atypical presentations included severe proctitis, colitis, and exacerbation of inflammatory bowel disease. In a patient with the hyperinfection syndrome, the diagnosis was made only at autopsy. Since strongyloidiasis seems to present like an opportunistic illness, all physicians, not just those in endemic areas, should consider its presence in the appropriate setting.

Giardiasis: a common, sexually transmissible parasitic diarrhea with pitfalls in diagnosis

Giardia lamblia is the number one intestinal parasite in the United States. Symptoms of giardiasis include upper abdominal pain and distress, flatulence, nervousness, and diarrhea. Multiple stool specimens examined for ova and parasites by nonexpert parasitologists will frequently not provide the diagnosis, and special studies must then be done. Antibiotics, antidiarrheals, certain enema preparations, and oily laxatives can cause a temporary disappearance of parasites from the stool. Treatment of choice is a five-day course of quinacrine hydrochloride. Recently, attention has been brought to the fact that oral sex may be responsible for transmission in a significant number of cases of giardiasis.

Three-step stool examination for cryptosporidiosis in 10 homosexual men with protracted watery diarrhea

Cryptosporidiosis, a zoonosis caused by Cryptosporidium species, is a newly recognized coccidial protozoan infection causing severe protracted watery diarrhea in humans. In August 1981, the first case of cryptosporidiosis in a homosexual man with acquired immune deficiency syndrome (AIDS) was reported; diagnosis was determined by intestinal biopsy. It is necessary to adopt a simple laboratory diagnostic procedure to screen large numbers of suspected cases. A three-step stool examination was developed to demonstrate Cryptosporidium oocysts and the diagnostic and infective stages of the infection in 10 homosexual men with AIDS. This is a less invasive, less costly, and more sensitive test than intestinal biopsy and has been designed to prevent confusion caused by yeast cells that are frequently present in stool, leading to a false diagnosis. The examination consists of preliminary differential determination by iodine wet mount, definitive identification by modified Kinyoun acid-fast staining, and a more effective method of concentrating oocysts, by Sheather's sugar cover-slip flotation method.

Bacteria, parasitic agents and rotaviruses associated with acute diarrhoea in hospital in-patient Indonesian children

Faeces from children (aged from one month to 12 years) with acute diarrhoea admitted to hospital in Yogyakarta, Indonesia, from June 1978 to June 1979, were examined for the presence of enteric pathogens. One or more recognized enteropathogens were identified in 56% of children. Rotaviruses were identified in 38% of all children. Toxigenic coliforms (predominantly Escherichia coli) were isolated from 12% of children. Salmonella sp. (6%), Shigella sp. (4%) and enteropathogenic parasites (predominantly Trichuris trichiura) from 3.5% of children. Mixed infections with two or more enteric pathogens were found in 7.6% of children. The incidence rate of each pathogen was correlated with age of the child, socio-economic level of the family and duration of breast feeding. Toxigenic coliforms were equally common in all age groups from both well-to-do and poor families. Enteropathogenic parasites appeared in increasing frequency with age. They were more common in artificially fed children and in children from families of low socio-economic level. The occurrence of multiple infection with mixtures of enteric pathogens increased with increasing age. Mixtures of parasites and other enteric pathogens only occurred in children with acute diarrhoea. These results provide baseline data about the relative importance of different enteropathogens in Indonesian children.

[Cryptosporidiosis in calves during the period of milk nutrition]

It has been found out by examining faeces of 83 calves from calf house in Uhercice (Breclav district) that 52 calves excreted coccidium oocysts, genus Cryptosporidium Tyzzer, 1907, during the period of milk nutrition. The calves excreted oocysts from the eighth day of age, and at the end of the milk nutrition period (43rd-47th ridium Tyzzer, 1907, during the period of milk nutrition. The calves excreted oocysts of cryptosporidia were found in two thirds of calves suffering from diarrheas. By histological examination of a 27-day-old calf, developmental stages of this coccidium were found on the surface of villus epithelium in the distal part of ileum. Villi were shortened and expanded, submucous connective tissue was penetrated by inflammatory infiltrate with large quantity of eosinophil granulocytes. For demonstration of oocysts in faeces, Breza flotation method combined with sedimentation and staining by modified Giemsa panoptic method were used.

Cryptosporidiosis in Idaho lambs: natural and experimental infections

Cryptosporidiosis was diagnosed in lambs of a farm flock and an orphan-lamb rearing operation and in a hospitalized lamb. The clinical course was brief, with mild diarrhea and oocyst shedding during the diarrheic episode. Feces from the hospitalized lamb were used to reproduce the disease. Diarrhea and oocyst shedding occurred in inoculated lambs and their contact twin siblings but not in uninoculated noncontact control lambs or in inoculated ewes.

[Diarrhea caused by parasites]

The role of parasites as etiologic agents in diarrhea is emphasized. In countries of western Europe, Entamoeba histolytica and Giardia lamblia are the most prevalent species, although some other 20 protozoans and helminths may lead to diarrheic disturbances. Parasitology, pathogenesis, clinical signs, diagnosis and therapy are briefly outlined. The need for competence on the part of the personnel responsible for laboratory diagnosis is emphasized; also, newly developed immunodiagnostic methods may render appreciable services in doubtful cases. Adequate therapy yields successful results in over 90% of patients.

Field study of coccidial and rotaviral diarrhoea in unweaned piglets

A study of diarrhoea in unweaned piglets was carried out in nine herds, with special reference to the enteropathogenic agents which could be demonstrated. Coccidial (Isospora suis) and rotaviral infections were both identified, either singly or in combination. More extensive studies of I suis infection were undertaken in two of the herds and it was found that diarrhoea occurred most commonly in five- to 14-day-old piglets. Piglets with I suis infection were not necessarily diarrhoeic but grew poorly compared to uninfected piglets. I suis infection in litters correlated with oocyst excretion in sows. In herds with I suis infection, amprolium and monensin were used in the sow ration to achieve control, and in one herd oral dosing of piglets with amprolium in the first three or four days of life was carried out.