Human isosporiasis in an AIDS patient--report of first case in Malaysia

An AIDS patient with multiple opportunistic infections (Candida, Pneumocystis carinii and Isospora belli) was identified at the University Hospital, Kuala Lumpur. The patient presented with profuse diarrhoea associated with lethargy, anorexia and weight loss. Routine stool examination showed Isospora belli oocysts. The infection responded to treatment with trimethroprim-sulfamethoxazole but relapse occurred 8 weeks later. This represents the first documented case of isosporiasis to occur in an AIDS patient in Malaysia.

Parasitic infections in AIDS patients. Cryptosporidiosis, isosporiasis, microsporidiosis, cyclosporiasis

AIDS is characteristically associated with several intracellular enteric protozoan infections that often cause chronic and sometimes fatal intractable large-volume diarrhea. Until the AIDS epidemic, several of these parasitic infections were almost unknown as causes of human disease. This article reviews the diseases produced by cryptosporidia, isospora, cyclospora, and microsporidia in humans.

[Isospora belli infection in a patient with adult T cell leukemia]

A 53-year-old man was hospitalized for the development of watery diarrhea associated with decreased appetite and progressive weight loss and was found to have leukocytosis. The white blood cell count was 14,600/microliters with 66 percent abnormal lymphocytes. Serum anti-HTLV-I was positive and monoclonal insertion of HTLV-I provirus into the atypical cell genome was confirmed with the southern blotting hybridization technique. A diagnosis of ATL was made. Examination of fresh stool specimens revealed Isospora belli (I. belli) oocysts. Initial treatment for I. belli consisted of oral trimethoprim 160mg and sulfamethoxazole 400mg given twice daily for nine days. Diarrhea ceased within 2 days of the start of treatment, but I. belli oocysts were again detected after 20 days. Trimethoprim 160mg and sulfamethoxazole 400mg were reinstituted four times daily for 10 days, and then twice daily for 21 days. The clinical response was again dramatic, with rapid clearance of oocysts from the stool. There has been no recurrence of diarrhea. The patient's leukemia was refractory to chemotherapy; the white blood cell count continued to rise, pneumonia developed, and the patient died. I. belli is a previously unrecognized opportunistic pathogen that must be considered in the clinical setting of chronic diarrhea in patients with ATL.

The prevalence of Giardia and other intestinal parasites in children, dogs and cats from aboriginal communities in the Kimberley

OBJECTIVE

To determine the prevalence of Giardia duodenalis and other intestinal parasites in children, dogs and cats from Aboriginal communities in the west Kimberley region of Western Australia.

DESIGN

A four-year parasitological survey of faecal specimens from humans and faecal and intestinal specimens from dogs and cats.

SETTING

Local hospital servicing Aboriginal communities surveyed in this study and the Veterinary School, Murdoch University.

POPULATION

Children (under 14 years) and adults, as well as dogs and cats, from five Aboriginal communities.

RESULTS

G. duodenalis was the most prevalent parasite in children and adults (32.1% in children, n = 361; 12.5% in adults, n = 24). Human infections with Hymenolepis nana (20.5%) and Entamoeba coli (13.0%) were also common. Ancylostoma duodenale (1.3%), Pentatrichomonas hominis (1.0%), Chilomastix mesnili (0.52%), Entamoeba hartmanni (0.52%), Sarcocystis sp. (0.52%), Trichuris trichiura (0.26%), Enterobius vermicularis (0.26%), Strongyloides stercoralis (0.26%) and Isospora belli (0.26%) were present at low rates. Dogs were most commonly infected with Ancylostoma caninum (51.1%) and G. duodenalis (17.0%). Cats were found to have a high prevalence of Ancylostoma tubaeforme (18.2%), Toxoplasma gondii (18.2%), Isospora felis (15.1%) and Spirometra erinacei (15.1%).

CONCLUSIONS

This study has shown that children from Aboriginal communities in the west Kimberley region of Western Australia, particularly in the age group one to five years, are commonly infected with intestinal parasites. The dogs and cats in these communities are also infected. The high prevalence rates of Giardia and other enteric parasites in this survey are indicative of poor living conditions and low levels of hygiene. In addition, the high prevalence of hookworm and Giardia infection in dogs and hookworm and Toxoplasma infection in cats is of potential zoonotic significance for humans in these communities.

[Isospora belli infection in a patient with adult T-cell leukemia]

An adult T cell leukemia (ATL) accompanied with Isospora belli infection was described. A 65-year-old male was admitted to our hospital because of a two month history of watery diarrhea. On admission, physical examination showed slight pallor but no detectable superficial lymphadenopathies. Hepatosplenomegaly was not observed. Laboratory examination revealed a leukocyte count 5,500/microliters with 10% abnormal lymphoid cells. A majority of the abnormal lymphoid cells expressed both CD 4 and CD 8 antigens. The patient was diagnosed as chronic ATL, since anti-HTLV-1 antibody in his serum and monoclonal integration of HTLV-1 proviral DNA in his peripheral mononuclear cells were detected. Isospora belli was found in his feces thereafter, and trimethoprim/sulfamethoxazole was effective for diarrhea. In Japan, there have been only 9 reported cases of lymphoproliferative disorders (including five ATL patients) accompanied with Isospora belli infection. From the descriptions in those reports, these 9 cases might all be ATL patients.

[The acquired immunodeficiency syndrome in the elderly]

Three cases of AIDS in patients older than 60 years of age are presented and are characterized by the delay in diagnosis even in the face of suggestive clinical manifestations because of the lack of suspicion leading to fatal short term evolution in all the cases. The importance of HIV infection and its characteristics at this age are discussed. Transfusion is the most frequent method of transmission. The clinical manifestations do not differ from those of other ages with neurological and psychiatric manifestations being significant as a form of presentation. Evolution is usually rapidly progressive. The need to suspect HIV infection is emphasized in elderly patients when presenting typical AIDS pathology or atypical dementia or rapid evolution specially if pertaining to a risk group.

[A case of fatal malabsorption syndrome caused by strongyloidiasis complicated with isosporiasis and human cytomegalovirus infection]

This 54-year-old Korean coal miner suffered from continuous watery diarrhea and weight loss after corticosteroid treatment (beta-methasone, 4 mg daily for 1 week) due to hip-bone fracture in January 1991. Except for the short therapy of steroid, no other histories were contributory. The malabsorption syndrome was aggravated while the case was treated under the impression of amebiasis or intestinal tuberculosis. AIDS antibody test by EIA was negative and quantitative analysis of serum immunoglobulins was in normal ranges. Nine months after the onset of symptoms, the case was diagnosed as malabsorption syndrome caused by complexed and aggravated infection by Strongyloides stercoralis, Isospora and cytomegalovirus in the small intestine, which were proved by stool examination and duodenal biopsy. His clinical course became worse even after high-dosed and prolonged albendazole treatment for strongyloidiasis with supportive fluid therapy. The patient was discharged in hopeless status in November, 1991 and died after one week at home.

[Diarrhea in AIDS. Group AIDS GIT]

Gastrointestinal (GI) infections are frequent in AIDS patients. The frequency and type of opportunistic GI infections are exactly the same in homosexuals and heterosexuals. Diarrhoea is the usual sign of GI infection, and its mechanism seems to combine a secretory component and a malabsorption. Although a number of pathogens can be isolated, in many cases the diarrhoea cannot be explained by an infection or a lesion. The hypothesis of a primary HIV infection in the epithelium of the small bowel and colon has not been confirmed by immunofluorescence and molecular hybridization. The HIV virus has been found in the GI mucosa, but it was probably carried by the immune cells in general circulation (CD4 lymphocytes and macrophages) which subsequently colonize the chorion of the mucosa.

Coccidian infections in AIDS. Toxoplasmosis, cryptosporidiosis, and isosporiasis

Cryptosporidium sp. and Isospora belli are coccidian protozoan parasites that were long recognized as pathogens for many animal species. The medical community became acquainted with these organisms with the advent of AIDS. Both parasites are associated with persistent, debilitating enteritis and, in the case of Cryptosporidium, biliary tract involvement in patients with AIDS. For the immunocompetent host, infection with these two pathogens usually results in self-limited diarrhea. Cryptosporidiosis appears to occur more often than isosporiasis, but the true prevalence of both infections for various populations of humans is unknown. Clinically, cryptosporidiosis is indistinguishable from isosporiasis. Diagnosis is based on finding the acid-fast (red staining oocyst in stained fecal specimens). There is no known effective therapy for cryptosporidiosis, whereas patients with isosporiasis respond promptly to treatment with trimethoprim-sulfamethoxazole. Patients with AIDS and isosporiasis have a high relapse rate after achieving complete remission and therefore need to be maintained on suppressive therapy. Much more needs to be learned about these two fascinating, "newly recognized" parasites.

[Histochemistry of nucleoside phosphatases and phosphoglucomutase in the small intestine during coccidiosis in piglets]

The first day after birth, 22 conventional piglets were experimentally infected with the oocysts of the coccidia of I. suis (infection dose 200,000 oocysts). The activity of 5-nucleotidase (5-ribonucleotide phosphohydrolase, EC.3.1.3.5) and phosphoglucomutase (alpha-D-glucoso-1-phosphate phosphotransferase, EC.5.4.2.2) was densitometrically assessed in the mucosa of the small intestines of these piglets. Enzyme activities were studied in the infected piglets during the 2nd to 10th day after infection. The same histochemical examination was simultaneously performed in the intestinal mucosa of five control conventional piglets at an age of 2-14 days. 5-nucleotidase and phosphoglucomutase were found to have a high density in the mucosa of the small intestine of the control piglets: the high-density locations of these enzymes include, first of all, the supranuclear area of the absorption cells, the microvillous zone of enterocytes and the smooth muscle elements of lamina muscularis mucosae. The experimentally infected piglets showed a marked decline of the density of both enzymes during the infection. The deficit affected, for a transient period, the microvillous zone and the supranuclear region of enterocytes; the musculature of the mucous layer was affected permanently. The inactivity was more protracted in the case phosphoglutamase (especially 5 to 9 days after infection). The density of 5-nucleotidase showed a partial return to the normal already the 7th day after infection, with an interruption of resumption of activity on the 10th day. Resumption of enzyme activity in the lamina muscularis mucosae was not recorded during the infection. In the three locations under study, the density of none of the enzymes did reach parameters comparable with the controls at the end of the trial (10 days after infection).

[Histochemistry of acid phosphatase in small intestine mucosa in experimental coccidiosis in suckling piglets]

The activity of acid phosphatase (phosphohydrolase of orthophosphate monoesters; EC. 3.1.3.2) was evaluated densitometrically in the mucosa of duodenum, jejunum and ileum of 22 conventional piglets which were experimentally infected by oocysts of the coccidiae Isospora suis (infection dose of 200,000 oocysts) on day one after parturition (DAP). The activity of the studied hydrolase was investigated in the infected piglets during days two to ten after infection (DAI) in the intestinal mucosa (enterocytes) and in goblet cells. The density of the reaction product of acid phosphatase was simultaneously determined in the same mucosal cells of different sections of the small intestine in five control conventional piglets at the age of 2-14 days. In the small intestine mucosa of control piglets the activity of acid phosphatase was demonstrated to be located especially in the supranuclear zone of enterocytes. As for goblet cells, the reaction product of acid phosphatase is distributed in all zones (supra-, para-, infranuclear zones); the lowest density of this enzyme was found in the infranuclear zone. The activity of acid phosphatase is also localized in intestinal crypts: in their cells the enzyme concentration is decreasing from duodenum to caudal sections. Important changes were revealed, in comparison with the control data, in the development of the activity of acid phosphatase in the intestinal mucosa cells in the experimentally infected piglets. In the period of investigation (DAI 2-10) there were two stages of the development of the density of the enzyme reaction product. The first stage can be characterized by an increase, the other by a decrease in the level of acid phosphatase activity. Enterocytes are influenced in both stages, but the decrease in the density of the reaction product of acid phosphatase was observed only in absorption cells, and not in goblet cells. The increase in the activity of acid phosphatase occurs in the periods of DAI 4 and 9-10. Enzymatic deviations occur mainly in the absorption cells of the mucosa of duodenum and middle jejunum; in the cells of posterior jejunum and ileum an increase in the density of the reaction product of acid phosphatase was also demonstrated, but at the lower quantitative level (especially on DAI 4). The decrease in the activity of acid phosphatase has a protracted development and it takes place on DAI 5 to 8.(ABSTRACT TRUNCATED AT 400 WORDS)

[Lysosomal activity in enterocytes in the small intestine in piglets experimentally infected with Isospora suis]

The lysosomal activity of enterocytes of the small intestine mucosa was investigated in gnotobiotic and conventional piglets experimentally infected on the first day after birth (DAB) by the oocysts of the coccidia Isospora suis. A method of the proof of beta-D-glucuronidase (EC.3.2.1.31.) activity was used to demonstrate lysosomes. The piglets were infected by different infection doses of oocysts (100,000 oocysts in gnotobiotic piglets and 200,000 oocysts in conventional piglets). In the gnotobiotic infected piglets the activity of beta-D-glucuronidase in enterocyte lysosomes was investigated in the period from day 3 to day 11 after infection (DAI) and in the infected conventional piglets in the period from day 2 to day 10 after infection. Comparing the control piglets, the group of gnotobiotic piglets at the age of 2-5 days and the group of conventional piglets at the age of 4-7 days, the higher activity of beta-D-glucuronidase was demonstrated in the lysosomes of intestinal mucosa enterocytes in the gnotobiotic control piglets (+5.30 of the average density value, Dx). In the infected gnotobiotic and conventional piglets the pattern of beta-D-glucuronidase activity was found to have three stages in the course of this infection. Two stages can be characterized by a great increase in the enzyme activity (DAI 3-9 in gnotobiotic piglets, DAI 2-3 and 7-9 in conventional piglets. The third stage, which is manifest mainly in the conventional infected piglets, is characterized by a marked decrease in the activity of beta-D-glucuronidase, reaching the level of control findings (DAI 10 and mainly 11 in gnotobiotic piglets. DAI 4-6 and 10 in conventional piglets). A topographical picture shows that the two stages of increase and the stage of beta-D-glucuronidase activity decrease occur in the whole small intestine without any predisposition defect of the enzyme in the different sections of the small intestine.

Effects of experimentally induced Isospora suis infection on morbidity, mortality, and weight gains in nursing pigs

Forty-nine pigs from 6 litters were inoculated at 3 days of age with 300,000 sporulated oocysts of Isospora suis to determine the effects of neonatal coccidiosis on morbidity, mortality, and weight gain in nursing pigs. Fifty-one control pigs from 6 litters were not inoculated. Three to 5 days after inoculation, the inoculated pigs developed a nonhemorrhagic diarrhea, generally lasting 6 to 10 days, that lead to visible dehydration, loss of condition, and 20.4% mortality. Control pigs did not die or develop coccidiosis during the 3-week study and had significantly (P less than 0.05) greater body weights at 7, 14, and 21 days of age than did the inoculated pigs.

Interfering effect of Isospora suis infection on Salmonella typhimurium infection in swine

Piglets were each orally inoculated daily for 4 consecutive days, with 10(4)-10(5) nalidixic acid-resistant Salmonella typhimurium and, starting 1 day after inoculation, with 50 000 Isospora suis sporulated oocysts. Control pigs were given S. typhimurium alone following the same inoculation schedule. Fecal samples were taken 5, 7 and 10 days after the coccidial inoculation, and all the pigs were necropsied 13 days after inoculation. S. typhimurium counts in the feces and in the cecal contents and the numbers of pigs positive for presence of S. typhimurium in the mesenteric lymph nodes of the dual-infected pigs were significantly (P less than 0.05) smaller than in those infected with S. typhimurium alone.

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.

Isospora belli enteritis in three homosexual men

Isospora belli is an uncommon cause of diarrhea in man. Like the closely related Cryptosporidium, the organism causes disease that may be more severe and chronic in patients with underlying immune deficiency states. We describe three male homosexuals with Isospora enteritis. Each had several months of diarrhea. All three patients had lymphopenia and two had profound T cell helper-suppressor ratio reversal. In addition, two of the patients admitted to oral-anal contact, a practice associated with the acquisition of parasites and other enteric pathogens in the homosexual population. We suggest that Isospora belli may be a sexually transmitted pathogen which should be considered in the diagnosis of homosexual patients with diarrhea.

Coccidiosis in preruminating calves the effect of management and short-term treatment on the spread of infection and reinfection

In farms with large numbers of individually-housed calves, the spread of coccidia is slow. In group pens, however, all the calves became infected within 3-4 weeks of being housed together. At the beginning of group housing no oocysts were found in the faeces of any of the calves. Sulphadimidine (SDM) was administered for 3 or 12 days at different doses and different times. Administration of the drug on Days 3-5 of group housing had no effect. Given between Days 11 and 13 or 17-19, the drug lowered (for a short period) the number of animals found to be excreting oocysts. SDM given between Days 6 and 17 kept the animals oocyst-free during that period. Within 2-3 weeks after the treatment all animals were excreting oocysts.

Prevalence of intestinal parasites in feral cats in some urban areas of England

Of 92 feral cats necropsied from the London and Sheffield areas, 49 (53.3%) were infected with Toxocara cati, 32 (34.8%) with Dipylidium caninum, 11 (12.0%) with Taenia taeniaeformis and 1 (1.1%) with Toxascaris leonina. Isospora felis was seen in 3 (4.3%) of 69 samples of faeces. Twenty-two cats (23.9%) were simultaneously infected with 2 helminth species.