Diloxanide furoate for treating asymptomatic Entamoeba histolytica cyst passers: 14 years' experience in the United States

Diloxanide furoate is used for treating asymptomatic or mildly symptomatic persons who are passing cysts of Entamoeba histolytica. The Centers for Disease Control (Atlanta) released this drug for 4,371 treatment courses from 1977 through 1990. Of the 2,815 report forms (64%) returned, 656 adverse effects were reported for 390 treatment courses (14%); they included flatulence (260), diarrhea or cramping (100), nausea (93), headache (17), disorientation or dizziness (9), and diplopia (4). During 1984-1990 uniform collection of data allowed more detailed analysis of toxicity and efficacy; fewer adverse effects were reported for persons aged 20 months to 10 years than for persons aged greater than 10 years (6 of 206 [3%] vs. 89 of 763 [12%], relative risk = 0.27, 95% confidence interval = 0.12 less than relative risk less than 0.61). Parasitological cures were achieved during 497 (86%) of the 575 treatment courses (52%) administered to asymptomatic persons who were passing cysts, who had received a full 10-day treatment course, and for whom results of a follow-up stool examination (greater than or equal to 14 days post-treatment) were available. Diloxanide furoate is safe and effective for treating asymptomatic persons who are passing E. histolytica cysts and may be particularly well tolerated in children.

[A case of focal necrotizing granulomatous hepatitis in childhood]

Granulomatous hepatitis make up a group of conditions of various aetiologies. The diagnosis of granulomatous hepatitis is histologic, since the aspect of the granulomatous lesion is not always indicative of a specific disease. It is important to take into consideration for the aetiologic diagnosis a good response to a specific therapy or the execution of complementary examinations. The 25% of granulomatous hepatitis remain undiagnosed.

[Entamoeba histolytica: a standing threat]

The importance and limitations of microscopic differential diagnosis of Entamoeba histolytica in asymptomatic carriers is reviewed. The possibility that some nonpathogenic strains of E. histolytica could be Entamoeba hartmanni is discussed. The imperative necessity to encourage research in epidemiology and diagnosis is emphasized. The need to know the prevalence in Mexico and distinguish E. histolytica from E. hartmanni is also discussed. This differential diagnosis is fundamental in the treatment of carriers and in epidemiological studies. Treatment must be directed only to acute and chronic patients and asymptomatic carries who prepare food. Appropriate drugs are still metronidazole and quinolines.

[3 cases of hematogenous lung abscess of amebic origin]

Invasive amebiasis is a very serious health problem in Mexico as it is presumably related to the presence of virulent strains of Entamoeba histolytica and poor hygienic and sanitary conditions; other factors related to invasive amebiasis are undernutrition, alcoholism, and homosexuality. We present three patients with pulmonary amebic hematogenous abscess. Clinically all patients had the typical "chocolate" exudate. The three patients had pulmonary consolidations by chest roentgenogram; one of them had multiple opacities with air fluid level, and the others had an isolated opacity with air fluid level. The ultrasound and hepatogammagram were negative for diaphragmatic communication in all; in one of them the pneumoperitoneum was negative for diaphragmatic communication. The transthoracic needle biopsy of the lesions was positive to ameba in two patients. The serologic tests were positive in all. We treated the patients with metronidazole and emetine during 10 days; since the clinical picture and the radiologic findings did not remit completely, we gave a second course of metronidazole during 10 days more and achieved complete resolution.

Atrial septal defect presenting as recurrent primary amoebic lung abscess

A middle-aged female with an atrial septal defect (secundum type) presented with a primary pulmonary amoebic abscess. She was successfully treated with antiamoebic therapy. One year later she presented with a similar lung abscess which again responded to antiamboebic treatment. Attention is drawn to the fact that a patient with a left to right shunt can present with a recurrent rare primary parasitic infection of the lung.

Intestinal parasites in Cambodians: comparison of diagnostic methods used in screening refugees with implications for treatment of populations with high rates of infestation

We performed a retrospective review of screening parasitology examinations on a Cambodian refugee population served by an urban neighborhood health center. Five-hundred twenty of 1084 patients were examined for ova and parasites either by purged stool, which was examined immediately, or preserved stool, examined at a teaching hospital and proprietary laboratories. Overall, 335 (64 percent) of the tested patients had at least one parasite. The prevalence of infection varied by test technique (purged stool examined immediately, 86 percent; preserved stool examined at a hospital, 65 percent; preserved stool sent to a proprietary laboratory, 31 percent, P less than 0.01). In this population where Entamoeba histolytica infection was 44 percent as measured by the purged warm stool technique, the cold preserved stool test had a measured relative sensitivity of 33 percent. Assuming a selectivity of 99 percent, it would take eight negative tests to reach a greater than 95 percent negative predictive value. The high rate of intestinal carriage of pathogenic parasites in this population and the insensitivity of commonly available diagnostic tests make routine presumptive treatment of intestinal parasites an option when the purged stool examination is unavailable.

Entamoeba histolytica infections in flight personnel of an international airline

A cohort of 99 subjects, members of the flight staff of Lufthansa German airlines, all infected with Entamoeba histolytica, were followed over a period of 2.5 years to monitor their clinical and parasitological status. All but 4 of the subjects were infected with non-pathogenic zymodemes of E. histolytica and had negative amoebic serology, and most were clinically well. One male heterosexual carrying a pathogenic zymodeme was found, despite massive treatment regimes, to carry the infection persistently for 12 months. Most non-pathogenic infections were left untreated.

Comparative study of aminosidine, etophamide and nimorazole, alone or in combination, in the treatment of intestinal amoebiasis in Kenya

417 patients suffering from intestinal amoebiasis were randomly allocated to 6 different treatment groups in a controlled study in 3 District Hospitals in Kenya. The patients received either aminosidine (A), etophamide (E), nimorazole (N), or the combinations NA, NE, EA. Treatment in all cases was given twice daily for 5 days. Before and after treatment, rectosigmoidoscopy was done in each patient, and stool examination with characterization of invasive (IF) and non invasive (NIF) forms of amoeba was done daily throughout treatment, and on Days 15, 30 and 60 of follow-up. Clinical cure was good after all the treatments, varying from 90 to 100%; parasitological cure at the end of treatment was 100% in the NA and EA treatments groups, and 98% in A group. The incidence of relapses was nil in the EA group, followed by 3% in NA and 6% in A groups. Anatomical cure (healing of ulcers) was 97.8% in the NA group, 95.5% in the N group and 88.5% in the A group. Drug tolerance was excellent or good after all the treatments, except that the EA combination produced diarrhoea in 76.5% of patients. Overall analysis of the findings, including tolerance of the various treatments, showed that aminosidine either alone or in combination with nimorazole gave the best results. Ulcers seen on rectosigmoidoscopy were more common in patients excreting invasive forms of amoebae in their stools.

[Amebiasis. Medical treatment. Is there anything better than metronidazole?]

Since 1961, when Cosar pointed out for the first time that metronidazol was a useful pharmacological agent against E. histolytica, several authors have demonstrated its effectiveness against invasive amebiasis in its colonic or extraintestinal variety. The obtained results with metronidazol were so far better compared with the rest of the known amebecides, that in 1974, Elsdon Dew stated that a new era in the medical treatment of the amebiasis had started with the forthcoming use of the agent. However, the frequent and important adverse collateral effects produced in a good number of patients have forced to look for other nitroimidazole derivates, hopefully more efficient and, of course, better tolerated. Thus, the tinidazole, ornidazole, flunidazole, romidazole, ornidazole, flunidazole, dimetridazole, satranidazole, nitrimidazine, panidazole, have been tried and some others are still subject to experimentation, such as the Ro 7-0207 (alpha-chlorometil-2-metil-5-nitro-1-imidazol), the phexinidazole (HOE 239) and the CG 10213-Go from CIBA-Geigy and no significant advantage has been found over the metronidazol. The phexinidazole turned out to be twice as effective as the metronidazole in the experimental hepatic amebiasis of the golden hamster. This fact must be confirmed or discarded in the human hepatic amebiasis.

Therapy of entamebiasis

Therapy of entamebiasis is critical in that, if untreated, the disease can be fatal. Recently, a new method for differentiating pathogenic and non-pathogenic amebae has been standardized. This method relies upon the electrophoretic analysis of 4 isoenzymes which allow the identification of 20 different zymodemes. It is now widely accepted that non-pathogenic strains of Entamoeba histolytica are not a hazard for humans and therefore don't need therapy. As a consequence, treatment must be addressed only toward infections caused by pathogenic strains. As there are different drugs available for treating amebiasis, from a therapeutical point of view the disease must be divided into two forms: intestinal and extraintestinal. For the former, drugs which reach therapeutical levels in the gut are required. The mainstay for the treatment of asymptomatic carriage of pathogenic strains is DILOXANIDE FUROATE, a very well tolerated luminal amebicide. METRONIDAZOLE and other 5-nitroimidazole compounds such as ORNIDAZOLE are indicated for the treatment of symptomatic intestinal infections as they reach good concentrations in tissues, including the bowel where ulcerations develop. In order to ensure the clearance of amebae from the gut, a subsequent cycle with diloxanide furoate is advisable. Extraintestinal forms include amebic abscesses which can develop in many sites, but most commonly in the liver. Metronidazole and related compounds are the drugs of choice; in case of liver abscess, the addition of CHLOROQUINE is indicated because of its good concentration in tissues. A subsequent cycle with diloxanide furoate is also indicated.(ABSTRACT TRUNCATED AT 250 WORDS)

Mebendazole retention enema for severe Trichuris trichiura (whipworm) infection: a case report

The authors report a case of massive Trichuris trichiura infection, resulting in severe anaemia and congestive cardiac failure in a 9-year-old Iban boy, who was resistant to the usual oral anthelmintic treatment, but promptly responded to mebendazole retention enema. This patient also had an associated Entamoeba histolytica infection.

Amebiasis. The ancient scourge is still with us

Amebiasis is usually contracted in geographic areas where sanitation is poor, but outbreaks can still occur anywhere that drinking water becomes contaminated with sewage. In the majority of persons infected with the parasite, colonization of the intestine is asymptomatic. In others, symptoms of gastrointestinal distress can appear within a week. In rare cases, extra-intestinal amebiasis can cause abscesses in the liver or elsewhere. Many questions about the disease course in different patients remain to be answered. Diagnosis can be made through symptom identification; findings of right-upper-quadrant tenderness, leukocytosis, and an elevated level of alkaline phosphatase; and testing the feces for trophozoites or cysts. Clinicians disagree on whether asymptomatic persons need to be treated, but anyone who is capable of transmitting the disease should be advised of how to avoid exposing others to it.

[Pseudomembranous colitis after antibiotic therapy associated with the presence of Entamoeba histolytica histolytica. Apropos of 2 cases]

The authors report on two cases of pseudomembranous colitis (P.M.C.) developed in two Senegalese women of 38 and 36 years, and discovered at the 4th and 5th day respectively of an antibiotherapy based on ampicillin. In these two observations, cysts of Entamoeba histolytica histolytica were found in both feces and biopsies. They recall the circumstances of the occurrence, diagnosis techniques and treatment. They underline the unfrequency of this disease in Africa south of Sahara and they discuss the correlation with amoebiasis colitis. One has to keep in mind the possibility of a P.M.C. during any antibiotherapy, and consequently to have a rectoscopy to perform. Such an exploration is enough to pose a diagnosis. In day to day practice it is not necessary to show clearly the specific germ Clostridium difficile or its entero-toxin. To stop any antibiotherapy is required and beneficial. Metronidazole or Vancomycin are the best drugs in this case.

Paromomycin therapy of endemic amebiasis in homosexual men

A prospective evaluation was made of the therapeutic efficacy of paromomycin, an orally administered, nonabsorbable aminoglycoside, in 114 homosexual men with mild-to-moderate (nondysenteric) intestinal amebiasis. All patients received 25-35 mg/kg daily in three divided doses for seven days. Of the 80 patients with gastrointestinal complaints at the onset of therapy, 55 (80%) of 69 were asymptomatic within four to six weeks after completion of treatment; 11 patients were lost to follow-up. Paromomycin produced long-term eradication of intestinal Entameba histolytica infection in 92% of all men evaluated. The rate of microbiologic cure among patients with symptoms at the onset of therapy was comparable to that among asymptomatic individuals. Paromomycin was well tolerated, with mild diarrhea during therapy the only frequent adverse effect (67% of patients). Thus, paromomycin is an effective alternative to conventional multi-drug therapy for intestinal amebiasis, and it has the advantages of low toxicity, brief duration of therapy, and a high rate of patient compliance.

Antimicrobial therapy for infectious diarrhea

Acute diarrheal disease may be due to viral, bacterial, or protozoal enteropathogens. In our current state of knowledge and medical practice, specific antiviral agents are not used in the treatment of known or presumed viral diarrhea. In contrast, for a number of the bacterial and protozoal diarrheal infections, therapy with certain antimicrobial agents can significantly ameliorate the severity and duration of illness and curtail the excretion of the pathogen. A recurring theme encountered in reviewing information on the therapy for diarrheal infections is that demonstration of the susceptibility in vitro of a bacterial pathogen to a particular antibiotic by no means assures clinical success. Many antibiotics that show potent activity in vitro have little or no efficacy in vivo. Controlled clinical trials are necessary to assess the clinical and bacteriologic efficacy of an antibiotic in diarrheal infections.

Is Entamoeba histolytica in homosexual men a pathogen?

Entamoeba histolytica (EH) in homosexual men is generally considered to be pathogenic. To test this hypothesis, the generally accepted features of invasion (haematophagous trophozoites in faeces; high-titre serum antibody; moderate to severe acute inflammatory change; and presence of EH in the mucosa on rectal biopsy) and the zymodeme pattern of cultured trophozoites were assessed in twenty-three EH excretors and eleven control homosexual men. No trophozoites or antibody to EH were found in either group. When other pathogens were excluded, no patient in either group had severe, acute histopathological proctitis. Moderately severe change was seen in 38% of EH excretors and 18% of controls (not significant). All the zymodemes were non-pathogenic. Successful eradication of EH did not result in even a trend towards normalisation of the moderate inflammatory histopathology. There are, therefore, no data here to suggest that EH is a pathogen in homosexual men.

Secondary cerebral amebiasis due to infection with Entamoeba histolytica. A case report with computer tomographic findings

The clinical and serological findings and computer tomographic (CT) appearances of a case of secondary cerebral amebiasis due to Entamoeba histolytica are presented. The effect of therapy on the neurological symptoms as well as on the CT findings are described in detail. The multiple intracerebral lesions resolved almost completely and the patient survived without any neurological sequelae.