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Biomedical subjects

G R Healy

Publications and source records attributed to G R Healy.

At least 37 records · Page 2Linked to original sources
PubMed1980

An immunofluorescence test to detect serum antibodies to Giardia lamblia.

We used an indirect immunofluorescence test with Giardia lamblia trophozoites as antigen to detect anti-G. lamblia antibodies in serum. Seventy-one patients and control subjects were studied in a blinded protocol. Titers in 29 of 30 patients with symptomatic giardiasis (1:16 to 1:1024) did not overlap titers in 19 healthy control subjects (1:2 to 1:4); titers in 15 patients with hookworm, Entamoeba histolytica, or intestinal bacterial overgrowth were 1:16 or less Absorption of giardiasis patients' sera with G. lamblia trophozoites but not with E. histolytica, Trichomonas vaginalis, or Escherichia coli reduced the titers to, or nearly to, control values. Titers in individual sera were 93.9% reproducible within a fourfold or less dilution. Our results indicate that G. lamblia, an intestinal parasite often regarded as noninvasive, induces a systemic antibody response. The indirect immunofluorescence test for anti-G. lamblia antibodies is specific and reproducible; it may be useful in epidemiologic and immunologic studies of giardiasis.

Adult↗
PubMed1980

Serologic testing for amoebiasis.

The diagnosis of amoebiasis presents problems, particularly if one relies on finding the organism. Thus, serologic tests are expedient. A gel diffusion precipitin test (GDP), commercially available, simple to perform, and inexpensive, was compared with the indirect hemagglutination test (IHA). 257 Patients' sera were tested; 14 had amoebic colitis, 21 had amoebic liver abscess, 63 had suspected amoebic liver abscess, and 46 had inflammatory bowel disease. GDP tests were positive in 85% of amoebic colitis and 95% of amoebic liver abscess patients; IHA was positive in 91% of amoebic colitis and 94% of abscess patients. Within 6 mo, GDP tests became negative in 66% of patients. IHA tests were observed positive up to 20 yr. The performance characteristics of diagnostic methods in amoebiasis, fecal examination, IHA and GDP, show serologic tests have superior sensitivity and predictive value in recognizing invasive disease.

Dysentery, Amebic↗
PubMed1980

Blastocystis hominis in a pig-tailed macaque: a potential enteric pathogen for nonhuman primates.

Large numbers of Blastocystis hominis were found in fecal samples from a pig-tailed macaque (Macaca nemestrina) with chronic diarrhea that was refractory to conventional therapy. The animal's condition improved and fecal samples showed minimal numbers of Blastocystis hominis following therapy with an antiprotozoal agent. This organism, recently reclassified as a protozoa, appeared to be causally related to the diarrhea. The cytologic and ultrastructural features of the monkey Blastocystis were comparable to those reported for similar organisms from man.

Animals↗
PubMed1980

Epidemiologic studies among Amerindian populations of Amazonia. III. Intestinal parasitoses in newly contacted and acculturating villages.

The prevalences of intestinal parasites among the residents of three South American Indian villages in the process of acculturation were compared with those found in earlier unpublished surveys in two newly contracted village.s Although one individual in an acculturating village harbored 11 different intestinal parasites, in general the average number of different parasitic species carried per person was somewhat higher in the newly contacted villages. Helminth egg counts, performed on direct smears of each specimen from one newly contacted village, were low. There were no sex-associated differences in prevalences. The overall prevalences, unadjusted for age, were among the highest recorded for Amerindians. No Taenia species were present. Balantidium coli was present in two acculturating villages, concomitant with the beginning of agricultural practices which include raising swine. No cases of moderate or severe protein-calorie malnutrition was observed in any of the villages during the surveys. These limited data provide a baseline for future comparisons and, perhaps, a glimpse into the past.

Acculturation↗
PubMed1979

Babesia infections in man.

Only recently has it been recognized that hemotropic animal parasites of the genus babesia are also human pathogens. Similar to malaria in both symptoms and laboratory findings, acute babesiosis generally results in self-limited illness, but it can be fatal in the asplenic patient. The widely disseminated vector tick, Ixodes dammini, can transmit infection at each stage of its development, larva and nymph as well as adult.

Adult↗
PubMed1979

Epidemiologic studies among Amerindian populations of Amazonia. II. Prepvalence of Mansonella ozzardi.

The prevalence of microfilaremia among Indians in 13 Amazon Indian villages was determined by examining Giemsa-stained peripheral blood smears and preparations from peripheral blood lymphocyte cultures. Mansonella ozzardi was the only species found in the 601 persons tested. Prevalence was highly village-specific, ranging from 0% in four villages to as high as 93% among persons aged 10 years and older in others. Comparisons of the two methods showed that the concentration effect of the peripheral blood lymphocyte culture preparations allowed the detection of a greater number of microfilaria-positive persons, especially women and children with lower levels of parasitemia.

Adolescent↗
PubMed1979

Experimental Babesia microti infections in non-splenectomized Macaca mulatta.

Eight non-splenectomized Macaca mulatta were inoculated intravenously with strains of Babesia microti that originally were isolated from 2 human cases of babesiosis and then were maintained in hamsters in the laboratory. Patent infections developed in 7 animals with peak parasitemias of 496 to 3,906 organisms/mm3 blood. Prepatent periods ranged from 15 to 46 days. Parasitemia persisted for at least 90 days in all animals and in one, organisms were still present 559 days after inoculation.

Animals↗
PubMed1978

Retrospective identification of Acanthamoeba culbertsoni in a case of amoebic meningoencephalitis.

Acanthamoeba culbertsoni was identified retrospectively in a case of amoebic meningoencephalitis, previously reported by Jager and Stamm (Lancet, 2, 1343, 1972). This is the second report of this species causing secondary infection in man. Positive results were obtained only with anti-A. culbertsoni sera when the brain sections were stained by the indirect immunofluorescence antibody test with various antisera produced against different Acanthamoeba species. Antiserum raised against purified plasma membranes of A. culbertsoni showed once more its highly specific diagnostic value.

Adult↗
PubMed1978

Babesia microti infection in man: evaluation of an indirect immunofluorescent antibody test.

An indirect immunofluorescent antibody test was used to detect antibody to Babesia microti in human sera. Nine patients from Nantucket Island, Massachusetts infected with B. microti had serum titers greater than or equal to 1,024. Of 84 control sera from New York City residents, 246 sera from patients with possible exposure to ticks, and 36 sera from patients with suspected or confirmed tick bites, none was reactive at titers of 1:16 or above. The within-test reproducibility was within one fourfold dilution in 95% of trials. Test-to-test reproducibility was within one fourfold dilution in 33% of trials and within two fourfold dilutions in 100% of trials. Although cross-reactions among infected patients' sera and antigens of B. argentina, B. equi, B. bigemina, Plasmodium vivax, P. falciparum, and P. brasilianum were common, titers were highest to the homologous antigen.

Animals↗
PubMed1978

Amebiasis: epidemiologic studies in the United States, 1971-1974.

Seven investigations of suspected foci of amebiasis between October 1971 and June 1974 lead to three conclusions. (1) A number of laboratories have vastly overdiagnosed amebiasis and have reported leukocytes in stools as Entamoeba histolytica. Two laboratories found to be in error were in community hospitals, and one was at a teaching hospital associated with a medical school and a school of public health. These three laboratories had been diagnosing more than 1200 cases of amebiasis a year for 20 years. (2) When amebiasis does occur, it is likely to be misdiagnosed. In one outbreak with four cases and three deaths, amebiasis was not diagnosed until two patients had died and another was critically ill. Sporadic cases may be mistakenly diagnosed as ulcerative colitis and inappropriately treated with steroids. (3) Foci of endemic amebiasis continue to exist in the United States, both in institutions and in noninstitutional settings.

Amebiasis↗
PubMed1978

Intraerythrocytic parasitosis in humans with Entopolypoides species (family Babesiidae). Association with hepatic dysfunction and serum factors inhibiting lymphocyte response to phytohemagglutinin.

We have observed two cases of human infection with intraerythrocytic protozoa. The organisms appeared to be in the Entopolypoides group, which had not previously been associated with human infection. One patient was asplenic. Both patients had hepatic dysfunction, and their serum samples contained blocking factors that interfered in vitro with the stimulation of normal lymphocytes by phytohemagglutinin. It appears that in humans, as well as in experimental animals, host factors are important in resistance to infection by intraerythrocytic parasites. These factors include the presence of a spleen and cell-mediated and humoral immunities. Possibly similar infections will be observed in patients with other impairments of T-cell function, such as those induced by malignancy, thymic dysfunction, or immunosuppressive drugs.

Adult↗
PubMed1977

Human babesiosis on Nantucket Island. Clinical features.

Between 20 July and 15 Octoboer 1975, five cases of human infection with Babesia microti were diagnosed on Nantucket Island, Massachusetts. The illness was characterized by fever, drenching sweats, shaking chills, myalgia, arthralgia, extreme fatigue, and a mild-to-moderate hemolytic anemia. None of the patients had a history of splenetomy. Although all patients responded symptomatically to treatment with oral chloroquine phosphate, parasitemia and fatigue frequently persisted for several weeks to months.

Aged↗
PubMed1977

A communitywide outbreak of giardiasis with evidence of transmission by a municipal water supply.

Three hundred fifty residents of Rome, New York, had laboratory-confirmed cases of giardiasis between 1 November 1974 and 7 June 1975. A random household survey showed an overall attack rate for giardiasis (defined as a diarrheal illness of 5 days or more) of 10.6%. A significant association was discovered between having giardiasis and using city water and between having illness and drinking 1 or more glasses of water a day. The presence of human settlements in the Rome watershed area suggested that the water supply could have been contaminated by untreated human waste. The infectivity of municipal water was confirmed by producing giardiasis in specific pathogen-free dogs fed sediment samples of raw water obtained from an inlet of a city reservoir. A microscopic examination of the water sediments uncovered a Giardia lamblia cyst in one sample. This was the first time that a G. lamblia cyst has been found in municipal water in an epidemic and the first time that such water has been shown to infect laboratory animals.

Animals↗