Transfer factor: delayed hypersensitivity to Schistosoma mansoni and tuberculin in Macaca mulatta.

Delayed hypersensitivity in Macaca mulatta infected with either Schistosoma mansoni or mycobacteria was demonstrated by biopsies of skin test sites. Both dialyzable and nondialyzable leukocyte extracts from infected donors transferred delayed hypersensitivity to recipient monkeys. In two recipients, skin test conversion was associated with in vitro transformation of the recipients' lymphocytes.

A direct agglutination test for leishmaniasis.

Antigen suspensions of enzyme-treated, formalin-fixed promastigotes of three species of Leishmania (L. donovani, L. tropica, and L. braziliensis) were evaluated by using the direct agglutination test with serum samples from healthy individuals and patients with confirmed cases of visceral and cutaneous leishmaniasis. High cross-reactivity was obtained with the three antigens in tests with leishmania sera. Sera from patients with kala-azar were 61% to 96% positive when tested with all three antigens. In tests with sera from patients with American cutaneous leishmaniasis, 81% were positive with L. donovania and L. braziliensis antigen, whereas only 54% to 55% were positive with the other two antigens. Normal sera were reactive at low dilutions of 1:16 or less with L. braziliensis antigens. Normal sera tested with L. tropica antigen reacted to a titer of 128.

The serologic response of hamsters to experimental liver inoculations with Entamoeba histolytica as measured by indirect hemagglutination test and enzyme linked immunosorbent assay.

Results of testing 298 sera from hamsters inoculated in the liver with Entamoeba histolytica and from 25 uninoculated controls by indirect hemagglutination (IHA) and enzyme linked immunosorbent assay (ELISA) showed that measurable amounts of antibody appeared as early as 5 days after inoculation, generally increased to a high level within 20 days, and persisted for the duration of the experiments (58 days). There was fair correlation between size of liver lesion and titers. Strain differences in amebae used for antigen and for inoculation could not be detected by either test. The IHA test appeared to be very sensitive, and titers of 1:16 and above were specific. With the ELISA technique, it was tentatively concluded that titers of 1:32 were specific for anti-amebic antibodies but only those of 1:128 and above were indicative of liver infections in the experimentally infected hamsters.

The indirect hemagglutination test for malaria. Evaluation of antigens prepared from Plasmodium falciparum and Plasmodium vivax.

Soluble antigens were prepared from Plasmodium falciparum and P. vivax and were evaluated in the indirect hemagglutination test. These antigens, attached to aldehyde-fixed type "O" erythrocytes, detected antibodies in more than 91% of infections with the homologous Plasmodium species. Detection rates in infections caused by the heterologous species ranged from 72% to 76%. Positive reactions occurred in less than 2% of sera from persons without malaria infection.

Comparison of counterimmunoelectrophoresis (CIE) with other serologic tests in the detection of antibodies to Trypanosoma cruzi.

Application of counterimmunoelectrophoresis (CIE) in detection of antibodies against Trypanosoma cruzi in sera of 180 subjects from an endemic area (Bolivia), and 50 subjects from a nonendemic area (U.S.A.) was carried out, and the results were compared to ones obtained with latex agglutination (LA) and indirect hemagglutination (IHA). The optimal conditions for CIE were determined to be as follows: barbitone buffer of pH 8.2 and ionic strength 0.05 M was used in the chambers and in preparing the 1% agarose plates. The wells in the plates were 5 mm in diameter and 3 mm apart. Electric current was applied at 500 volts and 25 mA for 60 minutes. T. cruzi antigen (Center for Disease Control) was used in a dilution of 1:2. The sera were studied undiluted. The study population comprised the following groups: LA+ IHA+ (group I); LA+ IHA- (group II); LA- IHA+ (group III); LA- IHA- (group IV); and the control group (group V). Each group was comprised of 50 sera, except for group II which was comprised of only 30 sera. Antibodies were detected by CIE in 94% of sera in group I, 40% in group II, 76% in group III and 6% in group IV. There were no positive reactions in group V. CIE was positive in 74% of sera from the combined LA+ serum groups (I and II), and in 85% of sera from the IHA+ groups (I and III). A good correlation between CIE and the other tests in the LA+ and IHA+ group (I), and the lack of false positive reactions in group V suggest that CIE is a good diagnostic method for detection of T. cruzi antibodies. However, this study showed that IHA is a more sensitive test in epidemiological surveys than CIE. The finding of 6% sera positive by CIE in group IV may indicate a lower specificity of the test.

Acquired immunity in B cell-deficient mice to challenge exposure following primary infection with Schistosoma mansoni.

Mice were made B cell-deficient by injections of globulin prepared from goat antimouse mu-chain serum. Anti-mu globulin was administered throughout the experiments (18 or 23 weeks). B cell deficiency was determined at the time of assay of worm burden levels (7 weeks after challenge with Schistosoma mansoni) by quantitation of serum IgM and IgG, by assaying the specific antibody response to cercarial and adult worm antigens in enzyme-linked immunosorbent assay and by histologic examination of the spleen and mesenteric (regional) lymph nodes. Four-week-old mice were exposed to S. mansoni and 8 weeks later were challenged with a second exposure. The B cell-deficient mice developed a degree of resistance (79%) similar to that of the intact controls (81%). The IgM and IgG levels of the B cell-deficient mice were markedly suppressed. Follicular development was not detected in their lymph nodes; but in the spleen of some animals clusters of cells morphologically similar to B cells were observed peripheral to a central T cell-like area. B cell-deficient mice developed schistosome egg granulomas comparable to those of the intact controls. Control animals developed an antibody response with titers of 1:64 to 1:1,024 against cercarial and adult worm antigens; B cell-deficient animals were nonreactive in these assays. The data suggest that specific antibody does not play a major role in resistance acquired within 8 weeks as a result of a primary infection in murine schistosomiasis.

Schistosoma mansoni infection in intact and B cell deficient mice: the effect of pretreatment with BCG in these experimental models.

The course of infection with Schistosoma mansoni was determined in B cell deficient mice by means of a schistosomule lung recovery assay 6 days after infection or by determination of the adult worm burden 7 weeks after infection. The intensity of infection was not significantly different from that in age- and sex-matched intact controls. B cell deficiency was demonstrated by absence of surface immunoglobulin-bearing cells in the spleen and by absence of B cell areas in the lymphoid follicles of the spleen and mesenteric lymph nodes. In addition, B cell deficient mice infected for 7 weeks with S. Mansoni were unable to form anti-schistosome antibodies detectable by the Cercarienhüllenreaktion. A normal granulomatous response, however, was observed around schistosome eggs. Pretreatment with BCG suppressed infection with S. mansoni comparably in intact and B cell deficient mice. A marked depletion of eosinophils occurred in the schistosome egg granuloma of all BCG treated mice.

Investigation of the EVI antibody in parasitic diseases other than American trypanosomiasis. An anti-skeletal muscle antibody in leishmaniasis.

The specificity of a circulating antibody observed in American trypanosomiasis and reacting with endocardium, blood vessels, and the interstitium of striated muscle (EVI factor) was evaluated in the indirect fluorescent antibody test with 60 sera from patients with malaria, leishmaniasis, echinococcosis, amebiasis, African trypanosomiasis, toxoplasmosis, and trichinosis, collected from areas where Chagas' disease is not endemic. Two sera, 1 from a patient with Plasmodium falciparum malaria and 1 from a patient with a relapse pretreatment post kala-azar dermal leishmaniasis, were positive for the EVI factor. In the leishmaniasis group, 3 of 8 sera reacted with 0ovine, murine, and human skeletal muscle. In this reaction, which differs from the EVI test, the sarcolemma and the intracellular structures were stained.

Evaluation of the slide-latex agglutination and intradermal (Casoni) tests for echinococcosis.

Fifty-one patients with surgically proven hydatid disease were examined with the intradermal (ID) (Casoni) and latex-agglutination (LA) tests. Before surgery, results of the former test were 80.4% positive and of the latter were 82.3%. For 105 persons who were diagnosed free of hydatid cysts by surgical, clinical and serological observations, 6.7% were positive with the ID test and 4.8% with the LA test. The close agreement between results obtained with the LA and ID tests in this selected group of patients suggests that the LA test merits further evaluation as a diagnostic tool.

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.

Hydatid disease screening: Sanpete County, Utah, 1971-1976.

Between 1971 and 1976 approximately 20% (2,265) of the population of Sanpete County, Utah, was screened for hydatid disease (Echinococcus granulosus) by intradermal, indirect hemagglutination, and bentonite flocculation tests. Of 34 persons who had follow-up chest radiographs and radioisotope liver scans, 6 were found to have asymptomatic hepatic cysts. If a participant who had pulmonary cysts and negative screening tests were included, the prevalence of asymptomatic hydatid disease would be 3 per 1,000. During the same period, 82 (148 per 1,000) of 553 dogs successfully purged and examined had E. granulosus infections. Human cyst carriage was associated with dog ownership, particularly of infected dogs or in conjunction with sheep raising as the main livelihood. Combinations of immunodiagnostic tests were more efficacious in identifying cyst carriers than the tests used singly. Limitation of screening to high risk groups (e.g., sheep raisers with dogs) can reduce costs without reducing yield. Optimum management of the cyst carrier awaits further information on the natural history of asymptomatic hydatid disease.

Epidemiologic investigation of echinococcosis in American Indians living in Arizona and New Mexico.

Ten cases of echinococcosis diagnosed in American Indians in Arizona and New Mexico between 1972 and 1975 were investigated as part of a regional epidemiologic study. Patients were visited at home to discover factors associated with local parasite transmission, to detect possible additional cases among family members, and to perform diagnostic tests on dogs. Six patients were Navajo, 2 Zuni, and 2 Santo Domingo Indians. An additional case in a Navajo man was detected by serologic testing of patients' family members; this was the 20th case diagnosed in the region since 1965. Dogs owned by three of the Navajo patients were infected with Echinococcus granulosus. Arecoline-purge testing of 110 dogs in the Zuni pueblo demonstrated echinococcosis in a single stray dog. The findings at slaughter of Navajo-owned sheep indicate that the infection is enzootic in this intermediate host. The epidemiologic findings suggest that humans were infected from dogs which contracted their infections from two sources. The first was sheep raised locally in rural areas of the Navajo Reservation where the infection is enzootic in the dog-sheep cycle; transmission was apparently facilitated by the widespread practice of home butchering. A second source of human infection was dogs which became infected by eating viscera of sheep of off-reservation origin; these sheep were purchased and butchered by individual families in urban areas of the Navajo Reservation and in the Zuni and Santo Domingo pueblos.

Gross and histological studies of immediate, Arthus, and delayed skin test responses to schistosome antigen, and of delayed response to ubiquitous antigens in Egyptians.

Gross studies of skin reactions to adult antigen of Schistosoma mansoni were made on 156 hospitalized patients with schistosomiasis and 114 subjects from the nonendemic area of Hurghada in Egypt. Wheal areas equal to or greater than 1.0 cm2 indicated a positive immediate (15-min) reaction to adult worm antigen; the criterion of positivity for both 24-hour and 48-hour delayed reactions was an area of induration equal to or greater than 0.6 cm2. Immediate reactions with adult worm antigen were observed in 99% of the patients with schistosomiasis and 11% of the subjects from Hurghada: the percentages with delayed reaction were 58% and 2%, respectively. Biopsies of skin test sites at various intervals after antigen injection were done on 87 individuals. Eosinophilic and mononuclear infiltrates were characteristic of immediate and delayed skin responses, respectively. Biopsies from 22 patients with marked skin reactions 5 hours after antigen injection showed that a neutrophilic response indicative of Arthus reactivity was present in only 18. Thus, Arthus reactivity could not be determined on gross appearance alone. The studies did not show any evidence of delayed basophilic hypersensitivity to schistosome antigen. Immunofluorescent studies on a small number of biopsies suggested that a late phase (5-hour) reaction due to IgE may occur in some patients. Delayed reactivity to mumps and/or monilia skin test antigens was observed in 91% of Egyptians in a nonendemic area of schistosomiasis. Delayed hypersensitivity to PPD was detected in 44% of the same group.

Acute lymphatic filariasis in an American traveler.

Acute lymphatic filariasis developed in an American traveling recreationally to Asia. The illness was characterized by fatigue, eosinophilia, and lymphedema of the arm and chest wall, but no lymphangitis, lymphadenitis, or pain. Complete resolution occurred over 1-2 years. We discuss this syndrome and describe the use of new diagnostic tests in its diagnosis and management.

Use of a nomogram to quantitate plasma dilutions for serological testing following blood collection in capillary tubes.

A technique for the processing and quantitation of small volumes of plasma collected in heparinized capillary tubes is presented using a nomogram that determines the final amount of diluent needed for variable volumes of plasma.

Serodiagnosis of human cysticercosis by microplate enzyme-linked immunospecific assay (ELISA).

The micro-ELISA described in this report is simple and can give objective results for the serodiagnosis of human cysticercosis. The visual assessment of results was satisfactory. The ELISA results showed a remarkably good correlation with IHA. It gave good reproudcibility. Cross-reactions were eliminated by using whole worm antigen instead of the cysticercus.

Adoptive transfer of protective immunity in experimental schistosomiasis in the mouse.

Passive transfer of immune serum alone did not confer protection to recipient mice irrespective of the routes of serum transfer or cercarial challenge of Schistosoma mansoni. Mice that received both sensitized cells and immune serum were protected against challenge by subcutaneous injection of cercariae but not by percutaneous exposure. The immune serum could be transferred as late as 8 days after subcutaneous challenge, suggesting that the protection was afforded in part by a late parasite killing mechanism which functions after the schistosomula have migrated through the lungs.

Immunologic studies on hamsters infected with Entamoeba histolytica.

The serologic and cell-mediated immune responses of hamsters exposed to 2 strains of Entamoeba histolytica (HM-1 and HM-19) were evaluated by a series of in vitro tests. The pathogenicity of the 2 strains was evaluated in terms of their ability to produce liver abscesses and spleen enlargement. Antibody response was evaluated by the indirect hemagglutination test. The cellular immune response was assayed by increased DNA synthesis by lymphocytes and migration inhibition of macrophages.

Evaluation of an autoimmune type antibody in the sera of patients with Chagas' disease.

Utilizing cryostat sections of mouse heart as antigen, antibodies in the sera of patients with Chagas' disease were investigated for autoimmune-type interation. Sera from 47 normal, 70 patients with various contagious diseases, 116 sera from persons with leishmaniasis, and 90 from persons with Chagas' disease were evaluated. Antibodies in 44% of the sera tested from persons from Chile with xenodiagnostically proven infections of Chagas' disease showed antibodies that interacted with the heart sections of 65 sera from Brazil, 29 were positive by the complement fixation test, and 25 of these reacted with the heart sections. Of the 116 leishmania sera, 24 (20.7%) were reactive in the test. A second type of staining of heart tissue reported for patients with leishmaniasis was observed in 23 sera from patients with this disease and 34 sera from patients with syphilis, rheumatic fever, and malaria. This reaction was not observed in normal sera or in sera from patients with Chagas' disease.

Studies on putative adult worm-derived vaccines and adjuvants for protection against Schistosoma mansoni infection in mice.

Intraperitoneal transfer of viable adult worms of Schistosoma mansoni did not confer protection against a challenge infection to recipient mice. Antigens of schistosome origin were evaluated for their ability, with and without concomitantly administered nonspecific adjuvants, to stimulate protective immunity against S. mansoni. Freshly perfused ground worms or a putative membrane antigen extracted with 0.5 M KC1 from adult worms, when injected together with Corynebacterium parvum (or in a single experiment with poly [A : U]), resulted in a significant reduction in worm burden of a challenge infection with S. mansoni as compared with that of untreated controls. The membrane antigen was maintained carefully at low temperatures in buffers capable of retarding enzymatic degradation while it was being prepared.