Some newer knowledge in parasitology: a review

A review of the literature on parasitology, which we did not have the opportunity to get acquainted with during the Japanese occupation but which was made accessible to us after liberation, has disclosed a number of interesting facts and additional knowledge which are here presented for whatever benefit may be derived by the medical practitioners, medical students, and scientific investigators in this country. It includes new knowledge on: (1) the treatment of clinical malaria with bigger doses of atabrine-28 to 42 tablets of 0.10 Gm. for one course of 8 days instead of only 15 tablets in 5 days for adults; (2) the definite preference of the American forces for atabrine over quinine in both suppressive and clinical treatments of malaria; (3) the negative action of the wonder drug penicillin against induced or inoculation malaria in man; (4) the good effect of tyrothricin, another antibiotic, in experimental Plasmodium gallinaceum infection in chickens when given intravenously; (5) the most recently announced drugs such as Paludrine and SN 7618 against malaria: (6) the use of newer sulfonamides like sulfadiazine and sulfapyrazine in the eradication of the exo-erythrocytic stages of Plasmodium gallinaceum and the failure of the same drug against the same stages of Plasmodium elongatum; (7) the present status of immunity in malaria and its mechanism of production supporting the combined operation of the phagocytic and humoral theories; (8) the more recent attempt at active immunization of ducklings from Plasmodium lophurae infection with the use of plasmodial residues mixed with Staphylococcus toxoid, which may pave the way for the elaboration of a vaccine against human malaria; (9) the exo-erythrocytic cycle in malaria, with special emphasis on its present status as applied to the human species; (10) the use of DDT, the wonder insecticide of World War II in malaria control; (11) the new acid-ether technic of fecal examination for Schistosoma japonicum eggs; (12) the effectiveness of one part per million (1 P.P.M.) residual chlorine against Schistosoma japonicum cercariae when applied to infected waters; (13) the early manifestations of filariasis bancrofti and the use of the intra-dermal test for early diagnosis; (14) the improvement suggested in enhancing the positive diagnosis of amoebiasis by fixation of fecal smears at the bedside and the permanent staining afterwards of the same in the laboratory; (15) the present status of complement-fixation test in the diagnosis of amoebiasis; (16) the use of diodoquin as an anti-amoebic drug; (17) a report of vaginitis of amoebic etiology; (18) the possible pathogenicity of Dientamoeba fragilis; (19) some unusual radislogical findings in giardiasis which may prove confusing at times in the diagnosis of peptic ulcer; and(20) the previously unrecognized disease entity of man called human toxoplasmosis. (Summary)

A modified field stain for rapid staining of thick and thin blood smears

A modified Field stain for the rapid and accurate diagnosis of malaria in both thick and thin smears is here described. It is particularly useful in routine laboratory diagnosis and is very economical. Its usefulness may also be taken advantage of in studies of bone marrow, splenic, and brain smears; in other hematological studies; and in staining other haemoprotozoan parasites such as trypanosomes and microfilaria (Conclusion)

Results of a brief schistosomiasis survey around lake Mainit, Mindanao

The survey and field observations made by the writer in April, 1940, in Agusan and Surigao, around Lake Mainit, has brought to light for the first time a new endemic area in the Poblacion of Jabonga, Agusan, and confirmed previous findings regarding the endemicity of schistosomiasis japonica in some sitios of Mainit, Surigao. This survey showed an incidence of 6% in a series of 100 inhabitants in the first locality and 21.6% in a series of 125 in the second. In both localities, infected snails (Blanfordia quadrasi) were found and collected; and experimental infection of monkeys confirmed the fact that the fork-tailed cercariae obtained from them were no other than those of the S. japonicumIt is hoped that this paper would serve as a contribution to the accumulated data on the endemicity of schistosomiasis japonica in the Philippines, particularly around Lake Mainit, in northeastern Mindanao. The procedure followed and the findings in this survey may be of some help to present and future field workers in the campaign against this dreadful and serious disease, which is a great menace to the health of our people in endemic localities. More than that, it is hoped that this paper will stimulate interest and enthusiasm among medical men, especially the guardians of public health, because of the growing magnitude of this medical and health problem. (Summary and Conclusions)

Paragonimiasis westermani: an unexpected case with cystic formation in the anterior abdominal wall

1. A case of Paragonimiasis westermani diagnosed for the first time in life in the Philippines through a histopathological examination of an excised cyst from the anterior abdominal wall discharging pus through the umbilicus, is here presented as a unique contribution to the very meager literature on the subject. The parasitic nature of the cyst was never thought of even by the surgeons until after eggs were found in the tissue section, which were identified as Paragonimus ova by the senior author. This discovery through biopsy may be considered unusual at present; but it is hoped, that after this report, such findings would no longer be strange, especially considering that eggs of Paragonimus are found not only in the lungs but also in many other organs and tissues of the body. The attention of the general and cancer pathologists is called to this important possibility in biopsy2. A further study of the patient, as suggested by the histopathological finding, has revealed that it is not difficult to establish the presence of pulmonary paragonimiasis, since the ova are easily demonstrable both in the sputum and the feces. This procedure of demonstrating and recognizing the Paragonimus ova, especially in the grayish or brownish sputum of patient, can easily be done by a competent parasitologist3. The X-ray examination of this patient further revealed an important finding of cyst-like shadows on both sides of the lungs, more especially on the right, which, to the radiologist, is very suggestive of pulmonary paragonimiasis. The attention of the radiologist, especially those engaged in tuberculosis work, is called to this important X-ray finding; and, whenever such suspicious cases are encountered, the sputum of the patient whould always be examined, not only for T.B. bacilli, but also for Paragonimus ova. The stress should naturally be more in the intelligent and active search, in order to discover hidden, unseen, or hitherto unrecognized casesWith these few hints and the sustained interest of the entire medical profession all over the Islands in Paragonimiasis manifested either individually or with others who may have the facilities, we hope that, before long, we can become Paragonimus-conscious4. With the interest or Paragonimus-mindedness that might be brought about by the suggestions given in this paper, it is hoped that, in the near future, every-one will be able to contribute towards enriching our knowledge of Paragonimiasis, which is still very meager, because of our own neglect and indifference. (Summary and Conclusions)

The endemicity of schistosomiasis japonica in Sorsogon, Southeastern Luzon

For the first time, the endemicity of Schistosomiasis japonica in Irosin, Sorsogon has been definitely established, with the finding of both Oncomelania quadrasi snails and 22 human cases who had contracted the disease there. This is the first town in the island of Luzon so declared; and judging from conditions of climate and topography (low rice lands, and abundant streams) the neighboring towns of Juban and Bulan may also be marked as probable endemic fociIncidentally, it has also been found that paragonimiasis could be endemic in Irosin with the discovery of one case in a child of 7 years who had never left the town, and the presence of infected crabs in the place. (Summary and Conclusion)

Studies on schistosomiasis: Further surveys in Mindanao

We have presented in this report the results of another schistosomiasis survey undertaken from October 19 to December 17, 1948 covering an extensive area of almost the whole island of Mindanao, during which we succeeded to establish definitely new endemic foci in the following localities: - Sitio Simaya, jurisdiction of Malaybalay, province of Bukidnon; Mactan, the rice-growing sector in the Davao Penal Colony; Calinan, district in the outskirts of Davao City; Tamparan in the eastern side of Lake Lanao; Barrio Salug, Aurora and Barrio Nipaan, Dipolog, southeastern and northern Zamboanga, respectively. In all these places, 1932 stool specimens were examined and 131 were found positive for Schistosoma japonicum eggs. Oncomelania quadrasi snails were also foundIn addition, 14 cases were also encountered in Barrio Panikepan, municipality of Pikit-Pagalungan, province of Cotabato, ten of whom never left the province. Despite an intensive but fruitless search for snails in and around that vicinity, the history of each of those ten cases who never left the province, strongly indicates that they could not have been infected elsewhere. Further search for snails in the future in these places may finally confirm this assumptionIn the light of the findings of this and of previous other surveys, it is very evident that the geographical distribution of schistosomiasis in the Philippines is much wider now than it was thought before. This should excite more and more the interest of all physicians throughout the country so that they will always be on the lookout for the first cases in their respective localities. Once, definite clues are found, we shall always be ready to assist in making a more thorough investigation, if called upon to do so. (Summary)

Schistosomiasis reconnaisance in North-Western Mindanao

Surveying the area around Panguil Bay in northwestern Mindanao from June 14 to 26, 1948, the writer was able to establish for the first time new endemic areas in southern Occidental Misamis and eastern Zamboanga, especially in the several barrios of the municipalities of Bonifacio and Tangub, Occidental Misamis; and in the barrios of the municipality of Aurora, Zamboanga, just south of the Occidental Misamis-Zamboanga boundary. The endemic focus in Maranding, Lanao discovered by Wright et al in 1945, was also confirmed; but it was found that this focus had extended as far as the adjoining barrios of Botadon and Balili towards the Lanao-Zamboanga boundaryOf the 304 stools examined in the area surveyed, 111 were found to be positive for Schistosoma japonicum eggs. Oncomelania quadrasi snails were found in the barrios of Santa Cruz, Liloan, Abaga, Usogan, Baluktot, Tambulig, Maramnding, and Botadon. The incidence of the disease in Liloan was found to be 17.4%The circumstances leading to the discovery of these new endemic foci are described; and the role that health officers, hospital physicians, maternity and charity clinic physicians, and private practitioners can play in the nationwide schistosomiasis-control program-especially in discovering new foci-is tressedBased mainly on climatic considerations and the possible influence of climate on the geographical distribution of schistosomiasis in the Philippines, it may be predicted that this disease may also be found sooner or later in other areas with the second and fourth types of climate-namely, the eastern half of Zamboanga, the eastern tip of Oriental Misamis, southern Bukidnon, Cotabato, Davao, western Leyte, Bohol, northern Cebu, central and northern Capiz, the Bicol provinces including Catanduanes, Tayabas, and parts of Nueva Vizcaya, Isabela, and Cagayan. However, such other factors as soil, topography, and types as well as amount of vegetation should also be considered. (Summary and Conclusion)

Studies on schistosomiasis: Second progress report on mass survey and other accomplishments as of December 31, 1951

From one field unit trained, equipped, and organized in 1949-later increased to six in 1950, then to eight in the early part of 1951-but which was reduced to seven toward the end of the same year,-we have been able to make extensive fact-finding surveys of 132 towns of 16 provinces in the Philippines continuously for two and one-half years ending on December 31, 1951. The results obtained in these surveys are presented in this paper, with tables and maps showing the incidence and distribution of the diseaseEndemic areas were definitely established in 61 towns of 12 provinces, 123,291 people were examined, and a total of 10,796 cases were found positive on stool examination, giving a general incidence of 12.2%. Of these cases, 5,318 were treated with Fuadin; and 272, with NilodinSnail surveys in all these towns except one (Barugo) revealed many streams and swamps positive for Oncomelania quadrrasi snails. The spotty distribution of the snail population was quite striking-the snail density ranging from a few to several hundreds per square meter. An index of all these spots (816 in all) which were found positive for Oncomelania quadrasi snails was prepared with the corresponding map for each town. These indexes and maps now form the bases of our studies on snail controlOur previous finding in 1950 showing the exceedingly high incidence of intestinal parasitism, reaching 98.79% even in areas where schistosomiasis was not found, was further confirmed in these series of 123,291 stool examinations, with an incidence of 97.82%. We also found an incidence of 85.77% for arcariasis; 52.7% for trichuriasis; and 38.75% for hookworm infectionWith the conclusion of these surveys, it is anticipated that, given more time for the analysis and study of the data obtained, and with the forthcoming technical assistance from the WHO, we may be able to prepare a well-balanced national schistosomiasis control program which we hope will be possible of implementation in the near future. (Summary)

Analysis of 4,302 cases of schistosomiasis japonica

An analysis, in part, of 4,302 cases of Schistosomiasis japonica encountered in the different towns of ten provinces covered by the six field units during the fiscal year, 1949-1050 was presented as to age, sex, and grade incidenceAmong them, there was a predominance of males (60.07%) over females (39.93%). Among 3,004 whose age records were available, 1,680 (55.44%) were from 11 to 20 years old and 651 (an additional 21.68%) below ten years. It is evident from these figures that the majority of them contracted the disease before reaching the age of 20A new scheme of classification of patients, introduced for the first time, was used in selecting patients as subjects in connection with research projects undertaken by all field units. This scheme was found to be practical and useful but because it is new, it may further be improved. (Summary)

Intradermal test for schistosomiasis japonica (preliminary report)

The results of our preliminary study on intradermal test on 532 subjects, using antigens prepared by us, are here presented and discussed. Thre principle of the test, preparation of the antigens (adult and cercaria), and technique of testing are explainedThis study seems to indicate that intradermal test may augment our methods of diagnosis of schistosomiasis, especially in mass-screening campaigns or mass stool surveys. To be of real significance, however, a potent antigen, freshly prepared, and whose dosage has been standardized with known positive and known negative controls should be used. For routine purposes, a dose of 0.01 to 0.02 of the 1:1000 or 1:2000 dilution of the adult antigen solution may be recommended. In the case of the cercarial antigen, we obtained a fairly good result, with 0.1 cc of the 1:600 dilutionAmong our negative controls, the presence of other parasites, such as ascaris, trichuris, and hookworm, filaria, and paragonimiasis, did not provoke false positive reactions. No false positive reaction was observed in one case of malaria and in one case of infectious hepatitis. (Conclusions)

Studies on liver function tests in schistosomiasis japonica

From the foregoing liver function tests made on 96 schistosomiasis patients before, during, and after one series of Fuadin treatment, we feel justified to make the following statements: 1. There was no interference in the bile flow in almost all of them, except in three who were in the late stage of the disease2. Appreciable liver cell damage was hardly noted in patients in the early stage of the disease, but were more apparent towards the late stage, depending on the condition and the degree of cirrhosis present3. Treatment with Fuadin seems to have improved the state of the liver, particularly in those patients treated in the early stage; but only slightly in those treated in the late stage. It may be added that Fuadin therapy did not seem to aggravate the existing condition in the liver in those cases, in spite of the appearance of certain toxic reactions in a number of them. It would seem unjustified, however, to push Fuadin further in those that showed toxic reactions. (Summary)

Hematological studies in schistosomiasis japonica

In 95 schistosomiasis patients, who were all positive for Schistosoma japonicum ova in the stools, our hematological studies revealed the following picture: A. Before Fuadin Treatment: 1. Strong tendency for the production of macrocytic hypochromic type of anemia with an erythrocyte count ranging from 4.033+-0.083 millions to 3.722+-0.85 millions in the early stage; and a marked decrease towards the late stages, with counts ranging from 2.656+-0.465 to 3.404+-0.1652. A leucocyte count from 11,038+-1,995 to 15,376+-891 in the early stages, with an eosinophilia ranging from 25.13 to 28.26%; and normal lymphocyte percentage and a tendency to lencepenia towards the late stage3. There was an increase sedeimentation rate, ranging from 23.66 to 47.83 mm. per hour4. Target cells were present in 68% of the casesB. During Fuadin Therapy: 1. A tendency for the anemia in the early stages to become normocytic hypochromic in type, and the late stages to remain macrocytic. Fuadin did not cause a further decrease of the Rbc count2. A slight decrease of the leucocyte counts in the early stages, ranging from 8,738+-583 to 12,018+-1,408, with a further increase of eosinophilia, the values ranging from 34.24 toi 35.63% in the early stages and from 25.99 to 43.2% in the later stages3. The sedimentation rate remained apparently the same as before treatment4. Target cells were present in 80% of casesC. After Fuadin Treatment: 1. Production of normocytic hypochromic anemia in almost all stages, with an almost stationary erythrocyte count in the early stage and a relative increase in the later stage2. Leucocytosis was still seen in the early stages, and even in the later stage, with eosinophilia still present, ranging from 28.14 to 35.44%3. There was a noticeable drop in sedimentation rate as compared with values before treatment4. Lymphocytosis was seen in all cases, with 30.66 to 38.14%5. Target cells were seen in 77% of casesThe concomitant presence of hookworm ova did not alter the macrocytic type of anemia found in schistosomiasis patientsFuadin, in its therapeutic dose, did not aggravate the blood picture. On the contrary, it could be the one that might have produced improvement. (Summary and conclusion)

Evaluation of fuadin therapy in schistosomiasis japonica

Treatment with Fuadin was tried in 2,407 patients who were found positive for Schistosoma japonicum ova on stool examination. These patients represented both sexes of all ages ranging from 5 to 50 years. Only 1,135 were able to complete one course of 40 cc. given intramuscularly in nine injections. Of this number, 1,083 were followed-up during and after treatmentAt the end of one course, 847 or 78.21% ceased to pass viable ova; 236 or 21.79% were still positive on stool examination . Of these 236 patients, 62 continued to receive additional injections until all became negative. Taken together, 909 or 83.91% no longer passed ova in the stool at the end of treatmentOnly 334 out of 909 were followed-up one month after completing treatment, and 34 or 9.28% were again positive for eggs. These cases were considered relapses or treatment failures rather than re-infectionsToxic reactions appeared in 63.3% (718) of the 1,135 patients, the most common of which were nausea, vomiting, and anorexia, general body weakness, headache, joint pains, and fever. Despite these reactions, the whole course of nine injections was continued in the 1,135 patients by simply prolonging the interval of injection as long as the toxic reactions were still present. (Summary)

Field studies on the treatment of schistosomiasis japonica with nilodin

Nilodin was tried in 238 cases of Schistosomiasis japonica, most of whom were early cases; but only in 233 was the treatment completedThe total dosage given per treatment was 60 mgm. per kilo body weight, administered by mouth in divided doses for a period of three to six days, proportionately reduced in children according to weight. That an adult of 50 kg. received a total of three Gm. or one Gm. a day for period of three days or 0.5 Gm. a day to six daysThe results showed that, of the 233 who completed the treatment 218 or 93.24% were still positive for viable eggs from one to four weeks after the treatment; only 13 or 5.40% became negativeToxic reactions, which were usually too mild and insufficient stop treatment, occurred in 229, or 96.6%, of the casesJudging from the results of this study, it would seem that Nilodin is not effective in the treatment of Schistosoma japonicum, with the same dosage used against S. mansoni and S. baematobium infections. It is hoped, however, that further studies on this treatment, with increased dosage, will be made. (Summary)

Screening of chemical compounds for molluscicidal activity against Oncomelania quadrasi

In view of the inherent problems associated with the medical, sanitary and educational approach to the control of schistosomiasis, it is the consensus that the control of the small intermediate host offers a better and more effective means of reducing the transmission of the disease. Having achieved some degree of success in the ecological control of the snail host (Oncomelania quadrasi) in the Philippines as shown by the evaluation done in 1962 by Hairston, a WHO Consultant it has nevertheless been noted that due to the varied hopographic characteristics of small areas, complete eradication may not be attained in certain instances. For it was noted that snails had continued to thrive in small pockets after ecological control measures had been applied. Molluscicides at this stage, therefore, could be used to great advantage as a terminal measure. (Author)

Serological studies in El tor cholera

Three test were utilized, namely agglutination, vibriocidal and the hemolysis-inhibition tests in determining the serological responses of 161 immunized individuals in this study. Three vaccines were given in different dosage regimen - El Tor, mixed El tor and cholera , and classical cholera vaccines. Higher agglutinative and vibriocidal antibody titers were obtained among those immunized with two or three doses of El Tor vaccine than with the other two types of vaccines. The agglutinating antibody response to classical Inaba and Ogawa challenge by those given the El tor vaccine was even higher than those that received classical cholera vaccine. Antibodies to both classical and El Tor strains of cholera vaccine but to a lesser degree than by either the pure El Tor or the mixed vaccine. These differences in percentage with rise in agglutinative titer were found significant by statistical analysisIt was further obseved that the reduction in vibriocidal antibody titer was not as marked as in the agglutinative antibody titer 6 months after primary immunization. It is of special interest and utmost importance to note that the usual single 1 cc. adult dose given as a booster 6 months after the primary immunization failed to produce sufficient agglutinative antibodies and on this basis it is felt that the double regimen should instead be preferred. (Summary)

The role of the enteroviruses in the etiology of aseptic meningitis

Direct isolation of the virus from the cerebrospinal fluid in 46 out of 100 consecutive cases labeled with the clinical diagnosis of aseptic meningitis undertaken over a period of 29 months from March 1964 to July 1966 is here reported. In all of them, tissue culture using primary monkey kidney cells was employed. All those negative in tissue culture were inoculated in suckling mice. Of the 46 strains of enteroviruses isolated, the Coxsackie group (Types A9, B1, and B4) accounts for 28 or 61; followed by polioviruses (Types 1, 2 and 3) in 22 and ECHO viruses (Types 7 and 14) in 17. Coxackie group B Type 1 virus, poliovirus Type 1 and ECHO virus type 14 were the predominant types in each of the three groups in each year of the study. However, Coxackie B Type 1 comprised the most frequent type isolated during the whole period of studyAmong the different age groups studied, the viruses were mostly isolated in children 15 years and below in 98 with Coxsackie group B predominating. The polioviruses were encountered mostly in the 1-4 and 5-9 age groups. These findings were constant from year to year showing a distinct pattern. The frequency of isolating the ECHO virus, on the other hand, varied greatlyAs far as it can be ascertained, this is the first time that the causal relation of the enteroviruses with sporadic cases of aseptic meningitis has been established in the Philippines with the Coxsackie, polio and ECHO viruses as the most frequently encountered in that order. From the figures on the frequency of enteroviruses association, it appears that aseptic meningitis is a syndrome of diverse etiology associated most frequently with the members of the enterovirus groupWith this new knowledge, the clinician may now be able to explain why the group manifesting signs and symptoms of aseptic meningitis does not respond to antibiotic therapy. (Summary)