Showing papers on "Plasmodium vivax published in 1973"

A comparative study on the ultrastructure of plasmodium sporozoites within the oocyst and salivary glands, with particular reference to the incidence of the micropore

Abstract: 1. 1. The ultrastructure of sporozoites of 5 species of malaria parasites, Plasmodium vivax, P. cynomolgi, P. gallinaceum, P. berghei nigeriensis and P. vinckei chabaudi has been studied both in the o6cyst and the salivary gland of the mosquito. 2. 2. Micropores were readily found in both situations in P. vivax, P. cynomolgi and P. gallinaceum , but none were detected in the rodent species. 3. 3. Usually only 1 micropore was seen in the sporozoite; 2 micropores were seen in single sporozoites of P. cynomolgi , and on one occasion 6 were seen on the surface of the maturing sporoblastoid in P. vivax . 4. 4. Sections of 2,000 sporozoites were examined in each group, the incidence of the micropore was rather over 1%, though it reached 5% in sporozoites of P. cynomolgi in the salivary gland. 5. 5. There was little difference in the incidence of the micropore between the oocyst and salivary gland. 6. 6. The possible relationship between the absence of a micropore in the sporozoites of the rodent species and the well known poor infectivity of these parasites is discussed.

Studies on human malaria in Aotus monkeys. I. Sporozoite transmission of Plasmodium vivax from El Salvador.

Abstract: Monkey-to-monkey transmission of a strain of Plasmodium vivax from El Salvador was obtained on 12 occasions via the bites or intrahepatic and/or intravenous inoculation of infected salivary glands from Anopheles freeborni, A. albimanus, A. maculatus, and A. balabacensis balabacensis mosquitoes. The prepatent periods ranged from 14 to 48 days. The mean prepatent period was 34 days in intact monkeys and 29 days in splenectomized animals. The transmission rate was approximately the same in intact (57%) and splenectomized (53%) monkeys. Since Porter and Young (1966) reported the successful infection of Aotus trivirgatus monkeys with Plasmodium vivax from Panama, there has been a great deal of interest in the use of these animals as biological models for many different malarial studies. Young et al. (1966) and Porter and Young (1966) reported the successful transmission of P. vivax from the owl monkey to man via the bites of Anopheles albimanus mosquitoes. Subsequently, Baerg et al. (1969) reported transmission of P. vivax from A. trivirgatus and Ateles fusiceps to A. fusiceps, A. trivirgatus, and Saguinus geoffroyi via the bites of A. albimanus mosquitoes. Ward et al. (1969) showed that the Chesson strain of P. vivax could be transmitted with relative ease to A. trivirgatus monkeys via the bites of A. balabacensis balabacensis, A. stephensi, and A. quadrimaculatus mosquitoes. Since 1966, we have studied a number of different isolates of the human malarias in Aotus monkeys. This paper, the first of a series, reports the results of attempts to transmit a strain of P. vivax from El Salvador from monkey to monkey by sporozoite inoculation. MATERIALS AND METHODS The Sal II strain of P. vivax was isolated from a natural infection in the area of Las Guarumas, in the state of La Paz, El Salvador. Blood was inoculated into an A. trivirgatus monkey (AO-219) which was then provided to us by the staff of the Central America Malaria Research Station, CDC, San Salvador. The strain has been maintained by Received for publication 9 March 1973. * Center for Disease Control, Malaria Program, 1600 Clifton Road, Atlanta, Georgia 30333. serial blood or sporozoite passage in A. trivirgatus monkeys. The A. trivirgatus monkeys were obtained commercially, their origin being Colombia, South America. Prior parasitologic and serologic examinations indicated that they were free of natural malarial infection. Some of the animals were splenectomized prior to infection according to the technique of Sodeman et al. (1970). The A. freeborni mosquitoes were originally from Marysville, California, and have been maintained in the laboratory since 1944. The A. maculatts were obtained from the Institute for Medical Research, Kuala Lumpur, Malaysia, in 1964 and have been maintained in our laboratory since then. The A. balabacensis balabacensis colony was originally from Thailand and was obtained from the Walter Reed Army Institute of Research. The A. albimanus were the Apastepeque strain from El Salvador and obtained from CAMRS, San Salvador, in 1971. For the transmission attempts, sporozoites were introduced either by the bites of infected mosquitoes or by the intrahepatic and/or intravenous inoculation of sporozoites from dissected salivary glands. The technique for the intrahepatic inoculation has been reported previously (Held et al., 1967; Sodeman et al., 1969). For the transmission attempts by mosquito bite, mosquitoes were individually caged and allowed to feed on the restrained monkey. After biting, the mosquitoes were dissected and the salivary glands examined for the presence of sporozoites. The gland infections were graded 1+ (1 to 10 sporozoites), 2+ (11 to 100 porozoites), 3+ (101 to 1,000 sporozoites), or 4+ (greater than 1,000 sporozoites). Daily blood smears were made beginning 7 days after sporozoite inoculation to determine the prepatent period. Blood smears were stained with Giemsa.

Five day primaquine therapy--an evaluation of radical curative activity against vivax malaria infection.

Abstract: The radical curative efficacy of the 5-day primaquine regimen for vivax malaria was assessed in nonimmune volunteers infected with a West Pakistan strain of Plasmodium vivax. Treatment of each primary attack was with chloroquine, 1,500 mg base followed by primaquine, 15 mg base daily for 5 consecutive days. There was a 100% failure rate of radical cure for the 5-day primaquine regimen. Data on the pattern of relapse activity for this strain are included.

Studies on human malaria in aotus monkeys. 3. Exoerythrocytic stages of the Salvador II strain of Plasmodium vivax.

Abstract: Exoerythrocytic stages of the Salvador II strain of Plasmodium vivax were demonstrated in sections of liver tissue from Aotus trivirgatus monkeys following the intrahepatic inoculation of sporozoites from Anopheles freeborni and A. maculatus mosquitoes. Six-, 7and 8-day forms were seen. In general, they appeared to be morphologically similar although smaller than those reported from

Transfusion-Induced Malaria: Plasmodium vivax in a 5-Month-Old Child

Abstract: A 5-month-old infant developed malaria 16 days after cardiac surgery. After transfusion, one must consider the possibility of transfusion-induced malaria in any patient with the triad of fever, hepatosplenomegaly, and hemolysis.

A multi-species malaria antigen for use in the indirect fluorescent antibody test.

Abstract: A multi-species thick smear antigen containing equal proportions of P. vivax, P. falciparum, and P. brasilianum schizonts was prepared for use in the indirect fluorescent antibody test for malaria. Tests with 80 sera showed that antibody titres with the multi-species antigen always equalled or exceeded the highest titre obtained when the sera were tested with the constituent mono-species antigens. Use of the multi-species antigen greatly reduces the time and labour required to screen serum specimens for malaria antibody. This study confirms the need for homologous antigens of all species to be detected if maximum sensitivity and reactivity are to be achieved.

Malaria reference laboratory.

Abstract: Farrow has set down this patient as not surviving for one year. In our data we have included her as a one-year survival. Accepting these differences our one-and-two-year survival figures would be 82% and 80% instead of our published figures of 85% and 82%. In fact, 10 months have now passed since the figures were compiled, and one further graft has been lost (one of the livedonor transplants). All of the remaining grafts are still functioning and have done so for at least 12 months, giving an actual overall one-year survival of 85%. If the cadaver transplants are taken alone, then the comparable figure is 82%. Two-year graft survival figures calculated on the actuarial method of Barnes will give us an overall two-year survival of 80% based on 12 of the 33 grafts which have now passed the two-year mark. The mortality for this group remains at 6%. While we have no doubt that Dr. Farrow's method of predicting graft survival may be valid, it requires time to be tested. It also suffers from the disadvantage that it compares individual results with pooled data. As we all know, pooled transplant data suffer from a number of disadvantages, including the fact that immunosuppression, tissue typing, etc. vary considerably from centre to centre. Barnes's method, in contrast, does not suffer from these disadvantages and has stood the test of time, something which Dr. Farrow's method has yet to do. In this connexion it may be relevant to state that according to his computer our projected one-year cadaver graft survival should be 71%° when in fact the actual survival is 82% for this group of patients. Although an 11% error may not seem much, it means a great deal when the case for and against transplantation is being argued.-We are, etc.,

Disseminated intravascular coagulation in benign tertian malaria.

Abstract: SIR,-No doubt Dr. I. A. Olson and his colleagues (3 February, p. 282) expected to receive some interesting comments from the older generation in the profession on their categorical statement that \"a qualification in Latin confers no advantage at all on the aspiring doctor.\" Perhaps it may be of interest for two young house surgeons to take issue with some of their conclusions. Firstly, we feel many of the findings may have little general relevance since the firstyear intake to a new medical school will not be comparable to that of an established institution. In particular, however, we consider that it would be very misleading to reject a knowledge of the classics, including Greek, by evaluating the use of Latin alone in understanding medical terminology. For in fact many medical terms have a Greek derivation, as do most words in the scientific vocabulary. (Note the origin of most of the words in level 6 of the appendix to Dr. Olson's paper. Latin was of course at one time the method of communication among doctors, aiding professional secrecy and keeping dangerous remedies out of the hands of the uninitiated. This is quite different from the value of Latin to the aspiring doctor today. Since we have found that a knowledge of Latin and Greek has increased our interest and enthusiasm for many aspects of our medical course, we feel it is unjustifiable to discourage the interested school pupil from studying these subjects before taking a medical training.-We are, etc.,

Transfusion-Induced Malaria

Abstract: To the Editor .—The article by Seeler et al in the January issue of theJournal(125:132, 1973) describes a case of transfusion malaria, due to Plasmodium vivax , treated successfully with chloroquine phosphate. The authors state that they subsequently treated the patient also with primaquine phosphate. They cite as their authority for this form of treatment the 14th (1968) edition of Pediatrics by Barnett. Since primaquine is effective only against the exoerythrocytic cycle of malaria, and since transfusion malaria, in contrast to that acquired through a mosquito bite, lacks the exoerythrocytic cycle, administration of this drug to the infant described by the authors was unnecessary. In view of the fact that primaquine has been associated with toxic side effects, the authors' error of commission ought not to be perpetuated. I am concerned that their article appearing in your widely read journal may do just that. It is true that the

Letter: Delayed attacks of malaria in visitors to the tropics.

Abstract: will have a limited application and that these may be at the expense of the basic needs of the clinical continuity and proper communication and co-ordination of care. To be specific on but one point is to refer to the hazards of cross-cover especially at a junior level of experience, where the pressure on the doctor will be high. These and other aspects of the situation referred to in your columns will continue to exercise every level of hospital staff in the coming months. In my district general hospital the senior medical staff committee which I represent as chairman has expressed considerable disquiet at the view expressed in the Department's communication. We shall seek to examine the advice given and to put it into effect, but where the only answer to increased leisure for some is increased work by others already committed, there is limited room for manoeuvre.-I am, etc., D. STONE Chairman, Visiting Medical Staff Committee Royal Berkshire Hospital, Reading

Delayed Attacks of Malaria in Visitors to the Tropics

Abstract: Out of 80 Danish college students and their teachers visiting the Middle East, West Pakistan, and India by bus in two four-month journeys during the summer and autumn of 1971, six individuals developed an apparently first attack of vivax malaria within seven to nine months after their return to Denmark. No cases of malaria were seen in the group during the journeys. Prophylaxis with chloroquine (Resochin) was strictly observed when visiting the areas in which malaria is endemic. All cases responded rapidly and completely to a full course of treatment with chloroquine. The most probable cause of the delay of the clinical manifestations is drug prophylaxis, which can prevent a clinical attack but not always eradicate the parasite.

Malaria in China and the Equatorial Pacific Area From 1937 to 1943

Abstract: Malariometric data in the endemic areas are available from most parts of the world (1), but information is still meager in areas such as China and Indonesia. It happened that the Japanese personnel contracted malaria themselves extensively, or investigated it on the local inhabitants in those areas during 1937-1943. The information may be valuable if the epidemiologic situation-particularly the ratio of parasite species prevalent there-remained the same now as it was a quarter of a century ago. An anonymous writer (2) mentions that the infectivity of mosquitoes in Africa is almost the same as it was in the days of Livingstone 100 years ago. Numerous reports of the heavy toll of wartime malaria are available (3), but our records appeared still worthy of publication as detailed parasitological investigation was made simultaneously. It is the purpose of this paper to present those old records and compare them with the results of recent investigation published from the endemic areas.

Use of stable sensitized cells in an improved indirect microhemagglutination test for malaria.

Abstract: Aldehyde-fixed cells sensitized with Plasmodium knowlesi and P. falciparum antigens were tested with sera from P. vivax and P. falciparum infections. Titers were improved by use of a mixture of cells sensitized with the two antigens.