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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Malaria remains prevalent throughout tropical and subtropical regions and almost a third of the World's population is exposed to the risk of infection. There is currently a serious resurgence of the disease in Asia and Central America. The failure of global eradication measures based upon the use of insecticides and chemotherapy has resulted from difficulties of practical implementation compounded by the spread of insecticide and drug resistance. Repeated natural infection does not produce detectable resistance to the exo-erythrocytic cycle of malaria in man. Irradiated sporzoite vaccines do, however, induce stage specific immunity in murine malaria and in a proportion of human subjects. Vaccinated individuals remain susceptible to blood stage infection which causes clinical malaria. In addition the vaccine is unstable and must be administered by intravenous inoculation. Since neither sporogonic nor exo-erythrocytic parasite development is cyclical in human malarias, there is little prospect for vaccine production through cultivation of these stages. The inhabitants of hyperendaemic areas become increasingly resistant to malaria during childhood and adolescence, through the slow development of specific, acquired immunity to asexual blood stage parasites. Immunity is mediated by antibody, which blocks merozoite invasion of red cells, as well as by cell mediated mechanisms and non-specific cytotoxic agents. Vaccination with merozoites induces long lasting immunity of broad serological specificity active against the blood-stage of the parasite. Merozoite vaccines can be preserved by freeze drying and harvested from continuous cultures of blood stage parasites. The major problem in development of a human merozoite vaccine concerns the requirement for Freund's complete adjuvant which is not acceptable for man. The effective immunity induced by vaccination contrasts with the slow development of incomplete resistance which follows repeated natural infection. The latter is associated with the generation of immune suppressor cells, lymphoid cell mitogens and soluble antigens, and in some species by the occurrence of antigenic variation--all of which may favour parasite survival. It is probable that vaccination with non-viable antigen of appropriate composition, induces immune effector processes without activating mechanisms which allow parasites to escape the consequences of immunity. Many effective vaccines such as those against measles, poliomyelitis, tetanus and rabies are commercially available but barely used in the developing world. The affected nations cannot afford their purchase, nor do the means exist for their distribution. It follows that if a safe and effective malaria vaccine were to be developed, its bulk manufacture and administration would require massive international support and cooperation.
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PMID:Immunity to malaria. 3 57

For major diseases for which control measures are inadequate, research is an inexpensive approach on the basis of cost per infected person per year. Priorities among the infectious diseases affecting the 3 billion people in the less developed world have been based on prevalence, morbidity, mortality and feasibility of control. With these priorities in mind, a program of selective primary health care is compared with other approaches and suggested as the most cost-effective form of medical intervention in the least developed countries. A flexible program delivered by either fixed or mobile units might include measles and diptheria-pertussis-tetanus vaccination, treatment for febrile malaria and oral rehydration for diarrhea in children, and tetanus toxoid and encouragement of breast feeding in mothers. Other interventions might be added on the basis of regional needs and new developments. Aiming services at the most important diseases is the only rational approach to absolute proverty and unsanitary conditions. The goal is to help the greatest number of people in the cost effective method possible.
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PMID:Selective primary health care: an interim strategy for disease control in developing countries. 11 30

Early referral for hospital delivery is important to reduce the risks during pregnancy and labor for 90% of the women in rural areas. Therefore, Tanzania has improved a record card for antenatal screening that would detect labor complications, indicate appropriate action, emphasize preventive treatment for pregnancy complications, and record labor outcome. A patient's obstetric history is obtained and the patient is examined with consideration given to height and limp or polio leg. Patients with raised blood pressure, signs of pre-eclamptic toxemia, or severe anemia are referred to the hospital and if breech, transverse lie, or twins are suspected, the patient is booked for a hospital delivery. Prevention of anemia, malaria, and neonatal tetanus are emphasized. Of 13,410 women screened, a height factor of 146 cm or less accounted for 41.6% of all risk factors, and 81% of all risk factors were detected from the patient's history and height measurement. By using the new antenatal cards there was a higher detection rate of risk cases an when used by different health workers, there was over 95% agreement in findings compared to 68% using the old cards.
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PMID:Use of an action-orientated record for antenatal screening. 30 47

A retrospective study to investigate infant mortality was conducted in one of the poorest rural areas in Mali. The study was conducted through questionnaires, and was made among 811 women in 11 different villages. 3204 live births were recorded; 615 newborns, however, died before 1 year of life, i.e. an infant mortality rate of almost 250/1000. Main causes of mortality were obstetrical factors, tetanus, malaria, several types of pneumopathies, toxicoses, and nutrition disorders. Symptoms were the same in all villages, convulsions, cough, fever, and diarrhea. Action to improve the socioeconomic development of the area, set up a working national health structure, and a program of control of communicable diseases should be the first concern of local leaders and of national authorities.
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PMID:[An example of the application of factorial analysis of correspondences to infant mortality and its prevention in a rural area of West Africa]. 46 54

This article describes the major activities carried out since 1959 in the field of pediatrics and child care in Cuba. In particular, it notes the improvements made through establishment of a national health system and through the participation of community organizations (the Federation of Cuban Women, Committees for the Defense of the Revolution, associations of small farmers, and trade unions) and shows how perinatal, infant, and childhood mortality have been significantly reduced. As of 1973 perinatal mortality had fallen to 27.9 deaths per 1,000 live births, infant mortality to 27.4 deaths per 1,000 live births, preschool mortality to 1.2 per 1,000 children, and school-age mortality, to 0.4 per 1,000 children. This report also cites data on available physical and manpower resources, and outlines a large range of activities linked to a Comprehensive Child Care Program undertaken in 1967. This program, in which newborns are enrolled upon leaving the maternity, seeks to encourage breast-feeding, to promote the activities of well-baby clinics, to provide special examinations for malnourished infants, to provide health care for preschool and school-age children, to promote pediatric medical visits to the home, to assist with camps for asthmatic and diabetic children, to provide pediatric services at pioneer and other camps for schoolchildren, to carry out health education activities, and to combat communicable disease. In particular, activites to prevent communicable disease appear responsible for a good part of the progress achieved to date. As a result of these activities malaria and diphtheria have been eradicated, poliomyelitis has been overcome, and the incidences of tuberculosis, tuberculous meningitis, tetanus (among both newborns and children under 15), and acute diarrheal disease have been substantially reduced.
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PMID:Advances in pediatrics and child care in Cuba, 1959-1974. 77 91

Plasmodium yoelii infection of mice depressed their capacity to build up humoral immune response to diphteria vaccine and protective immunity against tetanus toxin. This immunodepression was overcome by Freund's complete adjuvant or killed pertussis bacilli (whooping cough vaccine). These results suggest that vaccines should be given in association in malaria endemic area.
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PMID:Inhibition of the immune response to whooping cough and tetanus vaccines by malaria infection, and the effect of pertussis adjuvant. 86 3

The verbal autopsy (VA) is an epidemiological tool that is widely used to ascribe causes of death by interviewing bereaved relatives of children who were not under medical supervision at the time of death. This technique was assessed by comparison with a prospective survey of 303 childhood deaths at a district hospital in Kenya where medically confirmed diagnoses were available. Common causes of death were detected by VA with specificities greater than 80%. Sensitivity of the VA technique was greater than 75% for measles, neonatal tetanus, malnutrition, and trauma-related deaths; however, malaria, anaemia, acute respiratory-tract infection, gastroenteritis, and meningitis were detected with sensitivities of less than 50%. There may have been unwarranted optimism in the ability of VAs to detect some of the major causes of death, such as malaria, in African children. VA used in malaria-specific intervention trials should be interpreted with caution and only in the light of known sensitivities and specificities.
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PMID:Childhood deaths in Africa: uses and limitations of verbal autopsies. 135 14

PBL from individuals with no history of malaria exposure, as well as cord blood lymphocytes, were tested for proliferation to T cell epitopes from the malaria circumsporozoite proteins of Plasmodium falciparum and Plasmodium vivax. Cells from many individuals proliferated in response to these peptides, but for two peptides (P. vivax317-336 and P. falciparum CS331-350) the response rate ranged from 64 to 93%, with the specific stimulation indices reaching as high as 38. The phenotype of the cells responding to PfCS331-350 was predominantly CD4+,CD8-,CD45Ra+,CD45Ro-, which was the inverse of the phenotype of the cells responding to tetanus toxoid with respect to CD45 isoforms. T cell clones from different individuals specific for PfCS331-350 were restricted by at least four different HLA-DR molecules and there was no evidence that the peptide was a "superantigen." Overlapping peptides were used to demonstrate that clones had different fine specificities although the peptide specificities of the DR4-restricted and DR11-restricted clones were similar. Although the individuals tested here have had no history of malaria exposure, these data demonstrate that they have T cells specific for malaria sequences present in high frequency that proliferate as intensely as some memory responses. Although one clone from an individual with a history of BCG vaccination did react strongly with PPD, the phenotype of these cells suggests that they are not classical memory cells for a cross-reactive recall Ag. Such cells may affect the induction or expression of malaria immunity.
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PMID:Promiscuous malaria peptide epitope stimulates CD45Ra T cells from peripheral blood of nonexposed donors. 137 May 23

Synthetic constructs were assembled as multiple Ag peptide systems containing repetitive sequences of Plasmodium falciparum and Plasmodium berghei, the causative agents of human and murine malaria respectively, and two universal human tetanus toxin T cell epitopes 830-843 and 947-967. These constructs were tested for antibody production in mice and for their capacity to stimulate human PBL and tetanus toxin-specific T cell clones. A high antibody titer can be obtained in mice when multiple Ag peptide systems are injected in various adjuvants or in PBS alone. Furthermore, all constructs can activate PBL from every donor tested. However, a variable response was obtained when different clones specific for the two tetanus toxin universal epitopes were used. These constructs may represent possible candidates for a malaria vaccine.
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PMID:Use of human universally antigenic tetanus toxin T cell epitopes as carriers for human vaccination. 137 79

The study, which is based on data from a household level health survey conducted in 1990 in Freetown, Sierra Leone, examines the coverage of an Expanded Program on Immunization (EPI), infant mortality, and infant morbidity among children in Greater Freetown, capital of Sierra Leone. The results of the study indicate that there was a decline in infant mortality in the recent period of the survey, 1988-89, compared to earlier periods. This decline seemed to have been the result of immunization coverage, which considerably increased by 1989-90, reaching above 70% of the children under age 5. The study further reveals that the increased immunization coverage of children and their mothers might have considerably reduced the incidence of tetanus. While reduction of tetanus might have played the leading role in the latest reduction in infant mortality, the incidence of diarrhea, measles, and malaria continued to be high, suggesting that the increase in the quality and quantity of basic immunizations, oral therapy for diarrheal disease, and provision of chloroquine and improved drugs for malaria disease could further reduce most of the deaths from these prevailing diseases among children under age 5.
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PMID:Immunization coverage, infant morbidity and infant mortality in Freetown, Sierra Leone. 141 85


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