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We investigated the relationship between selected host haematological and parasitological parameters and the density and infectivity of Plasmodium falciparum gametocytes. 143 individuals (age range 1-62 years) attending an outpatient clinic in Farafenni, The Gambia, who had peripheral blood gametocytaemia were recruited (mean gametocyte density 123.7/microl, range 5-17,000/microl). Of the parameters measured, packed cell volume (PCV), reticulocyte count (RetC) and lymphocyte count (LyC) were significantly associated with gametocyte density (r = - 0.17, P < 0.05; r = 0.21, P < 0.01; r = 0.18, P < 0.05, respectively). Data from membrane feeding experiments in which 15 or more mosquitoes were dissected showed that 60.7% (53/87) of gametocyte carriers infected one or more mosquitoes. Gametocyte density was strongly correlated with transmission success (TS) (r = 0.3, P < 0.005) and, in successful infections, with both mosquito prevalence (MP) (r = 0.36, P < 0.005) and mean oocyst burden (MOB) (r = 0.65, P < 0.0001). None of the other factors measured were significantly associated with any of these indices in bivariate analysis. Regression modelling showed that both gametocyte density and PCV were positively associated with gametocyte carrier infectivity to mosquitoes (LRchi2 = 100.7 and 47.2, respectively) and, in successful infections, with MOB (beta = 0.16, t = 4.9, P < 0.001; beta = 0.02, t = 2.3, P < 0.05, respectively). The positive association with PCV suggests that blood meal quality influences infection probably as a nutritional requirement, however, as this effect was most apparent at high gametocyte densities, its epidemiological significance is questionable. Though the haematological parameters associated with gametocyte density are a direct consequence of asexual infection, they may also represent an adaptive mechanism for optimization of sexual stage development. [ABSTRACT FROM AUTHOR]

The lymphocytes infiltrating the liver of patients with tropical splenomegaly syndrome (TSS) were shown to be mainly T lymphocytes. Migration of leucocytes obtained from patients with TSS was inhibited by TSS liver extract, normal liver extract and liver-specific lipoprotein. These findings suggest that the hepatic infiltrates which occur in TSS are probably caused by a cell-mediated immune response to an antigen present in liver cells. [ABSTRACT FROM AUTHOR]

Cell-mediated immunity was studied in patients with group A meningococcal meningitis and in normal subjects give a group A meningococcal vaccine. Lymphocyte responsiveness to phytohaemagglutinin and to meningococcal antigens was markedly depressed in patients with acute meningococcal infection. This defect was present when lymphocytes were cultured in autologous or foetal calf serum. Patients also showed a transient increase in the degree of inhibition produced by whole group A meningococci in leucocyte migration assays. Meningococci of other groups produced a similar degree of inhibition. Vaccination with group A meningococcal polysaccharide vaccine had no effect on lymphocyte responsiveness to meningococcal antigens or on the inhibitory effect of group A meningococcl on leucocyte migration. [ABSTRACT FROM AUTHOR]

The presence of naturally occurring LMW (7S) IgM was suspected on Sephadex G-200 filtration of a serum pool from patients with tropical splenomegaly syndrome (TSS), It was found in nineteen out of thirty-one sera from these patients using a polyacrylamide/agarose gel-diffusion method, and in fifteen of the sera after precipitation of the 19S IgM with 10% polyethylene glycol (PEG). Free k-light chains was detected in twenty-five out of thirty-one sera from patients with the TSS while free λ-light chains was detected in four. The presence of 7S IgM and free light chains in sera of these patients is in keeping with our hypothesis that there is a disorder of control of immunoglobulin production in the tropical splenomegaly syndrome. [ABSTRACT FROM AUTHOR]

Low levels of complement components C3 C4 and factor B were found in the sera of most patients with early and advanced Gambian trypanosomiasis. C3 levels increased after treatment with melarsoprol (Mel B). Nearly all patients had high serum 1gM levels and a significant correlation was found between high serum 1gM levels and low serum C3 levels. concentrations of cryoglobulins, which contained 1gM and C3 were found in most of the sera tested. Formation of large molecular weight 1gM complexes may play an important part in producing the low C3 levels found in patients with Gambian sleeping sickness. [ABSTRACT FROM AUTHOR]

Free light chains were detected in the cerebrospinal fluid (CS F) of most patients with advanced trypanosomiasis but not in the CSF of patients with early trypanosomiasis or in the CSF of controls. Immunofluorescence showed free light chains in CSF plasma cells and morular cells, suggesting local production of light chains within the central nervous system. We believe that the presence of free light chains in the CSF of patients with advanced trypanosomiasis is a reflection of their disordered immunoglobulin synthesis and is in keeping with the view that the marked IgM synthesis seen in patients with this disease is due to the action of a mitogen and not the result of specific immune stimulation. [ABSTRACT FROM AUTHOR]

Low C3 levels were found in the sera of most children with acute Plasmodium falciparwn malaria. C4 and Clq levels were very low whilst glycine-rich β-glycoprotein (GBG) levels were only slightly depressed, suggesting that complement activation was occurring via the classical pathway. It is suggested that complement activation may play a part in initiating the complex series of changes that leads to the vascular damage seen in this infection. [ABSTRACT FROM AUTHOR]

The antigen detectable by counter-current immunoelectrophoresis in the cerebrospinal fluid and sera of patients with group A meningoeoccal meningitis was found to be a high molecular weight polysaccharide. Its composition was deduced from its immunochemical identity with a known group A meningoeoccal polysaccharide which has previously been shown to be a polymer of N-acetyl, O-acetyl mannosamine phosphate. [ABSTRACT FROM AUTHOR]

Immune complex levels were measured in serum and synovial fluid obtained from 10 patients who developed arthritis 3-8 days after the onset of meningococcal meningitis. Mean serum immune complex levels were lower in these patients than in eight age matched control patients with meningococcal disease who did not develop late complications. This observation suggests that meningococcal arthritis follows local formation of immune complexes in the synovium rather than deposition of circulating immune complexes. Purified meningococcal polysaccharide antigen-induced synovitis when injected into the knee of rabbits previously sensitized by i.v. injection with heat killed meningococci. [ABSTRACT FROM AUTHOR]

The 4-aminoquinolines, chloroquine or amodiaquine, have long been the drugs of choice for treating uncomplicated, falciparum malaria in Africa, although resistance to them is now common. Sulfadoxinepyrimethamine (SP) is the usual alternative when 4-aminoquinoline treatment fails. A combination-treatment regimen could combine the rapid symptom relief offered by the 4-aminoquinolines with the prolonged parasiticidal activity of SP, and also slow down development of resistance to the individual drugs. A systematic review of randomized trials was conducted so that the evidence of effectiveness and safety of such combination treatment could be summarized and compared with the results of treatment with either drug given alone. The results of trials were sought by searching through electronic databases and by contact with researchers in the field. Five studies were identified. Although there are few data, there is evidence that control of clinical symptoms is better when a 4-aminoquinoline is used with SP than when SP is used alone, and the cure rate also tends to be higher with the combination regimen. No evidence of serious side-effects was found. Larger scale trials are needed if this combination is to be adopted more widely. [ABSTRACT FROM AUTHOR]

West Africa has a rich medical history. Herbal medicine has been practiced for hundreds of years and the establishment of an effective herbal pharmacopoeia was probably the first medical research carried out in West Africa. Arabic medicine was practiced in the countries of the Sahel in the 15th and 16th centuries. The coming of the Europeans focused research on infectious diseases such as malaria, yellow fever and sleeping sickness, to which Europeans were very susceptible and which caused devastating epidemics among the populations of their new colonies. The end of the colonial era saw the establishment of a few large, well-equipped teaching hospitals but these proved too expensive for the newly independent states of West Africa to run effectively, and the second generation of West African medical schools was based on more modest government hospitals. This led to a change in the focus of research away from the more unusual conditions seen in a specialist referral hospital to an interest in conditions, such as the common infectious diseases, seen more frequently in district hospitals. The advent of the primary health care movement in the 1970s was followed by an increased emphasis on community studies. Molecular biology is likely to have an enormous impact on medicine in general in the coming years. One of the main challenges facing medical researchers in West Africa is how these new technologies can be used most effectively to improve health in countries with limited resources. [ABSTRACT FROM AUTHOR]

This study compared heartburn severity, number of episodes, and changes in esophageal pH induced by three meals. Symptomatic volunteers consumed the following on different occasions: McDonald's Quarter Pounder, french fries, and chocolate shake; McDonald's Sausage Biscuit with Egg, cheese, raw onion, and chocolate milk; and Wendy's Chili and red wine. Increases in reflux episodes over baseline for the hamburger, sausage biscuit, and chili meals were 28.8 +/- 5.7, 36 +/- 5.5 and 43.7 +/- 8.8, respectively. The sausage biscuit and chili increased reflux compared to the hamburger (P < 0.05), but the chili did not differ statistically from the sausage biscuit meal. Onset and peak heartburn for the hamburger, sausage biscuit, and chili meals were 45 and 90, 30 and 120, and 15 and 150 min, respectively. Despite lower fat content, chili and red wine promoted more reflux and heartburn pain than the other meals, demonstrating the importance of meal selection in provocative meal studies. [ABSTRACT FROM AUTHOR]

Background: There is a potential for interaction between malaria and human immunodeficiency virus (HIV) infection. HIV infection might reduce immunity to malaria resulting in more frequent and severe infections; conversely malaria might enhance the progression of HIV infection to AIDS. In this paper we have reviewed some of the studies that have addressed this topic.Methods: Studies identified by a MEDLINE search were systematically reviewed and the measures of association between the two infections were either abstracted or recalculated from the reported data. Inferences drawn from these studies and the biological plausibility of an interaction are discussed.Results: The prevalence ratio (PR) of peripheral parasitaemia among HIV seropositive (HIVSP) individuals compared to HIV seronegative (HIVSN) individuals ranged from 0.72 to 0.94 in children and from 3.3 to 0.69 in adults. However, only one study showed a statistically significant difference between HIVSP and HIVSN groups (PR 3.3, 95% CI: 2.7-4.2). The rate ratio of non-severe malaria among HIVSP children compared to HIVSN children was 1.4 (95% CI: 0.99-2.0). Data from a trial of chemoprophylaxis during pregnancy suggested that placental malaria may predispose to perinatal transmission of HIV. Studies that have investigated the immune response to P. falciparum among HIVSP subjects have given variable results.Conclusion: There is no convincing evidence for an interaction between malaria and HIV with the possible exception of an interaction between placental malaria and HIV infection. Several studies, however, had potentials for bias and/or an inadequate sample size. There is a need for carefully designed studies to resolve whether mortality from severe malaria, in particular cerebral malaria, is increased in HIVSP subjects, whether malaria infection of the placenta increases the risk of vertical transmission of HIV, and whether malaria infection increases the progression of HIV infection to AIDS. [ABSTRACT FROM AUTHOR]

Immunological aspects of 40 northern Nigerian children with nephrotic syndrome of recent onset are reported. Eight our of 30 had hepatitis-associated antigen in their sera. Hypocomplementaemia was rare. Measurement of serum C3, C4, and ASOT was not of diagnostic value. Proteinuria selectivity index was poor in half of the patients, and appeared t o depend on the severity of the kidney lesion. Abnormal immunofluorescence of kidney glomeruli to immunoglobulins, complement, Plasmodium malariae, and Plasmodium falciparum was found in 26 of the 29 children. The pattern of immunofluorescence was chiefly granular and was confined to the glomeruli. IgM was predominant. It was concluded that immunological reaction is involved in the pathogenesis of nephrotic syndrome in northern Nigerian children. [ABSTRACT FROM AUTHOR]

114 patients with meningococcal infection were studied; 72 had group C infection and 42 group A infection. 14 patients had acute meningococcaemia, all of whom had group C infection and 9 of whom died. Clinical and laboratory findings were similar in patients with meningitis due to a group A and C organisms, but arthritis and cutaneous vasculitis were more common in patients with group C infection. The overall mortality was 22% in patients with group C infection, and 12% in patients with group A infection, but was the same in both groups when cases of acute meningococcaemia are excluded. [ABSTRACT FROM AUTHOR]

Initial cerebrospinal fluid (CSF) samples obtained from patients with pneumococcal meningitis usually contain far greater numbers of bacteria than initial CSF samples obtained from patients with meningococcal meningitis. Normal CSF was found to have an inhibitory effect on the growth of group A meningococci but not on type 1 pneumococci. The inhibitory effect of normal CSF was abolished by dialysis, indicating that the inhibitory factor has a low molecular weight. Heating normal CSF to 62.5 degrees C for 30 min resulted in a considerable reduction in the inhibitory effect, indicating that the inhibitory factor is heat labile. [ABSTRACT FROM PUBLISHER]

Cascade enzyme inhibitors (C1-esterase inhibitor, C3b inactivator, antithrombin III) and other major proteolytic enzyme inhibitors (alpha 1 trypsin inhibitor, alpha 1 chymotrypsin inhibitor, inter-alpha-trypsin inhibitor, alpha 2 macroglobulin) as well as C3 and alpha 1 acid glycoprotein, have been examined in the sera of Nigerian patients suffering from meningococcal infection of varied severity. Patients with meningococcaemia had lower serum concentrations of important inhibitors than did patients with localised meningitic infection. Within the coccaemic group, those who died had the lowest values, notably of antithrombin III and alpha 2 macroglobulin (and also of C3). The clinical end-result of meningococcal infection may be related to the degree of disequilibrium of the linked system of proteolytic control induced by the meningococcal endotoxin. [ABSTRACT FROM PUBLISHER]

Cerebrospinal fluid (CSF) samples were tested for their cytotoxicity to polymorphonuclear neutrophil leucocytes (PMN) using a 51Cr release assay. Most samples from patients with pyogenic meningitis damaged PMN while normal CSF samples did not. No difference was found between the cytotoxic activity of CSF from patients with pneumococcal meningitis and from patients with meningococcal meningitis. It is, therefore, unlikely that a CSF leucocidin plays an important part in producing the high mortality of pneumococcal meningitis. [ABSTRACT FROM PUBLISHER]

Cerebrospinal fluid from patients with pyogenic meningitis was found to be chemotactic for polymorphonuclear neutrophil leucocytes. No significant difference was found between the mean chemotactic activity of cerebrospinal fluid obtained from patients with pneumococcal meningitis or meningococcal meningitis. The chemotactic factor present in cerebrospinal fluid is probably a low molecular weight protein, perhaps a complement component. [ABSTRACT FROM PUBLISHER]

This paper describes the value in diagnosis and the clinical implications of the detection of pneumococcal antigen in patients with lobar pneumonia. Ninety-eight patients with lobar pneumonia were investigated. Pneumococcal antigen was detected by counter-current immunoelectrophoresis in the sputum of 79% of patients with purulent sputum, in the serum of 29% of the patients, and in the urine of 54% of the patients. The diagnostic value of counter-current immunoelectrophoresis was not affected by prior antibiotic therapy. Patients with antigenaemia had a higher incidence of complications than those without as shown by an association between antigenaemia and jaundice, diarrhoea, and persistent pyrexia. Antigen persisted in the circulation for at least seven days in half the patients studied, possibly indicating the development of immunological tolerance to the polysaccharide antigen. [ABSTRACT FROM PUBLISHER]

Raised levels of fibrin degradation products were found in the cerebrospinal fluid of nearly all of 35 patients with pneumococcal meningitis. The mean level was higher in patients who died subsequently than in those who survived. Cerebrospinal fluid from patients with pneumococcal meningitis showed increased fibrinolytic activity as assessed by clot lysis, suggesting local production of fibrin degradation products within the subarachnoid space. [ABSTRACT FROM AUTHOR]

The epidemiology of infection due to Neisseria meningitidis and Neisseria lactamica was studied in a northern Nigerian community. A low meningococcal carriage rate was observed throughout the two-year survey. Initially, most meningococci isolated from nasopharyngeal carriers belonged to serogroup C or to serogroup Y. Following an outbreak of group A meningococcal disease, more group A meningococcal carriers were detected. Antibody studies indicated that infection with group A meningococci had been more widespread in the community than was suggested by regular carrier surveys. Carriage of meningococci was detected most frequently in children one to nine years of age. Children were identified as the first carriers in households more frequently than adults. The half-life of carriage was three months. The meningococcal carriage rate did not increase during the hot dry season when epidemics of meningococcal disease occur most frequently in Nigeria. Neisseria lactamica was isolated from the nasopharynx of children more frequently than were meningococci. [ABSTRACT FROM PUBLISHER]

In three cases of human rabies, in which the diagnosis was proved postmortem, rabies antigen was detected by direct immunofluorescence of frozen sections of facial skin. The antigen was thought to be in nerve fibers in association with hair follicles. Development of this technique might enable the establishment of a method for the diagnosis of human rabies during life. [ABSTRACT FROM PUBLISHER]

Cerebrospinal fluid from 15% of patients in whom a clinical diagnosis of meningitis due to Neisseria meningitidis had been made was sterile on culture and negative for meningococcal antigen on countercurrent immunoelectrophoresis. Evidence of active meningococcal infection was found in all 18 of these patients who were studied in detail. Initial samples of serum from antigen-negative patients frequently contained high titers of HA antibody, suggesting that these patients belong to a group of subjects capable of a rapid immune response to meningococcal infection. This view is supported by the observation that antigen-negative patients develop few of the serious complications of meningococcal meningitis. [ABSTRACT FROM PUBLISHER]

It has earlier been reported that the human monoclonal antibody (MoAb 33G2) and polyclonal antibodies reactive with Pf332 may interfere in vitro with the erythrocytic cycle of Plasmodium falciparum at two potential target sites for protective antibodies, indicating that the antigen may constitute an important target for immune responses during malaria infections. MoAb 33G2 shows its highest reactivity with repeated sequences in the antigen Pr332 and also cross-reacts with determinants in Pf155/RESA. This study was conducted in order to assess the prevalence of seroreactivity against Pf332 in individuals residing in areas of different malaria endemicity, and in children with different degrees of disease severity. We now report that individuals resident in malaria endemic regions show a high prevalence of seroreactivity to antigen Pf332 repeat sequences. The mean antibody concentrations were significantly higher in donors from Liberia. Madagascar and Gambia compared with Thai and Colombian donors, probably reflecting the higher degree of exposure in the African regions. Although the levels of such antibodies in individual sera correlated well with the levels of antibodies to one Pf155/RESA repeat peptide, only a minor part of the peptidereactive antibodies were cross-reactive between the two antigens. In Gambian children, the mean concentrations of antibodies reactive with PD32 or Pf 155/RESA peptides were significantly higher in children with severe than with mild malaria. Further longitudinal studies are needed to evaluate the capacity of Pf332 to induce potentially protective or harmful antibody responses. [ABSTRACT FROM AUTHOR]

Plasma levels of soluble IL-2 receptor (sIL-2R) were measured by immunoassay in 180 individuals, aged l-70years, living in a malaria-endemic community in West Africa, sIL-2R levels were compared with age, malaria parasitaemia, malaria-associated morbidity and cellular immune responses to Plasmodium falciparum antigens. Plasma levels of sIL-2R were independently associated with both age and patent malaria parasitaemia. No significant association was observed between IL-2R levels and concurrent malaria morbidity (i.e. fever associated with malaria), but the number of individuals with clinical malaria at the lime of sampling was small. Although there was no association between plasma sIL-2R levels and in vitro proliferative responses of peripheral blood mononuclear cells (PBMC) to a number of defined malaria antigens, we did find a significant negative association between sIL-2R and in vitro proliferation of unstimulated PBMC. High levels of sIL-2R (up to 5500 U/ml) were detected in the plasma of malaria-infected individuals: this is indicative of a vigorous cellular immune response lo malaria antigens in vivo and docs not support the notion that malaria infections are generally immunosuppressive. Indeed, we found that, at the low levels of parasitaemia present in study subjects, (here was no significant difference in the mean proliferalive response to malaria antigens in infected subjects when compared with uninfected subjects. [ABSTRACT FROM AUTHOR]

The reasons why only a small proportion of African children infected with Plasmodium falciparum develop severe or fatal malaria are not known. One possible reason is that children who develop severe disease have had less previous exposure to malaria infection, and hence have less acquired immunity, than children who develop a mild clinical attack. To investigate this possibility we have measured titres of a wide range of anti-P. falciparum antibodies in plasma samples obtained from children with severe malaria, children with mild malaria and from children with other illnesses. Mean antibody levels in patients with malaria were higher than those in patients with other conditions but, with only one exception, there were no significant differences in antibody titres between cases of severe or mild malaria. A parasitized-erythrocyte agglutination assay was used to estimate the diversity of parasite isolates to which children had been exposed; plasma samples obtained from children with cerebral malaria recognized as many isolates as did samples obtained from children with mild disease. Our findings do not provide any support for the view that the development of severe malaria in a small proportion of African children infected with P. falciparum is due to lack of previous exposure to the infection. [ABSTRACT FROM AUTHOR]

To investigate the involvement of tumour necrosis factor (TNF) in human malaria, we studied TNF production in patients infected with Plasmodium falciparum, and in co-cultures of human mononuclear cells and malaria parasites in vitro. In the examined sample, plasma TNF levels of over 39 pg/ml were detected in the plasma of 59% of Gambian children with acute malaria, 17% of convalescents, 9% of children with mild infections other than malaria, and 7% of healthy Gambian adults. Mononuclear cells of acute malaria patients, when stimulated with endotoxin in vitro, secreted twice as much TNF as did those of convalescent individuals, and three times that of healthy adult controls. Erythrocytic cultures of P. faiciparum stimulated increased TNF secretion by mononuclear cells from uninfected individuals, and a sharp rise in the rate of secretion occurred shortly after schizont rupture. We suggest that malaria fever is mediated, at least in part, through paroxysmal TNF release associated with schizont rupture. [ABSTRACT FROM AUTHOR]

Peripheral blood mononuclear cells from 63 Gambian children with acute Plasmodium falciparum malaria were examined for lymphoproliferation and interferon-γ (IFN) production in response to stimulation by mitogens, malaria antigens and other soluble antigens. Mitogen or Candida-induced proliferation was not depressed during acute infection but was enhanced 2 to 4 weeks after treatment. Responses to partially purified soluble P. falciparum antigens were minimal or absent in all children in the acute phase but approximately 50% of the children responded by proliferation or IFN-γ production during the 2 to 8 week convalescent period. These proliferative responses were severely depressed in the presence of the patient's own serum. Nine children with significant convalescent phase proliferative responses were re-examined several months after acute infection. Of these, four remained responsive for at least 8 months in the probable absence of reinfection. [ABSTRACT FROM AUTHOR]

Peripheral blood mononuclear cells from clinically immune Gambian adults were assayed for in vitro proliferation in response to crude and partially purified Plasmodium falciparurn antigens. Lympho- proliferative responses to malaria antigens, lectin mitogens and Candida albicans were compared with those of control donors with no previous exposure to malaria. Cells of malaria-immune individuals were significantly more responsive to conconavalin A, and less responsive to phytohaemagglutinin, than cells from the control donors in both non-immune human serum and autologous serum. Cells from a proportion of immune donors proliferated in response to soluble malaria antigens but a substantial minority did not. Young adults and women were over-represented in the non-responding population. Responses to soluble malaria antigens were depressed in autologous serum compared with normal human serum. Both immune and control cells produced low levels of γ-IFN when stimulated with crude P. falciparurn schizont antigens. Approximately half the immune donors, and none of the controls, produced significant levels of γ-IFN in response to purified soluble malaria antigen or malaria parasite culture supernatant. There was no direct correlation between lymphoproliferation and γ-IFN production. [ABSTRACT FROM AUTHOR]

Lymphocyte subpopulations in thirty-nine patients with the tropical splenomegaly syndrome (TSS) were studied using the E-rosette, EAC rosette and direct immunofluorescent staining techniques. In the peripheral blood a decrease in the percentage of T-lymphocytes was found which was accompanied by an increase in the percentage and number of B-lymphocytes. These abnormalities reverted towards normal on treatment. Splenic aspirates contained an increased proportion of T-lymphocytes. The relative T-cell lymphopenia in TSS is probably due to specific trapping or non-specific sequestration of lymphocytes in the liver and spleen. B-cell lymphocytosis is probably due to persistent antigenic or mitogenic stimulation by malaria. [ABSTRACT FROM AUTHOR]

Large amounts of cryoglobulins and soluble immune complexes were detected in the sera of thirteen patients with tropical spenomegaly syndrome (TSS). Complexes were detected by three different methods: radiobioassay, a modified rheumatoid factor-binding activity method and a modified Clq-binding assay. Protein precipitable by 4% polyethylene glycol (PEG) was also measured. The cryoglobulins contained IgM, IgG and in some cases, C3. It is likely that in TSS, marked immune complex formation is associated with hypergammaglobulinaemia and that continuous engulfment of these complexes by cells of the reticuloendothelial system (RES) is the cause of the hepatosplenomegaly. [ABSTRACT FROM AUTHOR]

Increased serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble endothelial leucocyte adhesion molecule-1 (sELAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were detected in Danish malaria patients infected with sequestering Plasmodium falciparum or non-sequestering P. vivax parasites, as well as in patients with sepsis or meningitis. Levels of soluble adhesion molecules remained elevated in the P. falciparum patients for several weeks after initiation of treatment. Plasma concentrations of sICAM-1, sVCAM-1 and sELAM-1 were higher in Crambian children with severe P. falciparum malaria than in children with mild malaria. Plasma levels of sVCAM-1 and sELAM-1 were significantly correlated. Plasma levels of sELAM-1 and sVCAM-1 may reflect endothelial inflammatory reactions and these reactions may be harmful for humans infected with malaria parasites. [ABSTRACT FROM AUTHOR]

Admission records from two paediatric units in The Gambia were used to explore the relationship between admission weight and different diseases. In total 13579 hospitalized children were analysed. For comparison, 7399 children were recruited from several surveys of well subjects to provide anthropometric values for healthy Gambian children. Compared to the control children, mean admission weights were lower for malaria (weight for age z-score: -1.602), cerebral malaria (-1.547), transfused malarial anaemia (-1.764), pneumonia (-1.725), meningitis (-1.362), gastro-enteritis (-2.497) and malnutrition (-3.786). Children with bronchiolitis did not have a significantly different weight for age than the controls. Outcome of the hospital admission was recorded and related to the weight on admission. In all disease categories the death rate rose with decreasing admission weight with the exception of bronchiolitis. For all diseases taken together, case fatality was 7.2% for children with a weight for age z-score above -2 Standard Deviations (SD), 9.3% between -2 and -3 SD, 15.6% between -3 and -4 SD and 22.7% for children with weight for age SD z-scores less than -4. Malnourished children are more susceptible to several infectious diseases frequently seen in developing countries and nutritional interventions, as well as standard treatment, may improve outcome. [ABSTRACT FROM AUTHOR]

Little is known about the epidemiology of respiratory syncytial virus (RSV) infection in tropical and developing countries; the data currently available have been reviewed. In most studies, RSV was found to be the predominant viral cause of acute lower respiratory tract infections (ALRI) in childhood, being responsible for 27-96% of hospitalised cases (mean 65%) in which a virus was found. RSV infection is seasonal in most countries; outbreaks occur most frequently in the cold season in areas with temperate and Mediterranean climates and in the wet season in tropical countries with seasonal rainfall. The situation on islands and in areas of the inner tropics with perennial high rainfall is less clear-cut. The age group mainly affected by RSV in developing countries is children under 6 months of age (mean 39% of hospital patients with RSV). RSV-ALRI is slightly more common in boys than in girls. Very little information is available about the mortality of children infected with RSV, the frequency of bacterial co-infection, or the incidence of further wheezing after RSV. Further studies on RSV should address these questions in more detail. RSV is an important pathogen ill young children in tropical and developing countries and a frequent cause of hospital admission. Prevention of RSV infection by vaccination would have a significant impact on the incidence of ALRI in children in developing countries. [ABSTRACT FROM AUTHOR]

Earlier studies in The Gambia suggested that the use of impregnated bednets might prove to be a useful malaria control strategy. Based on the results of these studies, in 1992 the Government of The Gambia was encouraged to initiate a National Impregnated Bednet Programme (NIBP) as part of the National Malaria Control Programme Strategy. This paper describes the implementation process/procedure of the NIBP. Evaluation results showed that, overall, 83% of the bednets surveyed has been impregnated, and 77% of children under the age of five years and 78% of women of childbearing age were reported to be sleeping under impregnated bednets. [ABSTRACT FROM AUTHOR]

ABSTRACT. The prevalence of bedbugs ( Cimex hemipterus L.), chicken ticks ( Argas persicus Oken) and headlice ( Pediculus capitis De Geer) was surveyed in a rural area of The Gambia. At the beginning of the study 37.5% of children's beds were infested with bedbugs and 3.9% with chicken ticks, whilst the prevalence rate of pediculosis in children under 10 years old was 28.8%. Both bedbugs and headlice were clustered within compounds. Headlice prevalence increased with hair length and they were more common on girls than boys. Following this cross-sectional survey all bednets in the sixteen hamlets were either dipped in permethrin or a placebo. About 4 months later it was found that bedbugs and chicken ticks had disappeared from homes in which the bednets had been impregnated with permethrin. There was no reduction in hamlets with placebo-treated bednets. The rate of acquiring headlice between the two surveys was reduced by 91.1% in children who slept under insecticide-treated bednets compared with children with placebo-treated bednets. There were also significantly fewer day-flying and crawling insects, except earwigs, in homes of children who slept under insecticide-treated bednets compared with those with placebo-treated nets. These additional benefits of permethrin-treated bednets should contribute to their widespread acceptance and utilization by the community for personal protection. [ABSTRACT FROM AUTHOR]

ABSTRACT. Malaria vector mosquitoes belonging to the Anopheles gambiae complex were studied in four hamlets in The Gambia. All inhabitants were given bednets treated either with a placebo (milk) in two hamlets or with the pyrethroid insecticide permethrin (500 mg/m2) in two other hamlets. Malaria transmission occurred mainly during a few weeks of the rainy season, in September and October 1987. The indoor resting densities of mosquitoes in permethrin-treated hamlets were reduced, and we estimated over 90% reduction in biting on man by An. gambiae Giles sensu stricto in these hamlets. No mosquitoes were found under permethrin-treated bednets compare.d with eighty-one recovered from placebo-treated bednets. Mosquitoes exited more readily from rooms where permethrin-treated bednets were used than from rooms with placebo-treated nets. The annual mean probability that a child would receive an infective bite was estimated to be 0.09 in hamlets with insecticide-treated bednets, compared with 1.9 where placebo-treated bednets were used. Permethrin-treated bednets are therefore recommended as a means of effectively reducing the risk of exposure to malaria transmission, particularly in areas of low seasonal transmission. [ABSTRACT FROM AUTHOR]

ABSTRACT. Population dynamics of the Anopheles gambiae complex of malaria vector mosquitoes were studied in four small hamlets in The Gambia. Bednets were used to reduce man/vector contact in two of the hamlets. High densities of An. gambiae, sensu lato, were present for only 3-8 weeks during the rainy season, depending on the position of the hamlet within the study area. The proportions of blood-fed mosquitoes caught indoors (83.0%) and exiting from houses (11.6%) were lower in hamlets where bednets were used than in hamlets without (96.5% and 33.1% respectively). Fewer of the blood-fed mosquitoes had fed on man in houses where people slept under bednets (68.2%) than in those without (81.5%). However, the average number of infective bites received by children was still greater than one a year in hamlets where bednets were used. Consequently bednets are considered unlikely to be an effective malaria control measure so long as they are untreated with insecticide. [ABSTRACT FROM AUTHOR]