A toxoplasmic uveitis case of a 60-year-old male in Korea.
(33/949)
A toxoplasmic uveitis case was reported on the focus of impairment of pathological findings and serological antibody titers after chemotherapy. A chief complaint of a 60-year-old male was a decreased and blurred vision in his right eye for 2 weeks after experiencing tremendous stress and fatigue. A steroid therapy for 3 weeks was not effective and the retinal lesion became necrotic. Anti-Toxoplasma gondii antibody titer was checked to be a strong positive by both ELISA and indirect latex agglutination assay (ILA). He was treated with Fansidar F for 8 weeks. His vision improved as the necrotic lesion healed by scarring, but the antibody titers still remained very high without any signs of negative conversion. It is suggested to be a recurrent case of the past asymptomatic infection by presumed immune suppression caused by excessive stress. (+info)
Antibiotics for prophylaxis of Plasmodium falciparum infections: in vitro activity of doxycycline against Senegalese isolates.
(34/949)
The in vitro activities of doxycycline, chloroquine, quinine, amodiaquine, artemether, pyrimethamine, and cycloguanil were evaluated against Plasmodium falciparum isolates from Senegal (Dielmo and Ndiop), using an isotopic, micro, drug susceptibility test. The 71-50% inhibitory concentration (IC50) values for doxycycline ranged from 0.7 to 108.0 microM and the geometric mean IC50 for the 71 isolates was 11.3 microM (95% confidence interval = 9.5-13.4 microM). The activity of doxycycline did not differ significantly (P = 0.0858) between the chloroquine-susceptible isolates and the chloroquine-resistant isolates. There was no in vitro correlation between the responses to doxycycline and those to artemether, chloroquine, quinine, amodiaquine, pyrimethamine, and cycloguanil, suggesting no in vitro cross-resistance among these drugs. Potency was increased by prolonged exposure. In 96-hr incubations, the activity of doxycycline was 4-5-fold more increased than in 48-hr incubations. The in vitro activity of doxycycline against intraerythrocytic stages of multidrug-resistant P. falciparum, its action against the preerythrocytic forms, the lack of correlation between the responses in vitro of P. falciparum to doxycycline and the other antimalarial drugs, and its original potential site of action are factors that favor its use as antimalarial drug. (+info)
Malaria, intestinal parasites, and schistosomiasis among Barawan Somali refugees resettling to the United States: a strategy to reduce morbidity and decrease the risk of imported infections.
(35/949)
In 1997, enhanced health assessments were performed for 390 (10%) of approximately 4,000 Barawan refugees resettling to the United States. Of the refugees who received enhanced assessments, 26 (7%) had malaria parasitemia and 128 (38%) had intestinal parasites, while only 2 (2%) had Schistosoma haematobium eggs in the urine. Mass therapy for malaria (a single oral dose of 25 mg/kg of sulfadoxine-pyrimethamine) was given to all Barawan refugees 1-2 days before resettlement. Refugees >2 years of age and nonpregnant women received a single oral dose of 600 mg albendazole for intestinal parasite therapy. If mass therapy had not been provided, upon arrival in the United States an estimated 280 (7%) refugees would have had malaria infections and 1,500 (38%) would have had intestinal parasites. We conclude that enhanced health assessments provided rapid on-site assessment of parasite prevalence and helped decrease morbidity among Barawan refugees, as well as, the risk of imported infections. (+info)
Epidemiologic tools for malaria surveillance in an urban setting of low endemicity along the Colombian Pacific coast.
(36/949)
An evaluation of 3 different methods for malaria diagnosis was carried out in an urban area of low endemicity on the Pacific coast of Colombia. Samples were collected from 833 symptomatic patients at a malaria clinic and examined by the polymerase chain reaction (PCR), quantitative buffy coat (QBC; Becton Dickinson, Franklin Lakes, NJ) method, and the traditional thick blood smear. The prevalence of Plasmodium falciparum malaria was 5.88% by thick blood smear, 7.34% by the QBC method, and 21.87% by PCR. The agreement between microscopists was 99.5%. The agreement between the QBC method and thick blood smear was 96.13% (n = 745). Samples positive by PCR but negative by thick blood smear or conversely negative by PCR and positive by thick blood smear were usually of low-level parasitemias. All 3 methods showed agreement in 76.3% of the samples. Sixty-nine (18.8%) samples were positive by PCR but negative by the other 2 methods. Ten samples were positive by both the QBC method and thick blood smear but negative by PCR; most of them had low-level parasitemias. The use of malaria diagnostic methods for epidemiologic surveillance is discussed. (+info)
Increased carriage of trimethoprim/sulfamethoxazole-resistant Streptococcus pneumoniae in Malawian children after treatment for malaria with sulfadoxine/pyrimethamine.
(37/949)
Treatment of malaria with sulfadoxine/pyrimethamine and of presumed bacterial infections with trimethoprim/sulfamethoxazole (cotrimoxazole) was assessed to see if either increases the carriage of cotrimoxazole-resistant Streptococcus pneumoniae in Malawian children. Children <5 years old treated with sulfadoxine/pyrimethamine, cotrimoxazole, or no antimicrobial agent were enrolled in a prospective observational study. Nasopharyngeal swabs were taken before treatment and 1 and 4 weeks later. Pneumococci were tested for antibiotic susceptibility by broth microdilution. In sulfadoxine/pyrimethamine-treated children, the proportion colonized with cotrimoxazole-nonsusceptible pneumococci increased from 38.1% at the initial visit to 44.1% at the 4-week follow-up visit (P=.048). For cotrimoxazole-treated children, the proportion colonized with cotrimoxazole-nonsusceptible pneumococci increased from 41.5% at the initial visit to 52% at the 1-week follow-up visit (P=.0017) and returned to 41.7% at the 4-week follow-up. Expanding use of sulfadoxine/pyrimethamine to treat chloroquine-resistant malaria may have implications for national pneumonia programs in developing countries where cotrimoxazole is widely used. (+info)
Gametocytemia and infectivity to mosquitoes of patients with uncomplicated Plasmodium falciparum malaria attacks treated with chloroquine or sulfadoxine plus pyrimethamine.
(38/949)
Plasmodium falciparum gametocytemia and its related infectivity for mosquitoes was studied in 115 patients (median age = 18 years, range = 4-45) with simple malaria attacks who lived in the hypoendemic area of Dakar, Senegal. Patients were included in a 28-day in vivo sensitivity test after treatment with chloroquine (CQ, n = 82) or sulfadoxine plus pyrimethamine (SP, n = 33). The prevalence of resistant infections was 58.5% in those treated with CQ and 0% in those treated with SP. The gametocytemia peaked at day 7 after treatment. The maximal gametocyte prevalence was 38.2% in the CQ-sensitive infection group, 89.6% in the CQ-resistant group, and 97.0% in those treated with SP The maximal geometric mean gametocytemia was 2.19/microl in the CQ-sensitive infection group, 29.12/microl in the CQ-resistant group and 85.55/microl in those treated with SP. The period between appearance of the first clinical symptom and treatment was positively related to gametocyte prevalence at days 0 and 2. Experimental infection of wild Anopheles arabiensis using membrane feeders was performed at days 0 and 7, and mosquito infectivity was measured by oocyst detection on the midgut. At day 0, 14.1% of the patients had infected at least 1 mosquito, and at day 7, this value was 38.5%. The mean percentage of infected mosquitoes was 3.2% at day 0 and 12.6% at day 7. At day 7 after treatment with CQ, the relative risk for patients with resistant infections of infecting anophelines was 4.07 higher than in those with sensitive infections. No difference was observed in infectivity for mosquitoes between RI-type resistance and the RII + RIII-type resistance. A sporonticidal effect of SP was observed at day 7 after treatment. These data show that P. falciparum gametocytes and their infectivity for mosquitoes were differentiated according to the drug used, its efficacy, and the duration of symptoms before treatment; they were not dependent on the density of asexual stages. Prompt treatment of malaria cases performed at the beginning of symptoms could limit the spread of resistant parasites. (+info)
Molecular epidemiology of malaria in Yaounde, Cameroon. VI. Sequence variations in the Plasmodium falciparum dihydrofolate reductase-thymidylate synthase gene and in vitro resistance to pyrimethamine and cycloguanil.
(39/949)
Pyrimethamine and cycloguanil, the major human metabolite of proguanil, are inhibitors of dihydrofolate reductase that play a key role in the treatment and prevention of chloroquine-resistant Plasmodium falciparum infections in sub-Saharan Africa. Resistance to these antifolate drugs has emerged in some areas of Africa. Earlier molecular studies have demonstrated that point mutations at key positions of the dihydrofolate reductase-thymidylate synthase gene are strongly associated with antifolate resistance. However, whether the same or distinct mutations are involved in the development of resistance to both pyrimethamine and cycloguanil has not been well established in naturally occurring P. falciparum isolates. In this study, the in vitro responses to both antifolate drugs were measured in 42 Cameroonian isolates and compared with the complete sequence of the dihydrofolate reductase domain of the gene (from 34 of 42 isolates) to analyze the genotype that may distinguish between pyrimethamine and cycloguanil resistance. The wild-type profile (n = 11 isolates) was associated with low 50% inhibitory concentrations (IC50s) ranging from 0.32 to 21.4 nanamole for pyrimethamine and 0.60-6.40 nM for cycloguanil. Mutant isolates had at least one amino acid substitution, Asn-108. Only three mutant codons were observed among the antifolate-resistant isolates: Ile-51, Arg-59, and Asn-108. The increasing number of point mutations was associated with an increasing level of pyrimethamine IC50 and, to a much lesser extent, cycloguanil IC50. These results support a partial cross-resistance between pyrimethamine and cycloguanil that is based on similar amino acid substitutions in dihydrofolate reductase and suggest that two or three mutations, including at least Asn-108, may be necessary for cycloguanil resistance, whereas a single Asn-108 mutation is sufficient for pyrimethamine resistance. (+info)
Disposition of intravenous pyrimethamine in healthy volunteers.
(40/949)
A proportion of patients with AIDS and toxoplasmic encephalitis (TE) sustain low plasma pyrimethamine concentrations during oral treatment, possibly because of incomplete and variable bioavailability. We wanted to develop a safe, practicable intravenous (i.v.) formulation of pyrimethamine and characterize its disposition in healthy volunteers. A neutral, aqueous, sterile solution of pyrimethamine was produced and presented in sealed glass ampoules. Pyrimethamine (1 mg/kg) was given to eight healthy male volunteers by i.v. infusion over 2 h, and blood was sampled over a 2 week period. Pyrimethamine levels in plasma were measured by high-performance liquid chromatography. The drug was well tolerated by all volunteers, and there were no changes in vital signs, electrocardiogram, hematology, or biochemical parameters. The maximum pyrimethamine concentration of 2,089+/-565 ng ml(-1) (mean +/- standard deviation) was achieved shortly after the end of the infusion; thereafter, concentrations declined in a log-linear manner, with a half-life of 140+/-31 h. (+info)