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Introduction: Antimalarial treatment effects on Plasmodium falciparum gametocytemia has been the focus of few studies in the Americas., Objective: Relationships are described that occur between falciparum gametocytemia and the treatment with amodiaquine-sulfadoxine-pyrimethamine, artesunate-sulfadoxine-pyrimethamine or amodiaquine-artesunate., Materials and Methods: The experimental design consisted of a randomized selection of patients not balanced or blinded. A total of 241 patients were evaluated, residents of Turbo, El Bagre and Zaragoza (Antioquia, Colombia). The follow up occurred 21-28 days after antimalarial treatment. The World Health Organization (1998) protocol was used., Results: The therapeutic efficacy of amodiaquine-sulfadoxine-pyrimethamine, artesunate-sulfadoxine-pyrimethamine and amodiaquine-artesunate were equal at day 21 of the follow up. Four cases (1.7%) were therapeutic failures. Amodiaquine-sulfadoxine-pyrimethamine was less effective than the artesunate treatments in reducing the gametocyte load. On day 7, none of the three treatments had eliminated completely the gametocytes. Most patients (56.0%) were observed not to have circulating gametocytes pre-treatment and did not develop them later., Conclusion: The three treatment schemes were similar in their therapeutic efficacy and in their incapacity to eliminate gametocytes at day seven.

Introduction: The decrease in the efficacy of antimalarial drugs in the world and in Colombia hampers its control., Objective: The in vivo therapeutic efficacy of the amodiaquine+sulfadoxine-pyrimethamine combination was evaluated in the treatment of uncomplicated Plasmodium falciparum malaria and of chloroquine for P. vivax malaria., Materials and Methods: From May to November 2006, in vivo efficacy studies of malaria treatments were undertaken in Tierralta, Córdoba, northeastern Colombia. Standard protocols were followed as recommended by the World Health Organization/Panamerican Health Organization, with some modifications. Patients older than two years with single P. falciparum or P. vivax infection, with asexual parasitemia between 500 and 50,000 parasites/microl, were selected according to established inclusion and exclusion criteria. Supervised treatment was administered, and clinical and parasitological follow-up was carried out on days 0 (inclusion), 1, 2, 3, 7, 14, 21 and 28. The outcome was defined as adequate clinical and parasitological response, early therapeutic failure, or late therapeutic failure., Results: Of 53 subjects selected, 50 (94.3%; CI 70%-100%) presented adequate clinical and parasitological response to the amodiaquine+sulfadoxine-pyrimethamine treatment for uncomplicated falciparum malaria. One patient presented early therapeutic failure, and two developed late therapeutic failure. All of the 50 patients (95%CI: 74%-100%) in the invivo efficacy study of chloroquine for vivax malaria presented adequate clinical and parasitological response., Conclusion: In Cordoba, the amodiaquine+sulfadoxine-pyrimethamine combination and chloroquine show a high efficacy for the treatment of uncomplicated falciparum and vivax malaria, respectively.

Introduction: The current antimalarial drug policy in Colombia has been based on studies conducted in Antioquia and the Pacific Coast. However, the efficacy of antimalarial drugs in other endemic regions is unknown., Objective: The therapeutic efficacy of three monotherapies was assessed: amodiaquine and sulfadoxine/pyrimethamine for uncomplicated Plasmodium falciparum malaria, and chloroquine for Plasmodium vivax malaria in the municipality of Tarapacá, located in the Colombian province of Amazonas., Materials and Methods: Treatment was supervised and clinical/parasitological follow-up was undertaken through a 28-day period following to World Health Organization standard protocols for subjects with a single P. falciparum or P. vivax infection., Results: Due to a decrease in malaria transmission at the time of the study, the sample size was very small. The treatment failed for two subjects who received amodiaquine, and treatment with sulfadoxine/pyrimethamine was discontinued due to a high frequency of therapeutic failures (7/8). Most subjects (18/20) with P. vivax infections showed an adequate therapeutic response., Conclusions: The use of sulfadoxine/pyrimethamine in Tarapacá, and possibly in the Amazon region of Colombia, needs to be reviewed. Therapeutic efficacy studies in other endemic areas in the Amazon and Orinoco regions in Colombia are desirable but not feasible. Alternative methods such as in vitro assays or detection of molecular markers for resistance in the parasite can provide a basis for decisions concerning antimalarial drug policy for the Amazon and Orinoco regions in Colombia.

Plasmodium falciparum gametocyte levels are influenced by level of regional endemicity, the antimalarial treatment, and the therapeutic response of patients. Few previous studies have related these factors in Colombia. Here, gametocytaemia was evaluated with respect to two treatment schemes (sulfadoxine/pyrimethamine and sulfadoxine/pyrimethamine plus chloroquine), the patient response (adequate or failure), and the locality (two areas of varying case frequency). One hundred forty-eight residents of Turbo and Zaragoza (Antioquia), all with uncomplicated malaria, were evaluated. The gametocytaemia and the rates of clinical malaria at the beginning of treatment were greater in Turbo than in Zaragoza. No statistically significant differences in the gametocytaemia by treatment schemes or therapeutic responses were noted, although the patients who received SP had more gametocytes than those treated with SP+CQ. Gametocytaemia was not correlated with asexual parasitemia or sex and age of patient. The difference in the level of gametocytaemia between Turbo and Zaragoza appears to be influenced by the time elapsed between the appearance of symptoms and the beginning of treatment.

The resurgence and spread of antimalarial drug resistance is one of the causes of the worldwide increase of malaria. In Colombia, uncomplicated Plasmodium falciparum malaria has been treated with a combination of amodiaquine (AQ) and sulfadoxine/pyrimethamine (SP) since 2000. The efficacy of these two antimalarials was evaluated after the implementation of the new malaria treatment scheme. In the municipalities of El Charco and Tumaco (Nariño) on the Pacific Coast region, the standard PAHO protocol was used to evaluate antimalarial efficacy in areas of low to moderate malaria transmission. Patients were randomly allocated to treatment regime in two cities of Nariño, El Charco (n = 48) and Tumaco (n = 50). After 14 days none of El Charco patients presented therapeutic failure to either antimalarial. However, in Tumaco after 28 days, 12 of 24 (95% CI: 30.6-69.4) patients presented AQ treatment failure while 4 of 26 (95% CI: 5.1-33.1) patients had SP treatment failure. The high level of AQ treatment failure in Tumaco was unexpected because it had been introduced only recently as an antimalarial treatment in Colombia. The results suggest that the use of the current dose of AQ in combination with SP will be therapeutically useful for less time than expected. Use of combined therapies is a key strategy to delay antimalarial resistance. Unfortunately, its success depends on the efficacy of antimalarial drugs individually.

Background: Few studies have been reported on the potential usefulness of Fansidar combination at a fixed doses of pyrimethamine and sulfadoxine as prophylaxis for pneumonia by Pneumocystis carinii and toxoplasmic encephalitis., Methods: The clinical histories of the patients seen in our department from January, 1992 to December, 1994 who were prescribed pyrimethamine and sulfadoxine for the above prophylactic treatment were reviewed., Results: One hundred fifty clinical histories fulfilled the requisites for evaluation. Thirty-seven patients (24%) had a previous diagnosis of AIDS, with the median CD4 count being of 134/mm3. The median follow up of treatment with Fansidar was of 31 months. Twenty-eight cases of pneumonia by Pneumocystis carinii (6.9 cases for 100 patients-years) and 10 cases of toxoplasmic encephalitis (2.5 cases for 100 patients-years) were diagnosed., Conclusions: These values are similar to those presented with respect to other pharmacologic interventions commonly used for the prevention of pneumonia by Pneumocystis carinii and toxoplasmic encephalitis and suggest that pyrimethamine and sulfadoxine is a useful alternative and requires consideration in individualized cases for the prophylaxis of these diseases.

In 1983, the first African cases of malaria due to Plasmodium falciparum resistant to sulfadoxine/pyrimethamine, were described. Currently, this resistance is frequently found in Kenya and Tanzania. It has also been described in other African countries. A young Spanish woman contracted Plasmodium falciparum malaria in Senegal and was treated in our hospital with sulfadoxine/pyrimethamine. Fever and symptoms disappear within two days. The thick smears taken on the eighth and thirteenth days of treatment contained an abundance of gametocytes, but neither trophozoites nor schizonts. As the risk of transmission of malaria to the rest of the community was considered practically nil, no other treatment was administered. A month late, she was admitted to the hospital due to fever, shivering, fatigue, loss of appetite and hemolytic anaemia. The thick smear test again showed trophozoites of P. Falciparum. Thus, it proved to be a delayed grade I resistance to sulfadoxine/pyrimethamine, detected in far west Africa. An oral dose of mefloquine was administered as well as a red cell transfusion. Both fever and symptoms finally disappeared.