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F Font

Publications and source records attributed to F Font.

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Diagnostic accuracy and case management of clinical malaria in the primary health services of a rural area in south-eastern Tanzania.

Malaria control continues to rely on the diagnosis and prompt treatment of both suspected and confirmed cases through the health care structures. In south-eastern Tanzania malaria is one of the leading causes of morbidity and mortality. The absence of microscopic examination in most of the health facilities implies that health workers must rely on clinical suspicion to identify the need of treatment for malaria. Of 1558 randomly selected paediatric consultations at peripheral health facilities throughout Kilombero District, 41.1% were diagnosed by the attending health worker as clinical malaria cases and 42.5% prescribed an antimalarial. According to our malaria case definition of fever or history of fever with asexual falciparum parasitaemia of any density, 25.5% of all children attending the health services had malaria. This yielded a sensitivity of 70.4% (IC95% = 65.9-74.8%) and a specificity of 68.9% (IC95% = 66.2-71.5%). Accordingly, 30.4% of confirmed cases left with no antimalarial treatment. Among malaria-diagnosed patients, 10% were underdosed and 10.5% were overdosed. In this area, as in many African rural areas, the low diagnostic accuracy may imply that the burden of malaria cases may be overestimated. Greater emphasis on the functioning and quality of basic health services in rural endemic areas is required if improved case management of malaria is to help roll back this scourge.

Antimalarials↗

The impact of placental malaria on gestational age and birth weight.

Maternal malaria is associated with reduced birth weight, which is thought to be effected through placental insufficiency, which leads to intrauterine growth retardation (IUGR). The impact of malaria on preterm delivery is unclear. The effects of placental malaria-related changes on birth weight and gestational age were studied in 1177 mothers (and their newborns) from Tanzania. Evidence of malaria infection was found in 75.5% of placental samples. Only massive mononuclear intervillous inflammatory infiltration (MMI) was associated with increased risk of low birth weight (odds ratio ¿OR, 4.0). Maternal parasitized red blood cells and perivillous fibrin deposition both were associated independently with increased risk of premature delivery (OR, 3.2; OR, 2.1, respectively). MMI is an important mechanism in the pathogenesis of IUGR in malaria-infected placentas. This study also shows that placental malaria causes prematurity even in high-transmission areas. The impact of maternal malaria on infant mortality may be greater than was thought previously.

Birth Weight↗

Maternal mortality in a rural district of southeastern Tanzania: an application of the sisterhood method.

BACKGROUND: Deaths from maternal causes represent the leading cause of death among women of reproductive age in most developing countries. It is estimated that the highest risk occurs in Africa, with 20% of world births but 40% of the world maternal deaths. The level of maternal mortality is difficult to assess especially in countries without an adequate vital registration system. Indirect techniques are an attractive cost-effective tool to provide estimates of orders of magnitude for maternal mortality. METHOD: The level of maternal mortality estimated by the sisterhood method is presented for a rural district in the Morogoro Region of Southeastern Tanzania and the main causes of maternal death are studied. Information from region-specific data using the sisterhood method is compared to data from other sources. RESULTS: The maternal mortality ratio (MMR) was 448 maternal deaths per 100,000 live births (95%CI : 363-534 deaths per 100,000 live births). Maternal causes accounted for 19% of total mortality in this age group. One in 39 women who survive until reproductive age will die before age 50 due to maternal causes. The main cause of death provided by hospital data was puerperal sepsis (35%) and postpartum haemorrhage (17%); this is compatible with the main causes reported for maternal death in settings with high levels of maternal mortality, and similar to data for other regions in Tanzania. The sisterhood method provides data comparable with others, together with a cost-effective and reliable estimate for the determination of the magnitude of maternal mortality in the rural Kilombero District.

Adolescent↗

Cost-effectiveness of iron supplementation and malaria chemoprophylaxis in the prevention of anaemia and malaria among Tanzanian infants.

Prerequisites for effective interventions against severe anaemia and malaria among infants are economic evaluations to aid the setting of priorities and the making of health policy. In the present study we analysed the cost and effectiveness of three control strategies hypothetically delivered through the Expanded Programme on Immunization (EPI). For the prevention of severe anaemia and from the perspective of the health provider, the cost-effectiveness ratios were, respectively, US$ 8, US$ 9, and US$ 21 per disability-adjusted life year (DALY) for malaria chemoprophylaxis with Deltaprim (a combination of 3.125 mg pyrimethamine and 25 mg dapsone) + iron, Deltaprim alone, or iron supplementation alone. For malaria prevention, Deltaprim + iron cost US$ 9.7 per DALY and Deltaprim alone cost US$ 10.2 per DALY. From a sociocultural perspective the cost-effectiveness ratios ranged from US$ 9 to US$ 26 for severe anaemia prevention and from US$ 11 to US$ 12 for the prevention of clinical malaria. These ratios were highly cost-effective, as defined by the World Bank's proposed threshold of less than US$ 25 per DALY for comparative assessments. Furthermore, all the preventive interventions were less costly than the current malaria and anaemia control strategies that rely on clinical case management. This economic analysis supports the inclusion of both malaria chemoprophylaxis and iron supplementation delivered through EPI as part of the control strategies for these major killers of infants in parts of sub-Saharan Africa.

Anemia, Iron-Deficiency↗

African children with malaria in an area of intense Plasmodium falciparum transmission: features on admission to the hospital and risk factors for death.

Malaria remains the most important parasitic cause of mortality in humans. Its presentation is thought to vary according to the intensity of Plasmodium falciparum transmission. However, detailed descriptions of presenting features and risk factors for death are only available from moderate transmission settings. Such descriptions help to improve case management and identify priority research areas. Standardized systematic procedures were used to collect clinical and laboratory data on 6,624 children admitted to hospital over a 1-year period in an intensely malarious part of Tanzania. Frequencies of signs and symptoms were calculated and their association with a fatal outcome was assessed using multivariate logistic regression. There were 72 deaths among 2,432 malaria cases (case fatality rate [CFR] = 3.0%); 44% of the cases and 54% of the deaths were in individuals less than 1 year of age. There was no association between level of parasitemia and CFR. Increased risk of dying was independently found in all children with hypoglycemia (odds ratio [OR] = 6.7, 95% confidence interval [CI] = 3.9-11.7), in children 1-7 months of age with tachypnea (OR = 8.8, 95% CI = 2.6-30.5) and dehydration (OR = 5.0, 95% CI = 1.9-14.2), and in children 8 months to 4 years of age with chest indrawing (OR = 4.7, 95% CI = 2.0-11.2) and inability to localize a painful stimulus (OR = 6.9, 95% CI = 2.9-16.5). Children in the bottom quartile of weight-for-age were more likely to die (OR = 2.1, 95% CI = 1.3-3.5). Eight percent of the malaria cases had severe anemia (packed cell volume < 15%) but 24% received a blood transfusion. The epidemiology of malaria disease may be more complex than previously thought. Improved case management in a wide variety of health facilities may result from adequate identification and treatment of dehydration and hypoglycemia. Transfusion-requiring anemia is a major problem and sustainable, effective preventive measures are urgently needed.

Adolescent↗

Randomised placebo-controlled trial of iron supplementation and malaria chemoprophylaxis for prevention of severe anaemia and malaria in Tanzanian infants.

BACKGROUND: Malaria and anaemia, especially that due to iron deficiency, are two leading causes of morbidity worldwide. Little is known about the relative contribution of Plasmodium falciparum infection and iron deficiency to the aetiology of anaemia in malaria-endemic areas. We undertook a randomised comparison of different strategies for control of anaemia and malaria in infants, including an assessment of the effect of iron supplementation on malaria susceptibility. METHODS: 832 infants born at one hospital in a malaria-hyperendemic area of Tanzania between January and October, 1995, were randomly assigned to group DI, receiving daily oral iron (2 mg/kg daily) plus weekly Deltaprim (3.125 mg pyrimethamine plus 25 mg dapsone); group IP, receiving iron plus weekly placebo; group DP, receiving daily placebo plus weekly Deltaprim; or group PP. supplementation was given from 8 to 24 weeks of age, and the weekly chemoprophylaxis from 8 to 48 weeks. The frequency of severe anaemia (packed-cell volume < 25%) and malaria episodes was assessed through a combination of passive case detection and cross-sectional surveys. FINDINGS: The groups that received iron supplementation had a lower frequency of severe anaemia than those that did not receive iron (0.62 vs 0.87 cases per person-year; protective efficacy 28.8% [95% CI 6.3-45.8). Iron supplementation had no effect on the frequency of malaria (0.87 vs 1.00 cases per person-year; protective efficacy 12.8% [-12.8 to 32.5]). The groups that received malaria prophylaxis had lower frequencies of both severe anaemia (0.45 vs 1.04 episodes per person-year; protective efficacy 57.3% [43.0-67.9]) and malaria (0.53 vs 1.34 episodes per person-year; protective efficacy 60.5% [48.2-69.9]) than the groups that did not receive prophylaxis. After the end of the intervention period, children who had received malaria chemoprophylaxis had higher rates of severe anaemia and malaria than non-chemoprophylaxis groups (relative risks 2.2 [1.3-3.7] and 1.8 [1.3-2.6]). INTERPRETATION: Malaria chemoprophylaxis during the first year of life was effective in prevention of malaria and anaemia but apparently impaired the development of natural immunity. Iron supplementation was effective in preventing severe anaemia without increasing susceptibility to malaria. Our findings support iron supplementation of infants to prevent iron-deficiency anaemia, even in malaria-endemic areas.

Adult↗

Duration of protection and age-dependence of the effects of the SPf66 malaria vaccine in African children exposed to intense transmission of Plasmodium falciparum.

The SPf66 synthetic vaccine is safe and partly efficacious against Plasmodium falciparum malaria among children 1-5 years old. The estimated vaccine efficacy [VE] for all clinical episodes over a period of 18 months after the third dose is 25% (95% confidence interval [CI], 1%-44%; P = .044). The observed temporal variations in efficacy could have been due to chance (likelihood ratio chi 2 = 13.8, 8 df; P = .086). Efficacy against clinical malaria did not vary significantly with age (chi 2 = 1.07, 4 df; P = .90). Overall parasite density was 21% lower in vaccine recipients than in the placebo group (95% CI, 0%-38%; P = .044). Further development of SPf66 may require trials to evaluate safety, immunogenicity, and efficacy when administered in the first year of life, together with other vaccines contained in the Expanded Programme of Immunization schedule.

Age Factors↗

A comparative study of the efficacies of chloroquine and a pyrimethamine-dapsone combination in clearing Plasmodium falciparum parasitaemia in school children in Tanzania.

A randomized study on the in vivo efficacies of chloroquine and a pyrimethamine-dapsone combination (Maloprim) in clearing P. falciparum parasitaemia was carried out in 77 asymptomatic semi-immune schoolchildren in the Kilombero District of Tanzania. Children were randomized to receive either chloroquine at a dose of 25 mg/kg over three days, or Maloprim (6.25 mg pyrimethamine + 50 mg dapsone for children under 10 years, and 12.5 mg pyrimethamine + 100 mg dapsone for children 10 or more years old) as a single dose. Children were followed-up for malaria parasitaemia at days 2, 7 and 14 after screening, randomization and treatment. The slide positivity rate was lower in the Maloprim group at all cross-sectional surveys (23 vs 37% at day 2; 9 vs 20% at day 7; 21 vs 32% at day 14) but none of these differences reached statistical significance. No cases in the Maloprim group showed RII resistance, whereas in the chloroquine group, 2 cases showed RII resistance and a further 2 cases RIII resistance (6%). No major side-effects were reported. The combination of pyrimethamine-dapsone appears to be a better choice than chloroquine as a chemoprophylactic regimen for malaria in this area. Although they need to be confirmed in a larger study, these results may be of interest to the policy-makers as well as researchers.

Antimalarials↗