Myocardial damage in falciparum malaria detectable by cardiac troponin T is rare

OBJECTIVES: To estimate the prevalence of myocardial damage in falciparum malaria by serum concentration of cardiac troponin T. METHODS: Retrospective study of stored sera and patient files; assessment of acute myocardial damage by serum concentration or activity of cardiac troponin T, creatine kinase, creatine kinase MB and myoglobin and by routine electrocardiography. RESULTS: A total of 161 patients with falciparum malaria were included in the study; troponin T was elevated in one case (0.6%), no CK-MB elevations were found, myoglobin was elevated in 10 of 161 patients (6.2%), all of whom were elderly and had concomitant elevated serum concentration levels of cystatin C; ECG abnormalities were seen in 23 patients. CONCLUSION: Assessed by troponin T, myocardial damage in falciparum malaria is rare.     

A randomized trial of amodiaquine and artesunate alone and in combination for the treatment of uncomplicated falciparum malaria in children from Burkina Faso

Combining artesunate (AR) with existing antimalarial drugs may improve cure rates, delay emergence of resistance and reduce parasite clearance time. In order to investigate the latter, we conducted a randomized clinical trial testing the AR plus amodiaquine (AQ) combination for the treatment of uncomplicated Plasmodium falciparum malaria in Burkina Faso. Children aged 1-15 years were randomly assigned to either AQ (10 mg/kg) or AR (4 mg/kg first day then half dose) or AQ + AR (AQAR) as a single daily dose under supervision for three consecutive days for all groups. Follow-up lasted 28 days. Primary endpoints were parasite and fever clearance time. Eighty-seven children were evaluated: 27 received AQ, 27 AR and 33 AQAR. Using an intention to treat analysis, fever clearance time was similar in the three groups. However, it was significantly faster in the AR (1.21 days; P = 0.02) and AQAR groups (1.19 days; P < 0.01) than in the AQ group (1.46 days) when excluding other concomitant causes of fever. Parasite clearance time was faster in AR (1.13 days; P = 0.008) and AQAR groups (1.13 days; P < 0.01) than in the AQ group (1.6 days). All children cleared their parasites by day 14, including the child with Late Parasitological Failure (LPF) at day 7 after rescue treatment. Only one child (4%) from the AR group and one (4%) from the AQ group presented with asymptomatic parasitaemia at day 7 and day 21, respectively (LPF). Gametocyte carriage was not detectable in any group during follow-up nor was any adverse reaction observed. While resistance to first-line treatment (chloroquine) is already established in the country, AQ and AR used alone or in combination therapy proved highly efficacious in our study. Burkina Faso stands in a very good situation for an internationally recommended switch to AR-containing combination as first-line treatment for uncomplicated malaria. Including AQ in this regimen seems the best option.     

The molecular and cellular basis of olfactory-driven behavior in Anopheles gambiae larvae

The mosquito Anopheles gambiae is the principal Afrotropical vector for human malaria. A central component of its vectorial capacity is the ability to maintain sufficient populations of adults. During both adult and preadult (larval) stages, the mosquitoes depend on the ability to recognize and respond to chemical cues that mediate feeding and survival. In this study, we used a behavioral assay to identify a range of odorant-specific responses of An. gambiae larvae that are dependent on the integrity of the larval antennae. Parallel molecular analyses have identified a subset of the An. gambiae odorant receptors (AgOrs) that are localized to discrete neurons within the larval antennae and facilitate odor-evoked responses in Xenopus oocytes that are consistent with the larval behavioral spectrum. These studies shed light on chemosensory-driven behaviors and represent molecular and cellular characterization of olfactory processes in mosquito larvae. These advances may ultimately enhance the development of vector control strategies, targeting olfactory pathways in larval-stage mosquitoes to reduce the catastrophic effects of malaria and other diseases.     

Reduced levels of transforming growth factor-beta1, interleukin-12 and increased migration inhibitory factor are associated with severe malaria

In the present study, we investigated plasma levels of interleukin (IL)-12 and transforming growth factor (TGF-beta1) in malaria patients as these two cytokines regulate the balance between pro- and anti-inflammatory cytokines. We compared plasma IL-12 and TGF-beta1 levels in groups of malaria patients categorized as uncomplicated, severe, cerebral and placental malaria. Both TGF-beta1 and IL-12 levels were significantly reduced in peripheral plasma of adults with severe and cerebral malaria as well as in plasma of Tanzanian children with cerebral malaria (P<0.05). Similar results were observed with both placental and peripheral plasma of pregnant women who were infected with Plasmodium falciparum. IL-18, a cytokine known to be critical for the induction of IFN-gamma along with IL-1, was produced more in uncomplicated adult patients than in aparasitimic healthy controls (P<0.05). However, IL-18 response rate declined as the symptoms of the disease became more severe suggesting that the IL-18 response may be impaired with increased malaria severity. Together, the results of the three cytokines support the notion that imbalance between pro- and anti-inflammatory cytokines may contribute to the development of severe malaria infection. With malaria infection during pregnancy, we demonstrated that macrophage migration inhibitory factor (MIF) levels in infected placental plasma were significantly higher than those in the paired peripheral plasma (P<0.05). MIF, therefore, may play an important role in the local immune response to placental P. falciparum infection.     

Exchange transfusion in complicated pediatric malaria: A critical appraisal

Complicated falciparum malaria is a killer disease resulting in high mortality in spite of appropriate treatment. Some workers have reported improved survival when adjunct exchange blood transfusion is included in the treatment modality while others opine against it. This review is an effort to address and critically appraise current evidence for the treatment mode for severe malaria. The literature was searched with a specified search strategy to identify reports of children who underwent exchange transfusion for severe malaria. Total 23 children who underwent exchange transfusion for severe falciparum malaria published by 9 authors were identified. Age ranged from 5 months to 16 years with a mean age of 6.4 years. The average preprocedure parasite index (PI) was 41.4% (95confidence interval [CI]; 31.2-51.4). The average blood volume exchanged was 118.6% (95% CI; 94.7-143) of the circulating blood volume. The average postexchange reduction in PI was 34.1% (95% CI; 25.4-42.8). Three out of 23 children encountered some complications. All the children survived     

Dermatological manifestations in onchocerciasis: A retrospective study of 400 imported cases

Introduction

Onchocerciasis is caused by Onchocerca volvulus and mainly leads to pruritus and skin and visual disorders, including blindness. Seventeen million people are infected in 38 countries; 31 of these are in sub-Saharan Africa, six in Latin America and one on the Arabian Peninsula. More than 99% of cases occur in sub-Saharan Africa where 120 million people are at risk of infection. Eye disorders have been well-documented; however, skin disorders have not been described accurately. The objective of our study was to describe the epidemiology, main skin manifestations and treatment of imported onchocerciasis.

Mother-to-child transmission of HIV-1: association with malaria prevention, anaemia and placental malaria

Objectives

Malaria infection may impact on mother‐to‐child transmission (MTCT) of HIV‐1. Prevention of malaria in pregnancy could thus potentially affect MTCT of HIV. We studied the impact of intermittent preventive treatment during pregnancy (IPTp) on HIV‐1 MTCT in southern Mozambique.

Methods

A total of 207 HIV‐positive Mozambican pregnant women were enrolled in the study as part of a randomized placebo‐controlled trial of two‐dose sulfadoxine‐pyrimethamine (SP) IPTp in women receiving single‐dose nevirapine to prevent MTCT of HIV. HIV RNA viral load, maternal anaemia and peripheral and placental malaria were assessed at delivery. Infant HIV status was determined by DNA polymerase chain reaction (PCR) at 1 month of age.

Results

There were 19 transmissions of HIV in 153 mother–infant pairs. IPTp with SP did not have a significant impact on MTCT (11.8% in the SP group vs. 13.2% in the placebo group; P=0.784) or on maternal HIV RNA viral load [16 312 (interquartile range {IQR} 4076–69 296) HIV‐1 RNA copies/mL in the SP group vs. 18 274 (IQR 5471–74 104) copies/mL in the placebo group; P=0.715]. In multivariate analysis, maternal HIV RNA viral load [adjusted odds ratio (AOR) 19.9; 95% confidence interval (CI) 2.3–172; P=0.006] and anaemia (haematocrit <33%; AOR 7.5; 95% CI 1.7–32.4; P=0.007) were independent risk factors for MTCT. Placental malaria was associated with a decrease in MTCT (AOR 0.23; 95% CI 0.06–0.89; P=0.034).

Conclusions

IPTp with SP was not associated with a significant impact on MTCT of HIV. Maternal anaemia was an independent risk factor for MTCT.     

Insecticide-treated bednet use, anaemia, and malaria parasitaemia in Blantyre District, Malawi

OBJECTIVE: To evaluate the use of insecticide-treated bednets and the effectiveness of social marketing for their distribution. METHODS: Systematic cluster sample survey of 1080 households in 36 census enumeration areas across Blantyre district, Malawi, in February 2000. RESULTS: A total of 672 households had one or more children under 5. Bednet ownership was low (20.5% of households) overall, and significantly lower in rural areas than urban areas (6.4 vs. 29.8%, P=0.001). Only 3.3% of rural children under 5 had slept under a net the previous night, compared with 24.0% of urban children (P < 0.001). When asked why they did not own a net, nearly all (94.9%) caretakers in households without nets stated they had no money to buy them. In multivariate statistical models that controlled for the influence of house structure, urban vs. rural location, gender of the head of household, and the primary caretaker's education, rural children under 5 in households without nets experienced a statistically significant higher prevalence of malaria parasitaemia [RR (risk ratio) 4.9, 95% CI (confidence interval) 2.3-10.5] than children in households with at least one bednet. This was also true for urban children under 5 (RR 2.1, 95% CI 1.0-4.2, P=0.04). CONCLUSION: Social marketing approaches to promoting insecticide-treated nets in Blantyre District may have produced measurable health benefits for children in those households in which residents bought and used the products. Market-based approaches may take years to achieve high levels of coverage and may exaggerate inequities between urban and rural populations.     

Does radical cure of asymptomatic Plasmodium falciparum place adults in endemic areas at increased risk of recurrent symptomatic malaria?

A cohort of 197 adults in Kassena-Nankana District (northern Ghana) was radically cured of malaria parasites to study subsequent incidence of malaria infection. During the following 20 weeks of the malaria transmission season, 49% experienced clinical attacks associated with Plasmodium falciparum parasitaemia. In a group of 202 adults identically followed-up 1 year later without being treated, only 38% experienced such episodes (log-rank test for equality of survivor functions, P=0.035). Clinical attacks in radically cured individuals presented with lower parasite densities but more symptoms. Randomized studies are needed to test the hypothesis that radical cure of P. falciparum enhances the risk and severity of subsequent clinical malaria attacks.     

Improving adherence to malaria treatment for children: the use of pre-packed chloroquine tablets vs. chloroquine syrup

Malaria is a major cause of morbidity and mortality among children under five in sub-Saharan Africa. Prompt diagnosis and adequate treatment of acute clinical episodes are essential to reduce morbidity and prevent complications and mortality. In many countries, chloroquine syrup is the mainstay of malaria treatment for children under five. Not only is syrup more expensive than tablets, adherence to the prescribed dose at home is a problem because mothers use wrongly sized measuring devices or have difficulty with the instructions. We investigated the impact of introducing pre-packed tablets for children on adherence to treatment and compared the total cost of the tablets with that of syrup. Children aged 0--5 years diagnosed with malaria at the clinic over a 6-week period received either pre-packed tablets or syrup by random assignment. The principal caregivers were interviewed at home on day 4 after attending the clinic. Of the 155 caregivers given pre-packed tablets, 91% (n=141) adhered to the recommended dosage, while only 42% (n=61) of 144 who were provided syrup did. Only 20% of caregivers who received syrup used an accurate 5 ml measure. The cost of treatment with tablets was about one-quarter that of syrup and 62% (n=96) of caregivers preferred tablets. Pre-packed chloroquine tablets are a viable alternative to syrup.