Malaria Control in Complex Humanitarian Emergencies

War, famine, civil conflict, and political persecution displacing large populations often leads to severe disruptions in health services, disease control programs, food distribution systems, and loss of shelter. When the dimensions of the crisis overwhelm the local and international communities' ability to respond quickly and effectively, significant morbidity and mortality result in what is termed a complex humanitarian emergency. The public health consequences have been most severe in underdeveloped nations where most deaths are caused by communicable diseases, which include malaria. This paper describes and analyses the factors that contribute to malaria morbidity and mortality and proposes effective measures to combat them.Les conflits armés, les famines, les guerres civiles, les persécutions politiques déplaçant de grandes portions de la population provoquent souvent de graves perturbations dans les services de santé, les programmes de contrôles sanitaires, les structures de distributions alimentaires, et entraînent fréquemment la perte du gîte ou de l'abris. Quand l'ampleur de la crise submerge les capacités locales et internationales à y répondre promptementet efficacement, le résultat de ce que l'on appelle une urgence humanitaire complexe est un accroissement significatif de la condition maladive et de la mortalité des populations en cause. Les conséquences en termes de santé publique sont particulièrement graves dans les nations sous-développées, où un plus grand nombre de pertes de vie sont dues à des maladies transmissibles, incluant notamment la malaria. Cet article décrit et analyse la série de facteurs contribuant à la condition maladive et à la mortalité liés à la malaria, et propose des mesures effectives pour combattre ces facteurs

The genetic change in P. falciparum populations of rural Tanzania resulting from national policy on firstline malaria treatment and pilot Sulfadoxine/pyrimethamine and Artesunate combination

Malaria Journal 2010, 9(Suppl 2):P20Theory predicts that we can protect the efficacy of future antimalarials by changing treatment practice or drug formulation, but the potential success of such interventions rests upon their impact on drug pressure in the field. So far, gathering field data on the relationship between policy, drug pressure, recombination and the evolution of resistance has been entirely challenging. To test these predictions, dhfr and dhps frequency changes were measured in two rural districts of Rufiji and Kilombero/Ulanga during 2000-2006, and the frequencies of the two genes compared prior, during and after antimalarial policy change from first line CQ to first line SP in 2001. Furthermore, while SP first line was maintained in Kilombero/Ulanga, pilot combination therapy of SP+Artesunate (ART) was introduced in Rufiji in 2002 to replace SP and dhfr and dhps frequency changes compared between the two districts. Size polymorphisms at three sets of microsatellite loci linked to dhfr and three other sets of unlinked microsatellite loci were analysed. Genetic analysis of SP resistance genes was carried out on 9,662 Plasmodium falciparum infections identified in a series of annual cross sectional surveys conducted in the two districts between 2000-2006. The frequency of dhfr and dhps resistance alleles did not change significantly while SP was the recommended second-line treatment, but highly significant changes occurred during the subsequent year after the switch to first line SP. The frequency of the triple mutant dhfr allele increased by 37% -63% and that of double mutant dhps allele increased 200%-300%. A strong association between these unlinked alleles also emerged; confirming that they are co-selected by SP. Distribution of major lineages indicates that there is extensive genetic exchange among the geographic regions. Combination therapy had visible effect on the frequencies of dhfr and dhps resistance alleles. The findings of this study provide insight on the interplay between policy, drug pressure, recombination and the evolution of resistance

Media, Health Workers, and Policy Makers' Relationship and Their Impact on Antimalarial Policy Adoption: A Population Genetics Perspective

Drug resistance negatively impacts malaria treatments, making treatment policy revision unavoidable. So far, studies relating sociopolitical and technical issues on policy change with malaria parasite genetic change are lacking. We have quantified the effect of malaria treatment policy on drug pressure and the influence of the media, policy makers, and health worker relationship on parasite population genetic change in Kilombro/Ulanga district. Cross-sectional surveys of asymptomatic infections conducted before, during and after the switch from chloroquine to sulphadoxine/pyrimethamine were used for genetic analysis of SP resistance genes in 4,513 asymptomatic infections identified, and their frequency change was compared with retrospective study of the documented process of policy change. Highly significant changes of dhfr and dhps resistance alleles occurred within one year of switch to SP first line, followed by a decline of their rate of selection caused by reduction of SP usage, as a result of negative media reports on SP usage and lack of adequate preparations

Quantification of markers of antimalarial drug resistance from an area of high malaria transmission: Comparing frequency with prevalence

Molecular monitoring of markers of antimalarial drug resistance offers an affordable alternative to the in vivo method for the detection of resistance, and has the potential to guide public health policy in a timely manner. However, the optimal way of analyzing and reporting these data, particularly those emanating from areas of moderate to high malaria transmission, has never been fully explored or agreed upon, given the potential of being confounded by coinfections. By using large number of real field samples, we quantified the difference between prevalence and frequency when reporting field data on antimalarial drug resistance obtained by direct counting of haplotypes. Polymerase chain reaction (PCR) and sequence specific oligonucleotide probing was used to generate point mutations which were used to construct haplotypes. Results indicate that frequency underestimates haplotypes present at low levels while also amplifying haplotypes present at high levels; prevalence on the other hand behaved in a vice versa manner. Both prevalence and frequency are therefore essential, as each may have relevance in different contexts in high malaria transmission settings. Frequency is essential to gauge the impact of intervention on antimalarial drug resistance while prevalence may be more relevant when the aim is to determine parasite clearance. Key words: Molecular markers, polymerase chain reaction (PCR) - sequence specific oligonucleotide probing (SSOP), prevalence, frequency

Dispensary level pilot implementation of rapid diagnostic tests: an evaluation of RDT acceptance and usage by providers and patients – Tanzania, 2005

BACKGROUND\ud \ud Malaria rapid diagnostic tests (RDTs) may assist in diagnosis, improve prescribing practices and reduce potential drug resistance development. Without understanding operational issues or acceptance and usage by providers and patients, the costs of these tests may not be justified.\ud \ud OBJECTIVES\ud \ud To evaluate the impact of RDTs on prescribing behaviours, assess prescribers' and patients' perceptions, and identify operational issues during implementation.\ud \ud METHODS\ud \ud Baseline data were collected at six Tanzanian public dispensaries. RDTs were implemented for eight weeks and data collected on frequency of RDT use, results, malaria diagnoses and the prescription of antimalarials. Patients referred for RDTs completed a standardised exit interview. Qualitative methods assessed attitudes toward and satisfaction with RDTs, perceptions about the test and operational issues related to implementation.\ud \ud RESULTS\ud \ud Of 595 patients at baseline, 200 (33%) were diagnosed clinically with malaria but had a negative RDT. Among the 2519 RDTs performed during implementation, 289 (11.5%) had a negative result and antimalarials prescribed. The proportion of "over-prescriptions" at baseline was 54.8% (198/365). At weeks four and eight this decreased to 16.1% (27/168) and 16.4% (42/256) respectively.A total of 355 patient or parent/caregiver and 21 prescriber individual interviews and 12 focus group discussions (FGDs) were conducted. Patients, caregivers and providers trusted RDT results, agreed that use of RDTs was feasible at dispensary level, and perceived that RDTs improved clinical diagnosis. Negative concerns included community suspicion and fear that RDTs were HIV tests, the need for additional supervision in interpreting the results, and increased work loads without added compensation.\ud \ud CONCLUSION\ud \ud Overprescriptions decreased over the study period. There was a high degree of patient/caregiver and provider acceptance of and satisfaction with RDTs. Implementation should include community education, sufficient levels of training and supervision and consideration of the need for additional staff

Routine delivery of artemisinin-based combination treatment at fixed health facilities reduces malaria prevalence in Tanzania: an observational study

BACKGROUND Artemisinin-based combination therapy (ACT) has been promoted as a means to reduce malaria transmission due to their ability to kill both asexual blood stages of malaria parasites, which sustain infections over long periods and the immature derived sexual stages responsible for infecting mosquitoes and onward transmission. Early studies reported a temporal association between ACT introduction and reduced malaria transmission in a number of ecological settings. However, these reports have come from areas with low to moderate malaria transmission, been confounded by the presence of other interventions or environmental changes that may have reduced malaria transmission, and have not included a comparison group without ACT. This report presents results from the first large-scale observational study to assess the impact of case management with ACT on population-level measures of malaria endemicity in an area with intense transmission where the benefits of effective infection clearance might be compromised by frequent and repeated re-infection. METHODS A pre-post observational study with a non-randomized comparison group was conducted at two sites in Tanzania. Both sites used sulphadoxine-pyrimethamine (SP) monotherapy as a first-line anti-malarial from mid-2001 through 2002. In 2003, the ACT, artesunate (AS) co-administered with SP (AS + SP), was introduced in all fixed health facilities in the intervention site, including both public and registered non-governmental facilities. Population-level prevalence of Plasmodium falciparum asexual parasitaemia and gametocytaemia were assessed using light microscopy from samples collected during representative household surveys in 2001, 2002, 2004, 2005 and 2006. FINDINGS Among 37,309 observations included in the analysis, annual asexual parasitaemia prevalence in persons of all ages ranged from 11% to 28% and gametocytaemia prevalence ranged from <1% to 2% between the two sites and across the five survey years. A multivariable logistic regression model was fitted to adjust for age, socioeconomic status, bed net use and rainfall. In the presence of consistently high coverage and efficacy of SP monotherapy and AS + SP in the comparison and intervention areas, the introduction of ACT in the intervention site was associated with a modest reduction in the adjusted asexual parasitaemia prevalence of 5 percentage-points or 23% (p < 0.0001) relative to the comparison site. Gametocytaemia prevalence did not differ significantly (p = 0.30). INTERPRETATION The introduction of ACT at fixed health facilities only modestly reduced asexual parasitaemia prevalence. ACT is effective for treatment of uncomplicated malaria and should have substantial public health impact on morbidity and mortality, but is unlikely to reduce malaria transmission substantially in much of sub-Saharan Africa where individuals are rapidly re-infected.Financial support for IMPACT-Tz came primarily from CDC, the U.S. Agency for International Development and the Wellcome Trust

dhfr and dhps genotype and sulfadoxine-pyrimethamine treatment failure in children with falciparum malaria in the Democratic Republic of Congo

To determine the relationship between mutations in dhfr and dhps and SP treatment failure in Plasmodium falciparum malaria in the Democratic Republic of the Congo (DRC

The Role of Public Health Institutions in Global Health System Strengthening Efforts: The US CDC's Perspective

Peter Bloland and colleagues from the US CDC lay out the agency's priorities for health systems strengthening efforts

Malaria in pregnant women in an area with sustained high coverage of insecticide-treated bed nets

BACKGROUND\ud \ud Since 2000, the World Health Organization has recommended a package of interventions to prevent malaria during pregnancy and its sequelae that includes the promotion of insecticide-treated bed nets (ITNs), intermittent preventive treatment in pregnancy (IPTp), and effective case management of malarial illness. It is recommended that pregnant women in malaria-endemic areas receive at least two doses of sulphadoxine-pyrimethamine in the second and third trimesters of pregnancy. This study assessed the prevalence of placental malaria at delivery in women during 1st or 2nd pregnancy, who did not receive intermittent preventive treatment for malaria (IPTp) in a malaria-endemic area with high bed net coverage.\ud \ud METHODS\ud \ud A hospital-based cross-sectional study was done in Ifakara, Tanzania, where bed net coverage is high. Primi- and secundigravid women, who presented to the labour ward and who reported not using IPTp were included in the study. Self-report data were collected by questionnaire; whereas neonatal birth weight and placenta parasitaemia were measured directly at the time of delivery.\ud \ud RESULTS\ud \ud Overall, 413 pregnant women were enrolled of which 91% reported to have slept under a bed net at home the previous night, 43% reported history of fever and 62% were primigravid. Malaria parasites were detected in 8% of the placenta samples; the geometric mean (95%CI) placental parasite density was 3,457 (1,060-11,271) parasites/mul in primigravid women and 2,178 (881-5,383) parasites/mul in secundigravid women. Fifteen percent of newborns weighed <2,500 g at delivery. Self-reported bed net use was statistically associated with lower risk for low birth weight [OR 0.34 (95% CI: 0.16-0.74) and OR 0.22 (95% CI: 0.08-0.59) for untreated and treated bed nets, respectively], but was not associated with placental parasitaemia [OR 0.74 (0.21-2.68) and OR 1.64 (0.44-6.19) for untreated and treated bed nets, respectively].\ud \ud CONCLUSION\ud \ud The observed incidence of LBW and prevalence of placental parasitaemia at delivery suggests that malaria remains a problem in pregnancy in this area with high bed net coverage when eligible women do not receive IPTp. Delivery of IPTp should be emphasized at all levels of implementation to achieve maximum community coverage