MalariaWorld journal最新文献

Background: Medicine preference, usage and health-seeking behaviour are very important in the treatment of malaria and prevention and management of drug resistance.

Materials and methods: A descriptive cross-sectional study, using a semi-structured questionnaire administered to 135 respondents, was carried out to assess antimalarial drug preference and usage among rural dwellers in Alajue, Ede, Osun State and peri-urban dwellers in Ajara, Badagry, Lagos State, Nigeria.

Results: Loss of appetite, fever, chill and rigour, headache and vomiting were the most frequently reported symptoms (83.3%, 78.6%, 71.4%, 69.0% and 64.3%, respectively). More than half (57.1%) of the respondents had their drugs prescribed by a qualified health practitioner. Sixty-eight (50.3%) respondents treated malaria with Artemisinin-based Combination Therapy (ACT) while Sulphadoxine-Pyrimethamine (SP), paracetamol and herbal medicine usage was reported by 11.9%, 9.6% and 4.4% of the respondents, respectively. Thirty-two respondents (23.7%) took nothing to treat the infection. Of them, only 64.3% completed their drugs regimen during their last episode with 35.7% reporting that fever subsided on/before day 2 of treatment and 64.3% reported that fever subsided two days post treatment. The majority (83.3%) of respondents had no adverse reaction to the drugs used (16.7% reported drowsiness, nausea, headaches and vomiting) with 64% of the respondents reporting that they will use ACT again anytime they have malaria and about 65% reported that the drug was very convenient for them (χ² = 18.192, p = 0.001).

Conclusions: The control of drug resistance in malaria parasites requires reducing the overall drug pressure, improving the ways the drugs are used and prescribing follow-up practices. The use of drug combinations that are not likely to foster resistance like ACT is also a good measure of resistance control. ACT would be expected to remain the key anti-malarial drug for treatment of multidrug resistance P. falciparum since there are no alternative drugs available at present.

Background: Malaria remains a disease of immense clinical and economic significance. Limited research has been carried out to estimate malaria treatment costs at the health care facility level using the patient's perspective. The objectives of this study were therefore to determine the direct and indirect costs of malaria treatment among adult outpatients and to assess the patients' perception of treatment costs.

Materials and methods: A cr oss-sectional study was conducted at the Pharmacy section of the General Practice Clinic, University of Benin Teaching Hospital, Benin City, Edo State, Nigeria. It involved adult outpatients diagnosed with malaria and who received a prescription of one or more anti-malarial medications. A cost-of-illness approach was employed in the assessment of costs of treatment of malaria per sick adult patient. Pre-tested semi-structured questionnaires were used in the study. Furthermore, self-reported incidence of malaria per year was assessed.

Results: The mean direct and indirect cost of tr eating malaria illness per adult outpatient was Nigerian Naira (NGN) 3417.70 ($ 20.34) and NGN 4870 ($ 29.0), respectively, giving a ratio of 0.7:1. Medications and laboratory tests for detection of malaria parasites contributed about 52 and 22% of the total direct cost, respectively. A total of 1592 malaria episodes were self-reported to occur annually, giving a mean value of 3.35 episodes per adult. Having a health care insurance was associated with the response that the cost of malaria treatment was low (P< 0.001).

Conclusion: The mean values of direct cost and indirect cost of treatment of malaria illness per adult outpatient were $ 20.34 and $ 29.0, respectively. Respondents who had health insurance perceived malaria treatment cost to be low, whereas those without such insurance felt otherwise.

Background: Use of insecticide treated bednets (ITNs) was a breakthrough in the fight against malaria. However, ITNs are only effective when properly used. Recent reports indicate low compliance in ITN usage and changes in biting times of malaria vectors with early and late biting cases recorded when people are not sleeping under their nets. Hence, there is a need to develop methods to supplement or replace the use of ITNs for malaria vector control. A field trial was conducted to investigate the effect and longevity of prototypes of long lasting impregnated UV protected eave nets, curtains and door hangers (fully screened houses), compared to houses with bednets only, in traditional East African houses.

Materials and methods: A randomised controlled trial was carried out in the Ahero rice irrigation scheme in Nyando district, Western Kenya. Eighty houses with open eaves were randomly selected. Forty of these houses were fully screened (FSH+LLINs) with long lasting insecticide-treated nets/curtains used to screen the eaves, windows and doors. The FSH materials were produced with anti-UV additives. The other 40 houses served as controls. Long lasting insecticide-treated bednets (LLINs) were suspended over all sleeping areas in the control and intervention houses. Indoor resting Anopheles mosquitoes were collected using pyrethrum spray catches (PSC) during both dry and wet seasons. Indoor population densities of anophelines were compared between intervention (FSH+LLINs) and control (LLINs) houses. Loss of insecticide (deltamethrin) was compared after 12 and 24 months for both the FSH materials and LLINs through bioassays and chemical analyses.

Results: In the FSH+LLINs houses densities of indoor resting Anopheles funestus and An. arabiensis were reduced by 82% (RR=0.18, 95% CI 0.09-0.36, P<0.0001) and 70% (RR=0.30, 95% CI 0.15-0.58, P<0.0001), respectively. No significant difference was recorded for indoor resting Culex spp. (RR=0.95, 95% CI 0.48-1.86, P=0.8). The population of indoor resting bloodfed An. arabiensis and An. funestus was reduced by 72% (RR=0.22, 95% CI 0.09-0.51, P<0.0001) and 84% (RR=0.16, 95% CI 0.07-0.33, P<0.0001) in the FSH+LLINs houses and LLIN houses, respectively. Insecticide loss in eave nets did not depend on the side of the house where the nets were placed. The eave nets showed little loss of bio efficacy over the 12-24 months period.

Conclusions: The study revealed that the use of insecticide-treated nets on the eaves and windows combined with door hangers largely impeded entrance of anopheline mosquitoes into houses and can be used to compliment LLINs for household protection. The eave nets were suspended from wood structures near the eave and remained in place when walls were re-plastered. The nets are therefore not depending on daily compliance behaviour and provide protection for the enti

Background: Widespread dr ug-resistant Plasmodium falciparum strains have challenged the pivotal role played by 4-aminoquinolines, including chloroquine (CQ), which has been delisted for the treatment of malaria in most parts of the world. This study assessed the in vitro sensitivity of P. falciparum clinical isolates (PfCIs) to amodiaquine (AQ) and CQ in Northeast Nigeria.

Materials and methods: PfCIs were collected from subjects with uncomplicated P. falciparum malaria in Azare, Bauchi State and Maiduguri, Borno State following an informed consent. The in vitro sensitivity was assessed by micro-test (MarkIII) method and the IC₅₀ of AQ and CQ was determined using HN-NonLin Version VI.1 software. The reference standard cut-off values for in vitro AQ and CQ resistance of 80 and 160 nmol/l, respectively, were used. Isolates that were inhibited by lower AQ and CQ concentrations were referred to as sensitive.

Results: Valid in vitro assay ^r esults were obtained for 88.9% (80/90) of the PfCIs; Azare had 93.3% (28/30) and Maiduguri had 86.7% (52/60) [χ2 = 0.35; df = 1; p = 0.486]. The geometric mean (GM) IC50 of AQ and CQ were 24.2 nmol/l (95% CI, 10.5 - 49.6 nmol/l) and 39.5 nmol/l (95% CI, 34.5 - 49.6 nmol/l), respectively. The AQ (p = 0.922) and CQ (p = 0.085) GM IC50 were similar between Azare and Maiduguri PfCIs. Only one isolate showed in vitro resistance to AQ giving a sensitivity of 98.8% (79/80) while 17 PfCIs showed in vitro resistance to CQ giving a sensitivity of 78.8% (63/80). The CQ sensitivity was similar between Azare (67.9%; 19/28) and Maiduguri (84.6%; 44/52) PfCIs (χ² = 3.05; df = 1; p = 0.081).

Conclusions: The findings may suggest that the AQ in vitro sensitivity remains high and the isolates in Northeast Nigeria may appear more sensitive to CQ than isolates from other parts. These findings may affect malaria treatment and control policy in Nigeria.

Background: The Roll Back Malaria (RBM) initiative recommended that all pregnant women receive Inter mittent Preventive Treatment (IPTp) and that by 2010 at least 80% of people at risk of malaria (including pregnant women) use insecticide-treated bednets (ITN) in areas with stable transmission. We evaluated ITN/IPTp coverage, explored its associated factors, and estimated the number of pregnancies protected from malaria.

Materials and methods: This analysis was based on data from the 2012 National HIV/AIDS and Reproductive Health Survey (NARHS Plus). To assess ITN coverage, we used the population of women that was pregnant (n=22,438) at the time of the survey. For IPTp coverage, we used women that had a live birth in the 5 years preceding the survey (n= 118,187) and extracted the population of pregnant women that, during their last pregnancy, received drugs for protection against malaria. We estimated the number of live births using the projected population of females in each state, population of women of child -bearing age and the total fertility rate. The estimated number of pregnancies covered/protected by ITN and IPTp was obtained from a product of the estimated live births and the reported coverage. Multivariate logistic regression was used to determine factors associated with ITN and IPTp use.

Results: We estimated that there were 5,798,897 live births in Nigeria in 2012, of which 3,537,327 and 2,302,162 pregnancies were protected by ITN and IPTp, respectively. Four of 36 states achieved the 80% RBM target for ITN coverage. No state achieved the 100% target for IPTp. Education and socio-economic status were associated with IPTp use.

Conclusion: ITN cover age was higher than in previous estimates even though it is still below the RBM targets. However, IPTp coverage remained low in 2012 and was not likely to increase to match the 2015 target coverage of 100%.

Background: In or der to combat the bur den of malaria, different strategies, including Insecticide Treated Nets (ITNs), have been put in place. ITNs have been distributed with support from international donors and this necessitates an increase in monitoring and evaluation efforts in order to determine ITN impact as well as prioritise future programmes. The current standard for estimating impact indicators of ITNs are household surveys. These, however, are expensive and not conducted frequently. Collecting information from school children has been found to be a cheap and fast means for routine monitoring and evaluation of malaria control programmes in sub-Saharan Africa. This study was conducted to explore school children's report of household ownership and use of ITNs in Oyo State, Nigeria.

Materials and methods: A cross-sectional survey was conducted. A three-stage sampling technique was used to select 611 pupils from 15 out of 88 primary schools. Information on pupils' socio-demographics, report of household ownership and use of ITNs were obtained using a semi-structured interviewer-administered questionnaire. Data was analysed using descriptive statistics and Chi-square tests at 5% level of significance.

Results: Respondents' mean age was 10.5±1.7 yrs; 52.7% were females, 84.6% were Yoruba and 65.3% lived with children below 5 yrs of age in their households. Most of the respondents (81.7%) reported household ownership of at least one ITN. The majority (76.4%) obtained nets through mass distribution campaigns. Most of the respondents (89%) reported use of ITNs by a household member the night preceding the survey. More than half of the respondents (51.6%) reported ITN use by children below 5 yrs of age. Class was significantly associated with reported household ownership of ITNs (χ2= 9.217, p <0.010).

Conclusion: The majority of the pupils reported household ownership and use of ITNs. They should be consider ed a potential source of information in monitoring and evaluation activities related to ITN ownership and use.

Background: While environmental factors such as temperature can influence the vector competence of mosquitoes directly, for example by affecting the longevity of the mosquito and the development of the malaria parasite they may also have an indirect impact on the parasite's transmission. By influencing larval development, they may affect the adult traits that are important for the parasite's development and transmission. We studied the influence of two larval environmental factors, food availability and temperature, on the probability that mosquitoes infected with the malaria parasite survived to harbour sporozoites in their salivary glands.

Materials and methods: Anopheles gambiae larvae were reared at 21ºC, 25ºC or 29ºC, and fed either a standard larval diet or half of it. Adults could blood feed on mice harbouring the infectious gametocytic stage of Plasmodium berghei ANKA transformed with green fluorescent protein (GFP). Survival was assessed every 24 hrs up to 21 days post infection, when surviving mosquitoes were dissected to check the salivary glands for sporozoites with a fluorescent microscope sensitive to GFP. Using a binomial GLM we analysed 'vector competence', i.e. if mosquitoes survived until dissection and harboured sporozoites in their salivary glands.

Results: Vector competence dropped by about a third if we fed larvae half the standard food regime. The effect of temperature during the larval period depended strongly on the food regime. At low food, increasing temperature from 21ºC to 29ºC increased vector competence from about 0.18 to 0.48, whereas at standard food, vector competence dropped from about 0.67 at 21ºC to 0.56 at 29ºC.

Conclusions: Thus, perceptions and models about the role of environmental change on the transmission of malaria should include how the environment changes adult life-history by influencing larval development.

Background: Falciparum malaria in endemic areas continues to occur in asymptomatic cases, which contribute to the persistence of transmission as well as the size of the parasite reservoirs. Recent successes in malaria control have resulted in renewed interest in malaria eradication and identification of the human infectious reservoir is essential for this. In this study, we evaluated prevalence of microscopic and submicroscopic gametocytes that were obtained from asymptomatic primary school children from Bagamoyo rural in Tanzania.

Materials and methods: Samples were collected from 501 asymptomatic primary school children (6-14 years of age) from 7 villages in Bagamoyo district. Participants were screened for malaria in the field using RDT, and samples were brought to the laboratory for microscopy and molecular analysis. Parasite density was determined by microscopy, and gametocyte carriage identification was performed by RT-qPCR targeting gametocyte-specific genes.

Results: Asymptomatic infection was found to be 45.1% (95% : CI=40.7-49.6) by RT-qPCR, followed by RDT, 14.2% (95%: CI=11.2-17.5) and microscopy 6.8% (95%: CI=4.7-9.4). Parasite prevalence by microscopy was 12% (23/191) in boys compared to 3.6% (11/310) in girls (p<0.001). Gametocytes were detected in 12.6% (226/501) of the asymptomatic school children by RT-qPCR compared to only 0.8% (4/501) of the children by microscopy (P=0.008).

Conclusions: Asymptomatic infection and submicroscopic gametocyte carriage were high in the study area. The detection of asymptomatic cases with circulating submicroscopic P. falciparum gametocytes in school children indicates that these form a substantive gametocyte reservoir that sustains malaria transmission. Asymptomatic carriers and submicroscopic infections should therefore be considered when implementing elimination strategies of the disease.

Background: Rapid diagnostic tests (RDTs) and microscopy are routinely used for the diagnosis of malaria in Ghana. DNA-based polymerase chain reaction (PCR) is not yet used routinely. We compared diagnostic methods and tested the sensitivities of different malaria diagnostic methods against PCR.

Materials and methods: Study participants from four hospitals with a suspicion of malaria donated finger -prick blood for RDT and blood film examination. In addition, a blood spot was collected for PCR analysis, prior to treatment. Retrospective species-specific PCR was performed on all samples collected.

Results: Using PCR we found an overall malaria prevalence of 39% among the 211 evaluable blood spots (83/211) and this ranged between 6-61% across the four hospitals. Of the 164 participants with RDT data, malaria prevalence was 57% (94/164), ranging from 3-100% from the four hospitals. Microscopy was the least sensitive with a parasite prevalence of 21% (25/119) of the evaluable 119 participants, varying from 9 to 35% across three health facilities. By comparison, we found the sensitivities and specificities of RDT results when compared to PCR to be slightly higher than microscopy compared to PCR. These were 56.4% versus 41.7% and 90% versus 81.9%, respectively, but generally lower than expected. Ninety-five percent of the PCR-detected infections were P. falciparum, while 4% were mixed species infections of P. falciparum and P. malariae, with the remaining being a mono-infection of P. malariae.

Conclusions: While using PCR as a gold standard, we found RDT to be more reliable in diagnosing malaria than microscopy. In addition, a majority of malaria-treated cases were not supported by PCR diagnosis, leading to possible overtreatment. Pragmatic strategies are needed to ensure suspected malaria cases are accurately diagnosed before treatment.

Background: A study was carried out on students of the University of Dschang, Cameroon, to examine the relationship between ABO blood group, rhesus factor and prevalence of Plasmodium falciparum infection.

Materials and methods: Blood group and rhesus factor were typed by agglutination using antisera while malaria infection was determined using Rapid Diagnostic Test CareStart malaria HRP2 pf. Out of 620 students 582 were screened for ABO blood group and Rhesus factor, and 276 were tested for P. falciparum infection.

Results: Faculty of Science (FS) members and male students were highly represented, with 356 (61.2% ) and 303 (52.1%) participants, respectively. Blood group O was most common (48.8%), followed by blood group A (25.8%), B (23.0%) and AB (2.4%). Total percentage of rhesus positive was 92.4%, and its distribution varied across ABO blood groups. Of the 276 students examined for malaria infection, 27 were found positive (9.8%). Except for blood group AB individuals, of which none were infected, malaria infection did not vary among blood groups.

Conclusion: Rhesus factor and blood group did not impact on malaria infection in the hypo-endemic highland area of Dschang, Cameroon.