Browsing by Author "Abdulla, Salim"
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Item Access to Artemisinin-Based Anti-Malarial Treatment and Its Related Factors in Rural Tanzania(2013-05) Khatib, Rashid A.; Selemani, Majige; Mrisho, Gumi A.; Masanja, Irene M.; Amuri, Mbaraka; Njozi, Mustafa; Dan, Kajungu; Kuepfer, Irene; Abdulla, Salim; De Savigny, DonBackground Artemisinin-based combination treatment (ACT) has been widely adopted as one of the main malaria control strategies. However, its promise to save thousands of lives in sub-Saharan Africa depends on how effective the use of ACT is within the routine health system. The INESS platform evaluated effective coverage of ACT in several African countries. Timely access within 24 hours to an authorized ACT outlet is one of the determinants of effective coverage and was assessed for artemether-lumefantrine (Alu), in two district health systems in rural Tanzania. Methods From October 2009 to June 2011we conducted continuous rolling household surveys in the Kilombero-Ulanga and the Rufiji Health and Demographic Surveillance Sites (HDSS). Surveys were linked to the routine HDSS update rounds. Members of randomly pre-selected households that had experienced a fever episode in the previous two weeks were eligible for a structured interview. Data on individual treatment seeking, access to treatment, timing, source of treatment and household costs per episode were collected. Data are presented on timely access from a total of 2,112 interviews in relation to demographics, seasonality, and socio economic status. Results In Kilombero-Ulanga, 41.8% (CI: 36.6–45.1) and in Rufiji 36.8% (33.7–40.1) of fever cases had access to an authorized ACT provider within 24 hours of fever onset. In neither of the HDSS site was age, sex, socio-economic status or seasonality of malaria found to be significantly correlated with timely access. Conclusion Timely access to authorized ACT providers is below 50% despite interventions intended to improve access such as social marketing and accreditation of private dispensing outlets. To improve prompt diagnosis and treatment, access remains a major bottle neck and new more innovative interventions are needed to raise effective coverage of malaria treatment in Tanzania.Item Challenges in Establishing A Cohort-Event Monitoring Drug Safety Study in Ifakara And Rufiji HDSS(2011-08) Amuri, Mbaraka; Kigahe, Brown; Njozi, Mustafa; Masanja, Irene M.; Selemani, Majige; Dan, Kajungu; Khatib, Rashid A.; Adounvo, Sharon A.; Abdulla, Salim; Binka, Fred; Dodoo, AlexanderThe recommended artemisinin combination therapy (ACT) for treatment of uncomplicated malaria in Tanzania is artemether-lumefantrine (AL). Although Artemisinin and its derivatives are generally thought to be safe, there is currently little or no data on its safety among populations in Tanzania. In view of this INESS established a phase IV study to evaluate safety of AL through comprehensive pharmacovigilance in large populations with the aim of documenting rare adverse drug reactions and to characterize known effects in ‘real-life’. The methodology employed is cohort event monitoring which is observational, longitudinal and prospective. Patients with diagnosis of malaria for whom AL was prescribed were recruited into the cohort from four health facilities in each HDSS. Information on demographics, use of all medicines, mode of diagnosis of malaria, presenting signs and symptoms, co-diagnoses, events suspected as adverse drug reactions, reasons for stopping the drug and cause of death (if any) were collected using standardized questionnaire. They were followed up on 7 to 10 days after AL was dispensed. This report is on the number recruited so far and the challenges in getting the cohort going. 9028 patients were recruited. 9016 (99.8%) completed follow-up on day 7, of which 668 (7.4%) were done by telephone calls. 12 (0.13%) were lost during follow-up. The main challenges encountered are getting enough trained staff to recruit and follow up patients since CEM is quite labour intensive. 38 health providers and 10 field workers were recruited and offered the relevant training in collaboration with regulatory authorities. This helped to overcome the human resource challenge. Another challenge involved is the difficult to reach areas which are cut off especially during the rainy season. Follow up by telephone was adopted for these areas and this helped to reduce number of lost to follow-up. Setting up a cohort event monitoring program takes time and is demanding in terms of human resource. Training is very important in overcoming this. Involvement of all stakeholders and sponsors is a key to successItem Diversity, Spatial and Temporal Abundance of Anopheles Gambiae Complex in the Rufiji River Basin, South-Eastern Tanzania(2010) Nkwengulila, Gamba; Magesa, S. M.; Abdulla, Salim; Kigadye, E. S. P.The Anopheles gambiae complex contains the most efficient malaria vectors in the world. Identification of the species and the concomitant distribution are vital for effective malaria control. The objective of the study was to establish the diversity, spatial and seasonal abundance of malaria vectors in the Rufiji River Basin in Tanzania and the implications on malaria vector control. Mosquitoes were collected using CDC light-traps. Anopheles mosquitoes were identified by conventional keys. Anopheles gambiae complex were speciated using standard PCR method. Of the 562 specimens analysed by PCR 69% produced fragments equivalent to An. gambiae s.s. (390 bp), 23% equivalent to An. arabiensis (315bp), and 7% as An. merus (464 bp). An. gambiae s.s. and An. merus were more abundant on the plateau than on the flood plain (Fisher’s exact test, P< 0001), whereas An. arabiensis was equally abundant between the two sites (Fisher’s exact test, P=1656). The density of the three sibling species of An. gambiae complex also varied with the seasons. An. gambiae s.s. and An. arabiensis were most predominant species during the start of the rainy season, but as season progresses, An. gambiae s.s. predominated. An. merus was only recorded during the short rainy season. In conclusion, both An. gambiae s.s., An. arabiensis and An.merus are malaria vectors in the Rufiji River basin and that An. merus is recorded for the first time in the south-eastern coast of Tanzania. These findings are important in the planning and implementation of malaria vector control activities in the Rufiji River basin, south-eastern Tanzania.Item Friend or Foe? Private Sector Sales of Anti-Malarial Drugs in Rural Tanzania(2005) Goodman, Catherine; Kachur, Patrick S.; Abdulla, Salim; Mwageni, Eleuther; Nyoni, Joyce E.; Schellenburg, J.; Mills, A.; Bloland, PeterItem Genetic Diversity of Plasmodium falciparum Strains in Children under Five Years of Age in Southeastern Tanzania(2010) Sumari, Deborah; Hosea, Ken M.; Mugasa, Joseph P.; Abdulla, SalimStrain diversity may play a role in delaying development of protective immunity in endemic areas. We evaluated genetic diversity of Plasmodium falciparum infected children before being treated with Sulphadoxine Pyrimethamine (SP) and Coartem™ in Southeastern Tanzania. Allelic diversity of P. falciparum strains were determined in order to further assist in correct estimation of recrudescent and new infections. P. falciparum isolated from 300 children aged 1-59 months was used in the study, where nested PCR followed by Restriction Fragment Length Polymorphism (RFLP) of highly polymorphic Merozoite surface protein 2 (msp2) was employed to understand the genetic diversity of the parasites population. Frequency of msp2 gene alleles was calculated and further associated with multiplicity of infection of children under five years of age. A total of 71 and 83 different msp2 alleles were found in Rufiji and Ulanga districts respectively. Children infected with either FC27 or 3D7 allelic type in Rufiji were 42% single, 55.3% double and 2.7% triple, while in Ulanga, 36.7% single, 62% double and 1.3% triple infections. Mean numbers of multiplicity of infections (MOI) in Rufiji and Ulanga were 1.6 and 1.3, respectively. These findings show a high genetic diversity of P. falciparum strains in study areas and low MOI could reflect production of susceptible parasites that immune response can accommodate or can be cleared by the drugs. Furthermore, 3D7 allelic type of msp2 gene was more prevalent than FC27 in Ulanga district, indicating association between msp2 allelic type and disease severity, hence predict possible vaccine candidate in the future.Item Health Worker Factors Associated With Prescribing of Artemisinin Combination Therapy for Uncomplicated Malaria in Rural Tanzania(2013-09) Selemani, Majige; Masanja, Irene M.; Dan, Kajungu; Amuri, Mbaraka; Njozi, Mustafa; Khatib, Rashid A.; Abdulla, Salim; De Savigny, DonImproving malaria case management is partially dependent on health worker compliance with clinical guidelines. This study assessed health worker factors associated with correct anti-malarial prescribing practices at two sites in rural Tanzania. Repeated cross-sectional health facility surveys were conducted during high and low malaria transmission seasons in 2010 and collected information on patient consultations and health worker characteristics. Using logistic regression, the study assessed health worker factors associated with correct prescription for uncomplicated malaria defined as prescription of artemisinin-based combination therapy (ACT) for patients with fever and Plasmodium falciparum asexual infection based on blood slide or malaria rapid diagnostic test (RDT) according to national treatment guidelines. The analysis included 685 patients with uncomplicated malaria who were seen in a health facility with ACT in stock, and 71 health workers practicing in 30 health facilities. Overall, 58% of malaria patients were correctly treated with ACT. Health workers with three or more years' work experience were significantly more likely than others to prescribe correctly (adjusted odds ratio (aOR) 2.9; 95% confidence interval (CI) 1.2-7.1; p = 0.019). Clinical officers (aOR 2.2; 95% CI 1.1-4.5; p = 0.037), and nurse aide or lower cadre (aOR 3.1; 95% CI 1.3-7.1; p = 0.009) were more likely to correctly prescribe ACT than medical officers. Training on ACT use, supervision visits, and availability of job aids were not significantly associated with correct prescription. Years of working experience and health worker cadre were associated with correct ACT prescription for uncomplicated malaria. Targeted interventions to improve health worker performance are needed to improve overall malaria case management.Item Investigations on Risk Factors for Malaria in Rufiji District, Tanzania(2013) Kigadye, E. S. P.; Nkwengulila, Gamba; Magesa, S.; Abdulla, SalimRufiji District is an area with endemic and perennial malaria. The aim ofthis study was to assess the factors contributing to increased malaria risk in thestudy area. The factors investigated included; mode of house construction,protection against mosquito bites and human behaviour. Parameters recorded forevaluating the mode of house construction were; type of wall, roofing materials,presence of open eaves between wall and roof and the type of window. Structuredquestionnaires were used to assess household mosquito avoidance behaviour andutilization of bed nets. Medium scale behavioural surveys were carried out todetermine time spent by individuals outdoors during the night. This was then plottedagainst mean hourly mosquito catches. Generally, house constructed using mud,grass, palm walls, and roofs made of grass/palm thatch, houses with no or openwindows and without mosquito gauze and houses with open eaves and lowutilization of bed nets (treated and untreated) were common over the entire studyarea. Of the 2,423 houses walls examined; 90% were constructed using mud, 61%were roofed using grass, 98% had eaves between wall and roof, and 49% had nowindows while 45% of windows had no mosquito gauzes. There were highlysignificant differences (p < 0.001) within all the above variables investigated. Only21% of the households used bed nets of which only 7.5% were insecticides treated.There were highly significant differences (p < 0.0001) within variables investigatedon mosquito avoidance behaviour. Most individuals, both children and adults,remained outdoors up to 22.00 hrs. Environmental factors, poorly constructedhouses, low rate of utilization of bed nets and other protective measures, andpoverty were identified as risk determinants for malaria in the study area.Intervention measures relevant to the study area are discussed.Item Population Pharmacokinetics and Clinical Response for Artemether-Lumefantrine in Pregnant and Nonpregnant Women with Uncomplicated Plasmodium falciparum Malaria in Tanzania(American Society for Microbiology, 2014-07) Mosha, Dominic; Guidi, Monia; Mwingira, Felista; Abdulla, Salim; Mercier, Thomas; Decosterd, Laurent Arthur; Csajka, Chantal; Genton, BlaiseABSTRACT Artemether-lumefantrine (AL) is the first-line treatment for uncomplicated malaria in the second and third trimesters of pregnancy. Its efficacy during pregnancy has recently been challenged due to altered pharmacokinetic (PK) properties in this vulnerable group. The aim of this study was to determine the PK profile of AL in pregnant and nonpregnant women and assess their therapeutic outcome. Thirty-three pregnant women and 22 nonpregnant women with malaria were treated with AL (80/480 mg) twice daily for 3 days. All patients provided five venous plasma samples for drug quantification at random times over 7 days. Inter- and intraindividual variability was assessed, and the effects of covariates were quantified using a nonlinear mixed-effects modeling approach (NONMEM). A one-compartment model with first-order absorption and elimination with linear metabolism from drug to metabolite fitted the data best for both arthemether (AM) and lumefantrine (LF) and their metabolites. Pregnancy status and diarrhea showed a significant influence on LF PK. The relative bioavailability of lumefantrine and its metabolism rate into desmethyl-lumefantrine were, respectively, 34% lower and 78% higher in pregnant women than in nonpregnant patients. The overall PCR-uncorrected treatment failure rates were 18% in pregnant women and 5% in nonpregnant women (odds ratio [OR] = 4.04; P value of 0.22). A high median day 7 lumefantrine concentration was significantly associated with adequate clinical and parasitological response (P = 0.03). The observed reduction in the relative bioavailability of lumefantrine in pregnant women may explain the higher treatment failure in this group, mostly due to lower posttreatment prophylaxis. Hence, a modified treatment regimen of malaria in pregnancy should be considered.Item Predictors of Antibiotics Co-Prescription with Antimalarials for Patients Presenting With Fever in Rural Tanzania(2013-11) Njozi, Mustafa; Amuri, Mbaraka; Selemani, Majige; Masanja, Irene M.; Kigahe, Brown; Khatib, Rashid A.; Dan, Kajungu; Abdulla, Salim; Dodoo, AlexanderSuccessful implementation of malaria treatment policy depends on the prescription practices for patients with malaria. This paper describes prescription patterns and assesses factors associated with co-prescription of antibiotics and artemether-lumefantrine (AL) for patients presenting with fever in rural Tanzania. From June 2009 to September 2011, a cohort event monitoring program was conducted among all patients treated at 8 selected health facilities in Ifakara and Rufiji Health and Demographic Surveillance System (HDSS).It included all patients presenting with fever and prescribed with AL. Logistic regression was used to model the predictors on the outcome variable which is co-prescription of AL and antibiotics on a single clinical visit. A cohort of 11,648 was recruited and followed up with 92% presenting with fever. Presumptive treatment was used in 56% of patients treated with AL. On average 2.4 (1 -- 7) drugs was prescribed per encounter, indicating co-prescription of AL with other drugs. Children under five had higher odds of AL and antibiotics co-prescription (OR = 0.63, 95% CI: 0.46 -- 0.85) than those aged more than five years. Patients testing negative had higher odds (OR = 2.22, 95%CI: 1.65 -- 2.97) of AL and antibiotics co-prescription. Patients receiving treatment from dispensaries had higher odds (OR = 1.45, 95% CI: 0.84 -- 2.30) of AL and antibiotics co-prescription than those from served in health centres even though the deference was not statistically significant. Regardless the fact that Malaria is declining but due to lack of laboratories and mRDT in most health facilities in the rural areas, clinicians are still treating malaria presumptively. This leads them to prescribe more drugs to treat allItem Retail Supply of Malaria-related Drugs in Rural Tanzania: Risks and Opportunities.(Wiley, 2004) Goodman, Catherine; Kachur, Patrick S.; Abdulla, Salim; Mwageni, Eleuther; Nyoni, Joyce E.; Schellenberg, Joanna A.; Mills, Anne; Bloland, PeterTo characterize availability of fever and malaria medicines within the retail sector in rural Tanzania, assess the likely public health implications, and identify opportunities for policy interventions to increase the coverage of effective treatment. A census of retailers selling drugs was undertaken in the areas under demographic surveillance in four Tanzanian districts, using a structured questionnaire. Drugs were stocked by two types of retailer: a large number of general retailers (n = 675) and a relatively small number of drug shops (n = 43). Almost all outlets stocked antipyretics/painkillers. One-third of general retailers stocking drugs had antimalarials, usually chloroquine alone. Almost all drug shops stocked antimalarials (98%): nearly all had chloroquine, 42% stocked quinine, 37% sulphadoxine-pyrimethamine and 30% amodiaquine. A large number of antimalarial brands were available. Population ratios indicate the relative accessibility of retail drug providers compared with health facilities. Drug shop staff generally travelled long distances to buy from drugs wholesalers or pharmacies. General retailers bought mainly from local general wholesalers, with a few general wholesalers accounting for a high proportion of all sources cited. Drugs were widely available from a large number of retail outlets. Potential negative implications include provision of ineffective drugs, confusion over brand names, uncontrolled use of antimalarials, and the availability of components of potential combination therapy regimens as monotherapies. On the other hand, this active and highly accessible retail market provides opportunities for improving the coverage of effective antimalarial treatment. Interventions targeted at all drug retailers are likely to be costly to deliver and difficult to sustain, but two promising points for targeted intervention are drug shops and selected general wholesalers. Retail quality may also be improved through consumer education, and modification of the chemical quality, packaging and price of products entering the retail distribution chain.Item Spatial Variability in the Density, Distribution and Vectorial Capacity of Anopheline Species in a High Transmission District in Tanzania(2011) Kigadye, Emmanuel; Nkwengulila, Gamba; Magesa, Stephen M.; Abdulla, SalimMalaria transmission varies from one area to another and there are also local difference in time and space. The objective of the study was to determine the local variability of entomological parameters namely, mosquito abundance, human biting rate (HBR), sporozoite rate for Plasmodium falciparum and entomological inoculation rate (EIR). The study was carried out in Rufiji District south eastern Tanzania from October 2001 and September 2004. Adult mosquitoes were collected indoors by CDC light traps. PCR was employed to identify the species within the Anopheles gambiae complex. ELISA was used to determine the sporozoite rate. Over a three year sampling period a total of 64,875 female mosquitoes were caught using light-traps, and of these 28% were Anopheles gambiae complex, 25% An. funestus Giles, 1% An. pharoensis Theobald, 46% Culex species and the rest were Mansonia uniformis Theobald. Mosquito abundance and species composition varied seasonally, spatially and between years. Using PCR, three members of the Anopheles gambiae complex namely An. gambiae s.s. Giles (69%), An. arabiensis Paton (23%) and An. merus Dönitz (7%) were confirmed to occur in the study area. Plasmodium falciparum circumsporozoite antigen (CSA) rates were 3.5% for An. gambiae complex and 2.3% for An. funestus. The mean EIR ranged from 28-275 infective bites/person/year. Transmission indices varied over short distances, seasonally and between years. In conclusion, malaria transmission indices in the study area are one of the highest in Tanzania; and there is high variability of entomological parameters over a small geographical area.