Effect of interventions to reduce malaria incidence among military personnel on active duty: study protocol for a cluster randomised controlled trial of the impact of etofenprox-treated uniforms, permethrin-treated uniforms and DEET insect repellent.

BACKGROUND: While there is strong evidence that bite protection methods such as permethrin-treated clothing and topical insect repellents are protective against insect bites, there are few studies assessing the impact on malaria infection. This study will estimate the protective efficacy of treated uniforms and DEET insect repellent on the incidence of malaria infection among military personnel in an operational setting. Permethrin-treated uniforms used with DEET lotion will be compared to etofenprox-treated uniforms with DEET lotion. The effect of DEET lotion will be estimated by comparing permethrin-treated uniforms with DEET or placebo lotion. METHOD: A cluster randomised double-blind placebo-controlled trial is planned to evaluate the effectiveness of the interventions on preventing malaria infections in soldiers on active duty at Mgambo National Service Camp in Tanga, Tanzania. The arms are (1) permethrin-treated uniform with 30% DEET liposome formula; (2) permethrin-treated uniform with placebo lotion; (3) candidate insect repellent system, i.e. etofenprox-treated uniform with 30% DEET liposome formula; and (4) placebo, i.e. untreated uniforms with placebo lotion. The primary outcome is the incidence of Plasmodium falciparum malaria infection detected by polymerase chain reaction (PCR) by active case detection using surveys every 2 weeks for 12 months. Rapid diagnostic tests will be used for the diagnosis of participants with symptoms. The unit of randomisation will be combania: companies formed by recruits aged 18 to 25 years; combania do activities together and sleep in the same dormitory. Unequal randomisation will be used to optimise statistical power for the primary comparison between permethrin-treated uniforms with DEET and etofenprox-treated uniforms with DEET. DISCUSSION: This trial will provide the estimate of the effects of permethrin with DEET compared to those of the new fabric treatment etofenprox with DEET and any additional effect of using DEET. The results will inform strategies to protect military personnel and civilians who have more outdoor or occupational malaria exposure than the general public. TRIAL REGISTRATION: ClinicalTrials.gov NCT02938975 .

Implementation of external quality assessment of microscopy for improved parasite detection and confirmatory diagnosis of malaria in Tanzanian Military health facilities.

OBJECTIVE: Good quality microscopy is critical for accurate detection and confirmation of malaria parasite infections. Microscopy relies on the skills of technicians to prepare and read slides, high quality reagents, and a good program of internal and external quality control (EQA), which are lacking in most malaria endemic settings. This study was undertaken between January 2016 and December 2018 to pilot an EQA of microscopy for improved diagnosis of malaria and patient care in Tanzanian Military health facilities. RESULTS: Of all blood smears crosschecked (n = 4000) at baseline, only 38.5% were incorrectly diagnosed by laboratory staff with false positive and negative rates of 46.7% and 16.4%, respectively. During the implementation of EQA, false positive and negative results decreased due to increased quality index of slide preparation and reading through supportive supervision, and retraining of laboratory personnel. There was a gradual increase of quarterly and annual total quality index for all laboratories, from 60% in 2016 to 78% in 2017 and 90% in 2018. The mean proficiency testing performance scores also increased from 75% in 2016 to 82% in 2017 and to 90% in 2018. Poor blood smear preparation and staining contributed to high false positive and negative rates while EQA helped in improvement of diagnostics.

The use of Fionet technology for external quality control of malaria rapid diagnostic tests and monitoring health workers' performance in rural military health facilities in Tanzania.

INTRODUCTION: Internal and external quality control (QC) of rapid diagnostic tests (RDTs) is important to increase reliability of RDTs currently used to diagnose malaria. However, cross-checking of used RDTs as part of quality assurance can rarely be done by off-site personnel because there is no guarantee of retaining visible test lines after manufacturers' recommended reading time. Therefore, this study examined the potential of using Fionet™ technology for remote RDT quality monitoring at seven clinics, identifying reasons for making RDT processing and interpretation errors, and taking corrective actions for improvement of diagnosis and consequently improved management of febrile patients. METHODS: The study was conducted at seven military health facilities in Mainland Tanzania and utilized RDTs capable of detecting Plasmodium falciparum specific Histidine-rich protein 2 (Pf-HRP2) and the genus specific Plasmodium lactate dehydrogenase (pLDH) for other species of plasmodium (P. vivax, P. malariae or P. ovale; pan-pLDH). Patients' data and images of processed RDTs from seven clinics were uploaded on a Fionet web portal and reviewed regularly to monitor preparation procedures and visual interpretation of test results compared to automated analysis using the Deki reader of RDT. Problems detected were rapidly communicated to remote laboratory personnel at the clinic for corrective action and follow-up of patients who were falsely diagnosed as negative and missed treatment. Factors contributing to making errors in visual interpretation of RDT results were analyzed during visits to the health facilities. RESULTS: A total of 1,367 (1.6%) out of 83,294 RDT test images uploaded to the Fionet portal had discordant test results of which 822 (60.1%) and 545 (39.9%) were falsely reported as negative and positive, respectively. False negative and false positive test results were common for a single test line in 515 (62.7%) and 741 (54.2%) tests, respectively. Out of 1,367 RDT images assessed, 98 (7.2%) had quality problems related to preparation procedures of which 95(96.9%) errors were due to putting too much blood on the sample well or insufficient buffer in the respective wells. The reasons for discrepant results included, false reporting of none existent lines in 526 (38.5%) tests, missing a faint positive line in 493 (36.1%), missing a strong positive line in 248(18.1%) and errors caused by poorly processed RDTs in 96 (7.2%) tests. Among the false negative tests (n = 822), 669 (48.9%) patients were eligible for follow-up and only 339 (48.5%) were reached and 291 (85.8%) received appropriate anti-malaria therapy. CONCLUSION: Fionet technology enabled remote monitoring of RDT quality issues, identifying reasons contributing to laboratory personnel making errors and provided a rapid method to implement corrective actions at remote sites to improve malaria diagnosis and consequently improved health care management of febrile patients infected with malaria.

Prescription and non-prescription antibiotic dispensing practices in part I and part II pharmacies in Moshi Municipality, Kilimanjaro Region in Tanzania: A simulated clients approach.

Antibiotic dispensing without a prescription poses a threat to public health as it leads to excessive antibiotic consumption. Inappropriate antibiotic availability to the community has been documented to be amongst drivers of antimicrobial resistance emergence. Community pharmacies are a source of antibiotics in low and middle-income countries (LMICs). We aimed at assessing antibiotic dispensing practices by community pharmacy retailers in Moshi urban, Kilimanjaro, Tanzania and recommend interventions to improve practice. Using a Simulated Client (SC) Method, an observational cross-sectional survey of antibiotic dispensing practices was conducted from 10th June to 10th July 2017. Data analysis was done using Stata 13 (StataCorp, College Station, TX, USA). A total of 82 pharmacies were visited. Part I pharmacies were 26 (31.71%) and 56 (68.29%) were part II. Overall 92.3% (95% CI 77.8-97.6) of retailers dispensed antibiotics without prescriptions. The antibiotics most commonly dispensed without a prescription were ampiclox for cough (3 encounters) and azithromycin for painful urination (3 encounters). An oral third generation cephalosporin (cefixime) was dispensed once for painful urination without prescription by a part I pharmacy retailer. Out of 21, 15(71.43%) prescriptions with incomplete doses were accepted and had antibiotics dispensed. Out of 68, 4(5.9%) retailers gave instructions for medicine use voluntarily. None of the retailers voluntarily explained drug side-effects. In Moshi pharmacies, a high proportion of antibiotics are sold and dispensed without prescriptions. Instructions for medicine use are rarely given and none of the retailers explain side effects. These findings support the need for a legislative enforcement of prescription-only antibiotic dispensing rules and regulations. Initiation of clinician and community antibiotic stewardship and educational programs on proper antibiotic use to both pharmacists and public by the regulatory bodies are highly needed.

Prevalence, determinants and knowledge of antibacterial self-medication: A cross sectional study in North-eastern Tanzania.

Self-medication is very common especially in developing countries and is documented to be associated with many health risks including antibiotic resistance. This study investigated the prevalence, determinants and knowledge of self-medication among residents of Siha District in Tanzania. A cross-sectional study was conducted among 300 residents in a rural District of Kilimanjaro region, North-eastern Tanzania from 1st to 28th April 2017. A semi-structured questionnaire was used to collect information regarding drugs used, knowledge, history and reasons for antibiotic self-medication. Log-binomial regression analysis was done using STATA 13 to examine factors associated with self-medication. A slightly majority of the respondents (58%) admitted to self-medication. Antibiotics most commonly utilized were amoxycillin (43%) and an antiprotozoal drug metronidazole (10%). The most common symptoms that led to self-medication were cough (51.17%), headache/ fever/ malaria (25.57%) and diarrhoea (21.59%). The most common reasons for self-medication were emergency illness (24.00%), health facility charges (20.33%), proximity of pharmacy to home (17.00%) and no reason (16.66%). Almost all reported that self-medication is not better than seeking medical consultation, 98% can result into harmful effects and 96% can result to drug resistance. The level of self-medication in this study is comparable with findings from other studies in developing countries. Pharmacies were commonly used as the first point of medical care. There is therefore a need for educative antibiotic legislative intervention to mitigate the adverse effects of antibiotic self-medication in Siha district in Tanzania.

Comparison of visual and automated Deki Reader interpretation of malaria rapid diagnostic tests in rural Tanzanian military health facilities.

BACKGROUND: Although microscopy is a standard diagnostic tool for malaria and the gold standard, it is infrequently used because of unavailability of laboratory facilities and the absence of skilled readers in poor resource settings. Malaria rapid diagnostic tests (RDT) are currently used instead of or as an adjunct to microscopy. However, at very low parasitaemia (usually < 100 asexual parasites/µl), the test line on malaria rapid diagnostic tests can be faint and consequently hard to visualize and this may potentially affect the interpretation of the test results. Fio Corporation (Canada), developed an automated RDT reader named Deki Reader™ for automatic analysis and interpretation of rapid diagnostic tests. This study aimed to compare visual assessment and automated Deki Reader evaluations to interpret malaria rapid diagnostic tests against microscopy. Unlike in the previous studies where expert laboratory technicians interpreted the test results visually and operated the device, in this study low cadre health care workers who have not attended any formal professional training in laboratory sciences were employed. METHODS: Finger prick blood from 1293 outpatients with fever was tested for malaria using RDT and Giemsa-stained microscopy for thick and thin blood smears. Blood samples for RDTs were processed according to manufacturers' instructions automated in the Deki Reader. Results of malaria diagnoses were compared between visual and the automated devise reading of RDT and microscopy. RESULTS: The sensitivity of malaria rapid diagnostic test results interpreted by the Deki Reader was 94.1% and that of visual interpretation was 93.9%. The specificity of malaria rapid diagnostic test results was 71.8% and that of human interpretation was 72.0%. The positive predictive value of malaria RDT results by the Deki Reader and visual interpretation was 75.8 and 75.4%, respectively, while the negative predictive values were 92.8 and 92.4%, respectively. The accuracy of RDT as interpreted by DR and visually was 82.6 and 82.1%, respectively. CONCLUSION: There was no significant difference in performance of RDTs interpreted by either automated DR or visually by unskilled health workers. However, despite the similarities in performance parameters, the device has proven useful because it provides stepwise guidance on processing RDT, data transfer and reporting.

A cluster-randomized trial of mass drug administration with a gametocytocidal drug combination to interrupt malaria transmission in a low endemic area in Tanzania.

BACKGROUND: Effective mass drug administration (MDA) with anti-malarial drugs can clear the human infectious reservoir for malaria and thereby interrupt malaria transmission. The likelihood of success of MDA depends on the intensity and seasonality of malaria transmission, the efficacy of the intervention in rapidly clearing all malaria parasite stages and the degree to which symptomatic and asymptomatic parasite carriers participate in the intervention. The impact of MDA with the gametocytocidal drug combination sulphadoxine-pyrimethamine (SP) plus artesunate (AS) plus primaquine (PQ, single dose 0.75 mg/kg) on malaria transmission was determined in an area of very low and seasonal malaria transmission in northern Tanzania. METHODS: In a cluster-randomized trial in four villages in Lower Moshi, Tanzania, eight clusters (1,110 individuals; cluster size 47- 209) were randomized to observed treatment with SP+AS+PQ and eight clusters (2,347 individuals, cluster size 55- 737) to treatment with placebo over three days. Intervention and control clusters were 1 km apart; households that were located between clusters were treated as buffer zones where all individuals received SP+AS+PQ but were not selected for the evaluation. Passive case detection was done for the entire cohort and active case detection in 149 children aged 1-10 year from the intervention arm and 143 from the control arm. Four cross-sectional surveys assessed parasite carriage by microscopy and molecular methods during a five-month follow-up period. RESULTS: The coverage rate in the intervention arm was 93.0% (1,117/1,201). Parasite prevalence by molecular detection methods was 2.2-2.7% prior to the intervention and undetectable during follow-up in both the control and intervention clusters. None of the slides collected during cross-sectional surveys had microscopically detectable parasite densities. Three clinical malaria episodes occurred in the intervention (n = 1) and control clusters (n = 2). CONCLUSIONS: This study illustrates the possibility to achieve high coverage with a three-day intervention but also the difficulty in defining suitable outcome measures to evaluate interventions in areas of very low malaria transmission intensity. The decline in transmission intensity prior to the intervention made it impossible to assess the impact of MDA in the chosen study setting. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00509015.

Defining malaria burden from morbidity and mortality records, self treatment practices and serological data in Magugu, Babati District, northern Tanzania.

Malaria morbidity and mortality data from clinical records provide essential information towards defining disease burden in the area and for planning control strategies, but should be augmented with data on transmission intensity and serological data as measures for exposure to malaria. The objective of this study was to estimate the malaria burden based on serological data and prevalence of malaria, and compare it with existing self-treatment practices in Magugu in Babati District of northern Tanzania. Prospectively, 470 individuals were selected for the study. Both microscopy and Rapid Diagnostic Test (RDT) were used for malaria diagnosis. Seroprevalence of antibodies to merozoite surface proteins (MSP-1(19)) and apical membrane antigen (AMA-1) was performed and the entomological inoculation rate (EIR) was estimated. To complement this information, retrospective data on treatment history, prescriptions by physicians and use of bed nets were collected. Malaria prevalence in the area was 6.8% (32/470). Of 130 individuals treated with artemisinin combination therapy (ACT), 22.3% (29/130) were slide confirmed while 75.3% (98/130) of them were blood smear negative. Three of the slides confirmed individuals were not treated with ACT. Fever was reported in 38.2% of individuals, of whom 48.8% (88/180) were given ACT. Forty-two (32.3%) of those who received ACT had no history of fever. About half (51.1%) of those treated with ACT were children < 10 years old. Immunoglobulin against MSP-119 was positive in 16.9% (74/437) while against AMA-1 was positive in 29.8% (130/436). Transmission intensity was estimated at <0.2 infectious bites per person per year. The RDT was highly specific (96.3%) but with low sensitivity (15.6%). In conclusion, Magugu is a low endemic area. There is substantial over diagnosis, over treatment and self treatment in the community. The burden of malaria based on medical records is over estimated as was mostly presumptive. The low sensitivity of RDT reflects the low number of immune individuals as well as the low parasite density.

Transmission intensity and malaria vector population structure in Magugu, Babati District in northern Tanzania.

A 1-year longitudinal study was conducted in Magugu in Babati district, northern Tanzania to determine malaria vector population structure and malaria transmission indices. Mosquitoes were sampled using the Centre for Disease Control (CDC) light traps. A total of 110,357 adult female mosquitoes were collected. Anopheles gambiae s.1. accounted 25% of the total female mosquito collected. Relatively fewer An. funestus were collected. Other mosquito species collected were An. pharoensis, An. coustani, An. maculipalpis, An. marshallii, Culex quinquefasciatus, Cx unnivittatus, Mansonia uniformis and Ma. africana. An analysis by Polymerase Chain Reaction revealed that An. arabiensis was the only member of the An. gambiae complex in the collected samples. The number of mosquito collected correlated with the increasing mean rainfall. Blood meal analysis showed a higher human enzymatic reaction among An. gambiae s.1. (63.5%) followed by An. funestus (42.9%). Bovine enzymatic reaction was higher among An. coustani (73.7%) followed by the An. pharoensis (66.7%). The Enzyme Linked Immunosorbent Assay (ELISA) was used to detect Plasmodium falciparum circumsporozoites proteins in 10,000 female Anopheles mosquitoes. Only two An. arabiensis were found to be infected. The entomological inoculation rate (EIR) was estimated at 0.51 infectious bites per person per year. This EIR was considered to be relatively low, indicating that malaria transmission in this area is low. Variability in mosquito blood meal shows availability of variety of preferred blood meal choices and impact of other factors inhibiting mosquito-human host contact. The study has provided information considered useful in the mapping of the vector distribution and population structure in the country. Such information is considered to be among the essential tools for planning malaria control interventions.

Child hospitalization due to severe malaria is associated with the ICAM-1Kilifi allele but not adherence patterns of Plasmodium falciparum infected red blood cells to ICAM-1.

This study aimed at determining whether the predisposition of a mutation at position 179 of the ICAM-1 gene to child hospitalization due to malaria was mediated by changes in adherence properties of IRBCs to ICAM-1. ICAM-1 genotypes were determined by nested polymerase chain reaction of isolated DNA from filter blood spots followed by Restriction Fragment Length Polymorphism (RFLP). Plasmodium falciparum adherence assays were done on immobilized purified ICAM-1. Our data indicate that the homozygosity for the ICAM-1(Kilifi) mutation occurs at a frequency of 22.3% in Magugu-Babati, Northern Tanzania. Our results show that there are no differences in IRBC binding profiles across genotypes. We show in this study that homozygosity for the ICAM-1(Kilifi) is associated with child hospitalization (X(2)=14.47, p<0.001). We have further shown that hospitalization was not associated with cytoadherence (X(2)=0.17, p=0.68). We conclude that the ICAM-1(Kilifi) allele occurs at a high frequency in Tanzania and that associations of this allele with higher child hospitalization frequencies is independent of cytoadherence patterns of IRBC isolated from ICAM-1 genotypes, implying that any associations reported to exist between the ICAM-1(Kilifi) mutation and severe malaria are unlikely to be mediated through altered IRBC cytoadherence properties.

Low density parasitaemia, red blood cell polymorphisms and Plasmodium falciparum specific immune responses in a low endemic area in northern Tanzania.

BACKGROUND: Low density Plasmodium falciparum infections, below the microscopic detection limit, may play an important role in maintaining malaria transmission in low endemic areas as well as contribute to the maintenance of acquired immunity. Little is known about factors influencing the occurrence of sub-microscopic parasitaemia or the relation with immune responses.We investigated possible associations between the occurrence of sub-microscopic P. falciparum parasite carriage and antibody responses to the asexual stage antigens, G6PD deficiency and alpha+-thalassaemia in 464 subjects from a low endemic area in northern Tanzania. METHODS: We used samples collected from two cross sectional surveys conducted during dry and wet season in 2005. Submicroscopic parasitaemia was detected by using quantitative nucleic acid sequence based amplification (QT-NASBA). Genotyping for G6PD and alpha+-thalassaemia were performed by high throughput PCR; the prevalence and level of total IgG antibodies against MSP-1, MSP-2 and AMA-1 were determined by ELISA. RESULTS: Compared to parasite free individuals, individuals carrying sub-microscopic densities of P. falciparum parasites had significantly higher median antibody levels to MSP-1 (p = 0.042) and MSP-2 (p = 0.034) but not to AMA-1 (p = 0.14) while no clear relation between sub-microscopic parasite carriage and G6PD deficiency or alpha+-thalassaemia was observed. CONCLUSION: Our data suggest a role for sub-microscopic parasite densities in eliciting or maintaining humoral immune responses without evidence for a modulating effect of G6PD deficiency or alpha+-thalassaemia.

Overuse of artemisinin-combination therapy in Mto wa Mbu (river of mosquitoes), an area misinterpreted as high endemic for malaria.

BACKGROUND: Adequate malaria diagnosis and treatment remain major difficulties in rural sub-Saharan Africa. These issues deserve renewed attention in the light of first-line treatment with expensive artemisinin-combination therapy (ACT) and changing patterns of transmission intensity. This study describes diagnostic and treatment practices in Mto wa Mbu, an area that used to be hyperendemic for malaria, but where no recent assessments of transmission intensity have been conducted. METHODS: Retrospective and prospective data were collected from the two major village health clinics. The diagnosis in prospectively collected data was confirmed by microscopy. The level of transmission intensity was determined by entomological assessment and by estimating sero-conversion rates using anti-malarial antibody responses. RESULTS: Malaria transmission intensity by serological assessment was equivalent to < 1 infectious bites per person per year. Despite low transmission intensity, > 40% of outpatients attending the clinics in 2006-2007 were diagnosed with malaria. Prospective data demonstrated a very high overdiagnosis of malaria. Microscopy was unreliable with < 1% of slides regarded as malaria parasite-positive by clinic microscopists being confirmed by trained research microscopists. In addition, many 'slide negatives' received anti-malarial treatment. As a result, 99.6% (248/249) of the individuals who were treated with ACT were in fact free of malaria parasites. CONCLUSION: Transmission intensity has dropped considerably in the area of Mto wa Mbu. Despite this, most fevers are still regarded and treated as malaria, thereby ignoring true causes of febrile illness and over-prescribing ACT. The discrepancy between the perceived and actual level of transmission intensity may be present in many areas in sub-Saharan Africa and calls for greater efforts in defining levels of transmission on a local scale to help rational drug-prescribing behaviour.