Contribution of community champions to accelerate the uptake of COVID-19 vaccination in Rukwa region, Tanzania, February - October 2022.

Introduction: Tanzania is among the African countries which started COVID-19 vaccination late (August 2021) compared to other countries in the African continent. By mid-March 2022, overall vaccine uptake was 13% of the targeted population, which was very low compared to other countries. We describe the contribution of champions in the Rukwa region that led to an increase in vaccine coverage rate in Tanzania. Methods: a community-based campaign was conducted using community champions from July 15th to August 31st, 2022. A baseline assessment was conducted focusing on the key drivers, barriers, and enablers for COVID-19 vaccine uptake in the region. A working session to develop IEC materials and messages tailored to addressing the issues raised in the community to be used in the campaign in the region was conducted, followed by the campaign's launch. Community engagement and sensitizations, which contributed to the rise of vaccinated people, were based on house-to-house visits, village meetings, and visiting community gatherings such as marketplaces, places of worship, and sports areas, which were done by champions alongside vaccinators. Results: the campaign contributed to the increase of vaccination coverage because, before the start of the campaign, the vaccination coverage was 10% as of July 14th, 2022. After the campaign, which started on July 15th to August 31st, 2022, the coverage increased by 12%. During the post-evaluation exercise after the campaign, the coverage keeps increased and reached 94% by October 2022. The coverage kept increasing even after the intervention's end due to the campaign's positive effect. Conclusion: the community still needs correct information to avoid misinformation and hesitancy, especially when introducing new disease response mechanisms such as vaccines. The community champions who are based in the community play a critical role in addressing community concerns and contribute to the effectiveness of the implementation; hence sustainability is crucial.

Stage-Dependent Increase of Systemic Immune Activation and CCR5+CD4+ T Cells in Filarial Driven Lymphedema in Ghana and Tanzania.

Chronic lymphedema caused by infection of Wuchereria bancrofti is a disfiguring disease that leads to physical disability, stigmatization, and reduced quality of life. The edematous changes occur mainly on the lower extremities and can progress over time due to secondary bacterial infections. In this study, we characterized participants with filarial lymphedema from Ghana and Tanzania as having low (stage 1-2), intermediate (stage 3-4), or advanced (stage 5-7) lymphedema to determine CD4+ T cell activation patterns and markers associated with immune cell exhaustion. A flow cytometry-based analysis of peripheral whole blood revealed different T cell phenotypes within participants with different stages of filarial lymphedema. In detail, increased frequencies of CD4+HLA-DR+CD38+ T cells were associated with higher stages of filarial lymphedema in patients from Ghana and Tanzania. In addition, significantly increased frequencies of CCR5+CD4+ T cells were seen in Ghanaian participants with advanced LE stages, which was not observed in the Tanzanian cohort. The frequencies of CD8+PD-1+ T cells were augmented in individuals with higher stage lymphedema in both countries. These findings show distinct activation and exhaustion patterns in lymphedema patients but reveal that immunological findings differ between West and East African countries.

The viability of utilising phone-based text messages in data capture and reporting morbidities due to lymphatic Filariasis by community health workers: a qualitative study in Kilwa district, Tanzania.

BACKGROUND: Globally, there is recognition of the value of using mobile phones among health providers in improving health systems performance. However, in many Low- and Middle-income countries where there is shortage of health providers, Community Health Workers have assumed some responsibilities especially relating to identifying and reporting on health problems within their communities. Despite the known benefits of using mobile phone technology to deliver health services, there is limited information on the extent to which Community Health Workers are able to effectively use the technology in data collection and reporting. The aim of this study was to determine the feasibility of utilizing phone-based text messages on Lymphatic Filariasis morbidity surveillance by Community Health Workers. METHODS: This was a cross sectional study whose data was collected through key informant interviews and focused group discussions among community health workers, health providers and staff of neglected tropical diseases control program. Collected transcripts were analysed through Thematic content analysis as it allowed for the identification of data codes through inductive reasoning. RESULTS: The use of mobile phone-based text messages in data collection and reporting lymphatic filariasis morbidity cases by Community Health Workers was perceived by study participants to be a relevant tool and feasible due to the ease of use of the technology. The tool was reported by end-users to significantly increase their performance and efficiency was gained in terms of reduced paper work, increased the number of patients accessing health care services and the ability to report in real-time. All respondents were confident that Community Health Workers were the right persons to interact with communities in tracking and reporting morbidity cases using mobile technology. CONCLUSION: Mobile phone-based text messages have proven to be effective in routine workflows such as, data collection and reporting on Lymphatic Filariasis morbidity cases, patient to provider communication, decision making and supportive supervision. Mobile phones have also improved efficiency and general performance of end users in terms of increased number of cases identified and efficiency gained in terms of reduced paper work and the ability to collect and report in real-time.

Step towards elimination of Wuchereria bancrofti in Southwest Tanzania 10 years after mass drug administration with Albendazole and Ivermectin.

BACKGROUND: Lymphatic filariasis is a mosquito transmitted parasitic infection in tropical regions. Annual mass treatment with ivermectin and albendazole is used for transmission control of Wuchereria bancrofti, the infective agent of lymphatic filariasis in many African countries, including Tanzania. METHODOLOGY: In a general population study in Southwest Tanzania, individuals were tested for circulating filarial antigen, an indicator of W. bancrofti adult worm burden in 2009 before mass drug administration commenced in that area. Seven annual rounds with ivermectin and albendazole were given between 2009 and 2015 with a population coverage of over 70%. Participants of the previous study took part in a follow-up activity in 2019 to measure the effect of this governmental activity. FINDINGS: One thousand two hundred and ninety nine inhabitants of Kyela district in Southwest Tanzania aged 14 to 65 years who had participated in the study activities in 2009 were revisited in 2010/11 and 2019. Among this group, the prevalence of lymphatic filariasis of the 14-65 years olds in 2009 was 35.1%. A follow-up evaluation in 2010/11 had shown a reduction to 27.7%. In 2019, after 7 years of annual treatment and an additional three years of surveillance, the prevalence had dropped to 1.7%, demonstrating successful treatment by the national control programme. Risk factors for W. bancrofti-infection were the occupation as farmer, male sex, and older age. Most infected individuals in the 2019 follow-up study already had a positive test for filarial antigen in 2009 and/or 2010/11. CONCLUSIONS: This data supports the findings of the Tanzanian Neglected Tropical Disease Control Programme (NTDCP), who conducted Transmission Assessment Surveys and found an impressive reduction in the prevalence of LF in children. Our results complement this data by showing a similar decrease in prevalence of LF in the adult population in the same area. The elimination of LF seems achievable in the near future.

Podoconiosis - From known to unknown: Obstacles to tackle.

Podoconiosis is a non-filarial and non-communicable disease leading to lymphedema of the lower limbs. Worldwide, 4 million individuals live with podoconiosis, which is accompanied by disability and painful intermittent acute inflammatory episodes that attribute to significant disability adjusted life years (DALYs). Different risk factors like contact with volcanic red clay soil, high altitude (above 1000 m), high seasonal rainfall (above 1000 mm/year) and occupation (e.g., subsistence farmer) are associated with the risk of podoconiosis. Although podoconiosis was described to be endemic in 32 countries in Africa, parts of Latin America and South East Asia, knowledge about related genetics, pathophysiology, immunology and especially the causing molecule(s) in the soil remain uncertain. Thus, podoconiosis can be considered as one of the most neglected diseases. This review provides an overview about this non-filarial related geochemical disease and aim to present perspectives and future directions that might be important for better understanding of the disease, prospect for point-of-care diagnosis, achieving protection and developing novel treatment strategies.

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.

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.

The blackfly vectors and transmission of Onchocerca volvulus in Mahenge, south eastern Tanzania.

The Mahenge Mountains onchocerciasis focus in south eastern Tanzania was historically one of the most heavily infected areas in the country. The vectors of Onchocerca volvulus are mainly Simulium damnosum complex blackflies, but a species of the Simulium neavei group may also contribute to transmission in some areas. The only detailed studies of parasite transmission in Mahenge were conducted in the late 1960s. The taxonomy of the S. damnosum complex has since been revised and onchocerciasis control through annual community directed treatment with ivermectin (CDTI) commenced in 1997. This study aimed to provide a cytogenetic and molecular update of the S. damnosum complex cytoforms present in Mahenge, and to evaluate the current status of O. volvulus transmission by blackflies following 19 years of annual CDTI. Rivers were surveyed to identify sites of S. damnosum s.l. breeding among the eastern slopes of the mountains, and human landing collections of adult female blackflies were made close to breeding sites. Identification of S. damnosum complex cytoforms was by cytotaxonomy of late-instar larvae and ITS1 amplicon size polymorphisms of larvae and adults. Adult blackflies were pool screened for O. volvulus infection using a triplex real-time PCR. The cytoforms 'Nkusi', Simulium kilibanum and 'Turiani' were found breeding in perennial rivers. 'Nkusi' and S. kilibanum were collected on human bait at 7/7 catch sites and possessed ITS1 profiles most closely resembling the molecular forms 'Nkusi J' and S. kilibanum 'T'. Whereas 'Turiani' was present in rivers, it was not collected on human bait and appears to be zoophilic. Simulium nyasalandicum was collected in low numbers on human bait at 3/7 catch sites. In total, 12,452 S. damnosum s.l. were pool screened and O. volvulus infection was detected in 97/104 pools of bodies and 51/104 pools of heads. The estimated percentage of S. damnosum s.l. carrying infective L3 stage parasites was 0.57% (95% CI 0.43%-0.74%). Onchocerca volvulus transmission by S. damnosum s.l. is continuing in the Mahenge Mountains after 19 years of annual CDTI. Infection rates appear similar to those reported in the 1960s, but a more detailed study is required to fully understand the epidemiological significance of the ongoing transmission. These results provide further evidence that annual CDTI may be insufficient to eliminate the parasite in formerly hyperendemic foci.

Evaluation of Onchocerciasis Transmission in Tanzania: Preliminary Rapid Field Results in the Tukuyu Focus, 2015.

To compare diagnostic tests for onchocerciasis in a setting that has suppressed transmission, a randomized, age-stratified study was implemented in an area in Tanzania that had received 15 rounds of annual mass drug administration (MDA) with ivermectin. Study participants (N = 948) from 11 villages underwent a questionnaire, skin examination, skin snips, and blood draw. The burden of symptomatic disease was low. Ov-16 antibody rapid diagnostic test (RDT) results were positive in 38 (5.5%) participants, with 1 (0.5%), 1 (0.4%), and 2 (0.8%) in children aged 0-5, 6-10, and 11-15 years, respectively. Despite significant impact of MDA on transmission, the area would have failed to meet World Health Organization serologic criteria for stopping MDA if a full evaluation had been conducted. The specificity of the RDT, which is 97-98%, may result in the identification of a number of false positives that would exceed the current stop MDA threshold.

Esperanza Window Traps for the collection of anthropophilic blackflies (Diptera: Simuliidae) in Uganda and Tanzania.

There is an increasing need to evaluate the impact of chemotherapeutic and vector-based interventions as onchocerciasis affected countries work towards eliminating the disease. The Esperanza Window Trap (EWT) provides a possible alternative to human landing collections (HLCs) for the collection of anthropophilic blackflies, yet it is not known whether current designs will prove effective for onchocerciasis vectors throughout sub-Saharan Africa. EWTs were deployed for 41 days in northern Uganda and south eastern Tanzania where different Simulium damnosum sibling species are responsible for disease transmission. The relative efficacy of EWTs and HLCs was compared, and responses of host-seeking blackflies to odour baits, colours, and yeast-produced CO2 were investigated. Blue EWTs baited with CO2 and worn socks collected 42.3% (2,393) of the total S. damnosum s.l. catch in northern Uganda. Numbers were comparable with those collected by HLCs (32.1%, 1,817), and higher than those collected on traps baited with CO2 and BG-Lure (25.6%, 1,446), a synthetic human attractant. Traps performed less well for the collection of S. damnosum s.l. in Tanzania where HLCs (72.5%, 2,432) consistently outperformed both blue (16.8%, 563) and black (10.7%, 360) traps baited with CO2 and worn socks. HLCs (72.3%, 361) also outperformed sock-baited (6.4%, 32) and BG-Lure-baited (21.2%, 106) traps for the collection of anthropophilic Simulium bovis in northern Uganda. Contrasting blackfly distributions were observed on traps in Uganda and Tanzania, indicating differences in behaviour in each area. The success of EWT collections of S. damnosum s.l. in northern Uganda was not replicated in Tanzania, or for the collection of anthropophilic S. bovis. Further research to improve the understanding of behavioural responses of vector sibling species to traps and their attractants should be encouraged.

Prevalence and risk factors associated with female anal sex in the context of HIV/AIDS in the selected districts of Tanzania.

BACKGROUND: Female anal sex is a receptive type of sexual practice among heterosexual couples where the penis is inserted into the anus of a female partner. In the Western world, a number of studies and interventions have been carried out on anal sex among men due to its potential risks to HIV transmission. In African countries, including Tanzania, there is dearth of information on the risks inherent in practices associated with female anal sex in the general population. The objective of this study was to determine the prevalence and risk factors associated with female anal sex in fuelling HIV transmission in selected districts of Tanzania. METHODS: This study was conducted in four districts of Tanzania of Kinondoni, Tanga Urban, Makete and Siha. Both quantitative and qualitative methods i.e. household interviews and focus group discussions were employed in data collection. Study participants included community members of aged 15 and above such as heads of the household, adolescents, bar workers and commercial sex workers. FINDINGS: A total of 903 individuals were interviewed, 60.6% of whom were females. When respondents were asked to indicate whether they had ever been tempted to practise FAS, 167 (18.5%) reported to have been tempted in the past 12 months. Of these, 44 (26.3%) respondents had at least practised FAS. Risky practices associated with FAS were forced sex, multiple partners, frequency of engaging in FAS, low use of condoms during FAS, low rates of HIV testing among partakers, poor perception of the risks to acquire HIV through FAS and use of lubricants. CONCLUSIONS: In this population, the frequency of FAS practice was rather low. And yet, FAS practice attendant risk factors are likely to exacerbate HIV transmission. As such, there is a need for further exploratory studies to determine and document drivers of FAS. In addition, public health education should be provided with regard to the risks of contracting HIV associated with FAS practices.

Retinoid Expression in Onchocercal Skin Disease: Pilot Study.

Based on the observation that the parasite Onchocerca volvulus selectively absorbs vitamin A from the host, and the known toxicity of vitamin A in higher concentration, it was hypothesized that dying microfilariae (mf) release their stores of vitamin A (retinoids) into the host circulation in toxic concentrations, inducing the signs and symptoms of onchocerciasis. We conducted a pilot study to test the hypothesis in Songea communities in Southern Tanzania, where mass drug administration with ivermectin had not been implemented by the time of the survey. The specific aim was to evaluate the correlation between the diagnosis of onchocerciasis and increased levels of retinoic acid at infection sites. The analysis was performed by determining copy numbers of a genome of O volvulus present in skin snip samples of persons with onchocerciacis, and correlating these numbers with expression levels of retinoic acid receptor-α (RAR-α), which is inducible by retinoic acid. Total DNA and RNA were extracted from each of 25 mf-positive and 25 mf-negative skin samples and evaluated using quantitative polymerase chain reaction with appropriate negative controls. Analysis of the samples, adjusted with glyceraldehyde 3-phosphate dehydrogenase gene levels, revealed that most samples with detectable RAR-α transcripts had higher levels of RAR-α expression than the assay control. However, the quality and number of samples were insufficient for statistical analysis. Fold data on the expression levels of both O volvulus DNA and RAR RNA suggested a possible trend toward higher relative RAR-α expression in samples with higher levels of O volvulus DNA ( r2 = 0.25, P = .079). Evidence of a contribution of vitamin A to the pathology of onchocerciasis thus remains elusive. Future studies on the role of retinoids in onchocerciasis will require larger groups of participants as well as careful monitoring of the cold chain and tissue storage procedures in view of the sensitivity of vitamin A to heat and light.

Magnitude and risk factors of non-communicable diseases among people living with HIV in Tanzania: a cross sectional study from Mbeya and Dar es Salaam regions.

BACKGROUND: HIV and Non communicable diseases (NCDs) are major problem of public health importance in developing countries. This study was conducted to explore and establish information on the magnitude, distribution of NCDs risk factors among people living with HIV (PLWHIV) which is scarce in Tanzania. METHOD: A cross sectional study was conducted to PLWHIV from 12 care and treatment clinics in Dar es Salaam and Mbeya regions from October 2011 to February 2012. Data on demographic characteristics, NCD risk factors including behavioral, biochemical tests and physical measurements was collected from PLWHIV. RESULTS: Of 754 PLWHIV recruited, 671(89.0%) consented to participate in the study and 354/671(52.8%) were on antiretroviral therapy (ART). The following NCD risk factors: raised blood levels of low density lipoprotein (61.3% vs 38.7%, p < 0.001) total cholesterol (TC) (71.6% vs 28.4%, p < 0.001) and triglyceride (67.0% vs 33.0%, p = 0.001) as well as overweight/obesity (61.1% vs 38.9%, p = 0.010), abnormal waist circumference (61.7% vs 38.3%, p < 0.001) and being aged >40 years (63.3% vs 36.7%, p < 0.001) were more prevalent among PLWHIV on ART than ART naïve. The prevalence of Diabetes mellitus among PLWHIV was 4.2% and was slightly high among those ART naïve (4.7% vs 3.7%). The prevalence of hypertension was 26.2% and was high among those on ART (30.0% vs 21.9%, p = 0.010). Being aged >40 years (AOR = 2.52, 95% CI 1.37-4.63), abnormal waist circumference (AOR = 2.37 95% CI 1.13-5.00), overweight/obesity (AOR = 2.71, 95% CI 1.26-5.84) and male sex (AOR = 1.17, 1.02-4.20) were the predictors of hypertension among patients on ART while raised TC (AOR = 1.47 (1.01-2.21) and being aged >40 years (AOR = 3.42, 95% CI 2.06-5.70) were predictors for hypertension among ART naïve patients. CONCLUSION: This study has revealed that the magnitude of NCD risk factors is significantly higher among PLWHIV on ART than those not on ART. Initiating and strengthening of interventions for minimizing preventable NCD risks should be considered when initiating ART among PLWHIV. Regular monitoring of NCD risk factors is of paramount importance among ART patients.

Surveillance of artemether-lumefantrine associated Plasmodium falciparum multidrug resistance protein-1 gene polymorphisms in Tanzania.

BACKGROUND: Resistance to anti-malarials is a major public health problem worldwide. After deployment of artemisinin-based combination therapy (ACT) there have been reports of reduced sensitivity to ACT by malaria parasites in South-East Asia. In Tanzania, artemether-lumefantrine (ALu) is the recommended first-line drug in treatment of uncomplicated malaria. This study surveyed the distribution of the Plasmodium falciparum multidrug resistance protein-1 single nucleotide polymorphisms (SNPs) associated with increased parasite tolerance to ALu, in Tanzania. METHODS: A total of 687 Plasmodium falciparum positive dried blood spots on filter paper and rapid diagnostic test strips collected by finger pricks from patients attending health facilities in six regions of Tanzania mainland between June 2010 and August 2011 were used. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to detect Pfmdr1 SNPs N86Y, Y184F and D1246Y. RESULTS: There were variations in the distribution of Pfmdr1 polymorphisms among regions. Tanga region had exceptionally high prevalence of mutant alleles, while Mbeya had the highest prevalence of wild type alleles. The haplotype YFY was exclusively most prevalent in Tanga (29.6%) whereas the NYD haplotype was the most prevalent in all other regions. Excluding Tanga and Mbeya, four, most common Pfmdr1 haplotypes did not vary between the remaining four regions (χ² = 2.3, p = 0.512). The NFD haplotype was the second most prevalent haplotype in all regions, ranging from 17% - 26%. CONCLUSION: This is the first country-wide survey on Pfmdr1 mutations associated with ACT resistance. Distribution of individual Pfmdr1 mutations at codons 86, 184 and 1246 varies throughout Tanzanian regions. There is a general homogeneity in distribution of common Pfmdr1 haplotypes reflecting strict implementation of ALu policy in Tanzania with overall prevalence of NFD haplotype ranging from 17 to 26% among other haplotypes. With continuation of ALu as first-line drug this haplotype is expected to keep rising, thus there is need for continued pharmacovigilance studies to monitor any delayed parasite clearance by the drug.

High levels of sulphadoxine-pyrimethamine resistance Pfdhfr-Pfdhps quintuple mutations: a cross sectional survey of six regions in Tanzania.

BACKGROUND: In 2006, the first-line anti-malarial drug treatment in Tanzania was changed from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (ALu), an artemisinin-based combination (ACT), since when the use of SP has been restricted for intermittent preventive treatment in pregnancy (IPTp). A number of Plasmodium falciparum mutations are known to be associated with resistance to SP, but it is not known if the prevalence of these mutations is increasing or decreasing under the conditions of reduced levels of SP use. This study reports on the current SP resistant quintuple Pfdhfr-Pfdhps mutations in six regions of Tanzania. METHODS: Finger-prick blood on filter paper and rapid diagnostic test strips from P. falciparum-positive individuals of all age groups attending health facilities in six regions of Tanzania between June 2010 and August 2011 were obtained. Using chelex-100 extracted DNA, genotyping was done for mutations on codons 51, 59 and 108 of Pfdhfr and 437 and 540 of Pfdhps genes using PCR-RFLP technique. RESULTS: A total of 802 malaria-positive samples were screened and genotyped. The prevalence of Pfdhfr 51I, Pfdhps 437G and 540E varied between the regions (p < 0.001) whereas Pfdhfr 59R (FE 10.79, p = 0.225) and 108 N (FE 10.61, p = 0.239) did not vary between the regions. The Pfdhfr triple mutant was above 84% and close to fixation levels in all regions, whereas the Pfdhps double mutation ranged from 43.8 to 97% between the regions. The quintuple mutant (IRNGE) was the most prevalent in all regions and it varied significantly from 37.5 to 90.2% (χ(2) = 1.11, p <0.001). CONCLUSIONS: There is evidence of persistent high levels of SP resistance markers in Tanzania with evidence of quintuple mutations that are likely to become fixed in the population. This threatens the future of SP not only in IPTp programmes, but as a combination drug for ACT. Continuous monitoring of SP-IPTp efficacy should be encouraged subsequent to searching for alternative drugs for IPTp in East Africa.

Trends in chloroquine resistance marker, Pfcrt-K76T mutation ten years after chloroquine withdrawal in Tanzania.

BACKGROUND: Plasmodium falciparum resistance to anti-malarial drugs remains a major obstacle to the control of malaria. In 2001 Tanzania replaced chloroquine (CQ) with sulphadoxine-pyrimethamine (SP) as first-line drug, which in turn was replaced by artemisinin combination therapy in 2006. SP has however, continued to be used in intermittent preventive treatment of malaria in pregnancy (IPTp) despite reports of high levels of resistance to SP due to the lack of alternatives to SP for IPTp. Recent reports have indicated recovery of CQ-susceptibility in Malawi, Kenya, Mozambique, and Tanzania based on the prevalence of wild types at codon 76 of the Pfcrt gene in indigenous P. falciparum populations. The current prevalence of this Pfcrt-76 CQ resistance marker from six regions of Tanzania mainland is hereby reported. METHODS: DNA extracted from filter-paper dried blood spots and rapid diagnostics kit strips collected from finger-prick blood were used to genotype the Pfcrt-76 resistance marker using PCR-RFLP. Data from previously published studies were used to generate CQ susceptibility recovery trends using logistic regression model. RESULTS: Seven hundred and forty one (741) samples were genotyped. The current frequency of the CQ-susceptible Pfcrt-K76 was above 92% and did not differ between regions in Tanzania (χ(2) = 2.37; p = 0.795). The K76 allelic prevalence was between 85.7 and 93% in regions (χ(2) = 7.88, p = 0.163). The CQ resistance recovery trends showed regional variability that may be caused by differences in malaria transmission intensity, but overall the trends converge as the susceptibility levels in all regions approach >90%. CONCLUSIONS: CQ withdrawal in Tanzania has resulted into >90% recovery of susceptibility in ten years of withdrawal. These findings are in support of the search for CQ-based combination drugs as a possible future alternative to SP for IPTp in places where full recovery of CQ-susceptibility will be evident.

Clinical manifestations and outcomes of severe malaria among children admitted at Rungwe and Kyela district hospitals in south-western Tanzania.

Malaria remains as an important public health and a major cause of childhood death and paediatric hospital admission in sub-Saharan Africa. This prospective hospital based cross sectional study was conducted from April 2007 to April 2008. The main objective was to assess clinical manifestations and outcomes of severe malaria in children admitted to district hospital in Rungwe and Kyela in south-western Tanzania. A total of 1371 children were selected as screening group of which 409 (29.8%) were tested positive for malaria. Mean age of the children was 2.7 (95%CI= 2.5, 2.8) years and the majority (86%) were under five years of age. The proportion of children severe malaria in Rungwe was significantly higher than that of Kyela by 21.3% (P=0.002). The common symptoms of severe malaria during admission were convulsions (50.9%) compensated shock (30.6%), prostration (29.1%) and symptomatic severe anaemia (14.9%). The case fatality rate (CFR) was 4.6% and the cure rate (CR) was 95.4%. Children with suspected severe acidosis and symptomatic severe anemia were 4.8 (95%CI=1.6, 14.6) and 5.5 (95%CI 1.1, 28.2), respectively, more likely to die compared to those without these symptoms. The proportion of deaths among children presenting ≥5 symptoms was 32.1% higher than among those presenting one symptom (OR =0.50, 95%CI 0.125-2.000; P=0.000). Convulsions and compensated shock were the leading symptoms at admission. Suspected severe acidosis and symptomatic severe anemia were the predictors of mortality for children. In order to reduce mortality among admitted children with severe malaria there is a need for health providers to deploy strategic management of fatal prognostic factors. In conclusion, convulsion and compensated shock were the leading symptoms among children at admission and that suspected severe acidosis and symptomatic severe anemia were the predictors of mortality. It is therefore important to emphasis early diagnosis and prompt treatment of severe cases of malaria to minimize mortality among children.

Clinical Manifestations and Outcomes of Severe Malaria among Children Admitted to Rungwe and Kyela District Hospitals in South-Western Tanzania

Abstract:Malaria remains as an important public health and a major cause of childhood death and paediatric hospital admission in sub-Saharan Africa. This prospective hospital based cross sectional study was conducted from April 2007 to April 2008. The main objective was to assess clinical manifestations and outcomes of severe malaria in children admitted to district hospital in Rungwe and Kyela in south-western Tanzania. A total of 1371 children were selected as screening group of which 409 (29.8) were tested positive for malaria. Mean age of the children was 2.7 (95CI= 2.5; 2.8) years and the majority (86) were under five years of age. The proportion of children severe malaria in Rungwe was significantly higher than that of Kyela by 21.3 (P=0.002). The common symptoms of severe malaria during admission were convulsions (50.9) compensated shock (30.6); prostration (29.1) and symptomatic severe anaemia (14.9). The case fatality rate (CFR) was 4.6 and the cure rate (CR) was 95.4. Children with suspected severe acidosis and symptomatic severe anemia were 4.8 (95CI=1.6; 14.6) and 5.5 (95CI 1.1; 28.2); respectively; more likely to die compared to those without these symptoms. The proportion of deaths among children presenting ?5 symptoms was 32.1 higher than among those presenting one symptom (OR =0.50; 95CI 0.125-2.000; P=0.000). Convulsions and compensated shock were the leading symptoms at admission. Suspected severe acidosis and symptomatic severe anemia were the predictors of mortality for children. In order to reduce mortality among admitted children with severe malaria there is a need for health providers to deploy strategic management of fatal prognostic factors. In conclusion; convulsion and compensated shock were the leading symptoms among children at admission and that suspected severe acidosis and symptomatic severe anemia were the predictors of mortality. It is therefore important to emphasis early diagnosis and prompt treatment of severe cases of malaria to minimize mortality among children