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BackgroundMalaria continued to be the major public health concern in sub-Sahara Africa, thus for better planning of control activities, periodic surveillance of both clinical and asymptomatic cases remains important. However, the usability of routinely collected malaria data in Kenyan hospitals as a predictor of the asymptomatic malaria infection in the community amidst rapid infection resurgence or reduction in different areas of disease endemicities remains widely unstudied. This study was therefore aimed to evaluate the utility of passive surveillance of malaria in health facilities as a proxy of infection transmission of the surrounding community in different transmission intensities.MethodsProspective multiple cross-sectional surveys were done in three villages in western Kenya. Monthly asymptomatic malaria positivity among school children, number of outpatient (OPD) confirmed malaria cases and abundancy of indoor resting malaria vectors were surveyed from June 2015 to August 2016. Community surveys on antimalarial drug use among adults and children were also done. Detection of malaria parasitaemia was done using thick and thin Giemsa stained blood slide microscopy for both clinical and school participants. A questionnaire was used to collect information on self-use of antimalarial drugs from randomly selected households.ResultsThe overall OPD blood slide positivity from all study sites was 26.6% (95%CI 26.2-27.0) and highest being among the 5-14 years (41.2% (95% CI 40.1-42.3). Asymptomatic malaria positivity among the school children were 6.4% (95%CI 5.3-7.5) and 38.3% (95%CI 36.1-40.5) in low and high transmission settings respectively. A strong correlation between overall monthly OPD positivity and the school age children positivity was evident at Marani (low transmission) (rho = 0.78, p = 0.001) and at Iguhu (Moderate transmission) (rho = 0.61, p = 0.02). The high transmission setting (Kombewa) showed no significant correlation (rho = - 0.039, p = 0.89).ConclusionHospital malaria data from low and moderate malaria transmission predicted the infection transmission dynamics of the surrounding community. In endemic sites, hospital based passive surveillance didn't predict the asymptomatic infection dynamics in the respective community.

BackgroundPassive surveillance of malaria in health facilities remains vital for implementation of control and elimination programs. It is therefore essential understanding current age profile of clinical malaria morbidity, mortality and presentations in areas with variant infection susceptibility. This study aimed at understanding the current malaria morbidity and mortality in Western Kenya.MethodsSurveillance of clinical and asymptomatic parasitological positivity rates of all malaria suspected patients and school children were respectively determined from June 2015 to August 2016. From 2014 to 2016, register books in hospitals were referred and the confirmed malaria cases in conjunction with total number of monthly outpatient visits (OPD) counted. All registered malaria admissions were counted together with other causes of admissions. Moreover, outcome of malaria admissions in terms of discharge or death was recorded using inpatient charts within the same time frame. Prospective surveillance of severe malaria collected information on clinical features of the disease. Giemsa stained blood slides confirmed existence of malaria parasitemia. Chi-square and analysis of variance tests were used, respectively, to compute proportions and means; then a comparison was made between different age groups, periods, and study areas.ResultsDuring the survey of asymptomatic infections among school children, overall blood slide positivity ranged from 6.4% at the epidemic prone site to 38.3% at the hyperendemic site. During the clinical malaria survey, school age children (5-14) presented with overall the highest (45%) blood slide positivity rate among those suspected to have the infection at the epidemic prone study site. The survey of all malaria confirmed and registered cases at OPD found 17% to 27% of all consultations among 0.05) and 40% of all malaria admissions were school age children. Malaria related death rate was highest among

BackgroundIn sub-Saharan Africa, malaria interventions over the last decades have been successful in reducing both mortality and morbidity. In western Kenya however some areas experience contrasting outcomes of the ongoing interventions while the causes for this observation remains not yet clearly known.MethodsThe WHO insecticide (deltamethrin) susceptibility test of the common malaria vectors was studied. Multiple surveys on household use and hospital prescriptions of antimalarial drugs from 2003 to 2015 were done. Along with this, cross sectional surveys on their availability in the local drug dispensing outlets were also done in 2015. Monthly precipitations and air temperature data was collected along with systematic review on abundance and composition of common malaria vectors in the study area before and during interventions. The above factors were used to explain the possible causes of contrasting outcome of malaria interventions between the three study sites.ResultsAreas with malaria resurgence or sustained high transmission (Kombewa and Marani) showed higher composition of Anopheles funestus sensu lato (s.l.) than the previously abundant Anopheles gambiae sensu stricto (s.s.) and the later had higher composition to an area with a sustained infection decline (Iguhu). Anopheles gambiae s.l. from Kombewa showed highest resistance (50% mortality) upon exposure to WHO deltamethrin discriminating dosage of 0.75% while those from Marani and Iguhu had reduced resistance status (both had a mean mortality of 91%). Sampled An. funestus s.l. from Marani were also highly resistant to deltamethrin as 57% of the exposed vectors survived. An increasing of mean air temperature by 2 °C was noted for Marani and Iguhu from 2013 to 2015 and was accompanied by an increased rainfall at Marani. Community drug use and availability in selling outlets along with prescription in hospitals were not linked to the struggling control of the disease.ConclusionsThe malaria vector species composition shift, insecticide resistance and climatic warming were the likely cause of the contrasting outcome of malaria intervention in western Kenya. Surveillance of malaria parasite and vector dynamics along with insecticide resistance and vector biting behaviour monitoring are highly recommended in these areas.

Objective To determine the regional- and district-level newborn prevalence of sickle cell trait and disease, and the prevalence of haemoglobin variants and genetic modifiers of sickle cell disease, in the nine regions of north-western United Republic of Tanzania. Methods We repurposed dried blood spot samples from children (aged 0-24 months) born to mothers living with human immunodeficiency virus (HIV), collected as part of the HIV Early Infant Diagnosis programme, for sickle cell diagnosis. We performed isoelectric focusing to determine whether samples had normal haemoglobin, sickle cell trait, sickle cell disease or a rare haemoglobin variant. We shipped samples diagnosed as disease or variant to Cincinnati Children's Hospital in the United States of America for deoxyribonucleic-acid-based analyses to determine the prevalence of [alpha]-thalassaemia, glucose-6-phosphate dehydrogenase (G6PD) deficiency or fetal haemoglobin genetic modifiers. Findings We analysed a total of 17 200 specimens during February 2017-May 2018. We observed a prevalence of sickle cell trait and disease of 20.3% (3492/17 200) and 1.2% (210/17 200), respectively. District-level trait varied from 8.6% (5/58) to 28.1% (77/274). Among confirmed sickle cell disease specimens, we noted 42.7% (61/143) had 1-gene deletion and 14.7% (21/143) had 2-gene deletion [alpha]-thalassaemia trait. We documented G6PD [A.sup.-] deficiency in 19.2% (14/73) of males. Conclusion Our calculated prevalence is twice as high as previously reported and reinforces the need for enhanced sickle cell diagnostic services. Our district-level data will inform public health policy, allowing screening and disease-modifying hydroxyurea therapy to be focused on high-prevalence areas, until universal newborn screening is available. Objectif Determiner la prevalence de la drepanocytose et du trait drepanocytaire chez les nouveau-nes, ainsi que la prevalence de variants d'hemoglobine et de modificateurs genetiques de la drepanocytose dans les neufregions du nord-ouest de la Republique-Unie de Tanzanie. Methodes Nous avons reutilise des echantillons de gouttes de sang seche provenant d'enfants (ages de 0 a 24 mois) nes de meres atteintes du virus de l'immunodeficience humaine (VIH), preleves dans le cadre du programme de diagnostic precoce de l'infection a VIH chez le nourrisson pour detecter une eventuelle drepanocytose. Nous avons procede a une focalisation isoelectrique pour savoir si les echantillons presentaient une hemoglobine normale, un trait drepanocytaire, une drepanocytose ou un variant d'hemoglobine rare. Ensuite, nous avons envoye les echantillons identifies comme porteurs de la maladie ou d'un variant a l'hopital pour enfants de Cincinnati, aux Etats-Unis, afin d'analyser l'acide desoxyribonucleique et de mesurer la prevalence d'une [alpha]-thalassemie, d'un deficit en glucose-6-phosphate deshydrogenase (G6PD) ou de modificateurs genetiques de l'hemoglobine foetale. Resultats Nous avons etudie 17 200 specimens au total entre fevrier 2017 et mai 2018. Nous avons observe une prevalence de 20,3% (3492/17 200) pour la drepanocytose, et de 1,2% (210/17 200) pour le trait drepanocytaire. D'un district a l'autre, la presence du trait variait de 8,6% (5/58) a 28,1% (77/274). Nous avons constate que 42,7% (61/143) des specimens chez qui une drepanocytose avait ete confirmee etaient prives d'un gene, et 14,7% (21/143) de deux genes du trait [alpha]-thalassemique. Enfin, nous avons repertorie un deficit en G6PD [A.sup.-] chez 19,2% (14/73) des males. Conclusion La prevalence que nous avons calculee est deux fois superieure aux chiffres mentionnes precedemment, et souligne la necessite d'instaurer de meilleurs services de diagnostic de la drepanocytose. Nos donnees reparties par district fourniront des informations en matiere de politique de sante publique, afin que le depistage et le traitement modificateur de la maladie, a base d'hydroxyuree, se concentrent sur les zones de forte prevalence jusqu'a ce qu'un depistage universel des nouveau-nes soit disponible. Objetivo Determinar la prevalence de la enfermedad y del rasgo de las celulas falciformes en los recien nacidos a nivel regional y de distrito, y la prevalencia de las variantes de hemoglobina y de los modificadores geneticos de la drepanocitosis en las nueve regiones del noroeste de la Republica Unida de Tanzania. Metodos Se reutilizaron las muestras de las manchas de sangre seca de los ninos (de 0 a 24 meses de edad) nacidos de madres que padecian el virus de la inmunodeficiencia humana (VIH); estas muestras se obtuvieron a traves del programa de Diagnostico precoz del VIH en ninos para diagnosticar las celulas falciformes. Se aplico la tecnica del enfoque isoelectrico para determinar si las muestras tenian hemoglobina, rasgos de celulas falciformes, drepanocitosis normales o una variante de hemoglobina poco frecuente. Se enviaron muestras diagnosticadas como enfermedad o variante al Hospital Infantil de Cincinnati (Cincinnati Children's Hospital) en los Estados Unidos de America para analizarlas a base de acido desoxirribonucleico y asi determinar la prevalencia de talasemia a, de deficiencia de glucosa-6-fosfato deshidrogenasa (G6PD, por sus siglas en ingles) o de modificadores geneticos de hemoglobina fetal. Resultados Se analizaron un total de 17 200 muestras entre febrero de 2017 y mayo de 2018. Se observo una prevalencia del rasgo de las celulas falciformes y de la drepanocitosis del 20,3 % (3492/17 200) y del 1,2 % (210/17 200), respectivamente. El rasgo a nivel de distrito vario del 8,6 % (5/58) al 28,1 % (77/274). Se observo que en las muestras de drepanocitosis confirmadas, el 42,7 % (61/143) presentaba la eliminacion de un gen y el 14,7 % (21/143) la eliminacion de dos genes en el rasgo de talasemia a. Se registro una deficiencia de G6PD [A.sup.-] en el 19,2 % (14/73) de los varones. Conclusion La prevalencia que se calcula aqui es el doble de la que se notifico anteriormente y refuerza la necesidad de mejorar los servicios para el diagnostico de la drepanocitosis. Estos datos a nivel de distrito contribuiran a la politica de salud publica, ya que permitiran que los cribados y la terapia con hidroxicarbamida que modifica la enfermedad se centren en las zonas de alta prevalencia, hasta que se disponga de un cribado universal de los recien nacidos. [phrase omitted], Introduction Sickle cell disease is an inherited disorder of haemoglobin, caused by a mutation in the [beta]-globin subunit of adult haemoglobin. In classic autosomal recessive fashion, inheritance of one abnormal [...]

Background: Therapeutic efficacy studies (TESs) and detection of molecular markers of drug resistance are recommended by the World Health Organization (WHO) to monitor the efficacy of artemisinin-based combination therapy (ACT). This study assessed the trends of molecular markers of artemisinin resistance and/or reduced susceptibility to lumefantrine using samples collected in TES conducted in Mainland Tanzania from 2016 to 2021. Methods: A total of 2,015 samples were collected during TES of artemether-lumefantrine at eight sentinel sites (in Kigoma, Mbeya, Morogoro, Mtwara, Mwanza, Pwani, Tabora, and Tanga regions) between 2016 and 2021. Photo-induced electron transfer polymerase chain reaction (PET-PCR) was used to confirm presence of malaria parasites before capillary sequencing, which targeted two genes: Plasmodium falciparum kelch 13 propeller domain (k13) and P. falciparum multidrug resistance 1 (pfmdr1). Results: Sequencing success was ≥ 87.8%, and 1,724/1,769 (97.5%) k13 wild-type samples were detected. Thirty-seven (2.1%) samples had synonymous mutations and only eight (0.4%) had non-synonymous mutations in the k13 gene; seven of these were not validated by the WHO as molecular markers of resistance. One sample from Morogoro in 2020 had a k13 R622I mutation, which is a validated marker of artemisinin partial resistance. For pfmdr1, all except two samples carried N86 (wild-type), while mutations at Y184F increased from 33.9% in 2016 to about 60.5% in 2021, and only four samples (0.2%) had D1246Y mutations. pfmdr1 haplotypes were reported in 1,711 samples, with 985 (57.6%) NYD, 720 (42.1%) NFD, and six (0.4%) carrying minor haplotypes (three with NYY, 0.2%; YFD in two, 0.1%; and NFY in one sample, 0.1%). Between 2016 and 2021, NYD decreased from 66.1% to 45.2%, while NFD increased from 38.5% to 54.7%. Conclusion: This is the first report of the R622I (k13 validated mutation) in Tanzania. N86 and D1246 were nearly fixed, while increases in Y184F mutations and NFD haplotype were observed between 2016 and 2021. Despite the reports of artemisinin partial resistance in Rwanda and Uganda, this study did not report any other validated mutations in these study sites in Tanzania apart from R622I suggesting that intensified surveillance is urgently needed to monitor trends of drug resistance markers and their impact on the performance of ACT. [ABSTRACT FROM AUTHOR]

High‐throughput Plasmodium genomic data is increasingly useful in assessing prevalence of clinically important mutations and malaria transmission patterns. Understanding parasite diversity is important for identification of specific human or parasite populations that can be targeted by control programmes, and to monitor the spread of mutations associated with drug resistance. An up‐to‐date understanding of regional parasite population dynamics is also critical to monitor the impact of control efforts. However, this data is largely absent from high‐burden nations in Africa, and to date, no such analysis has been conducted for malaria parasites in Tanzania countrywide. To this end, over 1,000 P. falciparum clinical isolates were collected in 2017 from 13 sites in seven administrative regions across Tanzania, and parasites were genotyped at 1,800 variable positions genome‐wide using molecular inversion probes. Population structure was detectable among Tanzanian P. falciparum parasites, approximately separating parasites from the northern and southern districts and identifying genetically admixed populations in the north. Isolates from nearby districts were more likely to be genetically related compared to parasites sampled from more distant districts. Known drug resistance mutations were seen at increased frequency in northern districts (including two infections carrying pfk13‐R561H), and additional variants with undetermined significance for antimalarial resistance also varied by geography. Malaria Indicator Survey (2017) data corresponded with genetic findings, including average region‐level complexity‐of‐infection and malaria prevalence estimates. The parasite populations identified here provide important information on extant spatial patterns of genetic diversity of Tanzanian parasites, to which future surveys of genetic relatedness can be compared. [ABSTRACT FROM AUTHOR]

Both anemia and sickle cell disease (SCD) are highly prevalent across sub-Saharan Africa, and limited resources exist to diagnose these conditions quickly and accurately. The development of simple, inexpensive, and accurate point-of-care (POC) assays represents an important advance for global hematology, one that could facilitate timely and life-saving medical interventions. In this prospective study, Robust Assays for Point-of-care Identification of Disease (RAPID), we simultaneously evaluated a POC immunoassay (Sickle SCAN™) to diagnose SCD and a first-generation POC color-based assay to detect anemia. Performed at Bugando Medical Center in Mwanza, Tanzania, RAPID tested 752 participants (age 1 day to 20 years) in four busy clinical locations. With minimally trained medical staff, the SCD POC assay diagnosed SCD with 98.1% sensitivity and 91.1% specificity. The hemoglobin POC assay had 83.2% sensitivity and 74.5% specificity for detection of severe anemia (Hb ≤ 7 g/dL). Interobserver agreement was excellent for both POC assays (r = 0.95-0.96). Results for the hemoglobin POC assay have informed the second-generation assay design to be more suitable for low-resource settings. RAPID provides practical feasibility data regarding two novel POC assays for the diagnosis of anemia and SCD in real-world field evaluations and documents the utility and potential impact of these POC assays for sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

Dehydration from diarrhea leads to a loss of vital electrolytes in the body. The prevalence of electrolytes deficiency and its outcomes due to diarrhea among children under five in Mwanza, Tanzania was not clearly known, thus this study was performed to determine this statistic. A cohort study was conducted among 66 children less than five years old suffering from diarrhea attended and admitted to health centers in Mwanza, Tanzania. Vein puncture was performed to obtain peripheral blood, processed, and analyzed for two major electrolytes, Potassium and Sodium. This study was conducted because the loss of vital electrolytes (sodium and potassium) from diarrhea can be fatal if poorly treated. The median age of study participants was 1 year, ranged from 0.6 to 3 years. The prevalence of electrolytes deficiency in the cohort was determined to be 54.5%. Sodium deficiency (Hyponatremia) was the most prevalent (37.9%). After medication and oral rehydration therapy, all of the diarrheagenic children recovered, and those with electrolytes deficiency had their electrolytes balanced. Proper medication with oral rehydration therapy ensures complete recovery from diarrhea and electrolytes balance. [ABSTRACT FROM AUTHOR]