Knowledge and practice regarding dengue and chikungunya: a cross-sectional study among Healthcare workers and community in Northern Tanzania.

OBJECTIVE: To investigate knowledge and prevention practices regarding dengue and chikungunya amongst community members, as well as knowledge, treatment and diagnostic practices among healthcare workers. METHOD: We conducted a cross-sectional survey with 125 community members and 125 healthcare workers from 13 health facilities in six villages in the Hai district of Tanzania. A knowledge score was generated based on participant responses to a structured questionnaire, with a score of 40 or higher (of 80 and 50 total scores for community members and healthcare workers, respectively) indicating good knowledge. We conducted qualitative survey (n = 40) to further assess knowledge and practice regarding dengue and chikungunya fever. RESULTS: 15.2% (n = 19) of community members had good knowledge regarding dengue, whereas 53.6%, (n = 67) of healthcare workers did. 20.3% (n = 16) of participants from lowland areas and 6.5% (n = 3) from highland areas had good knowledge of dengue (χ2 = 4.25, P = 0.03). Only 2.4% (n = 3) of all participants had a good knowledge score for chikungunya. In the qualitative study, community members expressed uncertainty about dengue and chikungunya. Some healthcare workers thought that they were new diseases. CONCLUSION: There is insufficient knowledge regarding dengue and chikungunya fever among community members and healthcare workers. Health promotion activities on these diseases based on Ecological Health Mode components to increase knowledge and improve preventive practices should be developed.

Prevalence of dengue and chikungunya virus infections in north-eastern Tanzania: a cross sectional study among participants presenting with malaria-like symptoms.

BACKGROUND: In spite of increasing reports of dengue and chikungunya activity in Tanzania, limited research has been done to document the general epidemiology of dengue and chikungunya in the country. This study aimed at determining the sero-prevalence and prevalence of acute infections of dengue and chikungunya virus among participants presenting with malaria-like symptoms (fever, headache, rash, vomit, and joint pain) in three communities with distinct ecologies of north-eastern Tanzania. METHODS: Cross sectional studies were conducted among 1100 participants (aged 2-70 years) presenting with malaria-like symptoms at health facilities at Bondo dispensary (Bondo, Tanga), Hai hospital (Hai, Kilimanjaro) and TPC hospital (Lower Moshi). Participants who were malaria negative using rapid diagnostic tests (mRDT) were screened for sero-positivity towards dengue and chikungunya Immunoglobulin G and M (IgG and IgM) using ELISA-based kits. Participants with specific symptoms defined as probable dengue and/or chikungunya by WHO (fever and various combinations of symptoms such as headache, rash, nausea/vomit, and joint pain) were further screened for acute dengue and chikungunya infections by PCR. RESULTS: Out of a total of 1100 participants recruited, 91.2 % (n = 1003) were malaria negative by mRDT. Out of these, few of the participants (<5 %) were dengue IgM or IgG positive. A total of 381 participants had fever out of which 8.7 % (33/381) met the defined criteria for probable dengue, though none (0 %) was confirmed to be acute cases. Chikungunya IgM positives among febrile participants were 12.9 % (49/381) while IgG positives were at 3.7 % (14/381). A total of 74.2 % (283/381) participants met the defined criteria for probable chikungunya and 4.2 % (11/263) were confirmed by PCR to be acute chikungunya cases. Further analyses revealed that headache and joint pain were significantly associated with chikungunya IgM seropositivity. CONCLUSION: In north-eastern Tanzania, mainly chikungunya virus appears to be actively circulating in the population. Continuous surveillance is needed to determine the contribution of viral infections of fever cases. A possible establishment of arboviral vector preventive control measures and better diagnosis of pathogens to avoid over-treatment of other diseases should be considered.

Prevalence and Associated Factors of Dengue Virus Circulation in the Rural Community, Handeni District in Tanga, Tanzania.

Dengue virus is among the most important re-emerging arbovirus that causes global public health attention. Dengue has historically been thought of as an urban disease that frequently occurs in rapidly urbanized settings. However, dengue has become more widespread in rural regions in recent years. Understanding the changing dengue epidemiology in different geographical settings is important for targeted intervention. In Tanzania, dengue fever is not frequently reported because of the poor surveillance infrastructure, underestimation, and a lack of consideration of dengue as a priority. Therefore, the true burden as well as the risk factors for increased transmission has not been fully ascertained, particularly in rural areas. A cross-sectional community-based study was conducted in June 2021, involving a total of 362 participants of all age groups. We investigated the prevalence of acute dengue infection, seroprevalence, and associated factors among the community in three villages of the rural Handeni district. The prevalence of acute dengue infection (based on PCR) was 2.2% (8/362). Dengue-specific IgM and IgG antibodies were detected in 3.3% (12/362) and 5.2% (19/362) of the participants, respectively. Adult participants who were having vegetation around their houses were more likely to be DENV seropositive (AOR = 2.4, CI = 1.88-4.18, p value = 0.05). Children living in houses with garbage pit around their households were less likely to be DENV seropositive (AOR = 0.13, CI = 0.03-0.56, p value <0.01). DENV continues to circulate in rural Tanzania, causes an alarming situation, and necessitates prompt public health action to enhance vector surveillance and control in rural communities.

The Impact of Submicroscopic Parasitemia on Malaria Rapid Diagnosis in Northeastern Tanzania, an Area with Diverse Transmission Patterns.

Global malaria epidemiology has changed in the last decade with a substantial increase in cases and deaths being recorded. Tanzania accounts for about 4% of all cases and deaths reported in recent years. Several factors contribute to the resurgence of malaria, parasite resistance to antimalarials and mosquito resistance to insecticides being at the top of the list. The presence of sub-microscopic infections poses a significant challenge to malaria rapid diagnostic tests (mRDT). Our cross-sectional surveys in Handeni and Moshi, Tanzania assessed the effect of low parasite density on mRDT. Handeni had higher malaria prevalence by mRDT (39.6%), light microscopy (LM) (16.9%) and polymerase chain reaction (PCR) (18.5%), compared to Moshi with prevalence of 0.2%, 1.3% and 2.3%, respectively. A significant difference (p ˂ 0.001) in malaria prevalence by mRDT, LM and nested PCR was found among age groups. In comparison to all other groups, school-age children (5-15 years) had the highest prevalence of malaria. Our results show that mRDT may miss up to 6% of cases of malaria mainly due to low-density parasitemia when compared to LM and PCR. Routinely used mRDT will likely miss the sub-microscopic parasitemia which will ultimately contribute to the spread of malaria and hinder efforts of elimination.

Proportions of Pathogenic Bacteria Isolated from Door Locks and Working Benches in Clinical Laboratory: A Laboratory Based Study.

Background: Numerous studies have revealed the association of the door handle and contamination of pathogenic bacteria. Door handles of clinical and research laboratories have higher chances of contamination with pathogenic bacteria during closing and opening with contaminated gloves on, or sometimes after visiting the toilets without the use of disinfectant materials. There is limited epidemiological data regarding bacteria cross contamination of door locks of the Clinical laboratory at Kilimanjaro Christian Medical Centre. This study aimed at providing the proportions of bacteria contaminating medical laboratory doors. Methods: A cross section laboratory-based study was conducted and it involved collection of swab samples from doors and working benches in the clinical laboratory. Results: Prevalence of Staphylococcus aureus, Escherichia coli, Coagulase Negative Staphylococcus, Bacillus spp., Pseudomonas aeroginosa and coliforms were (26%, 22%, 18%, 8%, 4% and 4% respectively. Conclusion: This study has reported high proportion of pathogenic bacteria. The results entails that, internal and external environments are responsible for laboratory door contamination.

Human IgG responses to Aedes mosquito salivary peptide Nterm-34kDa and its comparison to Anopheles salivary antigen (gSG6-P1) IgG responses measured among individuals living in Lower Moshi, Tanzania.

BACKGROUND: The level of human exposure to arbovirus vectors, the Aedes mosquitoes, is mainly assessed by entomological methods which are labour intensive, difficult to sustain at a large scale and are affected if transmission and exposure levels are low. Alternatively, serological biomarkers which detect levels of human exposure to mosquito bites may complement the existing epidemiologic tools as they seem cost-effective, simple, rapid, and sensitive. This study explored human IgG responses to an Aedes mosquito salivary gland peptide Nterm-34kDa in Lower Moshi, a highland area with evidence of circulating arboviruses and compared the Aedes IgG responses to Anopheles mosquitoes' salivary antigen (GSG6-P1) IgG responses. METHODS: Three cross-sectional surveys were conducted in 2019: during the first dry season in March, at the end of the rainy season in June and during the second dry season in September in five villages located in Lower Moshi. Blood samples were collected from enrolled participants above six months of age (age span: 7 months to 94 years) and analysed for the presence of anti-Nterm-34kDa IgG antibodies. Possible associations between Nterm-34kDa seroprevalence and participants' characteristics were determined. Levels of IgG responses and seroprevalence were correlated and compared to the already measured IgG responses and seroprevalence of Anopheles mosquitoes' salivary antigen, GSG6-P1. RESULTS: During the first dry season, Nterm-34kDa seroprevalence was 34.1% and significantly increased at the end of the rainy season to 45.3% (Chi square (χ2) = 6.42 p = 0.011). During the second dry season, the seroprevalence significantly declined to 26.5% (χ2 = 15.12 p<0.001). During the rainy season, seroprevalence was significantly higher among residents of Oria village (adjusted odds ratio (AOR) = 2.86; 95% CI = 1.0-7.8; p = 0.041) compared to Newland. Moreover, during the rainy season, the risk of exposure was significantly lower among individuals aged between 16 and 30 years (AOR = 0.25; 95% CI = 0.1 = 0.9; p = 0.036) compared to individuals aged between 0 and 5 years. There was weak to moderate negative correlation between N-term 34kDa IgG and gSG6-P1 antigens. N-term 34kDa seroprevalence were higher compared to gSG6-P1 seroprevalence. CONCLUSION: The findings of this study support that IgG antibody responses towards the Aedes mosquito salivary peptide Nterm-34kDa are detectable among individuals living in lower Moshi and vary with season and geographical area. More individuals are exposed to Aedes mosquito bites than Anopheles mosquito and those exposed to Aedes bites are not necessarily exposed to Anopheles mosquitoes.

High Carriage Rate of Extended-Spectrum ß-Lactamase-Producing Escherichia coli and Klebsiella Species among Poultry Meat Vendors in Dar es Salaam: The Urgent Need for Intervention to Prevent the Spread of Multidrug-Resistant Pathogens.

BACKGROUND: Bacteria possessing extended-spectrum beta-lactamase (ESBL), especially E. coli and Klebsiella species, are problematic, particularly in hospitalized patients. Poultry meat vendors are at risk of carrying ESBL-producing bacteria when processing and handling meat products in an unhygienic environment. There is limited information on the carriage rate of ESBL-producing pathogens among poultry meat vendors that necessitated the conduction of the study. METHOD: A cross-sectional study was conducted among poultry meat vendors in Dar es Salaam, Tanzania. Participants provided rectal swabs in transport media upon instruction. The primary isolation of ESBL-producing bacteria was carried out using MacConkey agar supplemented with ceftazidime. Identification of isolates relied on conventional methods. Double-disk synergy was the method used to confirm ESBL-producing isolates. We performed descriptive statistics using Statistical Package for Social Sciences version 23. A p value < 0.05 was considered statistically significant. RESULTS: A total of 300 participants were recruited from five districts, with a mean age of 27.2 ± 6.7 years. The majority was male (67.3%), and 74.7% worked as poultry meat vendors for more than one year. Out of 300 participants, 107 (35.7%) had confirmed ESBL-producing E. coli and Klebsiella spp. The majority of confirmed ESBL-producing isolates was E. coli (78.5%). Participants from Ubungo District had significantly higher carriage of ESBL-producing Escherichia coli and Klebsiella spp. (48.0%, 95% CI: 34.8-47.7) than Temeke District (21.4%, 95% CI: 13.4-32.4). Only 28.0% of participants had access to latrines at the workplace, and all working areas lacked access to running water. CONCLUSION: The study revealed a relatively high fecal carriage rate of ESBL-producing E. coli and Klebsiella spp. among poultry meat vendors. Poor working environments and hygienic practices are risks for spread of these multidrug-resitant pathogens.

Predictive markers of transmission in areas with different malaria endemicity in north-eastern Tanzania based on seroprevalence of antibodies against Plasmodium falciparum.

OBJECTIVE: A community-based cross-sectional study was done to assess Plasmodium falciparum exposure in areas with different malaria endemicity in north-eastern Tanzania using serological markers; PfAMA-1 and PfMSP-119. RESULTS: Bondo had a higher seroprevalence 36.6% (188) for PfAMA-1 as compared to Hai 13.8% (33), χ2 = 34.66, p < 0.01. Likewise, Bondo had a higher seroprevalence 201(36.6%) for PfMSP-1 as compared to Hai 41 (17.2%), χ2 = 29.62, p < 0.01. Anti-PfAMA-1 titters were higher in malaria positive individuals (n = 47) than in malaria negative individuals (n = 741) (p = 0.07). Anti-PfMSP-1 antibody concentrations were significantly higher in malaria-positive individuals (n = 47) than in malaria-negative individuals (n = 741) (p = 0.003). Antibody response against PfAMA-1 was significantly different between the three age groups; < 5 years, 5 to 15 years and > 15 years in both sites of Bondo and Hai. Likewise, antibody response against PfMSP-119 was significantly different between the three age groups in the two sites (p < 0.001). We also found significant differences in the anti-PfAMA-1and anti-PfMSP-119 antibody concentrations among the three age groups in the two sites (p = 0.004 and 0.005) respectively. Immunological indicators of P. falciparum exposure have proven to be useful in explaining long-term changes in the transmission dynamics, especially in low transmission settings.

Adherence, Awareness, Access, and Use of Standard Diagnosis and Treatment Guideline for Malaria Case Management among Healthcare Workers in Meatu, Tanzania.

BACKGROUND: Effective case management is a vital component of malaria control and elimination strategies. However, the level of adherence to the malaria diagnostic test and treatment guideline is not known, particularly at Meatu district. Therefore, this study aimed at determining the adherence, awareness, access, and use of standard diagnosis and treatment guidelines among healthcare workers in Meatu district. METHOD: This was a descriptive cross-sectional study, which enrolled a total of 196 healthcare workers in Meatu district. Healthcare workers were sampled purposively to reach the required sample size. A structured questionnaire was used for data collection. RESULTS: Generally, 189 (96.4%) were aware of malaria treatment guidelines, while 148 (75.5%) had access and 98 (50.0%) used malaria treatment guidelines. One hundred and seven (54.6%) of all the healthcare workers adhered strictly to the diagnosis and national treatment guidelines. Ten (5.1%) partially adhered to the guideline when choosing antimalarials without confirmed malaria cases. Nonadherence to the prescription of recommended antimalarial drugs and laboratory confirmation was 79 (40.3%). CONCLUSION: Half of healthcare worker's adhere to malaria diagnostic test and treatment guidelines. Most the healthcare workers are aware of the malaria diagnostic test and treatment guidelines. Continued education and assessment of the personal attitudes towards malaria diagnostic test and treatment guidelines are recommended.

Factors and Causes of Puerperal Sepsis in Kilimanjaro, Tanzania: A Descriptive Study among Postnatal Women who Attended Kilimanjaro Christian Medical Centre.

BACKGROUND: Puerperal sepsis is the major cause of maternal morbidity and mortality worldwide. About 94% of maternal mortality occur in low and middle-income countries including Tanzania. OBJECTIVE: To estimate the prevalence, document factors and causes of puerperal sepsis among postnatal women who attended postnatal care in Kilimanjaro Christian Medical Centre Hospital in the year 2015. METHODOLOGY: A descriptive cross-sectional study was carried out at Kilimanjaro Christian Medical Centre, Tanzania. A total of 183 medical records of attendance in 2015 were used for the study. Information about the isolated organism in culture was retrieved from the Laboratory Information System. RESULTS: The prevalence of puerperal sepsis was 11.5% (21/183). The most common factors and causes of puerperal sepsis included caesarean section 66.7% (14/21), postpartum haemorrhage 57.1% (12/21), moderate to severe anaemia 61.9% (13/21), prolonged labour 76.2% (16/21) and bacterial infection 90.5% (19/21). The difference was significant at p<.05. The most bacteria species isolated among women with puerperal sepsis was Staphylococcus spp 50.0% (7/14), Escherichia 28.6% (4/14) and Streptococcus spp 21.4% (3/14). CONCLUSION: Puerperal sepsis is prevalent (11.5%) at Kilimanjaro Christian Medical Centre. Staphylococcus spp was found to be a predominant isolate which causes puerperal sepsis followed by E. coli and Streptococcus spp.

Healthcare workers knowledge and diagnostic practices: a need for dengue and chikungunya training in Moshi Municipality, Kilimanjaro Tanzania.

OBJECTIVE: Dengue and chikungunya virus diseases are becoming an increasingly important global health threats and are continuously expanding their geographical range. The study aims to investigate knowledge and diagnostic practice of dengue and chikungunya fever among healthcare workers in Moshi Municipality. RESULTS: Most of healthcare workers heard of chikungunya and dengue 146 (71.2%) and 203 (99%) respectively. Ninety-five (46.3%) and 152 (74.1%) had good knowledge regard chikungunya and dengue respectively. One hundred and twenty-two of HCWs 122 (59.5%) reported that there is no vaccination for dengue virus. Most HCWs 199 (97.0%) reported that the absence of diagnostic tool for dengue virus lead to difficult in managing the infection. The finding of this study showed that there is insufficient knowledge regarding chikungunya while knowledge regarding dengue is relatively fair. This calls for training regarding these infections.

Prevalence and causes of blood donor deferrals among clients presenting for blood donation in northern Tanzania.

INTRODUCTION: Blood is an important requirement in different medical and surgical conditions with half of all donations are from developing countries. Lack of eligibility among blood donors who present for blood transfusion, called blood donor deferral is associated with the unsustainable and inadequate amount of blood collected by blood banks worldwide. However, the prevalence and causes of blood donor deferrals are not well known in Tanzania where less than one-third of actual needs of blood is collected, leading to unmet demand of blood for transfusion, and causing unwanted morbidity and mortality. MATERIALS AND METHODS: This was a retrospective analysis of blood donors at northern zone blood transfusion center, Tanzania from January to December. 2016. Donor's data were transferred to Statistical Package for Social Studies (SPSS) program version 20.0 for analysis. Descriptive statistics was used to summarize data and comparisons made by type of donor and deferrals using Chi-square test. RESULTS: A total of 14377 participants were studied whereby 12775 (88.9%) were voluntary non-remunerated blood donors. The blood donor deferral rate was 12.7% and deferral was significantly more likely in females, with increasing age above 31 years, who came from nearby regions from where the blood bank is located and/or a family replacement donor (P value <0.01). Overall, infections contributed to 62% of all deferrals and low hemoglobin was the leading cause of temporary deferrals while Hepatitis B lead the permanent deferral causes. CONCLUSIONS: Blood donor deferral is a significant problem in northern Tanzania and accounts for more than one-tenth of all prospective blood donors. Latent and active infections are the leading cause of blood donor deferrals, a picture that mirrors other low income countries especially those located in sub-Saharan Africa. Results of this study calls for appropriate preventive interventions to address prevalent causes of deferrals such as infections with HIV and HBV to tackle low hemoglobin.

Cross-sectional Survey on Antibiotic Prescription Practices Among Health Care Providers in Rombo District, Northern Tanzania.

BACKGROUND: Irrational and inappropriate antibiotic prescription is a worldwide phenomenon - increasing the threat of serious antibiotic resistance. A better understanding of health care providers' knowledge, attitudes, and prescription practices related to antibiotics is essential for formulating effective antibiotics stewardship programmes. The aim of the present study was to assess knowledge, attitudes, and prescription practices toward antibiotics among health care providers. METHODS: A descriptive cross-sectional study was conducted between March and June 2017 to assess knowledge, attitudes, and prescription practices toward antibiotics among health care providers in the Rombo district of northern Tanzania. A total of 217 health care providers were interviewed using a structured questionnaire. RESULTS: Over half of health care providers (n=111, 51.2%) strongly agreed that the inappropriate prescription of antibiotics puts patients at risk. More than half (n=112, 51.6%) reported that their decision to start antibiotic therapy was influenced by a patient's clinical condition, while 110 (50.7%) reported they were influenced by positive microbiological results in symptomatic patients. Almost two-thirds of the health care providers (n=136, 62.7%) reported that they had access to and used antibiotic therapy guidelines. Less than a quarter (n=52, 24.0%) received regular training and education in antibiotic prescription practice in their work place. CONCLUSION: Knowledge and prescription practice of antibiotics among health care providers was generally unsatisfactory. Training and education for health care providers is needed in the area of prescribing antibiotics.

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.

Principal component analysis of socioeconomic factors and their association with malaria and arbovirus risk in Tanzania: a sensitivity analysis.

Principal component analysis (PCA) is frequently adopted for creating socioeconomic proxies in order to investigate the independent effects of wealth on disease status. The guidelines and methods for the creation of these proxies are well described and validated. The Demographic and Health Survey, World Health Survey and the Living Standards Measurement Survey are examples of large data sets that use PCA to create wealth indices particularly in low and middle-income countries (LMIC), where quantifying wealth-disease associations is problematic due to the unavailability of reliable income and expenditure data. However, the application of this method to smaller survey data sets, especially in rural LMIC settings, is less rigorously studied.In this paper, we aimed to highlight some of these issues by investigating the association of derived wealth indices using PCA on risk of vector-borne disease infection in Tanzania focusing on malaria and key arboviruses (ie, dengue and chikungunya). We demonstrated that indices consisting of subsets of socioeconomic indicators provided the least methodologically flawed representations of household wealth compared with an index that combined all socioeconomic variables. These results suggest that the choice of the socioeconomic indicators included in a wealth proxy can influence the relative position of households in the overall wealth hierarchy, and subsequently the strength of disease associations. This can, therefore, influence future resource planning activities and should be considered among investigators who use a PCA-derived wealth index based on community-level survey data to influence programme or policy decisions in rural LMIC settings.

Spectrum and antibiogram of bacteria isolated from patients presenting with infected wounds in a Tertiary Hospital, northern Tanzania.

OBJECTIVE: This study aimed to determine the spectrum and antibiogram of the isolated bacteria from patients presenting with infected wounds at Kilimanjaro Christian Medical Centre in northern Tanzania. RESULTS: Bacterial growth was observed in the vast majority of wound swabs (91.4%). Most of the bacteria isolated (62.3%) were Gram-negative rods. Staphylococcus aureus was the most common isolated organism (16%) followed by other Coliforms and Enterococcus spp. (12.5% each). Enterococcus spp. (36.4%) was the most common isolated bacteria in diabetic wounds whereas S. aureus was the most common isolated bacteria from the wounds caused by trauma (40.0%) and surgical site infection (20.6%). Resistance was high to most common antibiotics used in the hospital.

10 Years of Environmental Change on the Slopes of Mount Kilimanjaro and Its Associated Shift in Malaria Vector Distributions.

INTRODUCTION: Malaria prevalence has declined in the Kilimanjaro region of Tanzania over the past 10 years, particularly at lower altitudes. While this decline has been related to the scale-up of long-lasting insecticidal nets to achieve universal coverage targets, it has also been attributed to changes in environmental factors that are important for enabling and sustaining malaria transmission. OBJECTIVES: Herein, we apply spatial analytical approaches to investigate the impact of environmental and demographic changes, including changes in temperature, precipitation, land cover, and population density, on the range of the major malaria vector species Anopheles arabiensis in two districts of Tanzania, situated on the southern slope of Mount Kilimanjaro. These models are used to identify environmental changes that have occurred over a 10-year period and highlight the implications for malaria transmission in this highland region. METHODS: Entomological data were collected from the Hai and Lower Moshi districts of Tanzania in 2001-2004 and 2014-2015. Vector occurrence data were applied alongside satellite remote sensing indices of climate and land cover, and gridded population data, to develop species distribution models for An. arabiensis for the 2004 and 2014 periods using maximum entropy. Models were compared to assess the relative contribution of different environmental and demographic factors to observed trends in vector species distribution in lowland and highland areas. RESULTS: Changes in land cover were observed in addition to increased population densities, increased warm season temperature, and decreased wetness at low altitudes. The predicted area and extent of suitable habitat for An. arabiensis declined across the study area over the 10-year period, with notable contraction at lower altitudes, while species range in higher altitude zones expanded. Importantly, deforestation and warmer temperatures at higher altitudes may have created stable areas of suitable vector habitat in the highlands capable of sustaining malaria transmission. CONCLUSION: We show that environmental changes have had an important influence on the distribution of malaria vector species in a highland area of northern Tanzania. Highland areas may be at continued risk for sporadic malaria outbreaks despite the overall range contraction of principal vector species at lower altitudes, where malaria transmission remains at low intensity.

Occurrence of pfatpase6 Single Nucleotide Polymorphisms Associated with Artemisinin Resistance among Field Isolates of Plasmodium falciparum in North-Eastern Tanzania.

We aimed to determine the current prevalence of four P. falciparum candidate artemisinin resistance biomarkers L263E, E431K, A623E, and S769N in the pfatpase6 gene in a high transmission area in Tanzania in a retrospective cross sectional study using 154 archived samples collected from three previous malaria studies in 2010, 2011 and 2013. Mutations in pfatpase6 gene were detected in parasite DNA isolated from Dried Blood Spots by using PCR-RFLP. We observed overall allelic frequencies for L263E, E431K, A623E, and S769N to be 5.8% (9/154), 16.2% (25/154), 0.0% (0/154), and 3.9% (6/154). The L263E mutation was not detected in 2010 but occurred at 3.9% and 2.6% in 2011 and 2013 respectively. The L263E mutation showed a significant change of frequency between 2010 and 2011, but not between 2011 and 2013 (P < 0.05). Frequency of E431K was highest of all without any clear trend whereas S769N increased from 2.2% in 2010 to 3.6% in 2011 and 5.1% in 2013. A623E mutation was not detected. The worrisome detection and the increase in the frequency of S769N and other mutations calls for urgent assessment of temporal changes of known artemisinin biomarkers in association with in vivo ACT efficacy.