Mosquito Net Coverage and Utilisation for Malaria\ud Control in Tanzania\ud

\ud In recent years malaria parasites have developed resistance to the most commonly used antimalarial drugs in Tanzania, posing a major challenge for its control. This has led to frequent changes of malaria treatment guidelines, more recently to expensive, yet more effective arthemether/lumefantrine. The use of insecticide treated mosquito nets (ITNs) and long lasting nets (LLINs) in Tanzania has increased slowly over the past few years. Despite the introduction of a voucher scheme to the vulnerable groups, the proportion of households with at least an ITN/LLIN in the country has not been able to achieve the Abuja Declaration of 60% net coverage. Statistics available on the utilisation of nets do not provide a good estimate of the coverage, because of the different study design used to collect the information. This survey was carried out in 21 districts of Tanzania to determine the coverage and utilisation of insecticide treated nets to provide baseline information of the net requirement to cover every sleeping bed in the country. Specifically, this study aimed to (i) determine the ITN coverage by and its distribution in the country; and (ii) determine knowledge, attitudes and practice of the householders as regards to malaria prevention and control Twenty one districts (one from each region) of Mainland Tanzania were selected for the survey. Selection of the district was random. In each district, two wards were selected, one urban (within the district capital) and one rural or sub‐urban. Households were selected randomly using a table of random numbers. At household level, the head or any adult who represented the head of household was interviewed. A structured pre‐tested questionnaire was used to collect information on knowledge, attitude and practices in malaria control, with emphasis on mosquito net ownership and utilisation. Of the 9549 targeted households, 9166 (96%) participated in the survey. Majority of the respondents (76.8%) were from rural district.The mean household size was 3.9 persons. On average, children <5 years old accounted for 39.3% of the members of the households. Respondents with no formal education accounted for 15.8‐37.4% of the interviewees. Most of them were from Mkuranga (55%), Kigoma‐Ujiji (44.2%) and Newala (37.9%). High literate rates were observed in Arumeru and Moshi districts. The majority of the respondents knew that the mosquito is the vector of the malaria parasite (92.6‐99.4%) and infection is through a mosquito bite (92.7‐99.8%). The knowledge of respondents on malaria transmission was generally high (94.0‐99.0%). The majority of the respondents (95.2%) considered the use of mosquito nets as the most effective way of malaria prevention. However, of these, only 66.7% said to have actually used nets in their life time. Knowledge on the use of mosquito nets in the control of malaria was highest and lowest in Eastern and Central zones, respectively.\ud Seventy‐seven percent (4457/8933) agreed to have the investigator entry into their houses and verify the\ud number of nets owned. On average, 62.9% (5,785/8933) of the households had at least a mosquito net. Majority of the respondents in Northern (76.5%) and Southern (76.5%) zones owned at least a mosquito net. The lowest mosquito net ownership was observed among respondents in Western Zone (39.6%). District‐wise, net ownership was highest in Lindi (94.5%), Kyela (91.3%) Arumeru (86.1%), Ilala (83.1%)\ud and Nyamagana (80.0%). Ownership of net was very low in Kilolo (34.8%), Kigoma (36.5%) and Musoma Rural (41.3%). Of the households with nets, 74.4% were using nets all year round. A larger proportion of respondents in Kilolo (68.5%), Mpwapwa (51.9%), Songea Rural (49.2%) and Shinyanga Rural (46.3%) were only using the nets during the rainy season. Out of 9,166 households visited, 3,610 (39.3%) had at least one under five child. Of these, in 1,939 (53.7%) of the households the child slept under a mosquito net during the previous night. Use of nets in children <5 years was most common in northern zone (74%); followed by eastern (66.9%) and southern zone (61.1%). Districts with the largest proportion of <5 year children sleeping under a mosquito nets were Lindi (90.0%), Kyela (85.2%), Ilala (83.2%) and Arumeru (78.2%). Only about a quarter (27%) of the children <5% in western zone were sleeping under a mosquito net. Lowest net coverage for <5 year was in Kigoma (22.7%), Kilolo (25%) and Bukoba Rural (31.2%). A total of 5,785 (62.9%) owned at least a mosquito net. Of these, 4,219 and 1,566 were from the rural and urban districts, respectively. More households in the urban districts (73.4%) than rural districts (59.7%) owned at least a mosquito net. Likewise, there were more households (64.9%) in the urban districts with <5years children sleeping under mosquito nets than in the rural districts (50.4%). More households in urban (32.8%) than in rural districts (25.1%) had at least one insecticide treated net. The number of households with mosquito nets enough for all members of the households ranged from 18.9% (in Urambo) to 37.4% (in Hanang). Households with at least 50% or more occupants using mosquito nets ranged from 16.4% (in Urambo) to 42.8% (in Arumeru). Districts with the largest proportion of ≥50% of the household members sleeping under mosquito nets were Arumeru (46.9%) and Lindi (46.7%). In Manyoni and Lindi, 3.1% and 5% of the households were found to have more nets than the number of household occupants. Only 9% (801/9196) of the households had all occupants sleeping under a mosquito net. Kyela district had about a quarter (23.9%) of the households with all occupants sleeping under nets. Only 29% of the households had at least one insecticide treated mosquito nets. All nets in 51.4% of the households surveyed were ITNs. The largest proportion of households with ITN was observed in northern zone (40.2%), with Arumeru (46%) and Hanang (44.1%) districts having the highest ITN coverage. The lowest proportion (15.5%) of households with ITN was found in the Western Zone. Districts which had the lowest ITN coverage were Musoma Rural (12.6%), Kigoma‐Ujiji (13.2%), and Shinyanga Rural (14.4%). On average, 90.7% (8,123/8,953) of the respondents would prefer using ITN than having their house sprayed with long lasting residual insecticide. More households in urban (32.8%) than in rural districts (25.1%) had at least an ITN> A total of 1939 children underfives were sleeping under mosquito net (any type). Of these, 1140 (58.8%) were using insecticide treated nets (ITN). Overall, 31.6% of the underfives slept under an insecticide treated net during the previous night. Highest coverage was reported in Kyela (47.7%), Nyamagana (47.7%) and Arumeru (46.4%). Lowest ITN in underfives was reported in Kigoma‐Ujiji (16.0%), Musoma (17.2%) and Urambo (17.7%). In Songea more underfives children were sleeping under ITN (43.6%) than in untreated nets (40.9%). Control of bedbugs, lice, fleas, mites and cockroaches was the major added advantage of using insecticide treated nets. On average, 30.8% and 19.6% of the respondents mentioned cockroach and bedbug control as the main advantage of using ITN, respectively. The majority (52.9%) preferred blue coloured net (Northern=45.6%; Central=59.2%; Eastern=56.4%; Lake= 54.4%; Southern= 60.3%, Western= 58.5%) and Southern Highlands= 49.1%). Other colour preferences were white (29.6%), green (14.1%), black (2.1%) and pink (1.2%). A strong preference for blue mosquito nets was observed among respondents in Musoma (77.3%) and Newala (75.5%) districts. On the other hand, the weakest preference (24.7%) for blue nets was observed among respondents in Arumeru district. The majority of the respondents (82%) preferred rectangular shaped net. A larger percent (61.8%) the respondents preferred to have the map of Tanzania as a national logo to identify nets distributed in the country. On average, 62.7% and 28.8% of the households in Tanzania own at least one mosquito net (any type) and insecticide treated net, respectively. Tanzania expects that ITN coverage of under fives in 2009, after the Under Five Catch‐up Campaign is complete, to be at least 80%. If this is to be achieved, there is a need for concerted effort in scaling up the distribution and demand for long lasting nets throughout the country. Moreover, the planned use of IRS in malaria control, currently considered unpopular should be accompanied by rigorous community health education to avoid resistance from household members.\u

Improved Income of Nguvu Moja Youth Group Through Ice-Cream Distribution in Sinza Ward, Ubungo District, Dar Es Salaam.

The overall objective of the project was to find out the challenges that the community is facing and resources which are available in the community and later to come up with the project which would improve their income. The project also reviewed the contribution of income generating activity to smallholder livelihoods economically as well as socially and culturally. The project was the result of community needs assessment which was conducted at Sinza Ward. The community needs assessment is the process of encountering the community members asking them what are the most pressing need, voting for prioritization and conducting intervention of the most pressing need of the community. With the limited time available the questionnaire was limited to 10 respondents selected randomly inclusively both gender and age groups. The tools used to gather information included household questionnaires, focus group discussions, interviewing and observation. The project revealed challenges face by youth such as farming skills, how to increase income and starting capital. The project outputs resulted where by 10 group members were trained on marketing of the ice-cream through channel marketing. The implementation of the project was based on community needs assessment which was carried out during the participatory assessment process. This involved understanding of their income generating activities of the community members. The project has been successful in a such way that, the municipality were able to give a loan of fourteen million to ensure the project put in place and all stakeholders in the project and other people involved during the Community Needs Assessment found that the project is worthwhile in improving income of the youth in Sinza ward that before the project were absolutely having no direction and lacks marketing skills of their income generating activity

Increased tolerance of Anopheles gambiae s.s. to chemical insecticides after exposure to agrochemical mixture

Resistance of mosquitoes to insecticides is mainly attributed to their adaptation to insecticide-based vector control interventions. Although pesticides used in agriculture have been frequently mentioned as an additional force driving the selection of resistance, only a few studies were dedicated to validate this hypothesis. The objective of this study was to investigate the effect of exposure of the malaria mosquito, Anopheles gambiae s.s. larvae for 72h to sub-lethal concentrations of the agrochemical mixture (pesticides, herbicides and fungicides). Their subsequent tolerances were measured to deltamethrin (pyrethroid), DDT (organochlorine) and bendiocarb (carbamate) currently used for vector control. The mean LC50 was determined and tolerance ratios for larvae exposed to agrochemical comparatively with unexposed larvae were calculated and expressed as fold increased tolerance. Bioassays revealed a significant increase in larval tolerance to detamethrin (1.83-2.86 fold), DDT (1.31-1.53 fold) and bendiocarb (1.14-1.19 fold) following exposure to 0.1 µM and 1µM agrochemical mixture. The observed increased tolerance in this study is likely to be based on metabolic resistance mechanisms. Overall, this study reveals the potential of agrochemicals to increase the tolerance of mosquito larvae to chemical insecticides

Evidence of Chikungunya but not Dengue Virus Circulating among Febrile Patients during Low Transmission Period in Morogoro Municipality, Tanzania

This research article published by International Journal of TROPICAL DISEASE & Health, 2020Background: There is currently sufficient evidence available indicating that dengue and chikungunya viruses could be among the causes of fever in Tanzania. Overlapping clinical manifestations of chikungunya and dengue with other vector-borne parasitic diseases pose a challenge for medical diagnosis in Tanzania. A virus surveillance study was conducted in Morogoro Municipality which had no reports of outbreaks during high risk of transmission with dengue epidemics in the neighbouring Dar es Salaam. Methodology: The present study was carried out to screen for dengue (DENV) and chikungunya (CHIKV) in sera from patients with fever and malaria-like symptoms on selected health centres in Morogoro municipality (n = 5) during March-May 2018. Three hundred and twelve febrile individuals presenting to the outpatient department were screened for the presence of chikungunya and dengue viruses using Multiplex real-time reverse transcription-polymerase chain reaction. Results: Acute CHIKV infection was confirmed in four (1.28%) cases whereas no acute DENV infection was detected. Acute chikungunya cases were exclusively prevailing amongst female patients aged between 20 and 49 years. Conclusion: Our findings indicate an active circulation of chikungunya virus among febrile patients seeking medical attention in Morogoro Municipality, Tanzania. The improvement of CHIKV case detection and reporting is critical to its control and prevention. Surveillance programmes in monitoring arboviral activities in human populations as well as in mosquitos should be performed to avoid maintenance of CHIKV in mosquitoes that may lead to future outbreaks

How do community health workers institutionalise: an analysis of Brazil's CHW programme

Community health workers (CHWs) are framed as the link between communities and the formal health system. CHWs must establish trusting relationships with the community and with the broader health service. How to find the optimal balance between the various strands of work for CHWs, and how to formalise this, has been the focus of different studies. We performed an extensive documentary analysis of federal legislation in Brazil to understand the institutionalisation of the CHW workforce in Brazil over the last 3 decades. The paper offers three contributions to the literature: the development and application of an analytical framework to consider the institutionalisation process of CHWs; a historical analysis of the professional institutionalisation of CHW in Brazil; and the identification of the paradoxes that such institutionalisation faces: firstly, institutionalisation focused on improving CHW remuneration created difficulties in hiring and paying these professionals; when CHW are incorporated within state bureaucracy they start to lose their autonomy as community agents; and that the effectiveness of CHW programmes depends on the improvement of clinical services in the most deprived areas

Fetal Hemoglobin is Associated with Peripheral Oxygen Saturation in Sickle Cell Disease in Tanzania.

Fetal hemoglobin (HbF) and peripheral hemoglobin oxygen saturation (SpO2) both predict clinical severity in sickle cell disease (SCD), while reticulocytosis is associated with vasculopathy, but there are few data on mechanisms. HbF, SpO2 and routine clinical and laboratory measures were available in a Tanzanian cohort of 1175 SCD individuals aged≥5years and the association with SpO2 (as response variable transformed to a Poisson distribution) was assessed by negative binomial model with age and sex as covariates. Increase in HbF was associated with increased SpO2 (rate ratio, RR=1.19; 95% confidence intervals [CI] 1.04, 1.37 per natural log unit of HbF; p=0.0004). In univariable analysis, SpO2 was inversely associated with age, reticulocyte count, and log (total bilirubin) and directly with pulse, SBP, hemoglobin, and log(HbF). In multivariable regression log(HbF) (RR 1.191; 95%CI 1.04, 1.37; p=0.013), pulse (RR 1.01; 95%CI 1.00, 1.01; p=0.026), SBP (RR 1.008; 95%CI 1.00, 1.02; p=0.014), and hemoglobin (1.120; 95%CI 1.05, 1.19; p=0.001) were positively and independently associated with SpO2 while reticulocyte count (RR 0.985; 95%CI 0.97, 0.99; p=0.019) was independently inversely associated with SpO2. In SCD, improving SpO2, in part through cardiovascular compensation and associated with reduced reticulocytosis, may be a mechanism by which HbF reduces disease severity

Insights from agriculture for the management of insecticide resistance in disease vectors

Key to contemporary management of diseases such as malaria, dengue, and filariasis is control of the insect vectors responsible for transmission. Insecticide-based interventions have contributed to declines in disease burdens in many areas, but this progress could be threatened by the emergence of insecticide resistance in vector populations. Insecticide resistance is likewise a major concern in agriculture, where insect pests can cause substantial yield losses. Here, we explore overlaps between understanding and managing insecticide resistance in agriculture and in public health. We have used the Global Plan for Insecticide Resistance Management in malaria vectors, developed under the auspices of the World Health Organization Global Malaria Program, as a framework for this exploration because it serves as one of the few cohesive documents for managing a global insecticide resistance crisis. Generally, this comparison highlights some fundamental differences between insect control in agriculture and in public health. Moreover, we emphasize that the success of insecticide resistance management strategies is strongly dependent on the biological specifics of each system. We suggest that the biological, operational, and regulatory differences between agriculture and public health limit the wholesale transfer of knowledge and practices from one system to the other. Nonetheless, there are some valuable insights from agriculture that could assist in advancing the existing Global Plan for Insecticide Resistance Management framework

Multiple insecticide resistance in Anopheles gambiae from Tanzania: a major concern for malaria vector control.

BACKGROUND: Malaria vector control in Tanzania is based on use of long-lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS), which both rely on the use of chemical insecticides. The effectiveness of these control tools is endangered by the development of insecticide resistance in the major malaria vectors. This study was carried out to monitor the susceptibility status of major malaria vectors to insecticides used for IRS and LLINs in mainland Tanzania. METHODS: Mosquito larvae were collected in 20 sites of Tanzania mainland in 2015. Phenotypic resistance was determined using standard WHO susceptibility tests. Molecular assay were used to determine distribution of Anopheles gambiae sub-species. A microplate assay approach was used for identifying enzyme levels on single mosquitoes from each sites compared with a susceptible reference strain, An. gambiae sensu stricto (s.s.) Kisumu strain. RESULTS: Anopheles arabiensis was the dominant malaria specie in the country, accounting for 52% of the sibling species identified, while An. gambiae s.s. represented 48%. In Arumeru site, the dominant species was An. arabiensis, which was resistant to both pyrethroids (permethrin and deltamethrin), and pirimiphos-methyl, and had significant elevated levels of GSTs, non-specific esterases, and oxidase enzymes. An. arabiensis was also a dominant species in Kilombero and Kondoa sites, both were resistant to permethrin and deltamethrin with significant activity levels of oxidase enzymes. Resistance to bendiocarb was recorded in Ngara site where specie composition is evenly distributed between An. gambiae s.s. and An.arabiensis. Also bendiocarb resistance was recorded in Mbozi site, where An. gambiae s.s. is the dominant species. CONCLUSIONS: Overall, this study confirmed resistance to all four insecticide classes in An. gambiae sensu lato in selected locations in Tanzania. Results are discussed in relation to resistance mechanisms and the optimization of resistance management strategies