Adult Anopheles Mosquito Distribution at a Low and High Malaria Transmission Site in Tanzania.

Malaria parasites are only transmitted by female mosquitoes of the genus Anopheles; hence, the disease's distribution is linked to that of the vector mosquitoes. As such, the goal of this study was to find out the spatial and temporal distribution of Anopheles mosquito adults in the research sites. This was a repeated cross-sectional ecological study that took place in Morogoro and Dodoma, Tanzania. Vacuum aspiration was used to collect mosquitoes both outside and inside human dwellings. All mosquito-related data was collected and entered into appropriate data collection forms. Female mosquitoes were recognized morphologically using Gillies and Coetzee morphological criteria, followed by PCR. In total, about 2742 Anopheles mosquitoes with an average collection of 18.21 ± 1.12 per day were collected outside human houses of which 1717 (10.51 ± 1.17) and 1025 (8.42 ± 1.41) were collected from Morogoro and Dodoma, respectively. Of the captured mosquitoes, 89.0%, 10.0%, and 1.0% were recognized as Anopheles arabiensis, Anopheles gambiae s.s., and Anopheles quadrianulatus, respectively. The distribution varied significantly with seasons, whereby 302 (4.72 ± 1.04) and 2440 (12.96 ± 1.52) mosquitoes were captured in the cold-dry and warm-wet season, respectively (p < 0.0001). Of the captured mosquitoes, 42.33%, 16.33%, 14.96%, and 4.27 were found on the ceiling, stored junks, verandas, and barks/tree, respectively. In malaria-endemic countries, vector control forms an important component of the malaria control efforts. This study found significant variation of Anopheles mosquito abundance in time and space with Anopheles arabiensis being the most predominant malaria vector. This signifies the need to introduce mosquito control methods that will target the less anthropophilic Anopheles arabiensis or the immature aquatic stages. The study further found that underbeds, store room/piled bags, and undisturbed curtains were the most preferred resting places by mosquitoes signifying to be the most effective strategic sites for spraying insecticides during the implementation of indoor residual spraying (IRS).

The Role of Community Participation in Planning and Executing Malaria Interventions: Experience from Implementation of Biolarviciding for Malaria Vector Control in Southern Tanzania.

Background: Malaria remains a disease of great public health importance in 85 countries globally. Developing countries face resource constraints in implementing public health interventions aiming at controlling malaria. Promoting community participation may contribute to rational and effective use of resources and therefore facilitating achievement of intervention goals in a cost-effective manner while fostering sustainability. However, this can be possible if the community is engaged at all stages of the intervention, from designing, implementation, monitoring, and evaluation of results. This study aimed at understanding community participation in the implementation of a biolarviciding intervention for malaria vectors control in Southern Tanzania. Methods: The current study adopted explanatory mixed method study design in collecting data. Quantitative data were collected from 400 community members and 12 vector control coordinators using structured questionnaire while qualitative data was collected through key informant interviews to 32 participants and in-depth interviews to 5 vector control coordinators who were purposively selected from the 12 councils. Quantitative data analysis involved descriptive and inferential statistics. Thematic analysis was used to analyse qualitative data. Results: Of 400 community members, only 90 (22.5%) participated in biolarviciding implementation. Predictors of community participation were willingness to participate (AOR = 3.15, 95%CI = 1.14 - 8.71, P value = 0.027) and community involvement (AOR = 6.07, 95%CI = 2.69 - 13.71, P value < 0.001). The study revealed that the main barriers to community participation were lack of effective involvement and lack of incentive to community volunteers while high willingness to participate was a facilitating factor for community participation. Conclusion: The study revealed low community participation in biolarviciding implementation in Southern Tanzania with willingness to participate and community involvement being the main predictors for community participation while lack of incentive to community volunteers was one major barrier to community participation. This explains the persistence of an unresolved challenge of community participation in malaria interventions. Therefore, more efforts are needed to improve the participation of community members in Malaria interventions through advocacy, awareness creation of respective roles, and responsibilities of the community members and fostering community ownership. Additionally, councils need to design customized motivation package for the community members.

Biolarviciding implementation in southern Tanzania: Scalability opportunities and challenges.

BACKGROUND: The resistance to insecticides among malaria vectors poses a global challenge in the efforts towards malaria elimination. This calls for an addition of larval control methods such as biolarviciding. However, the implementation of biolarviciding in Tanzania has been very low. Therefore, this study explored factors affecting the implementation of biolarviciding in the councils of Southern Tanzania. METHODS: A mixed method descriptive qualitative, cross-sectional study design was used to collect data from 32 community leaders through key informant interviews and 12 Vectors Control Coordinators through in-depth interviews and questionnaire interviews and document review of implementation reports in 12 councils. Data were analysed using ATLAS.ti version 8, where content analysis was performed and SPSS for the quantitative data. RESULTS: The study found low implementation of biolarviciding intervention in 9 out of 12 (75%) surveyed councils. All Vector Control Coordinators reported a shortage of at least one type of resources: funds, trained personnel, transport, supply of biolarvicide, and equipment; low community involvement (50%) and low level of community participation 83.3% (10/12). CONCLUSION: This study highlights resource inadequacy and low community participation as main barriers to the implementation of biolarviciding. Availing adequate resources and strengthening community participation through involvement in all stages of implementation is crucial for successful and sustainable implementation.

Biolarviciding for malaria vector control: Acceptance and associated factors in southern Tanzania.

In the struggle towards malaria elimination, the government of Tanzania scaled up nationwide biolarviciding to supplement existing vector control measures. As with any community-based intervention, success of biolarviciding depends on acceptability to the community. This study sought to ascertain acceptance of biolarviciding among communities in southern Tanzania. A mixed-method study involved administration of questionnaires to 400 community members, with 32 key informant interviews and five in-depth interviews also held in selected councils of southern Tanzania. A multistage sampling method was employed in selecting community members, with purposive sampling used in selecting key informant and in-depth interviewees. The study found high community acceptance (80.3%) despite very low (19.3%) knowledge on biolarviciding. Community perception that biolarvicide is effective in reducing malaria infection was found to be a significant predictor of community acceptance to biolarviciding: those who perceived biolarvicide as effective in reducing malaria were five times more likely to accept biolarviciding compared to those with a negative perception (odds ratio = 4.67, 95% CI: 1.89-11.50, P = 0.001). We conclude that biolarviciding received high acceptance among community members in southern Tanzania and therefore the implementation is likely to get strong support from community members. To enhance and make community acceptance sustainable, heath education to enhance the level of community knowledge on biolarviciding is recommended.

Prevalence, Intensity, and Factors Associated with Urogenital Schistosomiasis among Women of Reproductive Age in Mbogwe District Council, Geita Region, Tanzania.

BACKGROUND: Urogenital schistosomiasis remains a public health problem in Tanzania. Control programs mostly target school-going children ignoring other vulnerable groups like women of child bearing age. Previous evidence has shown that women of reproductive age suffer greatest morbidities in endemic areas. This study sought to determine the prevalence, intensity, and factors associated with urogenital schistosomiasis among women of reproductive age in the Mbogwe District. METHODS: A population-based analytical cross-section study was conducted in the Mbogwe District. A semistructured questionnaire was administered. Urine samples of 20-30 mils collected between 10.00 am to 02.00 pm and examined for Schistosoma eggs and infection intensity microscopically. Data analysis was done using SPSS version 20. RESULTS: A total of 426 women of reproductive age, with median age of 26, and interquartile range of 11years were recruited and assessed. The prevalence of urogenital schistosomiasis was 4.5% and mean egg intensity of 19.5eggs/10mil of urine. After adjusting for confounders, lower level of education was associated with an increased risk of urogenital schistosomiasis infections (AOR 8.355, 95% CI 3.055-23.001). CONCLUSION: Urogenital schistosomiasis among women of reproductive age in the Mbogwe District is a problem. Education is the factor associated with the disease; the neglected tropical disease control program should develop strategies that should include provision of health education and should involve women of reproductive age as they act as infection reservoir. More studies are recommended to explore the possibility of reproductive complications among infected women in endemic areas.

Spatial and temporal distribution of Anopheles mosquito's larvae and its determinants in two urban sites in Tanzania with different malaria transmission levels.

BACKGROUND: In order to be able to design and implement control measures directed to the mosquito larva stages an understanding of the spatial and temporal distribution and its determinants in different malaria transmission settings is important. This study therefore, intended to determine the spatial and temporal distribution of Anopheles mosquito's larvae and its determinants in two urban sites with different transmission levels, in Tanzania. METHODOLOGY: This study was conducted in Dodoma and Morogoro regions in Tanzania. The study was an ecological study of repeated cross-sectional type. Searching for water bodies in the selected wards was done by going around all streets. Potential breeding sites were given unique identification numbers and larval sampling was done using the standard dipping method with a 350 ml mosquito scoop and a calibrated pipette. Visual identification of presence of larvae and its abundance in each sampling were used to describe the larvae density. A sample of Anopheles mosquitoes which emerged from collected larvae, were processed for species identification using PCR. Descriptive statistics were arrived at by calculating different proportions for the variables. The overall impact of the variables on the density of Anopheles larvae was tested using multiple logistic regression. Variables with p-value less than 0.05 were regarded as significant. RESULTS: A total of 724 water bodies out of which, 576 (79.6%) potential breeding sites were analyzed. It was found that, most (96.2%) of the potential breeding sites were manmade and most (59.5%) were less than 5 m in diameter and 87.2% were within 100 m from human settlement. Out of all the potential breeding sites, 69.8% and 30.2% were in Morogoro and Dodoma respectively, out of which 72.2% and 68.4% respectively, were found during rainy season. Habitats with clean water, at a distance of 10-100 m from the house, in natural, shaded and partial sunlight habitats had higher odds of having high density of mosquito larvae than their counterparts (p < .05). The PCR analysis showed that 72.5% were An. arabiensis, 4.5% An. gambiaes.s, 0.5% An.coustaniand 20% An. quadrianulatuswhile 2.5% of the samples could not be identified because DNA was not amplified. CONCLUSION AND RECOMMENDATION: Type of water, distance from the breeding site to human settlement, light intensity and habitat origin were significant predictors of variation on the spatial and temporal distribution of Anopheles mosquito breeding sites. With increased global emphasis on control measures that targets mosquito immature stages; we recommend that larval control measures should be developed while considering the findings from this study.

Knowledge, attitude and practice towards malaria among symptomatic patients attending Tumbi Referral Hospital: A cross-sectional study.

BACKGROUND: Despite significant improvement in prevention and control over the past decades malaria remains a significant public health concern in Tanzania with 93% of the population being at risk. To prevent malaria infection and promote malaria free zones, understanding the community's knowledge, attitudes, and practices toward malaria control are essential. This study therefore aimed at determining the levels of understanding, and attitudes, as well as socio-cultural aspects of malaria prevention and treatment-seeking behaviours among suspected malaria patients. METHODS: This study was a hospital based cross-sectional study, in which patients attending Tumbi Referral Hospital with symptoms and signs that warrant inclusion of suspicion of malaria, were recruited. We used a pre-tested semi-structured questionnaire to collect participants' demographic characteristics, as well as information on their knowledge, attitudes, and practices towards malaria infection. Data were analysed using Stata Version 12.1. RESULTS: We enrolled a total of 295 respondents of which 179 (60.68%) were females. Participants' ages ranged from 1-91 years, with a mean of 31.4 years. Seventy-nine (26.8%) patients reported having malaria in the previous 28 days, with 57 (72.2%) being laboratory confirmed. Only 52 (65.8%) individuals reported taking prescribed medications for malaria. A total of 277 (93.90%) were aware of malaria, and 264 (95.31%) knew that it is transmitted by mosquito. Nearly all participants (263, 94.95%), identified sleeping under bed nets to be protective against malaria. About half of the respondents either agreed 63 (22.74%) or strongly agreed 62 (22.38%) that malaria can be transmitted like the common cold. Self-reported mosquito net use was 88.09% (244). CONCLUSION: Despite the endemicity of malaria in our study site, patients had adequate knowledge, encouraging attitudes, and good practices related to malaria prevention and control.

Geographical and behavioral risks associated with Schistosoma haematobium infection in an area of complex transmission.

BACKGROUND: Schistosoma haematobium infection in endemic areas varies depending on the nature and complexity of the transmission networks present. Studies of micro-geographical transmission of S. haematobium infection indicate that discrepancy in prevalence between households is associated with diverse water contact behaviors and transmission that is restricted to particular sites harboring snail intermediate hosts. Detection of variations in the transmission sources with complex transmission networks of water bodies is required for optimization of malacological control. Longitudinal parasitological and malacological surveys were conducted to investigate geographical variations in transmission of urogenital schistosomiasis in Ikingwamanoti village, Shinyanga District, Tanzania. METHODS: Urine samples were collected at baseline and follow-up time points from 282 school-aged children and examined microscopically for the presence of S. haematobium eggs. Malacological surveys involved collection of Bulinus nasutus every month from 30 sites. Snails were examined for patent infections. Global positioning system was used to map household distances from S. haematobium transmission sites, while water contact behavior was assessed using a questionnaire. RESULTS: Schistosoma haematobium infection was observed to be prevalent among older children (12-14 years) compared to younger groups prior to treatment, but no significant difference in infection prevalence was observed at one-year. Boys were highly infected than girls at both time points. No spatial influence was observed between children's infection and the distance from child's residence to the nearby snail habitats nor was any significant association observed between children's reported water contact behavior with S. haematobium infection. However, malacological surveys with cercarial shedding combined with GPS data detected significant variation among different water sources in the transmission of S. haematobium with children living in households near to ponds with high B. nasutus populations having the highest prevalence of infection. CONCLUSIONS: Interaction between malacological surveys with cercarial shedding combined with GPS mapping in endemic settings can help detection of transmission sources even in areas with complex transmission networks. Subsequent studies are needed to determine whether the combination of GPS mapping and parasitology screens can aid the detection of transmission hotspots across varied transmission settings to enhance schistosomiasis control programmes.

Schistosoma mansoni Infections, Undernutrition and Anaemia among Primary Schoolchildren in Two Onshore Villages in Rorya District, North-Western Tanzania.

BACKGROUND: Undernutrition and anaemia remains to be a major public health problem in many developing countries, where they mostly affect children. Intestinal parasitic infections are known to affect both growth and haemoglobin levels. Much has been reported on the impact of geohelminths on anaemia and undernutrition, leaving that of Schistosoma mansoni not well studied. Therefore this study intended to determine the association between S.mansoni infections, anaemia and undernutrition among schoolchildren in Rorya district, Northwestern Tanzania. METHODOLOGY: A cross-sectional study was carried among schoolchildren in two onshore villages namely Busanga and Kibuyi in Rorya district. Single stool specimens were collected from 513 randomly selected schoolchildren and processed for microscopic examination using the Kato-Katz method. Nutritional status was determined by anthropometry. Blood samples were also collected and examined for malaria parasites and haemoglobin levels using the Giemsa stain and HaemoCue methods, respectively. A pretested questionnaire was used to collect socio-demographic data and associated factors. RESULTS: The prevalence of S. mansoni infection and malaria was 84.02% and 9.16%, respectively. Other parasites found were Ascaris lumbricoides (1.36%) and Hookworm (1.36%). The prevalence of stunting and wasting was 38.21% and 14.42%, respectively. The prevalence of anaemia was 29.43%, whereby 0.58% had severe anaemia. S. mansoni infection was not found to be associated with undernutrition or anaemia (p>0.05). The risk of stunting and wasting increased with increasing age (p<0.001). Anaemia was associated with age, sex and village of residence (p<0.05). CONCLUSIONS: S.mansoni, undernutrition and anaemia are highly prevalent in the study area. The observed rates of undernutrition and anaemia were seen not to be associated with S.mansoni infection suggesting possibly being a result of poor dietary nutrients. This study suggests that policy makers should consider Rorya district for inclusion into national schistosomiasis control and school feeding programmes.