Jasper Ijumba - Academia.edu (original) (raw)

Papers by Jasper Ijumba

Medical and Veterinary Entomology, Mar 1, 2002

Malaria vector Anopheles and other mosquitoes (Diptera: Culicidae) were monitored for 12 months d... more Malaria vector Anopheles and other mosquitoes (Diptera: Culicidae) were monitored for 12 months during 1994±95 in villages of Lower Moshi irrigation area (37 20 H E, 3 21 H S; $700 m a.s.l.) south of Mount Kilimanjaro in northern Tanzania. Adult mosquito populations were sampled fortnightly by five methods: human bait collection indoors (18.00±06.00 hours) and outdoors (18.00±24.00 hours); from daytime resting-sites indoors and outdoors; by CDC light-traps over sleepers. Anopheles densities and rates of survival, anthropophily and malaria infection were compared between three villages representing different agro-ecosystems: irrigated sugarcane plantation; smallholder rice irrigation scheme, and savannah with subsistence crops. Respective study villages were Mvuleni (population 2200), Chekereni (population 3200) and Kisangasangeni (population 91000), at least 7 km apart.

International Journal of Ecosystem, 2014

In Tropical regions, bio-monitoring indices for assessing pollution in streams and rivers are not... more In Tropical regions, bio-monitoring indices for assessing pollution in streams and rivers are not yet in place. As a result, indices that have been developed inconsistently in different non-tropical regions using their local macro-invertebrate species are adopted and used for assessing pollution in tropical rivers. In Africa, only one review on existing non-tropical bio-monitoring indices to assess river quality in southern Africa was previously reported in conjunction with comparisons with those developed in United States of America, Asia, Australia, Canada, and European countries. However, a comprehensive overview of the complete body of bio-monitoring applications of these indices to streams and rivers in tropical African countries, particularly East and Central Africa was not addressed. Similarly, comparisons of the different sampling techniques, taxonomic resolutions and sensitivity of bio-indicators' species that were used in different studies to develop the existing indices were not covered in that review. In that regard, this review work has highlighted the geographical compatibility, effectiveness, and capability of existing non-tropical bio-monitoring indices to assess pollution in tropical African rivers, in a view of improving bio-monitoring programmes. The need for tropical African regions to have or develop their own bio-monitoring index that will be more reliable than adopting indices from other geographical areas (i.e., non-tropical regions) is a supreme.

Parasites & Vectors, 2015

Background: The type of sprayable surface impacts on residual efficacy of insecticide used in ind... more Background: The type of sprayable surface impacts on residual efficacy of insecticide used in indoor residual spraying (IRS). However, there is limited data on common types of wall surfaces sprayed in Zanzibar and mainland Tanzania where IRS began in 2006 and 2007 respectively. The study investigated residual efficacy of micro-encapsulated lambda-cyhalothrin sprayed on common surfaces of human dwellings and domestic animal shelters in Zanzibar and mainland Tanzania. Methods: An experimental hut was constructed with different types of materials simulating common sprayable surfaces in Zanzibar and mainland Tanzania. Surfaces included cement plastered wall, mud-daub, white-wash, wood, palm-thatch, galvanized iron-sheets, burnt-bricks, limestone and oil-paint. The World Health Organization (WHO) procedure for IRS was used to spray lambda-cyhalothrin on surfaces at the dose of 20-25 mg/m 2 . Residual efficacy of insecticide was monitored through cone bioassay using laboratory-reared mosquitoes; Kisumu strain (R-70) of Anopheles gambiae ss. Cone bioassay was done every fortnight for a period of 152 days. The WHO Pesticide Evaluation Scheme (WHOPES) threshold (80% mortality) was used as cut-off point for acceptable residual efficacy. Results: A total of 5,800 mosquitoes were subjected to contact cone bioassay to test residual efficacy of lambda-cyhalothrin. There was a statistically significant variation in residual efficacy between the different types of wall surfaces (r = 0.24; p < 0.001). Residual efficacy decreased with increasing pH of the substrate (r = −0.5; p < 0.001). Based on WHOPES standards, shorter residual efficacy (42-56 days) was found in wall substrates made of cement, limestone, mud-daub, oil paint and white wash. Burnt bricks retained the residual efficacy up to 134 days while galvanized iron sheets, palm thatch and wood retained the recommended residual efficacy beyond 152 days. Conclusion: The study revealed a wide variation in residual efficacy of micro encapsulated formulation of lambda-cyhalothrin across the different types of wall surfaces studied. In areas where malaria transmission is bimodal and wall surfaces with short residual efficacy comprise > 20% of sprayable structures, two rounds of IRS using lambda-cyhalothrin should be considered. Further studies are required to investigate the impact of sprayable surfaces on residual efficacy of other insecticides commonly used for IRS in Zanzibar and mainland Tanzania.

Malaria journal, 2006

Integrated vector management (IVM) for malaria control requires ecological skills that are very s... more Integrated vector management (IVM) for malaria control requires ecological skills that are very scarce and rarely applied in Africa today. Partnerships between communities and academic ecologists can address this capacity deficit, modernize the evidence base for such approaches and enable future scale up. Community-based IVM programmes were initiated in two contrasting settings. On Rusinga Island, Western Kenya, community outreach to a marginalized rural community was achieved by University of Nairobi through a community-based organization. In Dar es Salaam, Tanzania, Ilala Municipality established an IVM programme at grassroots level, which was subsequently upgraded and expanded into a pilot scale Urban Malaria Control Programme with support from national academic institutes. Both programmes now access relevant expertise, funding and policy makers while the academic partners benefit from direct experience of community-based implementation and operational research opportunities. The...

The American journal of tropical medicine and hygiene, 2004

Africa bears more than 90% of the entire global malaria disease burden. Surprisingly, even with t... more Africa bears more than 90% of the entire global malaria disease burden. Surprisingly, even with the current renewed interest in malaria prevention and control and the enabling environment resulting from the Roll Back Malaria initiative and the political commitment made by the African Presidents at the Abuja Summit, there are still no significant initiatives for strengthening capacity for malaria control through training within the African continent itself. The Center for Enhancement of Effective Malaria Interventions (CEEMI) has been established in Dar es Salaam, Tanzania for results-oriented training. It is intended to provide the needed skills for identifying and solving malaria control problems and providing incentives to malaria control workers in their work performance. The intention is to produce implementers with leadership skills for planning and managing malaria control activities and who can use strategic thinking in improving their work performance. To sustain political c...

Phytopathology, 2015

Cassava brown streak disease (CBSD) is currently the most significant virus disease phenomenon af... more Cassava brown streak disease (CBSD) is currently the most significant virus disease phenomenon affecting African agriculture. In this study, we report results from the most extensive set of field data so far presented for CBSD in Africa. From assessments of 515 farmers&amp;#39; plantings of cassava, incidence in the Coastal Zone of Tanzania (46.5% of plants; 87% of fields affected) was higher than in the Lake Zone (22%; 34%), but incidences for both Zones were greater than previous published records. The whitefly vector, Bemisia tabaci, was more abundant in the Lake Zone than the Coastal Zone, the reverse of the situation reported previously, and increased B. tabaci abundance is driving CBSD spread in the Lake Zone. The altitudinal &amp;#39;ceiling&amp;#39; previously thought to restrict the occurrence of CBSD to regions &amp;lt;1000 masl has been broken as a consequence of the greatly increased abundance of B. tabaci in mid-altitude areas. Amongst environmental variables analysed, minimum temperature was the strongest determinant of CBSD incidence. B. tabaci in the Coastal and Lake Zones responded differently to environmental variables examined, highlighting the biological differences between B. tabaci genotypes occurring in these regions and the superior adaptation of B. tabaci in the Great Lakes region both to cassava and low temperature conditions. Regression analyses using multi-country datasets could be used to determine the potential environmental limits of CBSD. Approaches such as this offer potential for use in the development of predictive models for CBSD, which could strengthen country and continent-level CBSD pandemic mitigation strategies.

Journal of Ecosystems, 2014

Macroinvertebrates and physicochemical parameters were assessed at 15 sites along five rivers in ... more Macroinvertebrates and physicochemical parameters were assessed at 15 sites along five rivers in Kilimanjaro region, Tanzania, with the aim of understanding their ecological status and setting a base to the development of a biological index for tropical regions. Investigated rivers that occur within Pangani basin include Karanga, Rau, Lumbanga, Sere, and Umbwe. Sampling sites were categorized according to the level of water and habitat quality as follows: reference or least impacted (4 sites), moderately impacted (5 sites), and highly impacted (6 sites) sites. A total of 12,527 macroinvertebrates belonging to 13 orders and 48 families were recorded. The highest total abundance of 4,110 individuals per m 2 was found in Karanga river, while Umbwe river had the lowest with 1,203 individuals per m 2 . Chironomidae was the most abundant family (2,588 individuals per m 2 ) and the least were Hydridae and Thiaridae, each having 5 individuals per m 2 . High numbers of taxa were noted among the orders: Ephemeroptera (8), Odonata (8), Diptera , and Trichoptera (6). In conclusion, orders with greater diversity of macroinvertebrate families offer a wide range of tolerance to pollution and, thus can potentially be used to develop a biomonitoring index for evaluating pollution in tropical African rivers.

Transactions of the Royal Society of Tropical Medicine and Hygiene, 2002

There is concern that crop irrigation that results in increased numbers of vector mosquitoes will... more There is concern that crop irrigation that results in increased numbers of vector mosquitoes will lead to a rise in malaria in local communities. We evaluated the level of malaria experienced in 3 communities in northern Tanzania with different agricultural practices: rice irrigation, sugar-cane irrigation and tradi tional maize cultivation. Five cross-sectional surveys were used to measure the prevalence of infection with falciparum malaria in 1-4 years old children in each community over a period of 12 months. Active case detection was also carried out to record clinical episodes of malaria during the study period. Information on antimalarial measures was also recorded. Results from the cross-sectional surveys showed that the overall prevalence of malaria parasites was less near the rice irrigation (12-5%) and sugar-cane (16-9%) schemes than the savannah village (29-4%). There were also significantly fewer clinical episodes of malaria in the rice village (15 cases/1000 child-weeks at risk [cwar]) than either the sugar-cane (36 cases/1000 cwar) or savannah (40 cases/1000 cwar) villages. Overall, rice irrigation was associated with less malaria than alternative agricultural practices, despite the considerable numbers of vectors produced in the paddies. This finding supports other studies that indicate that irrigation in much of sub-Saharan Africa will not lead to increased malaria. Nonetheless, African governments planning irrigation projects need effective policies to encourage local communities to use personal protection measures, such as insecticide-treated bednets, and to ensure that these communities have access to effective antimalarial drugs and efficient health services.

Reproductive Health, 2014

Background: A study of health facility (HF) data on women receiving sulphadoxine-pyrimethamine (S... more Background: A study of health facility (HF) data on women receiving sulphadoxine-pyrimethamine (SP) for intermittent preventive treatment of malaria during pregnancy (IPTp) was carried out at antenatal care clinics in Mkuranga and Mufindi districts. Methods: A review of health management information system (HMIS) registers, interviews with health-care workers (HWs) and district and national level malaria control program managers corroborated by inter-temporal assessment through observations at HF levels. Statistical data were analyzed in Excel and interpreted in triangulation with qualitative data from interviews and observations.

Medical and Veterinary Entomology, 2002

Medical and Veterinary Entomology, 1990

1. Anopheles arabiensis Patton and An. funestus Giles were identified as vectors of Plasmodium fa... more 1. Anopheles arabiensis Patton and An. funestus Giles were identified as vectors of Plasmodium falciparum malaria in the Mwea-Tebere irrigation scheme, Kenya. An. arabiensis was the only member of the An. gambiae complex identified from chromosome characteristics. Other Anopheles species found included An. pharoensis Theobald, An. rufipes Gough and An. coustani Laveran. Survival rates per gonotrophic cycle for An. arabiensis averaged 0.37 during the short rains (October-November), 0.49 during the dry season (February) and 0.78 during the long rains (May-June). Vectorial capacities were correspondingly low due to low survival rates and a high degree of zoophily. The average duration of infective life for P. falciparum was 0.2 days for both An. arabiensis and An. funestus. In contrast, entomological inoculation rates were comparatively high: 6-8 infective bites/man/month. An. pharoensis averaged 110 bites/man/night during the short rains; 1/999 (0.1%) was positive by ELISA for P. falciparum circumsporozoite antigen, but the ELISA evidence is not conclusive for vector incrimination. In correspondence with clinical observations, the transmission of P. malariae and P. ovale is unlikely due to the low vector survival rates. The observed anomaly between low vectorial capacities and high entomological inoculation rates demonstrates the importance of accurately estimating vector sporozoite rates to monitor unstable malaria transmission in irrigated areas.

Medical and Veterinary Entomology, 1987

Laboratory tests of insect repellents by various different methods showed that An.stephensi Listo... more Laboratory tests of insect repellents by various different methods showed that An.stephensi Liston was consistently more susceptible than An.gambiae Giles, An.albimanus Wiedemann or An.pulcherrimus Theobald. The six repellents tested were di-ethyl toluamide (deet), di-methyl phthalate (DMP), ethyl-hexanediol, permethrin, citronella and cedarwood oil. Testing systems in which the mosquitoes were presented with a choice gave consistently lower ED,, values than when there was no choice, i.e. the standards of tolerance are not absolute but depend on the options available. In field tests in an experimental hut a curtain with a high dose of di-ethyl toluamide (deet) reduced biting in the hut but had to be re-impregnated frequently. Deet-impregnated anklets gave about 84% protection against Culex quinquefasciatus Say for 80 days after one impregnation, in a trial in which the anklets were brought out of sealed storage and tested for 2 h nightly. Similar protection was found against An. funestus Giles but the protection against An.gambiae s.l., An.coustuni Laveran and Mansonia spp. was not as good. There were highly significant differences between the four collectors' mosquito attractiveness but this varied highly significantly between the mosquito species.

Medical and Veterinary Entomology, 2001

The high population growth rate of the African continent has led to an increased demand for food ... more The high population growth rate of the African continent has led to an increased demand for food and is in danger of outstripping agricultural production. In order to meet this need, many governments have sought ways of improving food production by initiating large-scale irrigation projects, involving reclamation of arid and semi-arid areas for the cultivation of crops.

Health Policy, 2007

... But briefly, the district has an annual population growth rate of 2.4% and a total fertility ... more ... But briefly, the district has an annual population growth rate of 2.4% and a total fertility rate of 7.2 [24]. It is bordered by Kayunga district in the North and Lake Victoria in the South. ... Areas on the shores of Lake Victoria are holo-endemic. ...

International Journal of Plant & Soil Science, 2014