The performance of health laboratories and the quality of malaria diagnosis in six districts of Tanzania.

Early laboratory diagnosis is critical for the optimal management of human malaria, particularly following the introduction of relatively expensive, artemisinin-combination therapies (ACT). The performance of the laboratories and the quality of malaria diagnosis have recently been assessed in 36 healthcare facilities in six districts of Tanzania. Questionnaires, checklists and observations were used to collect information on the availability and functional status of equipment as well as on laboratory personnel and their performance in malaria diagnosis. Together, the surveyed facilities had 112 laboratory staff [almost half (41.1%) of whom were laboratory assistants] and 57 microscopes. Twenty-seven (75.0%) of the healthcare facilities included in the survey had only one functional microscope each. Only seven (12.3%) of the assessed microscopes had been serviced in the previous 2 years. Of the 38 microscopists who were assessed, 24 (63.2%) were re-using microscope slides, 29 (73.5%) were producing bloodsmears of low quality, and 30 (79.0%) were using Field's stain. Although the facility microscopists gave similar results to experienced research microscopists when reading bloodsmears prepared by the survey team, using high-quality reagents (kappa=0.769), they appeared far less competent when reading smears stained using the reagents from the study laboratories (kappa=0.265-0.489). The quality of malaria diagnosis at healthcare facilities in Tanzania, which is generally poor (largely because of inadequate supplies of consumables and the limited skills of laboratory staff in the preparation of bloodsmears), urgently needs to be improved if the utilization of ACT is to be sustainable.

Community directed approach beyond ivermectin in Tanzania: a promising mechanism for the delivery of complex health interventions.

The Community Directed Intervention (CDI) is currently used for Ivermectin distribution for the treatment of onchocerciasis in Africa. This study was carried out to determine the extent to which the CDI process can be used for the delivery of other health interventions with different degrees of complexity. The study was conducted in five districts of Kilosa, Muheza, Lushoto, Korogwe and Ulanga in Tanzania and involved communities, health facility and district healthcare providers. Implementation of CDI across these health interventions involved addressing six major processes, namely, stakeholder processes, health system dynamics, engaging communities, empowering communities, engaging CDI implementers and broader system effects. Community and health systems changes were triggered, such that the inherent value of community involvement and empowerment could be internalized by communities and health workers, leading to a more receptive health system. The CDI process was accepted at the community levels as many were willing and ready to adopt the approach. Health workers at community levels were readily available and supportive of the process. Additionally, noted were the verified willingness and ability of community implementers to deliver multiple interventions; confirmed efficiency of CDI leading to cost savings at health systems level; increasing interest of the health system in CDI; interest of health workers in the process of integrated planning. However, there were factors that may have a negative influence on the CDI process. Drug and supply policy for CDI process was lacking at the national and district levels and the presence of parallel community-based programmes that provide financial incentives for community members to run them discouraged Community-directed distributors who in most cases are volunteers. In conclusion, the results have clearly and evidently demonstrated the potential of CDI approach for effectively and efficiently control of other diseases such as malaria, tuberculosis and childhood illnesses. The study has provided unique information on the feasibility and effectiveness of integrated delivery of interventions at the community level.

Comparative efficacies of permethrin-, deltamethrin- and alpha-cypermethrin-treated nets, against Anopheles arabiensis and Culex quinquefasciatus in northern Tanzania.

Mosquito nets treated with permethrin, deltamethrin or alpha-cypermethrin at 25 mg/m(2) were evaluated in experimental huts in an area of rice irrigation near Moshi, in northern Tanzania. The nets were deliberately holed to resemble worn nets. The nets treated with permethrin offered the highest personal protection against Anopheles arabiensis (61.6% reduction in fed mosquitoes) and Culex quinquefasciatus (25.0%). Deltamethrin and alpha-cypermethrin provided lower personal protection against An. arabiensis (46.4% and 45.6%, respectively) and no such protection against Cx. quinquefasciatus. Permethrin performed poorly in terms of mosquito mortality, however, killing only 15.2% of the An. arabiensis and 9.2% of the Cx. quinquefasciatus exposed to the nets treated with this pyrethroid (after correcting for control mortality). The alpha-cypermethrin and deltamethrin performed marginally better, with respective mortalities of 32.8% and 33.0% for An. arabiensis and 19.4% and 18.9% for Cx quinquefasciatus. The poor killing effect of permethrin was confirmed in a second trial where a commercial, long-lasting insecticidal net based on this pyrethroid (Olyset) produced low mortalities in both An. arabiensis (11.8%) and Cx. quinquefasciatus (3.6%). Anopheles arabiensis survivors collected from the verandahs of the experimental huts and tested on 0.75%-permethrin and 0.05%-deltamethrin papers, in World Health Organization susceptibility kits, showed mortalities of 96% and 100%, respectively. The continued use of permethrin-treated nets is recommended for personal protection against An. arabiensis. In control programmes that aim to interrupt transmission of pathogens by mosquitoes and/or manage pyrethroid resistance in such vectors, a combination of a pyrethroid and another insecticide with greater killing effect should be considered.

Experimental hut evaluation of the pyrrole insecticide chlorfenapyr on bed nets for the control of Anopheles arabiensis and Culex quinquefasciatus.

OBJECTIVE: To determine the efficacy of chlorfenapyr against Anopheles arabiensis and Culex quinquefasciatus in East Africa and to identify effective dosages for net treatment in comparison with the commonly used pyrethroid deltamethrin. METHODS: Chlorfenapyr was evaluated on bed nets in experimental huts against A. arabiensis and C. quinquefasciatus in Northern Tanzania, at application rates of 100-500 mg/m(2). RESULTS: In experimental huts, mortality rates in A. arabiensis were high (46.0-63.9%) for all dosages of chlorfenapyr and were similar to that of deltamethrin-treated nets. Mortality rates in C. quinquefasciatus were higher for chlorfenapyr than for deltamethrin. Despite a reputation for being slow acting, >90% of insecticide-induced mortality in laboratory tunnel tests and experimental huts occurred within 24 h, and the speed of killing was no slower than for deltamethrin-treated nets. CONCLUSIONS: Chlorfenapyr induced low irritability and knockdown, which explains the relatively small reduction in blood-feeding rate. Combining chlorfenapyr with a more excito-repellent pyrethroid on bed nets for improved personal protection, control of pyrethroid-resistant mosquitoes and pyrethroid resistance management would be advantageous.

Community directed interventions for malaria, tuberculosis and vitamin A in onchocerciasis endemic districts of Tanzania.

In recognising the success attained through community-directed treatment with Ivermectin, there has been a growing interest to use a similar approach for delivery of interventions against other communicable diseases. This study was conducted in 2007 to evaluate the impact of community directed intervention (CDI) on delivering five health interventions namely Vitamin A supplementation (VAS), community-directed treatment with Ivermectin (CDTi), distribution of insecticide-treated nets (ITN), directly observed treatment of tuberculosis (DOTS), and home-based management of malaria (HMM). The study was carried out in onchocerciasis endemic districts of Kilosa, Muheza, Lushoto, Korogwe and Ulanga districts in Tanzania. A total of 250 households were involved in the study for the period of two years. During the first year, one new intervention was added in each study district. A second new intervention was then added in the same manner during the second study year. In the control district all interventions, with the exception of Ivermectin distribution, continued to be delivered in the traditional manner throughout the study period. Results showed that Ivermectin treatment coverage in the CDI districts (88%) was significantly (P<0.005) higher than in the control district (77%). The coverage of VAS was 84 +/- 7%, showing very little difference between control and intervention districts (P>0.05). The DOTS treatment completion rate was observed only in Korogwe where 4 out 7 patients had completed their treatment. The proportions of pregnant women and <5 years children sleeping under ITN in the CDI districts (range: 83-100%) were significantly higher (P< 0.05) than those in the control district (40-43%). There was also a higher proportion of malaria cases referred in the intervention districts (42%) than in the control district (21%) (P<0.005). Likewise, the proportion of <5 years children who were presumptively diagnosed with malaria and received appropriated treatment within 24 hours in the intervention districts (17-29%) was higher than those in the control district (4%) (P<0.005). The costs incurred per integrated programme in the intervention districts were much lower than those in the control district. In conclusion, our results showed higher coverage of interventions in the CDI districts without necessarily increasing the cost.