Sustained high coverage of insecticide-treated bednets through combined Catch-up and Keep-up strategies.

BACKGROUND: Mass, free distribution (Catch-up) of insecticide-treated bednets (ITNs) during measles vaccination campaigns achieves immediate, high and equitable coverage for both ITNs and measles vaccine. Maintaining high coverage over time requires long-term, routine access to new nets (Keep-up). In many settings, only one approach--either campaign or routine delivery--has been available and have been seen as competing methods. Relying only on campaigns achieves high coverage at the cost of lack of later access. Relying solely on routine coverage builds a delivery infrastructure but may lead to slower rates of coverage and inequities. A combined Catch-up/Keep-up approach has been a common feature of vaccination programs for many years. We assessed the 3-year effects of a one-time Catch-up campaign followed by clinic-based social marketing for routine Keep-up on ITN coverage and use. METHODS: In December 2002, ITNs were distributed to all children attending a measles vaccination campaign in a rural district of Ghana. In the 3 years following that campaign, the district began offering ITNs at a subsidized price to pregnant women attending ante-natal clinics. This Keep-up scheme did not become fully operational until 2 years after the campaign. A coverage survey was conducted 38-month post-campaign using a standard two-stage cluster sampling method. RESULTS: Coverage of nets was high due to the combined contributions of both Catch-up and Keep-up. There were 475 households in the survey with at least one child less than 5 years of age. Among these households, coverage was 95.6% with any net, 83.8% with a campaign net, and 73.9% with an ITN. Of all children, 95.7% slept in a household that had a net, 86.1% slept in a household that had a campaign net. Not all available nets were used as only 59.6% of children slept under an ITN. The source of the nets was 77.7% from the campaign and 20% from routine clinics. Compared to households that participated in the campaign, households with children born after the campaign had higher rates of net ownership (75.1% vs. 67.7%, P=0.04). Equity was high as the ratio of coverage in the lowest wealth quintile to that in the highest was 0.95 for ITN ownership and 1.08 for ITN use. These coverage and use rates were similar to those previously reported 5-month post-campaign, suggesting no decrease over 3 years. CONCLUSION: A high level of ITN coverage and use was achieved and sustained by sequential community-based mass campaign Catch-up and clinic-based Keep-up distribution. The campaign nets covered virtually all extant households while clinic-based distribution provided nets for the new sleeping spaces created post-campaign. Because nets can be shared, and most children are born into families that already have a net, the number of new nets needed to sustain high coverage is substantially lower than the number of newborn children. A Catch-up/Keep-up strategy combining mass campaigns for children and clinic-based distribution to pregnant women is an efficient strategy for achieving and sustaining high net coverage. Assuring proper use of nets is a remaining challenge.

Evaluation of bednets after 38 months of household use in northwest Ghana.

A total of 255 bednets were collected 38 months after distribution in Lawra District of northwest Ghana to examine their physical condition and residual insecticide levels. Physical condition varied from nearly pristine to highly damaged. In 50 selected nets, 2023 holes > or = 0.5 cm and 31 holes > or = 10 cm were counted. The incidence of holes increases toward the bottom edge of the net. Seam failures were found in 50% of the nets. Repairs, mostly sewn, were evident in 64% of the nets. Using a combination of bromine x-ray fluorescence (XRF) spectrometry, high-pressure liquid chromatography, and cone bioassays, it was determined that 14.9% of the nets had retained full insecticidal strength. These results highlight the value of real-world data on bednet longevity to guide decisions regarding mosquito control strategies, bednet purchasing, frequency of bednet replacement, and product development.

Integrating insecticide-treated bednets into a measles vaccination campaign achieves high, rapid and equitable coverage with direct and voucher-based methods.

Population coverage of insecticide-treated nets (ITNs) in Africa falls well below the Abuja target of 60% while coverage levels achieved during vaccination campaigns in the same populations typically exceed 90%. Household (HH) cost of ITNs is an important barrier to their uptake. We investigated the coverage, equity and cost of linking distribution of free ITNs to a measles vaccination campaign. During a national measles vaccination campaign in Zambia, children in four rural districts were given a free ITN when they received their measles vaccination. In one urban district, children were given a voucher, which could be redeemed for a net at a commercial distribution site. About 1700 HHs were asked whether they received vaccination and an ITN during a measles campaign, as well as questions on assets (e.g. type roofing material or bicycle ownership) to assess HH wealth. Net ownership was calculated for children in each wealth quintile. In the rural areas, ITN coverage among children rose from 16.7% to 81.1% and the equity ratio from 0.32 to 0.88 and in the urban area from 50.7% to 76.2% (equity ratio: 0.66-1.19). The operational cost per ITN delivered was dollar 0.35 in the rural area with direct distribution and $1.89 in the urban areas with voucher distribution. Mass distribution of ITNs through vaccination campaigns achieves rapid, high and equitable coverage at low cost.

New evidence of spontaneous cure in human Chagas' disease.

A new case of spontaneous cure of human Chagas' disease is described in Uruguay. An 87-year-old man who had a typical acute phase of Trypanosoma cruzi infection in 1947 and never received specific treatment against the disease, when examined in 1998 revealed several completely negative parasitological and serological tests, including traditional serology, PCR and flow cytometry. As a whole, such findings fulfill the current criteria to define the cure of Chagas' disease. Clinical data suggest the possibility of a benign evolution of Chagas' disease in this case, but the basic findings (slight cardiac and esophageal impairment) could also be due to the advanced age of the patient.

New evidence of spontaneous cure in human Chagas' disease

A new case of spontaneous cure of human Chagas' disease is described in Uruguay. An 87-year-old man who had a typical acute phase of Trypanosoma cruzi infection in 1947 and never received specific treatment against the disease, when examined in 1998 revealed several completely negative parasitological and serological tests, including traditional serology, PCR and flow cytometry. As a whole, such findings fulfill the current criteria to define the cure of Chagas' disease. Clinical data suggest the possibility of a benign evolution of Chagas' disease in this case, but the basic findings (slight cardiac and esophageal impairment) could also be due to the advanced age of the patient

Mobile computing in the humanitarian assistance setting: an introduction and some first steps.

We developed a Palm operating system-based handheld computer system for admin istering nutrition questionnaires and used it to gather nutritional information among the Burmese refugees in the Mae La refugee camp on the Thai-Burma border Our experience demonstrated that such technology can be easily adapted for such an austere setting and used to great advantage. Further, the technology showed tremendous potential to reduce both time required and errors commonly encountered when field staff collect information in the humanitarian setting. We also identified several areas needing further development.