Multi-Indicator and Multistep Assessment of Malaria Transmission Risks in Western Kenya.

Malaria risk factor assessment is a critical step in determining cost-effective intervention strategies and operational plans in a regional setting. We develop a multi-indicator multistep approach to model the malaria risks at the population level in western Kenya. We used a combination of cross-sectional seasonal malaria infection prevalence, vector density, and cohort surveillance of malaria incidence at the village level to classify villages into malaria risk groups through unsupervised classification. Generalized boosted multinomial logistics regression analysis was performed to determine village-level risk factors using environmental, biological, socioeconomic, and climatic features. Thirty-six villages in western Kenya were first classified into two to five operational groups based on different combinations of malaria risk indicators. Risk assessment indicated that altitude accounted for 45-65% of all importance value relative to all other factors; all other variable importance values were < 6% in all models. After adjusting by altitude, villages were classified into three groups within distinct geographic areas regardless of the combination of risk indicators. Risk analysis based on altitude-adjusted classification indicated that factors related to larval habitat abundance accounted for 63% of all importance value, followed by geographic features related to the ponding effect (17%), vegetation cover or greenness (15%), and the number of bed nets combined with February temperature (5%). These results suggest that altitude is the intrinsic factor in determining malaria transmission risk in western Kenya. Malaria vector larval habitat management, such as habitat reduction and larviciding, may be an important supplement to the current first-line vector control tools in the study area.

Safe Anesthesia Care in Western Kenya: A Preliminary Assessment of the Impact of Nurse Anesthetists at Multiple Levels of Government Hospitals.

BACKGROUND: Only 20% of the surgical burden in eastern sub-Saharan Africa is currently met, leaving >17 million surgical cases annually in need of safe surgery and anesthesia. Similarly, there is an extreme shortage of anesthesia providers in East Africa, with just 0.44 anesthesiologists per 100,000 people in Kenya compared to 20.82 per 100,000 in the United States. Additionally, surgical access is not equally distributed within countries, with rural settings often having the greatest unmet need. We developed and tested a set of tools to assess if graduates of the Kenya registered nurse anesthetist (KRNA) training program, who were placed in rural hospitals in Kenya, would have any impact on surgical numbers, referral patterns, and economics of these hospitals. METHODS: Cross-sectional data were collected from facility assessments in 9 referral hospitals to evaluate the possible impact of the KRNAs on anesthesia care. The hospitals were grouped based on both the number of beds and the assigned national hospital level. At each level, a hospital that had KRNA graduates (intervention) was matched with comparison hospitals in the same category with no KRNA graduates (control). The facility assessment survey included questions capturing data on personnel, infrastructure, supplies, medications, procedures, and outcomes. At the intervention sites, the medical directors of the hospitals and the KRNAs were interviewed. Descriptive statistics were used to present the findings. RESULTS: Intervention sites had a density of anesthesia providers that was 43% higher compared to the control sites. Intervention sites performed at least twice as many surgical cases compared to the control sites. Most KRNAs stated that the anesthesia training program had given them sufficient training and leadership skills to perform safe anesthesia in their clinical practice setting. Medical directors at the intervention sites reported increased surgical volumes and fewer referrals to larger hospitals due to the anesthesia gaps that had been addressed. CONCLUSIONS: Our findings from this study suggest that KRNAs may be associated with an increased volume of surgical cases completed in these rural Kenyan hospitals and may therefore be filling a known anesthetic void. The presence of skilled anesthesia providers is a first step toward providing safe surgery and anesthesia care for all; however, significant gaps still remain. Future analysis will focus on surgical outcomes, the appropriate anesthesia delivery model for a rural population, and how the availability of anesthesia infrastructure impacts referral patterns and safe surgery capacity.

The impact of long-lasting microbial larvicides in reducing malaria transmission and clinical malaria incidence: study protocol for a cluster randomized controlled trial.

BACKGROUND: The massive scale-up of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) has led to a substantial increase in malaria vector insecticide resistance as well as in increased outdoor transmission, both of which hamper the effectiveness and efficiency of ITN and IRS. Long-lasting microbial larvicide can be a cost-effective new supplemental intervention tool for malaria control. METHODS/DESIGN: We will implement the long-lasting microbial larvicide intervention in 28 clusters in two counties in western Kenya. We will test FourStar controlled release larvicide (6 % by weight Bacillus thuringiensis israelensis and 1 % Bacillus sphaerius) by applying FourStar controlled release granule formulation, 90-day briquettes, and 180-day briquettes in different habitat types. The primary endpoint is clinical malaria incidence rate and the secondary endpoint is malaria vector abundance and transmission intensity. The intervention will be conducted as a two-step approach. First, we will conduct a four-cluster trial (two clusters per county, with one of the two clusters randomly assigned to the intervention arm) to optimize the larvicide application scheme. Second, we will conduct an open-label, cluster-randomized trial to evaluate the effectiveness and cost-effectiveness of the larvicide. Fourteen clusters in each county will be assigned to intervention (treatment) or no intervention (control) by a block randomization on the basis of clinical malaria incidence, vector density, and human population size per site. We will treat each treatment cluster with larvicide for three rounds at 4-month intervals, followed by no treatment for the following 8 months. Next, we will switch the control and treatment sites. The former control sites will receive three rounds of larvicide treatment at appropriate time intervals, and former treatment sites will receive no larvicide. We will monitor indoor and outdoor vector abundance using CO2-baited CDC light traps equipped with collection bottle rotators. Clinical malaria data will be aggregated from government-run malaria treatment centers. DISCUSSION: Since current first-line vector intervention methods do not target outdoor transmission and will select for higher insecticide resistance, new methods beyond bed nets and IRS should be considered. Long-lasting microbial larviciding represents a promising new tool that can target both indoor and outdoor transmission and alleviate the problem of pyrethroid resistance. It also has the potential to diminish costs by reducing larvicide reapplications. If successful, it could revolutionize malaria vector control in Africa, just as long-lasting bed nets have done. TRIAL REGISTRATION: U.S. National Institute of Health, study ID NCT02392832 . Registered on 3 February 2015.

Evaluation of universal coverage of insecticide-treated nets in western Kenya: field surveys.

BACKGROUND: Mass distribution of insecticide-treated nets (ITNs) is a cost-effective way to achieve universal coverage, but maintaining this coverage is more difficult. In addition to commonly used indicators, evaluation of universal coverage should include coverage of effective nets and changes in coverage over time. METHODS: Longitudinal and cross-sectional household ITN surveys were carried out from 2010 to 2013 in six locations representing a variety of settings across western Kenya. Five indicators were used to evaluate the current status of universal coverage: 1) ITN ownership--proportion of households that own at least one ITN, 2) access index--ratio of the number of family members over the number of ITNs owned by that household, 3) operational coverage--proportion of the at-risk population potentially covered by ITNs, assuming one ITN for every two people, 4) effective coverage--population coverage of effective ITNs, and 5) usage--proportion of the population that used ITNs the previous night. RESULTS: ITN ownership and operational coverage increased substantially from 2010 to 2013, but this increase was mostly due to the 2011 mass distribution campaign. In 2013, household ITN ownership was on average 84.4% (95% CI [78.4, 90.5]) across the six study areas, and operational coverage was 83.2% (95% CI [72.5, 93.8]). The ITN access rate was 59.1% (95% CI [56.6, 61.7]), and 40.8% (95% CI [38.3, 43.4]) of the people at risk needed more nets to achieve universal coverage. About 88.5% (95% CI [86.1, 90.9]) of the ITNs were below three years old and 16.5% (95% CI [12.1, 20.9]) of the ITNs had hole(s). The estimated effective long-lasting insecticide-treated net (LLIN) coverage was 70.5% (95 CI [58.7, 82.3]). Approximately 18.4% (95% CI [15.5, 21.4]) of the ITNs were shared by more than three persons, and the population ITN usage rate was about 75-87%. The reason for not using ITNs was almost exclusively "net not available". CONCLUSION: Current methods of delivering ITNs, i.e., one mass campaign every five years and regular distribution of ITNs from health center can barely maintain the current effective coverage. Inaccessibility and loss of physical integrity of ITNs are major hindrances to achieving and maintaining universal coverage.