Both insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS) reduce malaria in high malaria transmission areas.1–3 The combined effect of these interventions is unknown. We conducted a non-randomized prospective cohort study to determine protective efficacy of IRS with ITNs (ITN + IRS) compared with ITNs alone (ITN only) in preventing Plasmodium falciparum parasitemia. At baseline, participants provided blood samples for malaria smears, were presumptively treated for malaria, and received ITNs. Blood smears were made monthly and at sick visits. In total, 1,804 participants were enrolled. Incidence of P. falciparum parasitemia in the ITN + IRS and ITN only groups was 18 and 44 infections per 100 persons-years at risk, respectively (unadjusted rate ratio = 0.41; 95% confidence interval [CI] = 0.31–0.56). Adjusted protective efficacy of ITN + IRS compared with ITN only was 62% (95% CI = 0.50–0.72). The combination of IRS and ITN might be a feasible strategy to further reduce malaria transmission in areas of persistent perennial malaria transmission.

SARS-CoV-2: To have or to have not: In June 2021, official records in Kenya showed fewer than 4000 confirmed deaths and 180,000 confirmed cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These data tend to reflect the economically advantaged strata of society who can afford smartphones and have access to medical attention and tests. Brand et al . developed an epidemiological model to estimate the impact of the pandemic in Kenya, the population of which was split into two socioeconomic strata. The authors predicted that 75% of the Kenyan population (about 39 million people) had been exposed to the virus by June 2021. If a fourth wave of infection is observed in the future, it would likely be driven by a variant with enhanced transmissibility or natural immune escape. —CA

The prevalence of aflatoxin and fumonisin was investigated in maize intended for immediate human consumption in eastern Kenya at a time in 2010 when an aflatoxin outbreak was recognized. Samples were collected from people who brought their maize for processing at local commercial mills. Sites were selected using a geographical information system overlay of agroecological zones and Kenya's administrative districts. Interviews and collection of maize flour samples was conducted from 1,500 people who processed maize at 143 mills in 10 administrative districts. Mycotoxins were analyzed using enzyme-linked immunosorbent assays for aflatoxin and fumonisin, leading to detection at levels above the respective maximum tolerable limits in 39 and 37% of the samples, respectively. Samples with aflatoxin contamination above the legal limit ranged between 22 and 60% across the districts. A higher occurrence of aflatoxin was associated with smaller maize farms, lower grain yield, and monocropping systems, while a larger magnitude of the toxin was observed in the subhumid agroecological zone, in samples with more broken kernels, and, curiously, less maize ear damage at harvest. Analysis of paired grain samples (visually sorted and unsorted) showed that sorting reduced fumonisin by 65%, from above to below the legal limit of 1,000 ppb. Sorting did not, however, reduce aflatoxin levels. Although the aflatoxin problem is widely acknowledged, the high prevalence of fumonisin has not previously been reported. There is need for surveillance of the two mycotoxins and establishment of intervention strategies to reach vulnerable small-scale farmers.

School-based hygiene and water treatment programs increase student knowledge, improve hygiene, and decrease absenteeism, however health impact studies of these programs are lacking. We collected baseline information from students in 42 schools in Kenya. We then instituted a curriculum on safe water and hand hygiene and installed water stations in half (“intervention schools”). One year later, we implemented the intervention in remaining schools. Through biweekly student household visits and two annual surveys, we compared the effect of the intervention on hygiene practices and reported student illness. We saw improvement in proper handwashing techniques after the school program was introduced. We observed a decrease in the median percentage of students with acute respiratory illness among those exposed to the program; no decrease in acute diarrhea was seen. Students in this school program exhibited sustained improvement in hygiene knowledge and a decreased risk of respiratory infections after the intervention.