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Laurence Slutsker

Publications and source records attributed to Laurence Slutsker.

At least 19 recordsLinked to original sources
PubMed2007

HIV and malaria: interactions and implications.

PURPOSE OF REVIEW: This review summarizes accumulating evidence of interactions between HIV and malaria and implications related to prevention and treatment of coinfection. RECENT FINDINGS: HIV-infected persons are at increased risk for clinical malaria; the risk is greatest when immune suppression is advanced. Adults with advanced HIV may be at risk for failure of malaria treatment, especially with sulfa-based therapies. Malaria is associated with increases in HIV viral load that, while modest, may impact HIV progression or the risk of HIV transmission. Cotrimoxazole prophylaxis greatly reduces the risk of malaria in people with HIV; the risk can be further reduced with antiretroviral treatment and the use of insecticide treated mosquito nets. Increased numbers of doses of intermittent preventive treatment during pregnancy can reduce the risk of placental malaria in women with HIV. SUMMARY: Interactions between malaria and HIV have important public health implications. People with HIV should use cotrimoxazole and insecticide treated mosquito nets. Malaria prevention is particularly important for pregnant women with HIV, although more information is needed about the best combination of strategies for prevention. In people with HIV, malaria diagnoses should be confirmed, highly effective drugs should be used for treatment, and possible drug interactions should be considered.

Anti-HIV Agents↗
PubMed2006

HIV immunosuppression and antimalarial efficacy: sulfadoxine-pyrimethamine for the treatment of uncomplicated malaria in HIV-infected adults in Siaya, Kenya.

BACKGROUND: The altered immune response of persons with human immunodeficiency virus (HIV) infection could result in increased rates of antimalarial treatment failure. We investigated the influence of HIV infection on the response to sulfadoxine-pyrimethamine treatment. METHODS: Febrile adults with Plasmodium falciparum parasitemia were treated with sulfadoxine-pyrimethamine and were monitored for 28 days. HIV status and CD4 cell count were determined at study enrollment. RESULTS: Of the adults enrolled in the study, 508 attended all follow-up visits, including 130 HIV-uninfected adults, 256 HIV-infected adults with a high CD4 cell count (> or =200 cells/ micro L), and 122 HIV-infected adults with a low CD4 cell count (<200 cells/ micro L). The hazard of treatment failure at day 28 of follow-up was significantly higher for HIV-infected adults with a low CD4 cell count (20.5%) than for HIV-uninfected adults (7.7%). Anemia (hemoglobin level, <110 g/L) modified the effect of HIV status on treatment failure. When we controlled for fever and parasite density, the hazard of treatment failure for HIV-infected adults with a low CD4 cell count and anemia was 3.4 times higher than that for HIV-uninfected adults (adjusted hazard ratio, 3.38; 95% confidence interval, 1.56-7.34). CONCLUSIONS: HIV-infected persons with a low CD4 cell count and anemia have an increased risk of antimalarial treatment failure. The response to malaria treatment in HIV-infected persons must be carefully monitored. Proven measures for the control and prevention of malaria must be incorporated into the basic package of services provided by HIV/acquired immunodeficiency syndrome care and treatment programs in malarious areas.

Adult↗
PubMed2006

A randomized controlled trial of folate supplementation when treating malaria in pregnancy with sulfadoxine-pyrimethamine.

OBJECTIVES: Sulfadoxine-pyrimethamine (SP) is an antimalarial drug that acts on the folate metabolism of the malaria parasite. We investigated whether folate (FA) supplementation in a high or a low dose affects the efficacy of SP for the treatment of uncomplicated malaria in pregnant women. DESIGN: This was a randomized, placebo-controlled, double-blind trial. SETTING: The trial was carried out at three hospitals in western Kenya. PARTICIPANTS: The participants were 488 pregnant women presenting at their first antenatal visit with uncomplicated malaria parasitaemia (density of >or= 500 parasites/microl), a haemoglobin level higher than 7 g/dl, a gestational age between 17 and 34 weeks, and no history of antimalarial or FA use, or sulfa allergy. A total of 415 women completed the study. INTERVENTIONS: All participants received SP and iron supplementation. They were randomized to the following arms: FA 5 mg, FA 0.4 mg, or FA placebo. After 14 days, all participants continued with FA 5 mg daily as per national guidelines. Participants were followed at days 2, 3, 7, 14, 21, and 28 or until treatment failure. OUTCOME MEASURES: The outcomes were SP failure rate and change in haemoglobin at day 14. RESULTS: The proportion of treatment failure at day 14 was 13.9% (19/137) in the placebo group, 14.5% (20/138) in the FA 0.4 mg arm (adjusted hazard ratio [AHR], 1.07; 98.7% confidence interval [CI], 0.48 to 2.37; p = 0.8), and 27.1% (38/140) in the FA 5 mg arm (AHR, 2.19; 98.7% CI, 1.09 to 4.40; p = 0.005). The haemoglobin levels at day 14 were not different relative to placebo (mean difference for FA 5 mg, 0.17 g/dl; 98.7% CI, -0.19 to 0.52; and for FA 0.4 mg, 0.14 g/dl; 98.7% CI, -0.21 to 0.49). CONCLUSIONS: Concomitant use of 5 mg FA supplementation compromises the efficacy of SP for the treatment of uncomplicated malaria in pregnant women. Countries that use SP for treatment or prevention of malaria in pregnancy need to evaluate their antenatal policy on timing or dose of FA supplementation.

Journal Article↗
PubMed2006

Surveillance for bacterial diarrhea and antimicrobial resistance in rural western Kenya, 1997-2003.

BACKGROUND: Diarrhea is a major cause of preventable illness in sub-Saharan Africa. Although most cases of bacterial gastroenteritis do not require antimicrobial treatment, antimicrobial use is widespread. We examined the bacterial causes of diarrhea and monitored antimicrobial susceptibilities of isolates through clinic-based surveillance in a rural Kenyan community. METHODS: From May 1997 through April 2003, diarrheal stool samples from persons presenting to 4 sentinel health centers were cultured by standard techniques for routine bacterial enteric pathogens, for which antimicrobial susceptibilities were determined. A random subset of specimens was also evaluated for diarrheagenic Escherichia coli. RESULTS: Among stool specimens from 3445 persons, 1092 (32%) yielded at least 1 bacterial pathogen. Shigella species was most commonly isolated (responsible for 16% of all illnesses; 54% of isolates were Shigella flexneri). Campylobacter species and diarrheagenic E. coli predominated among children aged <5 years and were progressively replaced by Shigella species with increasing age. With the exception of Campylobacter species, susceptibility to the antimicrobials used most widely in the community was low: <40% for all isolates tested and <25% for Shigella species. Most persons were treated with an antimicrobial to which their isolate was resistant. Susceptibility to specific antimicrobials was inversely proportional to the frequency with which they were prescribed. CONCLUSIONS: The utility of available antimicrobials for treating bacterial diarrhea in rural western Kenya is substantially limited by reduced susceptibility. More judicious use of appropriate antimicrobials is warranted. Efforts to prevent illness through provision of clean water, improved hygiene, and vaccine development should be strengthened.

Drug Resistance, Multiple, Bacterial↗
PubMed2006

Antifolate resistance in Plasmodium falciparum: multiple origins and identification of novel dhfr alleles.

BACKGROUND: Sulfadoxine-pyrimethamine has been widely used as first-line therapy for uncomplicated malaria throughout sub-Saharan Africa. Recent studies conducted in Asia and Africa suggest the triple-mutant dhfr genotype (51I/59R/108N) may have been generated as a single event in Southeast Asia, with subsequent spread of the single lineage to the African continent, but this hypothesis needs further validation. METHODS: Direct sequencing of polymerase chain reaction (PCR) products, pyrosequencing, and cloning of PCR products were utilized to identify mutations in dhfr. To investigate the evolutionary history of dhfr alleles, we assayed microsatellite loci flanking dhfr along chromosome 4. RESULTS: A total of 15 of 479 samples from western Kenya showed the presence of I164L, in 5 different genotypes. We document C50R in 2 of our samples. Using microsatellite markers, we show 2 haplotypes for both the 51I/108N/164L and 51I/59R/108N/164L genotypes. Our results also show multiple lineages for the triple-mutant dhfr genotype in Africa. CONCLUSIONS: These findings highlight the importance of local characterization of alleles before molecular surveillance of drug-resistant alleles is considered in different endemic settings and populations.

Alleles↗
PubMed2006

Malaria surveillance--United States, 2004.

PROBLEM/CONDITION: Malaria in humans is caused by any of four species of intraerythrocytic protozoa of the genus Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae). These parasites are transmitted by the bite of an infective female Anopheles sp. mosquito. The majority of malaria infections in the United States occur among persons who have traveled to areas with ongoing malaria transmission. In the United States, cases can occur through exposure to infected blood products, congenital transmission, or local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers. PERIOD COVERED: This report summarizes cases in persons with onset of illness in 2004 and summarizes trends during previous years. DESCRIPTION OF SYSTEM: Malaria cases confirmed by blood film are mandated to be reported to local and state health departments by health-care providers or laboratory staff. Case investigations are conducted by local and state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report. RESULTS: CDC received reports of 1,324 cases of malaria, including four fatal cases, with an onset of symptoms in 2004 among persons in the United States or one of its territories. This number represents an increase of 3.6% from the 1,278 cases reported for 2003. P. falciparum, P. vivax, P. malariae, and P. ovale were identified in 49.6%, 23.8%, 3.6%, and 2.0% of cases, respectively. Seventeen patients (1.3% of total) were infected by two or more species. The infecting species was unreported or undetermined in 262 (19.8%) cases. Compared with 2003, the number of reported malaria cases acquired in the Americas (n = 173) increased 17.7%, whereas the number of cases acquired in Asia (n = 172) and Africa (n = 809) decreased 2.8% and 3.7%, respectively. Of 775 U.S. civilians who acquired malaria abroad, only 160 (20.6%) reported that they had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Four patients became infected in the United States; three cases were attributed to congenital transmission and one to laboratory-related mosquitoborne transmission. Four deaths were attributed to malaria, including two caused by P. falciparum, one by P. vivax, and one by a mixed infection with P. falciparum and P. malariae. INTERPRETATION: The 3.6% increase in malaria cases in 2004, compared with 2003, resulted primarily from an increase in the number of cases acquired in the Americas but was offset by a decrease in the number of cases acquired in Africa and Asia. This limited increase might reflect local changes in disease transmission, increased travel to regions in which malaria is endemic, or fluctuations in reporting to state and local health departments. These changes likely reflect expected variation in annual reporting and should not be interpreted as indicating a longer-term trend. In the majority of reported cases, U.S. civilians who acquired infection abroad had not adhered to a chemoprophylaxis regimen that was appropriate for the country in which they acquired malaria. PUBLIC HEALTH ACTIONS: Additional investigations were conducted for the four fatal cases and four infections acquired in the United States. Persons traveling to a malarious area should take one of the recommended chemoprophylaxis regimens appropriate for the region of travel and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently has a fever or influenza-like symptoms should seek medical care immediately and report their travel history to the clinician; investigation should include a blood-film test for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning malaria prevention can be obtained from CDC at http://www.cdc.gov/travel or by calling the Malaria Hotline at telephone 770-488-7788. Recommendations concerning malaria treatment can be obtained at http://www.cdc.gov/malaria/diagnosis_treatment/treatment.htm or by calling the Malaria Hotline.

Adolescent↗
PubMed2006

Use of antenatal services and delivery care among women in rural western Kenya: a community based survey.

BACKGROUND: Improving maternal health is one of the UN Millennium Development Goals. We assessed provision and use of antenatal services and delivery care among women in rural Kenya to determine whether women were receiving appropriate care. METHODS: Population-based cross-sectional survey among women who had recently delivered. RESULTS: Of 635 participants, 90% visited the antenatal clinic (ANC) at least once during their last pregnancy (median number of visits 4). Most women (64%) first visited the ANC in the third trimester; a perceived lack of quality in the ANC was associated with a late first ANC visit (Odds ratio [OR] 1.5, 95% confidence interval [CI] 1.0-2.4). Women who did not visit an ANC were more likely to have < 8 years of education (adjusted OR [AOR] 3.0, 95% CI 1.5-6.0), and a low socio-economic status (SES) (AOR 2.8, 95% CI 1.5-5.3). The ANC provision of abdominal palpation, tetanus vaccination and weight measurement were high (>90%), but provision of other services was low, e.g. malaria prevention (21%), iron (53%) and folate (44%) supplementation, syphilis testing (19.4%) and health talks (14.4%). Eighty percent of women delivered outside a health facility; among these, traditional birth attendants assisted 42%, laypersons assisted 36%, while 22% received no assistance. Factors significantly associated with giving birth outside a health facility included: age >or= 30 years, parity >or= 5, low SES, < 8 years of education, and > 1 hour walking distance from the health facility. Women who delivered unassisted were more likely to be of parity >or= 5 (AOR 5.7, 95% CI 2.8-11.6). CONCLUSION: In this rural area, usage of the ANC was high, but this opportunity to deliver important health services was not fully utilized. Use of professional delivery services was low, and almost 1 out of 5 women delivered unassisted. There is an urgent need to improve this dangerous situation.

Journal Article↗
PubMed2006

Anaemia, iron status and vitamin A deficiency among adolescent refugees in Kenya and Nepal.

OBJECTIVE: To investigate the prevalence of anaemia (haemoglobin<11.0 to 13.0 g dl(-1) depending on age and sex group), iron deficiency (transferrin receptor concentration>8.3 microg ml(-1)) and vitamin A deficiency (serum retinol <0.7 micromol l(-1)) in adolescent refugees. DESIGN: Cross-sectional surveys. SETTING: Kakuma refugee camp in Kenya and seven refugee camps in Nepal. SUBJECTS: Adolescent refugee residents in these camps. RESULTS: Anaemia was present in 46% (95% confidence interval (CI): 42-51) of adolescents in Kenya and in 24% (95% CI: 20-28) of adolescents in Nepal. The sensitivity of palmar pallor in detecting anaemia was 21%. In addition, 43% (95% CI: 36-50) and 53% (95% CI: 46-61) of adolescents in Kenya and Nepal, respectively, had iron deficiency. In both surveys, anaemia occurred more commonly among adolescents with iron deficiency. Vitamin A deficiency was found in 15% (95% CI: 10-20) of adolescents in Kenya and 30% (95% CI: 24-37) of adolescents in Nepal. Night blindness was not more common in adolescents with vitamin A deficiency than in those without vitamin A deficiency. In Kenya, one of the seven adolescents with Bitot's spots had vitamin A deficiency. CONCLUSIONS: Anaemia, iron deficiency and vitamin A deficiency are common among adolescents in refugee populations. Such adolescents need to increase intakes of these nutrients; however, the lack of routine access makes programmes targeting adolescents difficult. Adolescent refugees should be considered for assessment along with other at-risk groups in displaced populations.

Adolescent↗
PubMed2006

Evaluation of the WHO Haemoglobin Colour Scale for diagnosis of anaemia in children and pregnant women as used by primary health care nurses and community health workers in western Kenya.

OBJECTIVES: To evaluate the diagnostic accuracy of the WHO Haemoglobin Colour Scale (HCS) for anaemia in three groups of children aged 2 months to 2 years (sick children, those visiting an immunization clinic and a community-based random sample of children) and a sample of pregnant women. METHODS: Finger-prick blood samples were taken from all consenting participants. Haemoglobin (Hb) levels from the HCS were compared with results from a HemoCue portable haemoglobinometer. Sensitivity, specificity and positive and negative predictive values for the HCS were calculated. RESULTS: A total of 457 sick children, 336 children visiting immunization clinics, 454 children from the community at large and 643 pregnant women participated. The prevalence of anaemia (Hb<11 g/dl) in these groups was 87%, 79%, 74% and 52%, respectively. The prevalence of severe anaemia (Hb<7 g/dl) was 24%, 11%, 10% and 2%, respectively. The sensitivity of the HCS for anaemia ranged from 60% to 79% and specificity from 59% to 94%. The sensitivity of the HCS for severe anaemia ranged from 24% to 63% and the specificity from 97% to 100%. Through use of the HCS, the proportion of sick, anaemic children visiting peripheral health facilities diagnosed and treated for anaemia would increase from 3% to 65%. CONCLUSIONS: In an area with high prevalence of anaemia among sick children, use of the HCS has the potential to significantly increase the proportion of sick, anaemic children who are diagnosed with anaemia and given appropriate treatment. Further evaluations of the effect of the use of the HCS on treatment practices at the health facility level are required.

Adolescent↗
PubMed2006

Evaluation of various methods of maternal placental blood collection for immunology studies.

The collection of maternal placental intervillous blood (IVB), without contamination of fetal blood and with an accurate mononuclear cell profile, is essential for immunological studies of placental malaria and other infectious diseases of the placenta. We have compared five documented methods of IVB collection: perfusion, incision, biopsy, tissue grinding, and puncture (prick) for fetal blood contamination and mononuclear cell profiles using flow cytometry. Twenty-five placentas were obtained from Plasmodium falciparum and human immunodeficiency virus-negative primigravid and secundigravid women delivering at Nyanza Provincial Hospital in Kisumu, western Kenya. Each of the five methods was performed on the same placenta. Fetal red blood cell contamination was significantly lower for the prick and perfusion methods (4.1% and 8.3%, respectively) than for incision (59.5%), biopsy (42.6%), and tissue grinding (19.9%). Significant variation was noted among the five methods in the percentages of monocytes, total T cells, CD4+ and CD8+ T cells, B cells, and NK cells. Further, a pairwise comparison of prick and perfusion, the two methods with low fetal blood contamination, showed that they were not different for fetal red blood cell contamination levels; however, prick yielded significantly higher percentages of CD4 T cells and CD4 memory T cells than perfusion. Collection by prick was determined to be the best method of intervillous blood collection for immunology studies, and perfusion represented the next best method of choice due to high sample volume yield. Overall, in considering the advantages/disadvantages of the two methods with low fetal cell contamination, we conclude that a combination of prick and perfusion is most suitable for immunology studies.

B-Lymphocytes↗
PubMed2005

Epidemic diarrhea due to enterotoxigenic Escherichia coli.

BACKGROUND: In June 1998, we investigated one of the largest foodborne outbreaks of enterotoxigenic Escherichia coli gastroenteritis reported in the United States. METHODS: We conducted cohort studies of 11 catered events to determine risk factors for illness. We used stool cultures, polymerase chain reaction, and serologic tests to determine the etiologic agent, and we conducted an environmental inspection to identify predisposing conditions and practices at the implicated establishment. RESULTS: During 5-7 June, the implicated delicatessen catered 539 events attended by >16,000 people. Our epidemiological study of 11 events included a total of 612 attendees. By applying the median prevalence of illness (20%) among events with ill attendees to the total number of events with any ill attendees, we estimate that at least 3300 persons may have developed gastroenteritis during this outbreak. Multiple food items (potato salad, macaroni salad, egg salad, and watermelon) were associated with illness, all of which required extensive handling during preparation. Enterotoxigenic Escherichia coli serotype O6:H16 producing heat-labile and heat-stable toxins was isolated from the stool specimens from 11 patients. Eight patients with positive stool culture results, 11 (58%) of 19 other symptomatic attendees, and 0 (0%) of 17 control subjects had elevated serum antibody titers to E. coli O6 lipopolysaccharide. The delicatessen had inadequate hand-washing supplies, inadequate protection against back siphonage of wastewater in the potable water system, a poorly draining kitchen sink, and improper food storage and transportation practices. CONCLUSIONS: In the United States, where enterotoxigenic Escherichia coli is an emerging cause of foodborne disease, enterotoxigenic Escherichia coli should be suspected in outbreaks of gastroenteritis when common bacterial or viral enteric pathogens are not identified.

Adult↗
PubMed2005

Household based treatment of drinking water with flocculant-disinfectant for preventing diarrhoea in areas with turbid source water in rural western Kenya: cluster randomised controlled trial.

OBJECTIVE: To compare the effect on prevalence of diarrhoea and mortality of household based treatment of drinking water with flocculant-disinfectant, sodium hypochlorite, and standard practices in areas with turbid water source in Africa. DESIGN: Cluster randomised controlled trial over 20 weeks. SETTING: Family compounds, each containing several houses, in rural western Kenya. PARTICIPANTS: 6650 people in 605 family compounds. INTERVENTION: Water treatment: flocculant-disinfectant, sodium hypochlorite, and usual practice (control). MAIN OUTCOME MEASURES: Prevalence of diarrhoea and all cause mortality. Escherichia coli concentration, free residual chlorine concentration, and turbidity in household drinking water as surrogates for effectiveness of water treatment. RESULTS: In children < 2 years old, compared with those in the control compounds, the absolute difference in prevalence of diarrhoea was -25% in the flocculant-disinfectant arm (95% confidence interval -40 to -5) and -17% in the sodium hypochlorite arm (-34 to 4). In all age groups compared with control, the absolute difference in prevalence was -19% in the flocculant-disinfectant arm (-34 to -2) and -26% in the sodium hypochlorite arm (-39 to -9). There were significantly fewer deaths in the intervention compounds than in the control compounds (relative risk of death 0.58, P = 0.036). Fourteen per cent of water samples from control compounds had E coli concentrations < 1 CFU/100 ml compared with 82% in flocculant-disinfectant and 78% in sodium hypochlorite compounds. The mean turbidity of drinking water was 8 nephelometric turbidity units (NTU) in flocculant-disinfectant households, compared with 55 NTU in the two other compounds (P < 0.001). CONCLUSIONS: In areas of turbid water, flocculant-disinfectant was associated with a significant reduction in diarrhoea among children < 2 years. This health benefit, combined with a significant reduction in turbidity, suggests that the flocculant-disinfectant is well suited to areas with highly contaminated and turbid water.

Adolescent↗
PubMed2005

Novel antibiotic-resistant pneumococcal strains recovered from the upper respiratory tracts of HIV-infected adults and their children in Kisumu, Kenya.

In a survey of genetic diversity within penicillin-nonsusceptible pneumococcal isolates in Kenya, we examined 162 upper respiratory isolates from 104 human immunodeficiency virus (HIV)-infected adults and 46 children in a cotrimoxazole prophylaxis study. Antibiotic resistance levels were high; 152 (94.4%) were cotrimoxazole nonsusceptible (134 fully resistant) and 124 (77%) were intermediately penicillin resistant. Isolates nonsusceptible to penicillin and cotrimoxazole (PNCNP) were found among 24 of the 29 serotypes encountered, 15 of which have rarely or never had documented nonsusceptibility to penicillin. These included serotypes 3, 4, 7C, 7F, 10A, 11A, 13, 15A, 15B, 16F, 17F, 19B, 21, 35A, and 35B. Segments of pbp2b genes from 9 PNCNP (serotypes 3, 13, 15A, 16F, 20, and 35A) were typical of resistance-conferring alleles in that they were highly divergent and contained two substitutions thought to be critical for resistance. Similarly, the dhfr genes from 3 PNCNP were divergent and contained a substitution required for cotrimoxazole resistance. Multilocus sequence typing (MLST) of 48 PNCNP revealed 33 sequence types (STs), none of which were previously recorded at http://www.mlst.net. Comparisons with all known STs revealed that 23 of these STs were unrelated to other known STs, whereas 10 STs were highly related to STs from internationally disseminated strains, including 2 of the 26 antibiotic-resistant clones recognized by the Pneumococcal Molecular Epidemiology Network. Based upon differing serotypes expressed by strains of identical or closely similar genotypes, there has been an extensive history of capsular switching within seven genetic clusters represented by these 10 STs and related STs described at http://www.mlst.net.

Adult↗
PubMed2005

Evaluation of long-lasting insecticidal nets after 2 years of household use.

Development of long-lasting insecticidal nets (LLINs) may eliminate the need for insecticide retreatment of ITNs. While two LLINs (Olyset, Sumitomo Chemical Co., Japan; and PermaNet 1.0, Vestergaard-Frandsen, Denmark) have received recommendations from the World Health Organization Pesticide Evaluation Scheme, field-testing under normal use has been limited. We used a survival analysis approach to compare time to net failure of conventional polyester bednets treated only with deltamethrin to two LLINs and two candidate LLINs (Olyset; PermaNet; Insector, Athanor, France; and Dawa, Siamdutch Mosquito Netting Co., Thailand). Additionally, we evaluated nets treated with a process designed to increase the wash-durability of permethrin-treated nets through the addition of cyclodextrin (a starch) in the treatment process. Houses in western Kenya were randomly assigned to one of the six net types and nets were distributed to cover all sleeping spaces. Households were visited monthly to assess reported side effects in inhabitants and washing frequency. Nets were evaluated for insecticidal activity by periodic WHO cone bioassays with mortality assessed at 24 h. Nets with bioassay mortality <70% were assayed monthly until failure, defined as the first of two consecutive bioassay mortality rates <50%. Time to failure was analyzed using an extended Cox Proportional Hazards model controlling for the cumulative number of washes. We distributed 314 nets to 177 households in June-July 2002; 22 nets (7.0%) were lost to follow-up and 196 (62.4%) failed during the first 2 years of the evaluation. Controlling for cumulative number of washes, PermaNet 1.0 [Hazard Ratio (HR) 0.14, 95% Confidence Interval (CI) 0.06-0.31] had a significantly lower risk of failure than conventional nets while Insector had a significantly higher risk of failure (HR 2.57, 95% CI 1.06-4.15). The risks of failure of the remaining nets (Olyset: HR 1.29, 95% CI 0.79-2.10; Dawa: HR 0.58, 95% CI 0.32-1.18; cyclodextrin: HR 0.65, 95% CI 0.40-1.1) were not significantly different from that of a conventional net. PermaNet 1.0 performed significantly better than conventional nets and should be recommended to malaria control programs.

Animals↗
PubMed2005

Case-control study of an acute aflatoxicosis outbreak, Kenya, 2004.

OBJECTIVES: During January-June 2004, an aflatoxicosis outbreak in eastern Kenya resulted in 317 cases and 125 deaths. We conducted a case-control study to identify risk factors for contamination of implicated maize and, for the first time, quantitated biomarkers associated with acute aflatoxicosis. DESIGN: We administered questionnaires regarding maize storage and consumption and obtained maize and blood samples from participants. PARTICIPANTS: We recruited 40 case-patients with aflatoxicosis and 80 randomly selected controls to participate in this study. EVALUATIONS/MEASUREMENTS: We analyzed maize for total aflatoxins and serum for aflatoxin B1-lysine albumin adducts and hepatitis B surface antigen. We used regression and survival analyses to explore the relationship between aflatoxins, maize consumption, hepatitis B surface antigen, and case status. RESULTS: Homegrown (not commercial) maize kernels from case households had higher concentrations of aflatoxins than did kernels from control households [geometric mean (GM) = 354.53 ppb vs. 44.14 ppb; p = 0.04]. Serum adduct concentrations were associated with time from jaundice to death [adjusted hazard ratio = 1.3; 95% confidence interval (CI), 1.04-1.6]. Case patients had positive hepatitis B titers [odds ratio (OR) = 9.8; 95% CI, 1.5-63.1] more often than controls. Case patients stored wet maize (OR = 3.5; 95% CI, 1.2-10.3) inside their homes (OR = 12.0; 95% CI, 1.5-95.7) rather than in granaries more often than did controls. CONCLUSION: Aflatoxin concentrations in maize, serum aflatoxin B1-lysine adduct concentrations, and positive hepatitis B surface antigen titers were all associated with case status. RELEVANCE: The novel methods and risk factors described may help health officials prevent future outbreaks of aflatoxicosis.

Adolescent↗
PubMed2005

Effect of sustained insecticide-treated bed net use on all-cause child mortality in an area of intense perennial malaria transmission in western Kenya.

We present results from a study conducted in western Kenya where all-cause child mortality was assessed among a population with high levels of sustained insecticide-treated bed net (ITN) use for up to six years. Although ITNs were associated with significant reductions in all-cause mortality among infants 1-11 months old, there was no difference in the rate of all-cause mortality among children 12-59 months old with ITNs for 2-4 years, compared historically with children from villages without ITNs, after controlling for seasonality and underlying child mortality across calendar years (adjusted hazard ratio [AHR] = 0.91, 95% confidence interval [CI] = 0.77-1.07). There was no increase in the proportion of child deaths at older ages (12-59 months old) of all child deaths within villages with ITNs for 5-6 years (48.1%) compared historically with villages without ITNs (47.9%), after controlling for seasonality (AHR = 1.03, P = 0.834). We find no evidence that sustained ITN use increased the risk of mortality in older children in this area of intense perennial malaria transmission.

Animals↗
PubMed2005

Health and demographic surveillance in rural western Kenya: a platform for evaluating interventions to reduce morbidity and mortality from infectious diseases.

We established a health and demographic surveillance system in a rural area of western Kenya to measure the burden of infectious diseases and evaluate public health interventions. After a baseline census, all 33,990 households were visited every four months. We collected data on educational attainment, socioeconomic status, pediatric outpatient visits, causes of death in children, and malaria transmission. The life expectancy at birth was 38 years, the infant mortality rate was 125 per 1000 live births, and the under-five mortality rate was 227 per 1,000 live births. The increased mortality rate in younger men and women suggests high human immunodeficiency virus/acquired immunodeficiency syndrome-related mortality in the population. Of 5,879 sick child visits, the most frequent diagnosis was malaria (71.5%). Verbal autopsy results for 661 child deaths (1 month to <12 years) implicated malaria (28.9%) and anemia (19.8%) as the most common causes of death in children. These data will provide a basis for generating further research questions, developing targeted interventions, and evaluating their impact.

Adolescent↗