Impact of integrated water, sanitation, hygiene, health and nutritional interventions on diarrhoea disease epidemiology and microbial quality of water in a resource-constrained setting in Kenya: A controlled intervention study.

OBJECTIVES: We assessed the impact of water, hygiene and sanitation (WASH), maternal, new-born and child health (MNCH), nutrition and early childhood development (ECD) on diarrhoea and microbial quality of water in a resource-constrained rural setting in Kenya. METHODS: Through a controlled intervention study, we tested faecal and water samples collected from both the intervention and control sites before and after the interventions using microbiological, immunological and molecular assays to determine the prevalence of diarrhoeagenic agents and microbial quality of water. Data from the hospital registers were used to estimate all-cause diarrhoea prevalence. RESULTS: After the interventions, we observed a 58.2% (95% CI: 39.4-75.3) decline in all-cause diarrhoea in the intervention site versus a 22.2% (95% CI: 5.9-49.4) reduction of the same in the control site. Besides rotavirus and pathogenic Escherichia coli, the rate of isolation of other diarrhoea-causing bacteria declined substantially in the intervention site. The microbial quality of community and household water improved considerably in both the intervention (81.9%; 95% CI: 74.5%-87.8%) and control (72.5%; 95% CI: 64.2%-80.5%) sites with the relative improvements in the intervention site being slightly larger. CONCLUSIONS: The integrated WASH, MNCH, nutrition and ECD interventions resulted in notable decline in all-cause diarrhoea and improvements in water quality in the rural resource-limited population in Kenya. This indicates a direct public health impact of the interventions and provides early evidence for public health policy makers to support the sustained implementation of these interventions.

Tracking severe acute respiratory syndrome coronavirus 2 transmission and co-infection with other acute respiratory pathogens using a sentinel surveillance system in Rift Valley, Kenya.

BACKGROUND: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been the most significant public health challenge in over a century. SARS-CoV-2 has infected over 765 million people worldwide, resulting in over 6.9 million deaths. This study aimed to detect community transmission of SARS-CoV-2 and monitor the co-circulation of SARS-CoV-2 with other acute respiratory pathogens in Rift Valley, Kenya. METHODS: We conducted a cross-sectional active sentinel surveillance for the SARS-CoV-2 virus among patients with acute respiratory infections at four sites in Rift Valley from January 2022 to December 2022. One thousand two hundred seventy-one patients aged between 3 years and 98 years presenting with influenza-like illness (ILI) were recruited into the study. Nasopharyngeal swab specimens from all study participants were screened using a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for SARS-CoV-2, influenza A, influenza B and respiratory syncytial virus (RSV). RESULTS: The samples that tested positive for influenza A (n = 73) and RSV (n = 12) were subtyped, while SARS-CoV-2 (n = 177) positive samples were further screened for 12 viral and seven bacterial respiratory pathogens. We had a prevalence of 13.9% for SARS-CoV-2, 5.7% for influenza A, 2% for influenza B and 1% for RSV. Influenza A-H1pdm09 and RSV B were the most dominant circulating subtypes of influenza A and RSV, respectively. The most common co-infecting pathogens were Streptococcus pneumoniae (n = 29) and Haemophilus influenzae (n = 19), accounting for 16.4% and 10.7% of all the SARS-CoV-2 positive samples. CONCLUSIONS: Augmenting syndromic testing in acute respiratory infections (ARIs) surveillance is crucial to inform evidence-based clinical and public health interventions.

Factors Associated with Viral Suppression Among Adolescents on Antiretroviral Therapy in Homa Bay County, Kenya: A Retrospective Cross-Sectional Study.

BACKGROUND: Despite the success in initiating adolescents living with HIV on antiretroviral therapy (ART), questions remain about factors affecting viral suppression. In Kenya, only 63% of adolescents (aged 10-19 years) on ART had achieved viral suppression in 2016. We investigated factors associated with viral suppression among adolescents initiated on ART before November 30, 2017 in Homa Bay County, Kenya. METHODS: A retrospective cross-sectional analysis of 908 adolescents registered on ART for at least 6 months and with at least one documented viral load in the last 12 months, in six health facilities in Homa Bay County was conducted. Data were extracted from the electronic medical records and exported into an excel spreadsheet. Bivariate and multivariate logistic regression analyses were conducted to identify factors associated with viral suppression and adjust for confounding, using Stata 12.0. RESULTS: Out of all participants, 80% (726) had achieved viral suppression (<1,000 copies of viral RNA/mL of blood at latest viral load count). After adjusting for other covariates, adolescents with good adherence to ART (AOR=2.3, 95% CI=1.38-3.84) and a most recent CD4 count of above 500 cells/mm3 (AOR=1.87, 95% CI=1.13-3.08), were more likely to be virally suppressed. Adolescents on second line ART treatment (AOR=0.45, 95% CI=0.28-0.73) and having inadequate adherence to ART (AOR=0.26, 95% CI=0.11-63) were less likely to be virally suppressed. CONCLUSION: Viral suppression for adolescents on ART in this study is significantly higher than the national prevalence in 2016 (80% vs 63%), but it is still below the WHO target of 90%. Enhanced adherence support for adolescents on ART should be implemented to improve long-term adherence. Specific interventions are needed to "rescue" adolescents on second-line ART regimens who may have a history of poor adherence.

Lack of effect of dalcetrapib on QT interval in healthy subjects following multiple dosing.

PURPOSE: Evaluate dalcetrapib's potential to prolong QT intervals in healthy subjects. METHODS: This was a single-center, randomized, active and placebo-controlled, six-sequence, three-period cross-over study. Participants [18-65 years; body mass index (BMI) 18-30 kg/m(2)] were randomized to daily doses of dalcetrapib 600 mg (therapeutic) or 3,900 mg (supratherapeutic) or to dalcetrapib-matched placebo for 7 days. On Day 8, subjects received single-dose moxifloxacin 400 mg (active control) or placebo, following the placebo or dalcetrapib, respectively. Electrocardiographic parameters were recorded on Days -1, 1, 7, and 8. The primary endpoint was the difference to placebo of time-matched change from baseline in the study-specific corrected QT interval (QTcS) at seven time-points within 24 h after dalcetrapib 3,900 mg on Day 7. An upper 95% confidence interval (CI) <10 ms confirmed the absence of a significant effect. Pharmacokinetic and lipid-related parameters were measured. RESULTS: Subjects (n = 49) were predominantly male (71%), and all were white, with a mean age of 45 years and mean BMI of 25 kg/m(2). For the primary analysis, the upper 95% CI for dalcetrapib 3,900 mg was <10 ms at all time-points. Similar findings were obtained for dalcetrapib 600 mg. Following the administration of moxifloxacin, the QTcS increased by >5 ms. At Day 7, exposure for dalcetrapib 3,900 mg was approximately eightfold higher than that for dalcetrapib 600 mg [mean area under the plasma concentration-time curve between time 0 and 24 h 68,500 vs. 8,280 ng*h/mL; mean peak concentration 6,810 vs. 861 ng/mL]. Cholesteryl ester transfer protein activity was inhibited by 30%, and high-density lipoprotein cholesterol increased by 26% for dalcetrapib 600 mg. Dalcetrapib was well tolerated. CONCLUSIONS: Dalcetrapib is not associated with QT interval prolongation, even at doses markedly greater than intended therapeutically.

Modes of HIV transmission among adolescents and young adults aged 10-24 years in Kenya.

Understanding how HIV is acquired can inform interventions to prevent infection. We constructed a risk profile of 10-24 year olds participating in the 2012 Kenya AIDS Indicator Survey and classified them as perinatally infected if their biological mother was infected with HIV or had died, or if their father was infected with HIV or had died (for those lacking mother's data). The remaining were classified as sexually infected if they had sex, and the remaining as parenterally infected if they had a blood transfusion. Overall, 84 (1.6%) of the 5298 10-24 year olds tested HIV positive; 9 (11%) were aged 10-14 and 75 (89%) 15-24 years. Five (56%) 10-14 year olds met criteria for perinatal infection; 4 (44%) did not meet perinatal, sexual or parenteral transmission criteria and parental HIV status was not established. Of the 75 HIV-infected, 15 to 24 year olds, 5 (7%) met perinatal transmission, 63 (84%) sexual and 2 (3%) parenteral criteria; 5 (7%) were unclassified. Perinatal transmission likely accounted for 56% and sexual transmission for 84% of infections among 10-14 year olds and 15-24 year olds, respectively. Although our definitions may have introduced some uncertainty, and with the number of infected participants being small, our findings suggest that mixed modes of HIV transmission exist among adolescents and young people.

Development of multiplex serological assay for the detection of human African trypanosomiasis.

Human African trypanosomiasis (HAT) is a disease caused by Kinetoplastid infection. Serological tests are useful for epidemiological surveillance. The aim of this study was to develop a multiplex serological assay for HAT to assess the diagnostic value of selected HAT antigens for sero-epidemiological surveillance. We cloned loci encoding eight antigens from Trypanosoma brucei gambiense, expressed the genes in bacterial systems, and purified the resulting proteins. Antigens were subjected to Luminex multiplex assays using sera from HAT and VL patients to assess the antigens' immunodiagnostic potential. Among T. b. gambiense antigens, the 64-kDa and 65-kDa invariant surface glycoproteins (ISGs) and flagellar calcium binding protein (FCaBP) had high sensitivity for sera from T. b. gambiense patients, yielding AUC values of 0.871, 0.737 and 0.858 respectively in receiver operating characteristics (ROC) analysis. The ISG64, ISG65, and FCaBP antigens were partially cross-reactive to sera from Trypanosoma brucei rhodesiense patients. The GM6 antigen was cross-reactive to sera from T. b. rhodesiense patients as well as to sera from VL patients. Furthermore, heterogeneous antibody responses to each individual HAT antigen were observed. Testing for multiple HAT antigens in the same panel allowed specific and sensitive detection. Our results demonstrate the utility of applying multiplex assays for development and evaluation of HAT antigens for use in sero-epidemiological surveillance.

Spatial Distributions of HIV Infection in an Endemic Area of Western Kenya: Guiding Information for Localized HIV Control and Prevention.

HIV is still a major health problem in developing countries. Even though high HIV-risk-taking behaviors have been reported in African fishing villages, local distribution patterns of HIV infection in the communities surrounding these villages have not been thoroughly analyzed. The objective of this study was to investigate the geographical distribution patterns of HIV infection in communities surrounding African fishing villages. In 2011, we applied age- and sex-stratified random sampling to collect 1,957 blood samples from 42,617 individuals registered in the Health and Demographic Surveillance System in Mbita, which is located on the shore of Lake Victoria in western Kenya. We used these samples to evaluate existing antibody detection assays for several infectious diseases, including HIV antibody titers. Based on the results of the assays, we evaluated the prevalence of HIV infection according to sex, age, and altitude of participating households. We also used Kulldorff's spatial scan statistic to test for HIV clustering in the study area. The prevalence of HIV at our study site was 25.3%. Compared with the younger age group (15-19 years), adults aged 30-34 years were 6.71 times more likely to be HIV-positive, and the estimated HIV-positive population among women was 1.43 times larger than among men. Kulldorff's spatial scan statistic detected one marginally significant (P = 0.055) HIV-positive and one significant HIV-negative cluster (P = 0.047) in the study area. These results suggest a homogeneous HIV distribution in the communities surrounding fishing villages. In addition to individual behavior, more complex and diverse factors related to the social and cultural environment can contribute to a homogeneous distribution pattern of HIV infection outside of African fishing villages. To reduce rates of transmission in HIV-endemic areas, HIV prevention and control programs optimized for the local environment need to be developed.

Lay perceptions of breast cancer in Western Kenya.

AIM: To explore lay perceptions of causes, severity, presenting symptoms and treatment of breast cancer. METHODS: In October-November 2012, we recruited men and women (18 years and older) from households and health facilities in three different parts of Western Kenya, chosen for variations in their documented burdens of breast cancer. A standardized and validated tool, the breast cancer awareness measure (BCAM), was administered in face-to-face interviews. Survey domains covered included socio-demographics, opinions about causes, symptoms, severity, and treatment of breast cancer. Descriptive analyses were done on quantitative data while open-ended answers were coded, and emerging themes were integrated into larger categories in a qualitative analysis. The open-ended questions had been added to the standard BCAM for the purposes of learning as much as the investigators could about underlying lay beliefs and perceptions. RESULTS: Most respondents were female, middle-aged (mean age 36.9 years), married, and poorly educated. Misconceptions and lack of knowledge about causes of breast cancer were reported. The following (in order of higher to lower prevalence) were cited as potential causes of the condition: Genetic factors or heredity (n = 193, 12.3%); types of food consumed (n = 187, 11.9%); witchcraft and curses (n = 108, 6.9%); some family planning methods (n = 56, 3.6%); and use of alcohol and tobacco (n = 46, 2.9%). When asked what they thought of breast cancer's severity, the most popular response was "it is a killer disease" (n = 266, 19.7%) a lethal condition about which little or nothing can be done. While opinions about presenting symptoms and signs of breast cancer were able to be elicited, such as an increase in breast size and painful breasts, early-stage symptoms and signs were not widely recognized. Some respondents (14%) were ignorant of available treatment altogether while others felt breast cancer treatment is both dangerous and expensive. A minority reported alternative medicine as providing relief to patients. CONCLUSION: The impoverished knowledge in these surveys suggests that lay education as well as better screening and treatment should be part of breast cancer control in Kenya.

Species-Specific Serological Detection for Schistosomiasis by Serine Protease Inhibitor (SERPIN) in Multiplex Assay.

BACKGROUND: Both Schistosoma mansoni and Schistosoma haematobium cause schistosomiasis in sub-Saharan Africa. We assessed the diagnostic value of selected Schistosoma antigens for the development of a multiplex serological immunoassay for sero-epidemiological surveillance. METHODOLOGY/PRINCIPAL FINDINGS: Diagnostic ability of recombinant antigens from S. mansoni and S. haematobium was assessed by Luminex multiplex immunoassay using plasma from school children in two areas of Kenya, endemic for different species of schistosomiasis. S. mansoni serine protease inhibitor (SERPIN) and Sm-RP26 showed significantly higher reactivity to patient plasma as compared to the control group. Sm-Filamin, Sm-GAPDH, Sm-GST, Sm-LAP1, Sm-LAP2, Sm-Sm31, Sm-Sm32 and Sm-Tropomyosin did not show difference in reactivity between S. mansoni infected and uninfected pupils. Sm-RP26 was cross-reactive to plasma from S. haematobium patients, whereas Sm-SERPIN was species-specific. Sh-SEPRIN was partially cross-reactive to S. mansoni infected patients. ROC analysis for Sm-RP26, Sm-SERPIN and Sh-SERPIN showed AUC values of 0.833, 0.888 and 0.947, respectively. Using Spearman's rank correlation coefficient analysis, we also found significant positive correlation between the number of excreted eggs and median fluorescence intensity (MFI) from the multiplex immunoassays for Sm-SERPIN (ρ = 0.430, p-value = 0.003) and Sh-SERPIN (ρ = 0.433, p-value = 0.006). CONCLUSIONS/SIGNIFICANCE: Sm-SERPIN is a promising species-specific diagnostic antigen. Sh-SEPRIN was partially cross-reactive to S. mansoni infected patients. SERPINs showed correlation with the number of excreted eggs. These indicate prospects for inclusion of SERPINs in the multiplex serological immunoassay system.

If you text them, they will come: using the HIV infant tracking system to improve early infant diagnosis quality and retention in Kenya.

OBJECTIVE: The objective of this study is to evaluate the impact of the HIV Infant Tracking System (HITSystem) for quality improvement of early infant diagnosis (EID) of HIV services. DESIGN AND SETTING: This observational pilot study compared 12 months of historical preintervention EID outcomes at one urban and one peri-urban government hospital in Kenya to 12 months of intervention data to assess retention and time throughout the EID cascade of care. PARTICIPANTS: Mother-infant pairs enrolled in EID at participating hospitals before (n = 320) and during (n = 523) the HITSystem pilot were eligible to participate. INTERVENTION: The HITSystem utilizes Internet-based coordination of the multistep PCR cycle, automated alerts to trigger prompt action from providers and laboratory technicians, and text messaging to notify mothers when results are ready or additional action is needed. MAIN OUTCOME MEASURES: The main outcome measures were retention throughout EID services, meeting time-sensitive targets and improving results turn-around time, and increasing early antiretroviral therapy (ART) initiation among HIV-infected infants. RESULTS: The HITSystem was associated with an increase in the proportion of HIV-exposed infants retained in EID care at 9 months postnatal (45.1-93.0% urban; 43.2-94.1% peri-urban), a decrease in turn-around times between sample collection, PCR results and notification of mothers in both settings, and a significant increase in the proportion of HIV-infected infants started on antiretroviral therapy at each hospital(14 vs. 100% urban; 64 vs. 100% peri-urban). CONCLUSION: The HITSystem maximizes the use of easily accessible technology to improve the quality and efficiency of EID services in resource-limited settings.

Serological surveillance development for tropical infectious diseases using simultaneous microsphere-based multiplex assays and finite mixture models.

BACKGROUND: A strategy to combat infectious diseases, including neglected tropical diseases (NTDs), will depend on the development of reliable epidemiological surveillance methods. To establish a simple and practical seroprevalence detection system, we developed a microsphere-based multiplex immunoassay system and evaluated utility using samples obtained in Kenya. METHODS: We developed a microsphere-based immuno-assay system to simultaneously measure the individual levels of plasma antibody (IgG) against 8 antigens derived from 6 pathogens: Entamoeba histolytica (C-IgL), Leishmania donovani (KRP42), Toxoplasma gondii (SAG1), Wuchereria bancrofti (SXP1), HIV (gag, gp120 and gp41), and Vibrio cholerae (cholera toxin). The assay system was validated using appropriate control samples. The assay system was applied for 3411 blood samples collected from the general population randomly selected from two health and demographic surveillance system (HDSS) cohorts in the coastal and western regions of Kenya. The immunoassay values distribution for each antigen was mathematically defined by a finite mixture model, and cut-off values were optimized. FINDINGS: Sensitivities and specificities for each antigen ranged between 71 and 100%. Seroprevalences for each pathogen from the Kwale and Mbita HDSS sites (respectively) were as follows: HIV, 3.0% and 20.1%; L. donovani, 12.6% and 17.3%; E. histolytica, 12.8% and 16.6%; and T. gondii, 30.9% and 28.2%. Seroprevalences of W. bancrofti and V. cholerae showed relatively high figures, especially among children. The results might be affected by immunological cross reactions between W. bancrofti-SXP1 and other parasitic infections; and cholera toxin and the enterotoxigenic E. coli (ETEC), respectively. INTERPRETATION: A microsphere-based multi-serological assay system can provide an opportunity to comprehensively grasp epidemiological features for NTDs. By adding pathogens and antigens of interest, optimized made-to-order high-quality programs can be established to utilize limited resources to effectively control NTDs in Africa.

Anopheles gambiae and Anopheles arabiensis population densities and infectivity in Kopere village, Western Kenya.

INTRODUCTION: This study was conducted in a sugar belt region of western Kenya interfacing epidemic and endemic malaria transmission. We investigated Anopheles gambiae sensu stricto (ss) and Anopheles arabiensis species compositions and densities, human host choice, and infectivity. METHODOLOGY: Mosquitoes were captured using pyrethrum spray catch technique and first identified based on morphology; species were confirmed by PCR. Blood meal preference and sporozoite rates were determined by ELISA. Parity rates and entomological inoculation rates (EIR) were determined. Seasonal densities were compared against environmental temperatures, relative humidity and rainfall. RESULTS: In total 2,426 An. gambiae were collected.  Out of 1,687 female blood-fed mosquitoes, 272 were randomly selected for entomological tests. An. gambiae ss and An. arabiensis comprised 75% (205/272) and 25% (68/272) of the selection, respectively. An. gambiae ss had higher preference for human blood (97%; n=263/272) compared with An. arabiensis, which mostly fed on bovines (88%; n=239/272).  The sporozoite and parity rates were 6% (16/272) and 66% (179/272) for An. gambiae ss and 2% (4/272) and 53% (144/272) for An. arabiensis respectively, while EIR was 0.78 infective bites/person/night.  Climate (ANOVA; F=14.2; DF=23) and temperature alone (r=0.626; t=3.75; p=0.001) were significantly correlated with vector densities. CONCLUSION: An. gambiae ss are the most efficient malaria vector mosquito species in Kopere village. Because An. gambiae ss largely rests and feeds indoors, use of indoor residual spray and insecticide-treated nets is likely the most suitable approach to malaria vector control in Kopere village and other parts of Kenya where this species is abundant.