Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
PLOS Glob Public Health ; 3(11): e0002503, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37930951

RESUMEN

Despite occupational exposure to hazardous chemicals in cosmetics and personal care products (PCPs), salon workers receive minimal formal protections. Consequently, most salon workers rely on personal safeguards. However, the nature of such individual-level safeguards remains unknown. Knowledge of risks associated with occupational use of cosmetics and PCPs and information needs of salon workers were investigated in Kisumu City, Kenya. Responses from 302 respondents showed that 84% were women and 30% had post-secondary education. Seventy percent reported knowing that ingestion, inhalation, dermal absorption, and injection are the pathways through which harmful products in cosmetics and PCPs may enter the body. Salon workers who had been employed for more than 5 years were at least twice more likely to report that it is not the case that cosmetics and PCPs only cause harm to children (5-10 years vs 1 year: OR = 2.440, 95% CI, 1.160-5.239; >10 years vs 1 year: OR = 8.857, 95% CI, 3.163-29.377); they were about three times more likely to either agree with the statement that cosmetics and PCPs only cause harm under prolonged exposure or to say that they did not know compared to their counterparts who had worked in the industry for 1 year (5-10 years vs 1 year: OR = 2.750, 95% CI, 1.144-7.179; >10 years vs 1 year: 3.179, 95% CI, 1.173-9.096). Over 50% of the respondents reported that they need information on how to protect themselves and others; on available protective measures; and on cosmetic products and PCPs that are safe. Sixty percent reported that they would prefer to get such information from the Ministry of Health at the county or national level and on product inserts. Overall, salon workers in Kisumu City are knowledgeable about the risks associated with their occupation but also appreciate gaps in their knowledge, which can be filled by government-mandated interventions.

2.
BMC Genomics ; 24(1): 542, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37704951

RESUMEN

BACKGROUND: Plasmodium falciparum malaria is a leading cause of pediatric morbidity and mortality in holoendemic transmission areas. Severe malarial anemia [SMA, hemoglobin (Hb) < 5.0 g/dL in children] is the most common clinical manifestation of severe malaria in such regions. Although innate immune response genes are known to influence the development of SMA, the role of natural killer (NK) cells in malaria pathogenesis remains largely undefined. As such, we examined the impact of genetic variation in the gene encoding a primary NK cell receptor, natural cytotoxicity-triggering receptor 3 (NCR3), on the occurrence of malaria and SMA episodes over time. METHODS: Susceptibility to malaria, SMA, and all-cause mortality was determined in carriers of NCR3 genetic variants (i.e., rs2736191:C > G and rs11575837:C > T) and their haplotypes. The prospective observational study was conducted over a 36 mos. follow-up period in a cohort of children (n = 1,515, aged 1.9-40 mos.) residing in a holoendemic P. falciparum transmission region, Siaya, Kenya. RESULTS: Poisson regression modeling, controlling for anemia-promoting covariates, revealed a significantly increased risk of malaria in carriers of the homozygous mutant allele genotype (TT) for rs11575837 after multiple test correction [Incidence rate ratio (IRR) = 1.540, 95% CI = 1.114-2.129, P = 0.009]. Increased risk of SMA was observed for rs2736191 in children who inherited the CG genotype (IRR = 1.269, 95% CI = 1.009-1.597, P = 0.041) and in the additive model (presence of 1 or 2 copies) (IRR = 1.198, 95% CI = 1.030-1.393, P = 0.019), but was not significant after multiple test correction. Modeling of the haplotypes revealed that the CC haplotype had a significant additive effect for protection against SMA (i.e., reduced risk for development of SMA) after multiple test correction (IRR = 0.823, 95% CI = 0.711-0.952, P = 0.009). Although increased susceptibility to SMA was present in carriers of the GC haplotype (IRR = 1.276, 95% CI = 1.030-1.581, P = 0.026) with an additive effect (IRR = 1.182, 95% CI = 1.018-1.372, P = 0.029), the results did not remain significant after multiple test correction. None of the NCR3 genotypes or haplotypes were associated with all-cause mortality. CONCLUSIONS: Variation in NCR3 alters susceptibility to malaria and SMA during the acquisition of naturally-acquired malarial immunity. These results highlight the importance of NK cells in the innate immune response to malaria.


Asunto(s)
Anemia , Malaria Falciparum , Malaria , Humanos , Niño , Anemia/genética , Genotipo , Malaria Falciparum/genética , Alelos , Receptor 3 Gatillante de la Citotoxidad Natural
3.
BMC Infect Dis ; 22(1): 768, 2022 Oct 03.
Artículo en Inglés | MEDLINE | ID: mdl-36192672

RESUMEN

BACKGROUND: Malaria remains a public health problem in Kenya despite sustained interventions deployed by the government. One of the major impediments to effective malaria control is a lack of accurate diagnosis and effective treatment. This study was conducted to assess clinical malaria incidence and treatment seeking profiles of febrile cases in western Kenya. METHODS: Active case detection of malaria was carried out in three eco-epidemiologically distinct zones topologically characterized as lakeshore, hillside, and highland plateau in Kisumu County, western Kenya, from March 2020 to March 2021. Community Health Volunteers (CHVs) conducted biweekly visits to residents in their households to interview and examine for febrile illness. A febrile case was defined as an individual having fever (axillary temperature ≥ 37.5 °C) during examination or complaints of fever and other nonspecific malaria related symptoms 1-2 days before examination. Prior to the biweekly malaria testing by the CHVs, the participants' treatment seeking methods were based on their behaviors in response to febrile illness. In suspected malaria cases, finger-prick blood samples were taken and tested for malaria parasites with ultra-sensitive Alere® malaria rapid diagnostic tests (RDT) and subjected to real-time polymerase chain reaction (RT-PCR) for quality control examination. RESULTS: Of the total 5838 residents interviewed, 2205 residents had high temperature or reported febrile illness in the previous two days before the visit. Clinical malaria incidence (cases/1000people/month) was highest in the lakeshore zone (24.3), followed by the hillside (18.7) and the highland plateau zone (10.3). Clinical malaria incidence showed significant difference across gender (χ2 = 7.57; df = 2, p = 0.0227) and age group (χ2 = 58.34; df = 4, p < 0.0001). Treatment seeking patterns of malaria febrile cases showed significant difference with doing nothing (48.7%) and purchasing antimalarials from drug shops (38.1%) being the most common health-seeking pattern among the 2205 febrile residents (χ2 = 21.875; df = 4, p < 0.0001). Caregivers of 802 school-aged children aged 5-14 years with fever primarily sought treatment from drug shops (28.9%) and public hospitals (14.0%), with significant lower proportions of children receiving treatment from traditional medication (2.9%) and private hospital (4.4%) (p < 0.0001). There was no significant difference in care givers' treatment seeking patterns for feverish children under the age of five (p = 0.086). Residents with clinical malaria cases in the lakeshore and hillside zones sought treatment primarily from public hospitals (61.9%, 60/97) traditional medication (51.1%, 23/45) respectively (p < 0.0001). However, there was no significant difference in the treatment seeking patterns of highland plateau residents with clinical malaria (p = 0.431).The main factors associated with the decision to seek treatment were the travel distance to the health facility, the severity of the disease, confidence in the treatment, and affordability. CONCLUSION: Clinical malaria incidence remains highest in the Lakeshore (24.3cases/1000 people/month) despite high LLINs coverage (90%). The travel distance to the health facility, severity of disease and affordability were mainly associated with 80% of residents either self-medicating or doing nothing to alleviate their illness. The findings of this study suggest that the Ministry of Health should strengthen community case management of malaria by providing supportive supervision of community health volunteers to advocate for community awareness, early diagnosis, and treatment of malaria.


Asunto(s)
Antimaláricos , Malaria , Antimaláricos/uso terapéutico , Niño , Fiebre/tratamiento farmacológico , Fiebre/epidemiología , Fiebre/etiología , Humanos , Incidencia , Recién Nacido , Kenia/epidemiología , Malaria/diagnóstico , Malaria/tratamiento farmacológico , Malaria/epidemiología
4.
Parasit Vectors ; 15(1): 340, 2022 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-36167549

RESUMEN

BACKGROUND: Identification and characterization of larval habitats, documentation of Anopheles spp. composition and abundance, and Plasmodium spp. infection burden are critical components of integrated vector management. The present study aimed to investigate the effect of landscape heterogeneity on entomological and parasitological indices of malaria in western Kenya. METHODS: A cross-sectional entomological and parasitological survey was conducted along an altitudinal transect in three eco-epidemiological zones: lakeshore along the lakeside, hillside, and highland plateau during the wet and dry seasons in 2020 in Kisumu County, Kenya. Larval habitats for Anopheles mosquitoes were identified and characterized. Adult mosquitoes were sampled using pyrethrum spray catches (PSC). Finger prick blood samples were taken from residents and examined for malaria parasites by real-time PCR (RT-PCR). RESULTS: Increased risk of Plasmodium falciparum infection was associated with residency in the lakeshore zone, school-age children, rainy season, and no ITNs (χ2 = 41.201, df = 9, P < 0.0001). Similarly, lakeshore zone and the rainy season significantly increased Anopheles spp. abundance. However, house structures such as wall type and whether the eave spaces were closed or open, as well as the use of ITNs, did not affect Anopheles spp. densities in the homes (χ2 = 38.695, df = 7, P < 0.0001). Anopheles funestus (41.8%) and An. arabiensis (29.1%) were the most abundant vectors in all zones. Sporozoite prevalence was 5.6% and 3.2% in the two species respectively. The lakeshore zone had the highest sporozoite prevalence (4.4%, 7/160) and inoculation rates (135.2 infective bites/person/year). High larval densities were significantly associated with lakeshore zone and hillside zones, animal hoof prints and tire truck larval habitats, wetland and pasture land, and the wet season. The larval habitat types differed significantly across the landscape zones and seasonality (χ2 = 1453.044, df = 298, P < 0.0001). CONCLUSION: The empirical evidence on the impact of landscape heterogeneity and seasonality on vector densities, parasite transmission, and Plasmodium infections in humans emphasizes the importance of tailoring specific adaptive environmental management interventions to specific landscape attributes to have a significant impact on transmission reduction.


Asunto(s)
Anopheles , Malaria Falciparum , Malaria , Adulto , Animales , Anopheles/parasitología , Niño , Estudios Transversales , Humanos , Kenia/epidemiología , Larva , Malaria/epidemiología , Malaria Falciparum/parasitología , Mosquitos Vectores/parasitología , Plasmodium falciparum/genética , Estaciones del Año , Esporozoítos
5.
PLoS One ; 17(5): e0268463, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35576208

RESUMEN

BACKGROUND: Persons with submicroscopic malaria infection are a major reservoir of gametocytes that sustain malaria transmission in sub-Saharan Africa. Despite recent decreases in the national malaria burden in Kenya due to vector control interventions, malaria transmission continues to be high in western regions of the country bordering Lake Victoria. The objective of this study was to advance knowledge of the topographical, demographic and behavioral risk factors associated with submicroscopic malaria infection in the Lake Victoria basin in Kisumu County. METHODS: Cross-sectional community surveys for malaria infection were undertaken in three eco-epidemiologically distinct zones in Nyakach sub-County, Kisumu. Adjacent regions were topologically characterized as lakeshore, hillside and highland plateau. Surveys were conducted during the 2019 and 2020 wet and dry seasons. Finger prick blood smears and dry blood spots (DBS) on filter paper were collected from 1,777 healthy volunteers for microscopic inspection and real time-PCR (RT-PCR) diagnosis of Plasmodium infection. Persons who were PCR positive but blood smear negative were considered to harbor submicroscopic infections. Topographical, demographic and behavioral risk factors were correlated with community prevalence of submicroscopic infections. RESULTS: Out of a total of 1,777 blood samples collected, 14.2% (253/1,777) were diagnosed as submicroscopic infections. Blood smear microscopy and RT-PCR, respectively, detected 3.7% (66/1,777) and 18% (319/1,777) infections. Blood smears results were exclusively positive for P. falciparum, whereas RT-PCR also detected P. malariae and P. ovale mono- and co-infections. Submicroscopic infection prevalence was associated with topographical variation (χ2 = 39.344, df = 2, p<0.0001). The highest prevalence was observed in the lakeshore zone (20.6%, n = 622) followed by the hillside (13.6%, n = 595) and highland plateau zones (7.9%, n = 560). Infection prevalence varied significantly according to season (χ2 = 17.374, df = 3, p<0.0001). The highest prevalence was observed in residents of the lakeshore zone in the 2019 dry season (29.9%, n = 167) and 2020 and 2019 rainy seasons (21.5%, n = 144 and 18.1%, n = 155, respectively). In both the rainy and dry seasons the likelihood of submicroscopic infection was higher in the lakeshore (AOR: 2.71, 95% CI = 1.85-3.95; p<0.0001) and hillside (AOR: 1.74, 95% CI = 1.17-2.61, p = 0.007) than in the highland plateau zones. Residence in the lakeshore zone (p<0.0001), male sex (p = 0.025), school age (p = 0.002), and living in mud houses (p = 0.044) increased the risk of submicroscopic malaria infection. Bed net use (p = 0.112) and occupation (p = 0.116) were not associated with submicroscopic infection prevalence. CONCLUSION: Topographic features of the local landscape and seasonality are major correlates of submicroscopic malaria infection in the Lake Victoria area of western Kenya. Diagnostic tests more sensitive than blood smear microscopy will allow for monitoring and targeting geographic sites where additional vector interventions are needed to reduce malaria transmission.


Asunto(s)
Malaria Falciparum , Malaria , Estudios Transversales , Humanos , Kenia/epidemiología , Malaria/diagnóstico , Malaria/epidemiología , Malaria Falciparum/epidemiología , Masculino , Plasmodium falciparum/genética , Prevalencia , Reacción en Cadena en Tiempo Real de la Polimerasa
6.
Malar J ; 21(1): 129, 2022 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-35459178

RESUMEN

BACKGROUND: Accurate malaria diagnosis and appropriate treatment at local health facilities are critical to reducing morbidity and human reservoir of infectious gametocytes. The current study assessed the accuracy of malaria diagnosis and treatment practices in three health care facilities in rural western Kenya. METHODS: The accuracy of malaria detection and treatment recommended compliance was monitored in two public and one private hospital from November 2019 through March 2020. Blood smears from febrile patients were examined by hospital laboratory technicians and re-examined by an expert microscopists thereafter subjected to real-time polymerase chain reaction (RT-PCR) for quality assurance. In addition, blood smears from patients diagnosed with malaria rapid diagnostic tests (RDT) and presumptively treated with anti-malarial were re-examined by an expert microscopist. RESULTS: A total of 1131 febrile outpatients were assessed for slide positivity (936), RDT (126) and presumptive diagnosis (69). The overall positivity rate for Plasmodium falciparum was 28% (257/936). The odds of slide positivity was higher in public hospitals, 30% (186/624, OR:1.44, 95% CI = 1.05-1.98, p < 0.05) than the private hospital 23% (71/312, OR:0.69, 95% CI = 0.51-0.95, p < 0.05). Anti-malarial treatment was dispensed more at public hospitals (95.2%, 177/186) than the private hospital (78.9%, 56/71, p < 0.0001). Inappropriate anti-malarial treatment, i.e. artemether-lumefantrine given to blood smear negative patients was higher at public hospitals (14.6%, 64/438) than the private hospital (7.1%, 17/241) (p = 0.004). RDT was the most sensitive (73.8%, 95% CI = 39.5-57.4) and specific (89.2%, 95% CI = 78.5-95.2) followed by hospital microscopy (sensitivity 47.6%, 95% CI = 38.2-57.1) and specificity (86.7%, 95% CI = 80.8-91.0). Presumptive diagnosis had the lowest sensitivity (25.7%, 95% CI = 13.1-43.6) and specificity (75.0%, 95% CI = 50.6-90.4). RDT had the highest non-treatment of negatives [98.3% (57/58)] while hospital microscopy had the lowest [77.3% (116/150)]. Health facilities misdiagnosis was at 27.9% (77/276). PCR confirmed 5.2% (4/23) of the 77 misdiagnosed cases as false positive and 68.5% (37/54) as false negative. CONCLUSIONS: The disparity in malaria diagnosis at health facilities with many slide positives reported as negatives and high presumptive treatment of slide negative cases, necessitates augmenting microscopic with RDTs and calls for Ministry of Health strengthening supportive infrastructure to be in compliance with treatment guidelines of Test, Treat, and Track to improve malaria case management.


Asunto(s)
Antimaláricos , Malaria Falciparum , Malaria , Antimaláricos/uso terapéutico , Arteméter/uso terapéutico , Combinación Arteméter y Lumefantrina/uso terapéutico , Pruebas Diagnósticas de Rutina , Fiebre , Personal de Salud , Humanos , Kenia , Malaria/diagnóstico , Malaria/tratamiento farmacológico , Malaria Falciparum/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Población Rural , Sensibilidad y Especificidad
7.
Ann Glob Health ; 88(1): 12, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35281883

RESUMEN

Background: Perceived self-vulnerability to prostate cancer is known to influence screening uptake among men in the general population. However, knowledge gap persists on the influence of perceived self-vulnerability to prostate cancer on uptake of screening among male health workers; a demographic that has health insurance and is assumed to have knowledge of screening services for prostate cancer. Objective: This study aimed to assess the effect of perceived self-vulnerability to prostate cancer on screening uptake among male health workers in Kisumu County, western Kenya. Methods: This was a hospital-based cross-sectional study with a descriptive and analytical design. A modified self-administered questionnaire on self-vulnerability was issued to 197 male health workers who were randomly sampled from a study population of 336 eligible participants. The study was conducted at purposively selected public health facilities. Findings: Level of self-reported screening uptake was 27%. Rural residence (AOR = 0.71: 95% CI, 0.32-1.57, p = 0.019), education level (AOR = 5.01; 95% CI, 1.2-20.86, p = 0.027), participant's lack of knowledge about screening services covered by health insurance schemes of which they are members (AOR = 0.2, 95% CI, 0.08-0.5, p = 0.001), good perception of health status (AOR = 4; 95% CI: 1.52-10.53, p = 005) were determinants of screening uptake for prostate cancer. Perceived self-vulnerability to prostate cancer didn't influence screening uptake of participants (p < 0.05). Participants from rural set-up had a higher likelihood of perceiving themselves to be at risk of prostate cancer (AOR = 2.35, 95% CI, 1.17-4.72, p < 0.05) compared to those form urban settings. Old age of 60 years and above (AOR = 3.5, 95% CI: 0.3-40.98, p < 0.002) was predictive of perceived self-vulnerability. Conclusion: Findings from this study showed low uptake of screening and low perceived self-vulnerability to prostate cancer. Perceived self-vulnerability did not influence screening uptake for prostate cancer. Screening knowledge of prostate cancer as covered by health insurance, good perception of health status and level of education should be integrated in screening programs that are individualized on the basis of personal preferences and informed decision making regarding the uncertainty of benefit and the associated harms of screening.


Asunto(s)
Detección Precoz del Cáncer , Neoplasias de la Próstata , Estudios Transversales , Instituciones de Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Kenia/epidemiología , Masculino , Persona de Mediana Edad , Antígeno Prostático Específico , Neoplasias de la Próstata/diagnóstico
8.
Parasit Vectors ; 14(1): 552, 2021 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-34706760

RESUMEN

BACKGROUND: Understanding the ecology and behaviour of disease vectors, including the olfactory cues used to orient and select hosts and egg-laying sites, are essential for the development of novel, insecticide-free control tools. Selected graminoid plants have been shown to release volatile chemicals attracting malaria vectors; however, whether the attraction is selective to individual plants or more general across genera and families is still unclear. METHODS: To contribute to the current evidence, we implemented bioassays in two-port airflow olfactometers and in large field cages with four live graminoid plant species commonly found associated with malaria vector breeding sites in western Kenya: Cyperus rotundus and C. exaltatus of the Cyperaceae family, and Panicum repens and Cynodon dactylon of the Poaceae family. Additionally, we tested one Poaceae species, Cenchrus setaceus, not usually associated with water. The volatile compounds released in the headspace of the plants were identified using gas chromatography/mass spectrometry. RESULTS: All five plants attracted gravid vectors, with the odds of a mosquito orienting towards the choice-chamber with the plant in an olfactometer being 2-5 times higher than when no plant was present. This attraction was maintained when tested with free-flying mosquitoes over a longer distance in large field cages, though at lower strength, with the odds of attracting a female 1.5-2.5 times higher when live plants were present than when only water was present in the trap. Cyperus rotundus, previously implicated in connection with an oviposition attractant, consistently elicited the strongest response from gravid vectors. Volatiles regularly detected were limonene, ß-pinene, ß-elemene and ß-caryophyllene, among other common plant compounds previously described in association with odour-orientation of gravid and unfed malaria vectors. CONCLUSIONS: The present study confirms that gravid Anopheles gambiae sensu stricto use chemical cues released from graminoid plants to orientate. These cues are released from a variety of graminoid plant species in both the Cyperaceae and Poaceae family. Given the general nature of these cues, it appears unlikely that they are exclusively used for the location of suitable oviposition sites. The utilization of these chemical cues for attract-and-kill trapping strategies must be explored under natural conditions to investigate their efficiency when in competition with complex interacting natural cues.


Asunto(s)
Anopheles/fisiología , Mosquitos Vectores/fisiología , Odorantes/análisis , Aceites Volátiles/metabolismo , Poaceae/química , Animales , Conducta Animal , Bioensayo , Femenino , Cromatografía de Gases y Espectrometría de Masas , Kenia , Malaria/transmisión , Aceites Volátiles/análisis , Oviposición , Poaceae/metabolismo
9.
F1000Res ; 9: 1032, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33093949

RESUMEN

Background: Strategies that involve manipulations of the odour-orientation of gravid malaria vectors could lead to novel attract-and-kill interventions. Recent work has highlighted the potential involvement of graminoid plants in luring vectors to oviposition sites. This study aimed to analyse the association between water-indicating graminoid plants (Cyperaceae, sedges), other abiotic and biotic factors and the presence and abundance of early instar Anopheles larvae in aquatic habitats as a proxy indicator for oviposition. Methods: A cross-sectional survey of 110 aquatic habitats along the shores of Lake Victoria was done during the rainy season. Habitats were sampled for mosquito larvae using the sweep-net method and habitat characteristics recorded. Results: Anopheles arabiensis was the dominant species identified from aquatic habitats. Larvae of the secondary malaria vectors such as Anopheles coustani, An. rufipes and An. maculipalpis were found only in habitats covered with graminoids, whereas An. arabiensis, An. ziemanni and An. pharoensis were found in both habitats with and without graminoid plants. The hypothesis that sedges might be positively associated with the presence and abundance of early instar Anopheles larvae could not be confirmed. The dominant graminoid plants in the habitats were Panicum repens, Cynodon dactylon in the Poaceae family and Cyperus rotundus in the Cyperaceae family. All of these habitats supported abundant immature vector populations. The presence of early instar larvae was significantly and positively associated with swamp habitat types (OR=22, 95% CI=6-86, P<0.001) and abundance of late Anopheles larvae (OR=359, CI=33-3941, P<0.001), whilst the association was negative with tadpole presence (OR=0.1, CI=0.0.01-0.5, P=0.008). Conclusions: Early instar malaria vectors were abundant in habitats densely vegetated with graminoid plants in the study area but specific preference for any of the graminoids could not be detected. In search for oviposition cues, it might be useful to screen for chemical volatiles released from all dominant plant species.


Asunto(s)
Anopheles , Cyperaceae , Malaria , Animales , Estudios Transversales , Ecosistema , Femenino , Kenia , Lagos , Mosquitos Vectores , Poaceae , Prevalencia , Humedales
10.
Parasit Vectors ; 13(1): 43, 2020 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-32000840

RESUMEN

BACKGROUND: A good understanding of mosquito ecology is imperative for integrated vector control of malaria. In breeding sites, Anopheles larvae are concurrently exposed to predators and parasites. However, to our knowledge, there is no study on combined effects of predators and parasites on development and survival of larvae and their carry-over effects on adult survivorship and susceptibility to further parasite infection. METHODS: This study focused on effects of the nymphs of the dragonfly Pantala flavescens and the parasitic fungus Beauveria bassiana on Anopheles gambiae, to determine: predation efficacy of nymphs against An. gambiae larvae; development rate of An. gambiae larvae in the presence of one, two or four constrained nymphs; efficacy of B. bassiana against An. gambiae larvae at doses of 3, 6 and 12 mg; and survival of adult mosquitoes exposed to B. bassiana, following pre-exposure to a constrained predator and/or parasite at the larval stage. The experiments consisted of survival bioassays quantified as pupation day, or dead larvae and/or adults. RESULTS: Nymphs had an average predation efficacy of 88.3% (95% CI: 87.5-89.1) at 24 hours, against An. gambiae larvae. The presence of one or two nymphs reduced development time of larvae by 0.65 and 0.35 days, respectively. However, development time of larvae exposed to four nymphs was similar to the control larvae. Larvae exposed to 3, 6 and 12 mg of B. bassiana were 2.0, 2.5 and 3.5 times more likely to die, respectively, compared to control larvae. Adults not pre-exposed, those pre-exposed to predator, parasite, or both were 45.8, 67.4, 50.9 and 112.0 times more likely to die, respectively, compared to control that were unexposed to predator or parasite, at larval and adult stage. CONCLUSIONS: This study shows that both predator and parasite can reduce larval population of An. gambiae, and presence of predator cues decreases development time in breeding sites, as well as, increases the susceptibility of emerging adult to fungus. Predator and parasite both have an additive effect on survival of adults exposed to B. bassiana. Field studies are required for an in-depth understanding of predator and parasite influence on mosquito development time, survival and susceptibility in nature.


Asunto(s)
Anopheles/fisiología , Anopheles/parasitología , Mosquitos Vectores/fisiología , Mosquitos Vectores/parasitología , Conducta Predatoria/fisiología , Animales , Beauveria/patogenicidad , Bioensayo , Femenino , Humanos , Estimación de Kaplan-Meier , Larva/crecimiento & desarrollo , Larva/parasitología , Malaria/transmisión , Ninfa/patogenicidad , Odonata/patogenicidad
11.
Ecohealth ; 17(1): 41-51, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31811599

RESUMEN

Upsurge of antibiotic resistance in wildlife poses unprecedented threat to wildlife conservation. Surveillance of antibiotic resistance at the human-wildlife interface is therefore needed. We evaluated differences in antibiotic resistance of Escherichia coli isolates from human and the endangered black rhinoceros in Lambwe Valley, Kenya. We used standard microbiological techniques to carry out susceptibility assays using eight antibiotics of clinical and veterinary importance. Standard PCR method was used to characterize antibiotic resistance genes. There was no difference in resistance between E. coli isolates from human and those from rhinoceros (U = 25, p = 0.462). However, higher resistance in isolates from humans was noted for cotrimoxazole (p = 0.000, OR = 0.101), ceftriaxone (p = 0.005, OR = 0.113) and amoxicillin/clavulanic acid (p = 0.017, OR = 0.258), whereas isolates from rhinoceros showed higher gentamicin resistance (p = 0.001, OR = 10.154). Multi-drug resistance phenotype was 69.0% in humans and 43.3% in rhinoceros. Isolates from both species contained blaTEM, tetA, tetB, dfrA1 and sul1 genes. Resistance profiles in the two species suggest potential for cross-transfer of resistance genes or exposure to comparable selective pressure and call for a multi-sectorial action plan on surveillance of antibiotic resistance at the human-wildlife interface. Genome-wide studies are needed to explicate the direction of transfer of genes that confer antibiotic resistance at the human-wildlife interface.


Asunto(s)
Farmacorresistencia Microbiana/genética , Escherichia coli , Perisodáctilos/microbiología , Animales , Antibacterianos , Humanos , Kenia , Pruebas de Sensibilidad Microbiana
12.
J Health Care Poor Underserved ; 30(3): 1132-1150, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31422993

RESUMEN

INTRODUCTION: Kenya introduced free maternity services in June 2013. The main study objective was to investigate the effect of this intervention on maternal and newborn health and specifically to determine differences in 4th antenatal care visits, facility deliveries, post-abortion care, and occurrence of facility-based maternal and neonatal deaths two years pre-and-post intervention. METHODS: The study site was Gem Sub-County, Kenya. The study design was an interrupted time series (ITS). Longitudinal data from the District Health Information Software (DHIS2) were analyzed by the Chow test and segmented linear regression. RESULTS: In the post-intervention period, 4th antenatal care visits decreased by .6% (p = .839); facility deliveries decreased by 1.6% (p = .616); post-abortion care uptake increased by 54.4% (p = .000); maternal deaths increased by 10.1% (p = .192) whereas neonatal deaths decreased by .1% (p = .466). CONCLUSION: The intervention had a significant influence on the uptake of post-abortion care.


Asunto(s)
Política de Salud , Indicadores de Salud , Salud del Lactante/estadística & datos numéricos , Servicios de Salud Materna/economía , Salud Materna/estadística & datos numéricos , Cuidados Posteriores/estadística & datos numéricos , Parto Obstétrico/estadística & datos numéricos , Femenino , Humanos , Recién Nacido , Kenia/epidemiología , Estudios Longitudinales , Muerte Materna/estadística & datos numéricos , Servicios de Salud Materna/estadística & datos numéricos , Muerte Perinatal , Embarazo , Atención Prenatal/estadística & datos numéricos
13.
Horm Behav ; 94: 153-161, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28720488

RESUMEN

In many mammals, maturational milestones such as dispersal and the attainment of adult dominance rank mark stages in the onset of reproductive activity and depend on a coordinated set of hormonal and socio-behavioral changes. Studies that focus on the link between hormones and maturational milestones are uncommon in wild mammals because of the challenges of obtaining adequate sample sizes of maturing animals and of tracking the movements of dispersing animals. We examined two maturational milestones in wild male baboons-adult dominance rank attainment and natal dispersal-and measured their association with variation in glucocorticoids (fGC) and fecal testosterone (fT). We found that rank attainment is associated with an increase in fGC levels but not fT levels: males that have achieved any adult rank have higher fGC than males that have not yet attained an adult rank. This indicates that once males have attained an adult rank they experience greater energetic and/or psychosocial demands than they did prior to attaining this milestone, most likely because of the resulting participation in both agonistic and sexual behaviors that accompany rank attainment. In contrast, natal dispersal does not produce sustained increases in either fGC or fT levels, suggesting that individuals are either well adapted to face the challenges associated with dispersal or that the effects of dispersal on hormone levels are ephemeral for male baboons.


Asunto(s)
Distribución Animal/fisiología , Glucocorticoides/análisis , Papio/fisiología , Predominio Social , Testosterona/análisis , Animales , Animales Salvajes , Heces/química , Glucocorticoides/metabolismo , Masculino , Papio/metabolismo , Reproducción/fisiología , Conducta Social , Testosterona/metabolismo
14.
Horm Behav ; 64(2): 240-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23998668

RESUMEN

This article is part of a Special Issue "Puberty and Adolescence". The onset of reproduction is preceded by a host of organismal adjustments and transformations, involving morphological, physiological, and behavioral changes. In highly social mammals, including humans and most nonhuman primates, the timing and nature of maturational processes are affected by the animal's social milieu as well as its ecology. Here, we review a diverse set of findings on how maturation unfolds in wild baboons in the Amboseli basin of southern Kenya, and we place these findings in the context of other reports of maturational processes in primates and other mammals. First, we describe the series of events and processes that signal maturation in female and male baboons. Sex differences in age at both sexual maturity and first reproduction documented for this species are consistent with expectations of life history theory; males mature later than females and exhibit an adolescent growth spurt that is absent or minimal in females. Second, we summarize what we know about sources of variance in the timing of maturational processes including natal dispersal. In Amboseli, individuals in a food-enhanced group mature earlier than their wild-feeding counterparts, and offspring of high-ranking females mature earlier than offspring of low-ranking females. We also report on how genetic admixture, which occurs in Amboseli between two closely related baboon taxa, affects individual maturation schedules.


Asunto(s)
Distribución Animal/fisiología , Animales Salvajes/crecimiento & desarrollo , Papio/crecimiento & desarrollo , Maduración Sexual/fisiología , Animales , Femenino , Kenia , Masculino , Primates/crecimiento & desarrollo , Caracteres Sexuales
15.
Horm Behav ; 63(3): 430-6, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23206991

RESUMEN

Testosterone (T) is often positively associated with male sexual behavior and negatively associated with paternal care. These associations have primarily been demonstrated in species where investment in paternal care begins well after mating activity is complete, when offspring are hatched or born. Different patterns may emerge in studies of species where investment in mating and paternal care overlap temporally, for instance in non-seasonal breeders in which males mate with multiple females sequentially and may simultaneously have multiple offspring of different ages. In a 9-year data set on levels of T in male baboons, fecal concentrations of T (fT) were positively associated with both mate guarding ("consortship") - a measure of current reproductive activity - and with the number of immature offspring a male had in his social group - a measure of past reproductive activity and an indicator of likely paternal behavior. To further examine the relationship between T and potential paternal behavior, we next drew on an intensive 8-month study of male behavior, and found that fathers were more likely to be in close proximity to their offspring than expected by chance. Because male baboons are known to provide paternal care, and because time in proximity to offspring would facilitate such care, this suggests that T concentrations in wild male baboons may be associated with both current reproductive activity and with current paternal behavior. These results are consistent with the predicted positive association between T and mating effort but not with a negative association between T and paternal care; in male baboons, high levels of T occur in males that are differentially associating with their offspring.


Asunto(s)
Conducta Animal/fisiología , Conducta Paterna/fisiología , Reproducción/fisiología , Conducta Sexual Animal/fisiología , Testosterona/fisiología , Animales , Heces/química , Estudios Longitudinales , Masculino , Papio cynocephalus , Conducta Paterna/psicología , Investigación Cualitativa , Predominio Social , Testosterona/metabolismo
16.
Confl Health ; 5: 22, 2011 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-22011647

RESUMEN

BACKGROUND: Much of the literature on the relationship between conflict-related trauma and high risk sexual behaviour (HRSB) often focuses on refugees and not mass in-country displaced people due to armed conflicts. There is paucity of research about contexts underlying HRSB and HIV/AIDS in conflict and post-conflict communities in Uganda. Understanding factors that underpin vulnerability to HRSB in post-conflict communities is vital in designing HIV/AIDS prevention interventions. We explored the socio-cultural factors, social interactions, socio-cultural practices, social norms and social network structures that underlie war trauma and vulnerability to HRSB in a post-conflict population. METHODS: We did a cross-sectional qualitative study of 3 sub-counties in Katakwi district and 1 in Amuria in Uganda between March and May 2009. We collected data using 8 FGDs, 32 key informant interviews and 16 in-depth interviews. We tape-recorded and transcribed the data. We followed thematic analysis principles to manage, analyse and interpret the data. We constantly identified and compared themes and sub-themes in the dataset as we read the transcripts. We used illuminating verbatim quotations to illustrate major findings. RESULTS: The commonly identified HRSB behaviours include; transactional sex, sexual predation, multiple partners, early marriages and forced marriages. Breakdown of the social structure due to conflict had resulted in economic destruction and a perceived soaring of vulnerable people whose propensity to HRSB is high. Dishonour of sexual sanctity through transactional sex and practices like incest mirrored the consequence of exposure to conflict. HRSB was associated with concentration of people in camps where idleness and unemployment were the norm. Reports of girls and women who had been victims of rape and defilement by men with guns were common. Many people were known to have started to display persistent worries, hopelessness, and suicidal ideas and to abuse alcohol. CONCLUSIONS: The study demonstrated that conflicts disrupt the socio-cultural set up of communities and destroy sources of people's livelihood. Post-conflict socio-economic reconstruction needs to encompass programmes that restructure people's morals and values through counselling. HIV/AIDS prevention programming in post-conflict communities should deal with socio-cultural disruptions that emerged during conflicts. Some of the disruptions if not dealt with, could become normalized yet they are predisposing factors to HRSB. Socio-economic vulnerability as a consequence of conflict seemed to be associated with HRSB through alterations in sexual morality. To pursue safer sexual health choices, people in post-conflict communities need life skills.

17.
Proc Natl Acad Sci U S A ; 108(40): 16759-64, 2011 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-21940503

RESUMEN

The H19 gene, which localizes within a chromosomal region on human chromosome 11p15 that is commonly lost in Wilms tumor (WT), encodes an imprinted untranslated RNA. However, the biological significance of the H19 noncoding transcript remains unresolved because replacement of the RNA transcript with a neocassette has no obvious phenotypic effect. Here we show that the human H19 locus also encodes a maternally expressed, translated gene, antisense to the known H19 transcript, which is conserved in primates. This gene, termed HOTS for H19 opposite tumor suppressor, encodes a protein that localizes to the nucleus and nucleolus and that interacts with the human enhancer of rudimentary homolog (ERH) protein. WTs that show loss of heterozygosity of 11p15 or loss of imprinting of IGF2 also silence HOTS (7/7 and 10/10, respectively). Overexpression of HOTS inhibits Wilms, rhabdoid, rhabdomyosarcoma, and choriocarcinoma tumor cell growth, and silencing HOTS by RNAi increases in vitro colony formation and in vivo tumor growth. These results demonstrate that the human H19 locus harbors an imprinted gene encoding a tumor suppressor protein within the long-sought WT2 locus.


Asunto(s)
Nucléolo Celular/metabolismo , Cromosomas Humanos Par 11/genética , ADN sin Sentido/genética , Genes Supresores de Tumor , Proteínas Nucleares/genética , ARN no Traducido/genética , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Northern Blotting , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Clonación Molecular , Islas de CpG/genética , Cartilla de ADN/genética , Humanos , Inmunoprecipitación , Proteínas Nucleares/metabolismo , Interferencia de ARN , ARN Largo no Codificante , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Factores de Transcripción/metabolismo , Tumor de Wilms/genética , Tumor de Wilms/metabolismo
18.
Science ; 333(6040): 357-60, 2011 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-21764751

RESUMEN

In social hierarchies, dominant individuals experience reproductive and health benefits, but the costs of social dominance remain a topic of debate. Prevailing hypotheses predict that higher-ranking males experience higher testosterone and glucocorticoid (stress hormone) levels than lower-ranking males when hierarchies are unstable but not otherwise. In this long-term study of rank-related stress in a natural population of savannah baboons (Papio cynocephalus), high-ranking males had higher testosterone and lower glucocorticoid levels than other males, regardless of hierarchy stability. The singular exception was for the highest-ranking (alpha) males, who exhibited both high testosterone and high glucocorticoid levels. In particular, alpha males exhibited much higher stress hormone levels than second-ranking (beta) males, suggesting that being at the very top may be more costly than previously thought.


Asunto(s)
Jerarquia Social , Papio cynocephalus/fisiología , Papio cynocephalus/psicología , Predominio Social , Estrés Psicológico , Agresión , Animales , Conducta Animal , Dominación-Subordinación , Heces/química , Femenino , Glucocorticoides/análisis , Kenia , Masculino , Conducta Sexual Animal , Testosterona/análisis
19.
Am J Phys Anthropol ; 144(2): 169-76, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20721938

RESUMEN

In conditions characterized by energetic constraints, such as in periods of low food availability, some trade-offs between reproduction and self-maintenance may be necessary; even year-round breeders may then be forced to exhibit some reproductive seasonality. Prior research has largely focused on female reproduction and physiology, and few studies have evaluated the impact of environmental factors on males. Here we assessed the effects of season and ambient temperatures on fecal glucocorticoid (fGC) and testosterone (fT) levels in male baboons in Amboseli, Kenya. The Amboseli basin is a highly challenging, semiarid tropical habitat that is characterized by strongly seasonal patterns of rainfall and by high ambient temperatures. We previously reported that female baboons were impacted by these challenging environmental conditions. We ask here whether male baboons in the same environment and groups as females exhibit similar physiological effects. We found that after accounting for male age and individual variability, males exhibited higher fGC levels and lower fT levels during the dry season than during the wet season. Furthermore, fT but not fGC levels were lower in months of high average daily maximum temperatures, suggesting a direct impact of heat on testes. Our results demonstrate that male baboons, like females, experience ecological stress that alters their reproductive physiology. The impact of the environment on male reproduction deserves more attention both in its own right and because alteration in male physiology may contribute to the reduction in female fertility observed inchallenging environments.


Asunto(s)
Glucocorticoides/metabolismo , Papio/fisiología , Reproducción/fisiología , Testosterona/metabolismo , Animales , Heces/química , Conducta Alimentaria/fisiología , Femenino , Privación de Alimentos/fisiología , Respuesta al Choque Térmico/fisiología , Calor , Kenia , Modelos Lineales , Masculino , Papio/metabolismo , Estaciones del Año , Conducta Sexual Animal/fisiología , Estadísticas no Paramétricas
20.
Ann N Y Acad Sci ; 1204: 127-38, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20738283

RESUMEN

The pace of reproductive aging has been of considerable interest, especially in regard to the long postreproductive period in modern women. Here we use data for both sexes from a 37-year longitudinal study of a wild baboon population to place reproductive aging within a life history context for this species, a primate relative of humans that evolved in the same savannah habitat as humans did. We examine the patterns and pace of reproductive aging, including birth rates and reproductive hormones for both sexes, and compare reproductive aging to age-related changes in several other traits. Reproductive senescence occurs later in baboon females than males. Delayed senescence in females relative to males is also found in several other traits, such as dominance status and body condition, but not in molar wear or glucocorticoid profiles. Survival, health, and well-being are the product of risk factors in morphological, physiological, and behavioral traits that differ in rate of senescence and in dependence on social or ecological conditions; some will be very sensitive to differences in circumstances and others less so.


Asunto(s)
Envejecimiento/fisiología , Modelos Animales , Primates/fisiología , Reproducción/fisiología , Animales , Femenino , Humanos , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...