Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-9 (of 9 Records) |
Query Trace: Otiato F[original query] |
---|
A search for snail-related answers to explain differences in response of Schistosoma mansoni to praziquantel treatment among responding and persistent hotspot villages along the Kenyan shore of Lake Victoria (preprint)
Mutuku MW , Laidemitt MR , Beechler BR , Mwangi IN , Otiato FO , Agola EL , Ochanda H , Kamel B , Mkoji GM , Steinauer ML , Loker ES . bioRxiv 2019 394031 Following a four-year annual praziquantel treatment campaign the resulting prevalence of S. mansoni was seen to differ among individual villages along the Kenyan shore of Lake Victoria. We have investigated possible inherent differences in snail-related aspects of transmission among such 10 villages, including six persistent hotspot (PHS) villages (≤30% reduction in prevalence following repeated treatments) located along the west-facing shore of the lake, and four PZQ-responding (RESP) villages (>30% prevalence reduction following repeated treatment) along Winam Gulf. When taking into account all sampling sites and times and water hyacinth presence/absence, shoreline-associated B. sudanica from PHS and RESP villages did not differ in relative abundance or prevalence of S. mansoni infection. Water hyacinth intrusions were associated with increased B. sudanica abundance. The deeper water snail Biomphalaria choanomphala was significantly more abundant in the PHS villages and prevalence of S. mansoni among villages both before and after control was positively correlated with B. choanomphala abundance. Worm recoveries from sentinel mice did not differ between PHS and RESP villages, and abundance of non-schistosome trematode species was not associated with S. mansoni abundance. Biomphalaria choanomphala provides an alternative, deepwater mode of transmission that may favor greater persistence of S. mansoni in PHS villages. As we found evidence for ongoing S. mansoni transmission in all 10 villages, we conclude conditions conducive for transmission and reinfection occur ubiquitously. This argues for an integrated, basin-wide plan for schistosomiasis control to counteract rapid reinfections facilitated by large snail populations and movements of infected people around the lake. |
Knowledge and attitude of Kenyan healthcare workers towards pandemic influenza disease and vaccination: 9years after the last influenza pandemic
Andayi F , Emukule GO , Osoro E , Ndegwa LK , Otiato F , Muturi P , Azziz-Baumgartner E , Kalani R , Anyango E , Muthoka PM , Ebama MS , Bresee J , Chaves SS . Vaccine 2021 39 (29) 3991-3996 BACKGROUND: Healthcare workers (HCWs) are at high risk of exposure and transmission of infectious respiratory pathogens like influenza. Despite the potential benefits, safety and efficacy of influenza vaccination, vaccines are still underutilized in Africa, including among HCWs. METHOD: From May-June 2018, we conducted a cross-sectional, self-administered, written survey among HCWs from seven counties in Kenya and assessed their knowledge attitudes and perceptions towards pandemic influenza disease and vaccination. Using regression models, we assessed factors that were associated with the HCW's knowledge of pandemic influenza and vaccination. RESULTS: A total of 2,035 HCWs, representing 49% of the targeted respondents from 35 health facilities, completed the question. Sixty eight percent of the HCWs had ever heard of pandemic influenza, and 80.0% of these were willing to receive pandemic influenza vaccine if it was available. On average, Kenyan HCWs correctly answered 55.0% (95% CI 54.0-55.9) of the questions about pandemic influenza and vaccination. Physicians (65.6%, 95% CI 62.5-68.7) and pharmacists (61.7%, 95% CI 57.9-65.5) scored higher compared to nurses (53.1%, 95% CI 51.7-54.5). HCWs with 5 or more years of work experience (55.8, 95% CI 54.5-57.0) had marginally higher knowledge scores compared to those with less experience (53.9%, 95% CI 52.5-55.3). Most participants who were willing to receive pandemic influenza vaccine did so to protect their relatives (88.7%) or patients (85.9%). CONCLUSION: Our findings suggest moderate knowledge of pandemic influenza and vaccination by HCWs in Kenya, which varied by cadre and years of work experience. These findings highlight the need for continued in-service health education to increase the HCW's awareness and knowledge of pandemic influenza to increase acceptance of influenza vaccination in the case of a pandemic. |
Knowledge and attitudes towards influenza and influenza vaccination among pregnant women in Kenya
Otieno NA , Nyawanda B , Otiato F , Adero M , Wairimu WN , Atito R , Wilson AD , Gonzalez-Casanova I , Malik FA , Verani JR , Widdowson MA , Omer SB , Chaves SS . Vaccine 2020 38 (43) 6832-6838 BACKGROUND: Influenza vaccination during pregnancy benefits mothers and children. Kenya and other low- and middle-income countries have no official influenza vaccination policies to date but are moving towards issuing such policies. Understanding determinants of influenza vaccine uptake during pregnancy in these settings is important to inform policy decisions and vaccination rollout. METHODS: We interviewed a convenience sample of women at antenatal care facilities in four counties (Nairobi, Mombasa, Marsabit, Siaya) in Kenya. We described knowledge and attitudes regarding influenza vaccination and assessed factors associated with willingness to receive influenza vaccine. RESULTS: We enrolled 507 pregnant women, median age was 26 years (range 15-43). Almost half (n = 240) had primary or no education. Overall, 369 (72.8%) women had heard of influenza. Among those, 288 (78.1%) believed that a pregnant woman would be protected if vaccinated, 252 (68.3%) thought it was safe to receive a vaccine while pregnant, and 223 (60.4%) believed a baby would be protected if mother was vaccinated. If given opportunity, 309 (83.7%) pregnant women were willing to receive the vaccine. Factors associated with willingness to receive influenza vaccine were mothers' belief in protective effect (OR 3.87; 95% CI 1.56, 9.59) and safety (OR 5.32; 95% CI 2.35, 12.01) of influenza vaccines during pregnancy. CONCLUSION: Approximately one third of pregnant women interviewed had never heard of influenza. Willingness to receive influenza vaccine was high among women who had heard about influenza. If the Kenyan government recommends influenza vaccine for pregnant women, mitigation of safety concerns and education on the benefits of vaccination could be the most effective strategies to improve vaccine acceptance. |
Drivers and barriers of vaccine acceptance among pregnant women in Kenya
Otieno NA , Otiato F , Nyawanda B , Adero M , Wairimu WN , Ouma D , Atito R , Wilson A , Gonzalez-Casanova I , Malik FA , Widdowson MA , Omer SB , Chaves SS , Verani JR . Hum Vaccin Immunother 2020 16 (10) 1-9 Maternal vaccination coverage remains suboptimal globally and is lowest in low- and middle-income countries. Attitudes toward maternal vaccines have been characterized in middle-high income settings, however data from African countries are limited. We assessed drivers and barriers of vaccine acceptance among pregnant women in Kenya. We conducted a cross-sectional survey among pregnant women aged 15-49 y. We enrolled a convenience sample of women presenting for antenatal care at seven health-care facilities in four diverse counties (Nairobi, Mombasa, Marsabit, Siaya) of Kenya and from the community in two counties (Nairobi, Siaya). We described frequencies of socio-demographic characteristics of participants and their knowledge, attitudes, and beliefs regarding maternal vaccination. We enrolled 604 pregnant women with a median age of 26.5 y, of whom 48.2% had primary education or less. More than 95% agreed that maternal vaccines are "important for my health" and that getting vaccinated is "a good way to protect myself from disease". The most commonly cited reason in favor of maternal vaccination was disease prevention (53.2%). Fear of side effects to mother/baby (15.1%) was the most frequently reported potential barrier. Influenza vaccine is not in routine use in Kenya; however, 77.8% reported willingness to accept influenza vaccination during pregnancy. Maternal vaccination is well accepted among Kenyan pregnant women. We identified the provision of adequate vaccine information and addressing safety concerns as opportunities to improve maternal vaccine uptake. The expressed willingness to receive a vaccine not currently in routine use bodes well for implementation of new maternal vaccines in Kenya. |
The epidemiology and burden of influenza B/Victoria and B/Yamagata lineages in Kenya, 2012-2016
Emukule GO , Otiato F , Nyawanda BO , Otieno NA , Ochieng CA , Ndegwa LK , Muturi P , Bigogo G , Verani JR , Muthoka PM , Hunsperger E , Chaves SS . Open Forum Infect Dis 2019 6 (10) ofz421 Background: The impact of influenza B virus circulation in Sub-Saharan Africa is not well described. Methods: We analyzed data from acute respiratory illness (ARI) in Kenya. We assessed clinical features and age-specific hospitalization and outpatient visit rates by person-years for influenza B/Victoria and B/Yamagata and the extent to which circulating influenza B lineages in Kenya matched the vaccine strain component of the corresponding season (based on Northern Hemisphere [October-March] and Southern Hemisphere [April-September] vaccine availability). Results: From 2012 to 2016, influenza B represented 31% of all influenza-associated ARIs detected (annual range, 13-61%). Rates of influenza B hospitalization and outpatient visits were higher for <5 vs >/=5 years. Among <5 years, B/Victoria was associated with pneumonia hospitalization (64% vs 44%; P = .010) and in-hospital mortality (6% vs 0%; P = .042) compared with B/Yamagata, although the mean annual hospitalization rate for B/Victoria was comparable to that estimated for B/Yamagata. The 2 lineages co-circulated, and there were mismatches with available trivalent influenza vaccines in 2/9 seasons assessed. Conclusions: Influenza B causes substantial burden in Kenya, particularly among children aged <5 years, in whom B/Victoria may be associated with increased severity. Our findings suggest a benefit from including both lineages when considering influenza vaccination in Kenya. |
The impact of maternal HIV and malaria infection on the prevalence of congenital cytomegalovirus infection in Western Kenya
Otieno NA , Nyawanda BO , Otiato F , Oneko M , Amin MM , Otieno M , Omollo D , McMorrow M , Chaves SS , Dollard SC , Lanzieri TM . J Clin Virol 2019 120 33-37 BACKGROUND: Data on congenital cytomegalovirus (CMV) infection in Africa are limited. OBJECTIVE: To describe the prevalence of congenital CMV infection in a population with high prevalence of maternal HIV and malaria infection in western Kenya. STUDY DESIGN: We screened newborns for CMV by polymerase chain reaction assay of saliva swabs and dried blood spots (DBS), and assessed maternal CMV immunoglobulin G (IgG) status by testing serum eluted from newborn's DBS. We calculated adjusted prevalence ratios (aPRs) using log-binomial regression models. RESULTS: Among 1066 mothers, 210 (19.7%) had HIV infection and 207 (19.4%) had malaria infection; 33 (3.1%) mothers had both. Maternal CMV IgG prevalence was 93.1% (95% confidence interval [CI]: 88.3%-96.0%). Among 1078 newborns (12 sets of twins), 39 (3.6%, 95% CI: 2.7-4.9%) were CMV positive. The prevalence of congenital CMV infection by maternal HIV and malaria infection status was 5.0% (95% CI: 2.7-9.2%) for HIV only, 5.1% (95% CI: 2.7-9.4%) for malaria only, 8.8 (95% CI: 3.1-23.0) for HIV and malaria co-infection, and 2.6% (95% CI: 1.7-4.1%) for none. Congenital CMV infection was independently associated with maternal HIV infection (aPR=2.1; 95% CI: 1.0-4.2), adjusting for maternal age, parity, and malaria infection. CONCLUSIONS: The prevalence of congenital CMV infection was higher than the 0.2-0.7% in developed countries. Maternal HIV infection may increase the risk of congenital CMV infection, but the role of maternal malaria on intrauterine transmission of CMV remains unclear. |
A search for snail-related answers to explain differences in response of Schistosoma mansoni to praziquantel treatment among responding and persistent hotspot villages along the Kenyan Shore of Lake Victoria
Mutuku MW , Laidemitt MR , Beechler BR , Mwangi IN , Otiato FO , Agola EL , Ochanda H , Kamel B , Mkoji GM , Steinauer ML , Loker ES . Am J Trop Med Hyg 2019 101 (1) 65-77 Following a 4-year annual praziquantel (PZQ) treatment campaign, the resulting prevalence of Schistosoma mansoni was seen to differ among individual villages along the Kenyan shore of Lake Victoria. We have investigated possible inherent differences in snail-related aspects of transmission among such 10 villages, including six persistent hotspot (PHS) villages (</= 30% reduction in prevalence following repeated treatments) located along the west-facing shore of the lake and four PZQ-responding (RESP) villages (> 30% prevalence reduction following repeated treatment) along the Winam Gulf. When taking into account all sampling sites, times, and water hyacinth presence/absence, shoreline-associated Biomphalaria sudanica from PHS and RESP villages did not differ in relative abundance or prevalence of S. mansoni infection. Water hyacinth intrusions were associated with increased B. sudanica abundance. The deeper water snail Biomphalaria choanomphala was significantly more abundant in the PHS villages, and prevalence of S. mansoni among villages both before and after control was positively correlated with B. choanomphala abundance. Worm recoveries from sentinel mice did not differ between PHS and RESP villages, and abundance of non-schistosome trematode species was not associated with S. mansoni abundance. Biomphalaria choanomphala provides an alternative, deepwater mode of transmission that may favor greater persistence of S. mansoni in PHS villages. As we found evidence for ongoing S. mansoni transmission in all 10 villages, we conclude that conditions conducive for transmission and reinfection occur ubiquitously. This argues for an integrated, basin-wide plan for schistosomiasis control to counteract rapid reinfections facilitated by large snail populations and movements of infected people around the lake. |
Factors influencing acceptance of post-mortem examination of children at a tertiary care hospital in Nairobi, Kenya
Bunei M , Muturi P , Otiato F , Njuguna HN , Emukule GO , Otieno NA , Dawa J , Chaves SS . Ann Glob Health 2019 85 (1) BACKGROUND: Clinical autopsies are not often part of routine care, despite their role in clarifying cause of death. In fact, autopsy rates across the world have declined and are especially low in sub-Saharan Africa. OBJECTIVES: We set out to identify factors associated with acceptance of pediatric autopsies among parents of deceased children less than five years old, and examined local preferences for minimally invasive tissue sampling (MITS) procedures during post-mortem (PM) examinations. METHODS: From December 2016 to September 2017, we contacted 113 parents/next of kin who had been previously approached to consent to a PM examination of their deceased child as part of a Kenyan study on cause of death. Interviews occurred up to three years after the death of their child. FINDINGS: Seventy-three percent (83/113) of eligible study participants were enrolled, of whom 62/83 (75%) had previously consented to PM examination of their child. Those who previously consented to PM had higher levels of education, were more likely employed, and had more knowledge about certain aspects of autopsies than non-consenters. The majority (97%) of PM consenters did so because they wanted to know the cause of death of their child, and up to a third believed autopsy studies helped advance medical knowledge. Reasons for non-consent to PM examination included: parents felt there was no need for further examination (29%) or they were satisfied with the clinical diagnosis (24%). Overall, only 40% of study participants would have preferred MITS procedures to conventional autopsy. However, 81% of autopsy non-consenters would have accepted PM examination if it only involved MITS techniques. CONCLUSION: There is potential to increase autopsy rates by strengthening reasons for acceptance and addressing modifiable reasons for refusals. Although MITS procedures have the potential to improve autopsy acceptance rates, they were not significantly preferred over conventional autopsies in our study population. |
A comparison of Kenyan Biomphalaria pfeifferi and B. sudanica as vectors for Schistosoma mansoni, including a discussion of the need to better understand the effects of snail breeding systems on transmission
Mutuku M , Lu L , Otiato F , Mwangi IN , Kinuthia JM , Maina GM , Laidemitt MR , Lelo EA , Ochanda H , Loker ES , Mkoji GM . J Parasitol 2017 103 (6) 669-676 In Kenya, schistosomes infect an estimated 6 million people with >30 million people at risk of infection. We compared compatibility with, and ability to support and perpetuate, Schistosoma mansoni of Biomphalaria pfeifferi and Biomphalaria sudanica, 2 prominent freshwater snail species involved in schistosomiasis transmission in Kenya. Field-derived B. pfeifferi (from a stream in Mwea, central Kenya) and B. sudanica (from Nawa, Lake Victoria, in western Kenya) were exposed to S. mansoni miracidia isolated from fecal samples of naturally infected humans from Mwea or Nawa. Juvenile (<6 mm shell diameter), young adult (6-9 mm), and adult snails (>9 mm) were each exposed to a single miracidium. Schistosoma mansoni developed faster and consistently had higher infection rates (39.6-80.7%) in B. pfeifferi than in B. sudanica (2.4-21.5%), regardless of the source of S. mansoni or the size of the snails used. Schistosoma mansoni from Nawa produced higher infection rates in both B. pfeifferi and B. sudanica than did S. mansoni from Mwea. Mean daily cercariae production was greater for B. pfeifferi exposed to sympatric than allopatric S. mansoni (583-1,686 vs. 392-1,232), and mean daily cercariae production amongst B. sudanica were consistently low (50-590) with no significant differences between sympatric or allopatric combinations. Both non-miracidia exposed and miracidia-exposed B. pfeifferi had higher mortality rates than for B. sudanica, but mean survival time of shedding snails (9.3-13.7 weeks) did not differ significantly between the 2 snail species. A small proportion (1.5%) of the cercariae shedding B. pfeifferi survived up to 40 wk post-exposure. Biomphalaria pfeifferi was more likely to become infected and to shed more cercariae than B. sudanica, suggesting that the risk per individual snail of perpetuating transmission in Kenyan streams or lacustrine habitats may differ considerably. High infections rates exhibited by the preferential self-fertilizing B. pfeifferi relative to the out-crossing B. sudanica point out to the need to investigate further the role of host breeding systems in influencing transmission of schistosomiasis by snail hosts. |
- Page last reviewed:Feb 1, 2024
- Page last updated:May 13, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure