Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-18 (of 18 Records) |
Query Trace: Sreenivasan N[original query] |
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Typhoid conjugate vaccine perceptions and coverage among children and adults: Findings from a post-campaign coverage survey - Harare, Zimbabwe, 2019
Gharpure R , Longley AT , Takamiya M , Hidle A , Munyanyi M , Chawurura T , Maxwell L , Mamire G , Chaora G , Chakauya J , Rupfutse M , Poncin M , Gasasira A , Date K , Manangazira P , Sreenivasan N . Vaccine 2024 BACKGROUND: In 2019, following a large outbreak of typhoid fever, the Zimbabwe Ministry of Health and Child Care conducted a typhoid conjugate vaccine (TCV) vaccination campaign in nine high-risk suburbs of Harare. We aimed to evaluate TCV vaccination coverage, vaccine perceptions, and adverse events reported after vaccination. METHODS: We conducted a two-stage cluster survey to estimate vaccination coverage in the campaign target areas among children aged 6 months-15 years and to classify coverage as either adequate (≥75 % coverage) or inadequate (<75 % coverage) among adults aged 16-45 years in one suburb. Questionnaires assessed socio-demographic factors, TCV vaccination history, reasons for receiving or not receiving TCV, adverse events following immunization, and knowledge and attitudes regarding typhoid and TCV. RESULTS: A total of 1,917 children from 951 households and 298 adults from 135 households enrolled in the survey. Weighted TCV coverage among all children aged 6 months-15 years was 85.3 % (95 % CI: 82.1 %-88.0 %); coverage was 74.8 % (95 % CI: 69.4 %-79.5 %) among children aged 6 months-4 years and 89.3 % (95 % CI: 86.2 %-91.7 %) among children aged 5-15 years. Among adults, TCV coverage was classified as inadequate with a 95 % confidence interval of 55.0 %-73.1 %. Among vaccinated persons, the most reported reason for receiving TCV (96 % across all age groups) was protection from typhoid fever; the most common reasons for non-vaccination were not being in Harare during the vaccination campaign and not being aware of the campaign. Adverse events were infrequently reported in all age groups (10 %) and no serious events were reported. CONCLUSIONS: The 2019 TCV campaign achieved high coverage among school-aged children (5-15 years). Strategies to increase vaccination coverage should be explored for younger children as part of Zimbabwe's integration of TCV into the routine immunization program, and for adults during future post-outbreak campaigns. |
Implementation of an outbreak response vaccination campaign with typhoid conjugate vaccine - Harare, Zimbabwe, 2019
Poncin M , Marembo J , Chitando P , Sreenivasan N , Makwara I , Machekanyanga Z , Nyabyenda W , Mukeredzi I , Munyanyi M , Hidle A , Chingwena F , Chigwena C , Atuhebwe P , Matzger H , Chigerwe R , Shaum A , Date K , Garone D , Chonzi P , Barak J , Phiri I , Rupfutse M , Masunda K , Gasasira A , Manangazira P . Vaccine X 2022 12 100201 INTRODUCTION: Typhoid fever is a public-health problem in Harare, the capital city of Zimbabwe, with seasonal outbreaks occurring annually since 2010. In 2019, the Ministry of Health and Child Care (MOHCC) organized the first typhoid conjugate vaccination campaign in Africa in response to a recurring typhoid outbreak in a large urban setting. METHOD: As part of a larger public health response to a typhoid fever outbreak in Harare, Gavi approved in September 2018 a MOHCC request for 340,000 doses of recently prequalified Typbar-TCV to implement a mass vaccination campaign. To select areas for the campaign, typhoid fever surveillance data from January 2016 until June 2018 was reviewed. We collected and analyzed information from the MOHCC and its partners to describe the vaccination campaign planning, implementation, feasibility, administrative coverage and financial costs. RESULTS: The campaign was conducted in nine high-density suburbs of Harare over eight days in February-March 2019 and targeted all children aged 6 months-15 years; however, the target age range was extended up to 45 years in one suburb due to the past high attack rate among adults. A total of 318,698 people were vaccinated, resulting in overall administrative coverage of 85.4 percent. More than 750 community volunteers and personnel from the MOHCC and the Ministry of Education were trained and involved in social mobilization and vaccination activities. The MOHCC used a combination of vaccination strategies (i.e., fixed and mobile immunization sites, a creche and school-based strategy, and door-to-door activities). Financial costs were estimated at US$ 2.39 per dose, including the vaccine and vaccination supplies (US$ 0.79 operational costs per dose excluding vaccine and vaccination supplies). CONCLUSION: A mass targeted campaign in densely populated urban areas in Harare, using the recently prequalified typhoid conjugate vaccine, was feasible and achieved a high overall coverage in a short period of time. |
Enhanced surveillance for adverse events following immunization during the 2019 typhoid conjugate vaccine campaign in Harare, Zimbabwe
Shaum A , Mujuru HA , Takamiya M , Ticklay I , Nathoo K , Sreenivasan N , Nyambayo P , Chitando P , Marembo J , Koline Chigodo C , Mukaratirwa A , Jacha V , Gidudu JF , Rupfutse M , Kumar Jain S , Manangazira P , Bennett SD . Vaccine 2022 40 (26) 3573-3580 BACKGROUND: During February 25-March 4, 2019, Zimbabwe's Ministry of Health and Child Care conducted an emergency campaign using 342,000 doses of typhoid conjugate vaccine (TCV) targeting individuals 6 months-15 years of age in eight high-risk suburbs of Harare and up to 45 years of age in one suburb of Harare. The campaign represented the first use of TCV in Africa outside of clinical trials. METHODS: Three methods were used to capture adverse events during the campaign and for 42 days following the last dose administered: (1) active surveillance in two Harare hospitals, (2) national passive surveillance, and (3) a post-campaign coverage survey. RESULTS: Thirty-nine adverse events were identified during active surveillance, including 19 seizure cases (16 were febrile), 16 hypersensitivity cases, 1 thrombocytopenia case, 1 anaphylaxis case, and two cases with two conditions. Only 21 (54%) of 39 patients were hospitalized and 38 recovered without sequelae. Attack rates per 100,000 TCV doses administered were highest for seizures (6.27) and hypersensitivity (5.02). Only 6 adverse events were reported through passive surveillance by facilities other than the two active surveillance hospitals. A total of 177 (10%) of 1,817 vaccinees surveyed reported experiencing an adverse event during the post-campaign coverage survey, of which 25 (14%) sought care. CONCLUSIONS: In line with previous evaluations of TCV, enhanced adverse event monitoring during an emergency campaign supports the safety of TCV. The majority of reported events were minor or resulted in recovery without long-term sequelae. Attack rates for seizures and hypersensitivity were low compared with previous active surveillance studies conducted in Kenya and Burkina Faso. Strengthening adverse event monitoring in Zimbabwe and establishing background rates of conditions of interest in the general population may improve future safety monitoring during new vaccine introductions. |
Global oral cholera vaccine use, 2013-2018
Pezzoli L , Oral Cholera Vaccine Working Group of the Global Task Force on Cholera Control , Date K , Sreenivasan N . Vaccine 2020 38 Suppl 1 A132-a140 Vaccination is a key intervention to prevent and control cholera in conjunction with water, sanitation and hygiene activities. An oral cholera vaccine (OCV) stockpile was established by the World Health Organization (WHO) in 2013. We reviewed its use from July 2013 to all of 2018 in order to assess its role in cholera control. We computed information related to OCV deployments and campaigns conducted including setting, target population, timelines, delivery strategy, reported adverse events, coverage achieved, and costs. In 2013-2018, a total of 83,509,941 OCV doses have been requested by 24 countries, of which 55,409,160 were approved and 36,066,010 eventually shipped in 83 deployments, resulting in 104 vaccination campaigns in 22 countries. OCVs had in general high uptake (mean administrative coverage 1st dose campaign at 90.3%; 2nd dose campaign at 88.2%; mean survey-estimated two-dose coverage at 69.9%, at least one dose at 84.6%) No serious adverse events were reported. Campaigns were organized quickly (five days median duration). In emergency settings, the longest delay was from the occurrence of the emergency to requesting OCV (median: 26 days). The mean cost of administering one dose of vaccine was 2.98 USD. The OCV stockpile is an important public health resource. OCVs were generally well accepted by the population and their use demonstrated to be safe and feasible in all settings. OCV was an inexpensive intervention, although timing was a limiting factor for emergency use. The dynamic created by the establishment of the OCV stockpile has played a role in the increased use of the vaccine by setting in motion a virtuous cycle by which better monitoring and evaluation leads to better campaign organization, better cholera control, and more requests being generated. Further work is needed to improve timeliness of response and contextualize strategies for OCV delivery in the various settings. |
Human Monoclonal Antibody Derived from Transchromosomic (Tc) Cattle Neutralizes Multiple H1 Clades of Influenza A Virus by Recognizing a Novel Conformational Epitope in the HA Head Domain.
Gao R , Sreenivasan CC , Sheng Z , Hause BM , Zhou B , Wentworth DE , Clement T , Rausch D , Brunick C , Christopher-Hennings J , Wu H , Bausch CL , Sullivan EJ , Hoppe AD , Huber VC , Wang D , Li F . J Virol 2020 94 (22) ![]() Influenza remains a global health risk and challenge. Currently, NA inhibitors are extensively used to treat influenza, but their efficacy is compromised by the emergence of drug resistant variants. Neutralizing antibodies targeting influenza A virus surface glycoproteins are critical components of influenza therapeutic agents and may provide alternative strategies to the existing countermeasures. However, the major hurdle for the extensive application of antibody therapies lies in the difficulty of generating non-immunogenic antibodies in large quantities rapidly. Here, we report one human monoclonal antibody (mAb), 53C10, isolated from transchromosomic (Tc) cattle exhibits potent neutralization and hemagglutination inhibition titers against different clades of H1N1 subtype influenza A viruses. In vitro selection of antibody escape mutants reveals that 53C10 recognizes a novel non-continuous epitope in the HA head domain involving three amino acid residues, glycine (G), Serine (S) and glutamic acid (E) at positions172, 207 and 212, respectively. The results of our experiments supported a critical role for substitution of arginine at position 207 (S207R) in mediating resistance to 53C10, while substitutions at either G172E or E212A did not alter antibody recognition and neutralization. The E212A mutation may provide structural stability for the epitope, while the substitution G172E probably compensates for loss of fitness introduced by S207R. Our results offer novel insights into the mechanism of action of mAb 53C10 and indicate its potential role in therapeutic treatment of H1 influenza virus infection in humans.IMPORTANCE Respiratory diseases caused by influenza viruses still pose a serious concern to global health and neutralizing antibodies constitute a promising area of antiviral therapeutics. However, the potential application of antibodies is often hampered by the challenge in generating non-immunogenic antibodies in large scale. In the present study, the transchromosomic (Tc) cattle were used for the generation of non-immunogenic monoclonal antibodies (mAbs) and characterization of such mAbs revealed one monoclonal antibody 53C10, exhibiting a potent neutralization activity against H1N1 influenza viruses. Further characterization of the neutralization-escape mutant generated using this mAb, showed that three amino acid substitutions in the HA head domain contributed to the resistance. These findings emphasize the importance of Tc cattle in the production of non-immunogenic mAbs and highlight the potential of 53C10 mAb in the therapeutic application against H1 influenza virus infection in humans. |
Notes from the Field: Characteristics of Meat Processing Facility Workers with Confirmed SARS-CoV-2 Infection - Nebraska, April-May 2020.
Donahue M , Sreenivasan N , Stover D , Rajasingham A , Watson J , Bealle A , Ritchison N , Safranek T , Waltenburg MA , Buss B , Reefhuis J . MMWR Morb Mortal Wkly Rep 2020 69 (31) 1020-1022 Coronavirus disease 2019 (COVID-19) has been reported nationwide among meat processing facility workers (1). In late April 2020, through flyers and text messages, workers at a Nebraska meat processing facility were invited by the facility, in partnership with the Nebraska Department of Health and Human Services, to be tested for current SARS-CoV-2, the virus that causes COVID-19, at their worksite, free of charge. Specimens were analyzed using reverse transcription–polymerase chain reaction (RT-PCR) by a contracting laboratory. This investigation was determined by CDC to be public health surveillance.* Among 1,216 Nebraska-resident meat processing facility workers tested, 375 (31%) had positive results. During May 8–25, case investigators attempted to interview the 349 workers who had positive test results and available phone numbers; five refused, 99 were not reached after five attempts, and four did not report symptom status, leaving 241 (69%) of the attempted interviews for analysis. |
Notes from the Field: Cholera outbreak - Zimbabwe, September 2018-March 2019
Winstead A , Strysko J , Relan P , Conners EE , Martinsen AL , Lopez V , Arons M , Masunda KPE , Mukeredzi I , Manyara J , Duri C , Mashe T , Phiri I , Poncin M , Sreenivasan N , Aubert RD , Fuller L , Balachandra S , Mintz E , Manangazira P . MMWR Morb Mortal Wkly Rep 2020 69 (17) 527-528 During September 5–6, 2018, a total of 52 patients in Harare, Zimbabwe, were hospitalized with suspected cholera, an acute bacterial infection characterized by watery diarrhea. Rapid diagnostic testing was positive for Vibrio cholerae O1, and on September 6, Zimbabwe’s Ministry of Health and Child Care (MOHCC) declared an outbreak of cholera. From September 4, 2018, (date of the first reported cases) through March 12, 2019, a total of 10,730 cases and 69 (0.64%) deaths were reported nationally from nine of Zimbabwe’s 10 provinces (Figure). Most cases (94%) were reported from Harare Province, the country’s largest province, with a population of approximately 2 million. |
Oral cholera vaccination coverage after the first global stockpile deployment in Haiti, 2014
Burnett EM , Francois J , Sreenivasan N , Wannemuehler K , Faye PC , Tohme RA , Delly P , Deslouches YG , Etheart MD , Dismer AM , Patel R , Date K . Vaccine 2019 37 (43) 6348-6355 INTRODUCTION: In 2014, an oral cholera vaccine (OCV) campaign targeting 185,314 persons aged >/=1years was conducted in 3 departments via fixed post and door-to-door strategies. This was the first use of the global OCV stockpile in Haiti. METHODS: We conducted a multi-stage cluster survey to assess departmental OCV coverage. Target population estimates were projected from the 2003 Haiti population census with adjustments for population growth and estimated proportion of pregnant women. In the three departments, we sampled 30/106 enumeration areas (EAs) in Artibonite, 30/244 EAs in Centre, and 20/29 EAs in Ouest; 20 households were systematically sampled in each EA. Household and individual interviews using a standard questionnaire were conducted in each selected household; data on OCV receipt were obtained from vaccination card or verbal report. We calculated OCV campaign coverage estimates and 95% confidence intervals (CIs) accounting for survey design. RESULTS: Overall two-dose OCV coverage was 70% (95% CI: 60, 79), 63% (95% CI: 55, 71), and 44% (95% CI: 35, 53) in Artibonite, Centre, and Ouest, respectively. Two-dose coverage was higher in the 1-4years age group than among those>/=15years in Artibonite (difference: 11%; 95% CI: 5%, 17%) and Ouest (difference: 12%; 95% CI: 3, 20). A higher percentage of children aged 5-14years received both recommended doses than did those>/=15years (Artibonite: 14% (95% CI: 8%, 19%) difference; Centre: 11% difference (95% CI: 5%, 17%); Ouest: 10% difference (95% CI: 2%, 17%). The most common reason for not receiving any OCV dose was being absent during the campaign or not having heard about vaccination activities. CONCLUSIONS: While coverage estimates in Artibonite and Centre were comparable with other OCV campaigns in Haiti and elsewhere, inadequate social mobilization and outdated population estimates might have contributed to lower coverage in Ouest. |
Overview of rabies post-exposure prophylaxis access, procurement and distribution in selected countries in Asia and Africa, 2017-2018
Sreenivasan N , Li A , Shiferaw M , Tran CH , Wallace R , Blanton J , Knopf L , Abela-Ridder B , Hyde T . Vaccine 2019 37 Suppl 1 A6-A13 BACKGROUND: Rabies is a neglected zoonotic disease with a global burden of approximately 59,000 human deaths a year. Once clinical symptoms appear, rabies is almost invariably fatal; however, with timely and appropriate post-exposure prophylaxis (PEP) consisting of wound washing, vaccine, and in some cases rabies immunoglobulin (RIG), the disease is almost entirely preventable. Access to PEP is limited in many countries, and when available, is often very expensive. METHODS: We distributed a standardized assessment tool electronically to a convenience sample of 25 low- and middle-income countries in Asia and Africa to collect information on rabies PEP procurement, forecasting, distribution, monitoring and reporting. Information was collected from national rabies focal points, focal points at the World Health Organization (WHO) country offices, and others involved in procurement, logistics and distribution of PEP. Because RIG was limited in availability or unavailable in many countries, the assessment focused on vaccine. Data were collected between January 2017 and May 2018. RESULTS: We received responses from key informants in 23 countries: 11 countries in Asia and 12 countries in Africa. In 9 of 23 (39%) countries, rabies vaccine was provided for free in the public sector and was consistently available. In 10 (43%) countries, all or some patients were required to pay for the vaccine in the public sector, with the cost of a single dose ranging from US$ 6.60 to US$ 20/dose. The primary reason for the high cost of the vaccine for patients was a lack of funding at the central level to subsidize vaccine costs. In the remaining 4 (17%) countries, vaccine was provided for free but was often unavailable so patients were required to purchase it instead. The majority of countries used the intramuscular route for vaccine administration and only 5 countries exclusively used the dose-sparing intradermal (ID) route. Half (11/22; 50%) of all countries assessed had a standardized distribution system for PEP, separate from the systems used for routine childhood vaccines, and almost half used separate storage facilities at both central and health facility levels. Approximately half (9/22; 41%) of all countries assessed reported having regular weekly, monthly or quarterly reporting on rabies vaccination. CONCLUSIONS: While all countries in our assessment had rabies vaccines available in the public sector to some extent, barriers to access include the high cost of the vaccine to the government as well as to patients. Countries should be encouraged to use ID administration as this would provide access to rabies vaccine for many more people with the same number of vaccine vials. In addition, standardized monitoring and reporting of vaccine utilization should be encouraged, in order to improve data on PEP needs. |
Community-based household assessment of human papillomavirus (HPV) vaccination coverage and acceptability - HPV vaccine demonstration program, Cambodia - 2017
Garon J , Wuddhika IV , Sreenivasan N , Wannemuehler K , Vutthikol Y , Chhorvann C , Loharikar A . Vaccine 2019 37 (9) 1202-1208 BACKGROUND: In 2017, the Cambodia Ministry of Health introduced human papillomavirus (HPV) vaccine through primarily school-based vaccination targeting 9-year-old girls. Vaccination with a two-dose series of HPV vaccine took place in six districts in two provinces as a demonstration program, to better understand HPV vaccine delivery in Cambodia. METHODS: We conducted a community-based coverage survey using a one-stage sampling design to evaluate dose-specific vaccination coverage among eligible girls (those born in 2007 and residents in the areas targeted by the campaign). The household-level survey also assessed factors associated with vaccine acceptability and communication strategies. Trained data collectors interviewed caregivers and girls using a standard questionnaire; vaccination cards and health facility records were reviewed. RESULTS: Of the 7594 households visited in the two provinces, 315 girls were enrolled in the survey (188 in Siem Reap; 127 in Svay Rieng). Documented two-dose HPV vaccination coverage was 84% (95% confidence interval [CI]: 78-88%) overall [85% (95% CI: 78-90%) in Siem Reap; 82% (95% CI: 73-88%) in Svay Rieng.] Almost all girls (>99%) were reported to be enrolled in school and over 90% of respondents reported receipt of vaccine in school. Knowledge of HPV infection and associated diseases was poor among caregivers and girls; however, 58% of caregivers reported "protection from cervical cancer" as the primary reason for the girl receiving vaccine. No serious adverse events after immunization were reported. CONCLUSIONS: The HPV vaccine demonstration program in Cambodia achieved high two-dose coverage among eligible girls in both provinces targeted for vaccination in 2017, through primarily school-based vaccination. High school enrollment and strong microplanning and coordination were seen throughout the campaign. Cambodia will use lessons learned from this demonstration program to prepare for national introduction of HPV vaccine. |
Descriptive assessment of rabies post-exposure prophylaxis procurement, distribution, monitoring, and reporting in four Asian countries: Bangladesh, Bhutan, Cambodia, and Sri Lanka, 2017-2018
Li AJ , Sreenivasan N , Siddiqi UR , Tahmina S , Penjor K , Sovann L , Gunesekera A , Blanton JD , Knopf L , Hyde TB . Vaccine 2018 37 Suppl 1 A14-A19 BACKGROUND: There are approximately 35,000 human deaths from rabies in Asia annually. Rabies can be prevented through timely post-exposure prophylaxis (PEP) consisting of wound washing, rabies vaccine, and in some cases, rabies immunoglobulin (RIG). However, access to rabies PEP often remains limited to urban areas and is cost-prohibitive. There is little information on procurement, distribution, monitoring, and reporting of rabies PEP. METHODS: We interviewed key informants in the public sector from various levels in Bangladesh, Bhutan, Cambodia, and Sri Lanka between March 2017 and May 2018 using a descriptive assessment tool to obtain information on procurement, distribution, monitoring, and reporting of rabies PEP. These four countries in Asia were chosen to showcase a range of rabies PEP systems. National rabies focal points were interviewed in each country and focal points helped identify additional key informants at lower levels. RESULTS: A total of 22 key informants were interviewed at various levels (central level to health facility level) including national rabies focal points in each country. Each country has a unique system for managing rabies PEP procurement, distribution, monitoring, and reporting. There are varying levels of PEP access for those with potential rabies exposures. Rabies PEP is available in select health facilities throughout the country in Bangladesh, Bhutan, and Sri Lanka. In Cambodia, rabies PEP is limited to two urban centers. The availability of RIG in all four countries is limited. In these four countries, most aspects of the rabies PEP distribution system operate independently of systems for other vaccines. However, in Bhutan, rabies PEP and Expanded Programme on Immunization (EPI) vaccines share cold chain space in some locations at the lowest level. All countries have a monitoring system in place, but there is limited reporting of data, particularly to the central level. CONCLUSION: Systems to procure, deliver, monitor, and report on rabies PEP are variable across countries. Sharing information on practices more widely among countries can help programs to increase access to this life-saving treatment. |
Lessons learned from emergency response vaccination efforts for cholera, typhoid, yellow fever, and Ebola
Walldorf JA , Date KA , Sreenivasan N , Harris JB , Hyde TB . Emerg Infect Dis 2017 23 (13) S210-6 Countries must be prepared to respond to public health threats associated with emergencies, such as natural disasters, sociopolitical conflicts, or uncontrolled disease outbreaks. Rapid vaccination of populations vulnerable to epidemic-prone vaccine-preventable diseases is a major component of emergency response. Emergency vaccination planning presents challenges, including how to predict resource needs, expand vaccine availability during global shortages, and address regulatory barriers to deliver new products. The US Centers for Disease Control and Prevention supports countries to plan, implement, and evaluate emergency vaccination response. We describe work of the Centers for Disease Control and Prevention in collaboration with global partners to support emergency vaccination against cholera, typhoid, yellow fever, and Ebola, diseases for which a new vaccine or vaccine formulation has played a major role in response. Lessons learned will help countries prepare for future emergencies. Integration of vaccination with emergency response augments global health security through reducing disease burden, saving lives, and preventing spread across international borders. |
Cost evaluation of a government-conducted oral cholera vaccination campaign-Haiti, 2013
Routh JA , Sreenivasan N , Adhikari BB , Andrecy LL , Bernateau M , Abimbola T , Njau J , Jackson E , Juin S , Francois J , Tohme RA , Meltzer MI , Katz MA , Mintz ED . Am J Trop Med Hyg 2017 97 37-42 The devastating 2010 cholera epidemic in Haiti prompted the government to introduce oral cholera vaccine (OCV) in two high-risk areas of Haiti. We evaluated the direct costs associated with the government's first vaccine campaign implemented in August-September 2013. We analyzed data for major cost categories and assessed the efficiency of available campaign resources to vaccinate the target population. For a target population of 107,906 persons, campaign costs totaled $624,000 and 215,295 OCV doses were dispensed. The total vaccine and operational cost was $2.90 per dose; vaccine alone cost $1.85 per dose, vaccine delivery and administration $0.70 per dose, and vaccine storage and transport $0.35 per dose. Resources were greater than needed-our analyses suggested that approximately 2.5-6 times as many persons could have been vaccinated during this campaign without increasing the resources allocated for vaccine delivery and administration. These results can inform future OCV campaigns in Haiti. |
Recurrence of Guinea worm disease in Chad after a 10-year absence: Risk factors for human cases identified in 2010-2011
Sreenivasan N , Weiss A , Djiatsa JP , Toe F , Djimadoumaji N , Ayers T , Eberhard M , Ruiz-Tiben E , Roy S . Am J Trop Med Hyg 2017 97 (2) 575-582 A decade after reporting its last case of Guinea worm disease (GWD), a waterborne parasitic disease targeted for eradication, Chad reported 20 confirmed human cases from 17 villages-10 cases in 2010 and 10 cases in 2011. In 2012, the first GWD dog infections were diagnosed. We conducted a case-control study during April-May 2012 to identify human transmission risk factors and epidemiologic links. We recruited 19 cases and 45 controls matched by age, sex, time, and location of exposure based on the case patients' periods of infection 10-14 months earlier. Data were analyzed with simple conditional logistic regression models using Firth penalized likelihood methods. Unusually, GWD did not appear to be associated with household primary water sources. Instead, secondary water sources, used outside the village or other nonprimary sources used at home, were risk factors (matched odds ratio = 38.1, 95% confidence interval = 1.6-728.2). This study highlights the changing epidemiology of GWD in Chad-household primary water sources were not identified as risk factors and few epidemiologic links were identified between the handfuls of sporadic cases per year, a trend that continues. Since this investigation, annual dog infections have increased, far surpassing human cases. An aquatic paratenic host is a postulated mode of transmission for both dogs and humans, although fish could not be assessed in this case-control study due to their near-universal consumption. GWD's evolving nature in Chad underscores the continued need for interventions to prevent both waterborne and potential foodborne transmission until the true mechanism is established. |
A qualitative inquiry about pruno, an illicit alcoholic beverage linked to botulism outbreaks in United States prisons
Walters MS , Sreenivasan N , Person B , Shew M , Wheeler D , Hall J , Bogdanow L , Leniek K , Rao A . Am J Public Health 2015 105 (11) e1-e6 OBJECTIVES: Since 2011, 3 outbreaks of botulism in US prisons have been attributed to pruno, which is an alcoholic beverage made by inmates. Following 1 outbreak, we conducted a qualitative inquiry to understand pruno brewing and its social context to inform outbreak prevention measures. METHODS: We interviewed staff, inmates, and parolees from 1 prison about pruno production methods, the social aspects of pruno, and strategies for communicating the association between botulism and pruno. RESULTS: Twenty-seven inmates and parolees and 13 staff completed interviews. Pruno is fermented from water, fruit, sugar, and miscellaneous ingredients. Knowledge of pruno making was widespread among inmates; staff were familiar with only the most common ingredients and supplies inmates described. Staff and inmates described inconsistent consequences for pruno possession and suggested using graphic health messages from organizations external to the prison to communicate the risk of botulism from pruno. CONCLUSIONS: Pruno making was frequent in this prison. Improved staff recognition of pruno ingredients and supplies might improve detection of brewing activities in this and other prisons. Consistent consequences and clear messages about the association between pruno and botulism might prevent outbreaks. |
International outbreak investigation of Salmonella Heidelberg associated with in-flight catering
Rebolledo J , Garvey P , Ryan A , O'Donnell J , Cormican M , Jackson S , Cloak F , Cullen L , Swaan CM , Schimmer B , Appels RW , Nygard K , Finley R , Sreenivasan N , Lenglet A , Gossner C , McKeown P . Epidemiol Infect 2014 142 (4) 833-42 Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10.2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations. |
Evaluation of the impact of a simple hand-washing and water-treatment intervention in rural health facilities on hygiene knowledge and reported behaviours of health workers and their clients, Nyanza Province, Kenya, 2008
Sreenivasan N , Gotestrand SA , Ombeki S , Oluoch G , Fischer TK , Quick R . Epidemiol Infect 2014 143 (4) 1-8 Many clinics in rural western Kenya lack access to safe water and hand-washing facilities. To address this problem, in 2005 a programme was initiated to install water stations for hand washing and drinking water in 109 health facilities, train health workers on water treatment and hygiene, and motivate clients to adopt these practices. In 2008, we evaluated this intervention's impact by conducting observations at facilities, and interviewing staff and clients about water treatment and hygiene. Of 30 randomly selected facilities, 97% had water stations in use. Chlorine residuals were detectable in at least one container at 59% of facilities. Of 164 interviewed staff, 79% knew the recommended water-treatment procedure. Of 298 clients, 45% had received training on water treatment at a facility; of these, 68% knew the recommended water-treatment procedure. Use of water stations, water treatment, and client training were sustained in some facilities for up to 3 years. |
Cholera epidemic associated with consumption of unsafe drinking water and street-vended water - eastern Freetown, Sierra Leone, 2012
Nguyen VD , Sreenivasan N , Lam E , Ayers T , Kargbo D , Dafae F , Jambai A , Alemu W , Kamara A , Islam MS , Stroika S , Bopp C , Quick R , Mintz ED , Brunkard JM . Am J Trop Med Hyg 2014 90 (3) 518-23 During 2012, Sierra Leone experienced a cholera epidemic with 22,815 reported cases and 296 deaths. We conducted a matched case-control study to assess risk factors, enrolling 49 cases and 98 controls. Stool specimens were analyzed by culture, polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE). Conditional logistic regression found that consuming unsafe water (matched odds ratio [mOR]: 3.4; 95% confidence interval [CI]: 1.1, 11.0), street-vended water (mOR: 9.4; 95% CI: 2.0, 43.7), and crab (mOR: 3.3; 95% CI: 1.03, 10.6) were significant risk factors for cholera infection. Of 30 stool specimens, 13 (43%) showed PCR evidence of toxigenic Vibrio cholerae O1. Six specimens yielded isolates of V. cholerae O1, El Tor; PFGE identified a pattern previously observed in seven countries. We recommended ensuring the quality of improved water sources, promoting household chlorination, and educating street vendors on water handling practices. |
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