Research Article: Evaluating the costs of cholera illness and cost-effectiveness of a single dose oral vaccination campaign in Lusaka, Zambia

Date Published: May 31, 2019

Publisher: Public Library of Science

Author(s): Tannia Tembo, Michelo Simuyandi, Kanema Chiyenu, Anjali Sharma, Obvious N. Chilyabanyama, Clara Mbwili-Muleya, Mazyanga Lucy Mazaba, Roma Chilengi, Khin Thet Wai.

http://doi.org/10.1371/journal.pone.0215972

Abstract

In 2016, for the very first time, the Ministry of Health in Zambia implemented a reactive outbreak response to control the spread of cholera and vaccinated at-risk populations with a single dose of Shancol—an oral cholera vaccine (OCV). This study aimed to assess the costs of cholera illness and determine the cost-effectiveness of the 2016 vaccination campaign.

From April to June 2017, we conducted a retrospective cost and cost-effectiveness analysis in three peri-urban areas of Lusaka. To estimate costs of illness from a household perspective, a systematic random sample of 189 in-patients confirmed with V. cholera were identified from Cholera Treatment Centre registers and interviewed for out-of-pocket costs. Vaccine delivery and health systems costs were extracted from financial records at the District Health Office and health facilities. The cost of cholera treatment was derived by multiplying the subsidized cost of drugs by the quantity administered to patients during hospitalisation. The cost-effectiveness analysis measured incremental cost-effectiveness ratio—cost per case averted, cost per life saved and cost per DALY averted—for a single dose OCV.

The mean cost per administered vaccine was US$1.72. Treatment costs per hospitalized episode were US$14.49–US$18.03 for patients ≤15 years old and US$17.66–US$35.16 for older patients. Whereas households incurred costs on non-medical items such as communication, beverages, food and transport during illness, a large proportion of medical costs were borne by the health system. Assuming vaccine effectiveness of 88.9% and 63%, a life expectancy of 62 years and Gross Domestic Product (GDP) per capita of US$1,500, the costs per case averted were estimated US$369–US$532. Costs per life year saved ranged from US$18,515–US$27,976. The total cost per DALY averted was estimated between US$698–US$1,006 for patients ≤15 years old and US$666–US$1,000 for older patients.

Our study determined that reactive vaccination campaign with a single dose of Shancol for cholera control in densely populated areas of Lusaka was cost-effective.

Partial Text

Cholera is a significant global health problem and is endemic in Africa and Asia where access to improved water and sanitation is inadequate [1]. It can be acquired through ingestion of food or water contaminated with bacterium Vibrio Cholerae serogroup O1 or O139. Cholera disease is characterized by a sudden onset of acute watery diarrhea that can rapidly lead to death by severe dehydration, if untreated [2,3].

While some studies report vaccine delivery costs disaggregated by activities, several others disaggregate costs by inputs such as vaccine purchase, shipment, insurance, cold chain management, personnel incentives, training, transportation, social mobilization and local delivery. The delivery costs of OCVs via mass campaigns differ by country and even within the same country and the same setting [20,41–45]. The variations in cost estimates could considerably impact the scale up of OCV campaigns to prevent cholera outbreaks, hence the need to ascertain associated costs for individual settings.

Outbreak driven diseases often have considerable costs that may not be associated with providing patient care. Such costs may be problematic to collect. For instance, this study did not calculate costs associated with loss of tourism due to the cholera outbreak or movement of economic activity from a cholera affected area to a non- affected area. Neither did we estimate time and money incurred by households on acquiring vaccines, loss of income due to stigma suffered by cholera patients nor costs of burying deceased cholera patients.

In conclusion, a cost-effectiveness analysis based on defined vaccine effectiveness and treatment costs shows that a vaccination campaign using a single dose of Shancol among a single, homogeneous population is very cost effective. However, policy makers must consider other budgetary and logistical factors such as vaccine purchase and delivery, personnel training, distribution of Information, Communication and Education (IEC) materials before deciding to introduce OCVs as a control measure for cholera. Since this CEA was based on a single dose OCV, costs of may be significantly higher if two doses were to be administered within recommended time intervals.

 

Source:

http://doi.org/10.1371/journal.pone.0215972

 

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