Document [original]

HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

Economic impact of cholera in

households in rural southern Malawi: a

prospective study

Amber Hsiao ,1 Enusa Ramani,1,2 Hye- Jin Seo,3 GiDeok Pak,4 Dan Vuntade,5

Maurice M’bang’ombe,6 Bagrey Ngwira,5 Wilm Quentin,1 Florian Marks ,7,8

Vittal Mogasale 2

To cite: HsiaoA, RamaniE,

SeoH- J, etal. Economic

impact of cholera in households

in rural southern Malawi: a

prospective study. BMJ Open

2022;12:e052337. doi:10.1136/

bmjopen-2021-052337

►Prepublication history and

additional supplemental material

for this paper are available

online. To view these files,

please visit the journal online

(http://dx.doi.org/10.1136/

bmjopen-2021-052337).

BN since deceased.

Received 13 April 2021

Accepted 08 March 2022

For numbered affiliations see

end of article.

Correspondence to

Dr Vittal Mogasale;

vmogasale@ gmail. com

Original research

employer(s)) 2022. Re- use

permitted under CC BY.

Published by BMJ.

ABSTRACT

Introduction Cholera remains a significant contributor

to diarrhoeal illness, especially in sub- Saharan Africa.

Few studies have estimated the cost of illness (COI) of

cholera in Malawi, a cholera- endemic country. The present

study estimated the COI of cholera in Nsanje, southern

Malawi, as part of the Cholera Surveillance in Malawi

(CSIMA) programme following a mass cholera vaccination

campaign in 2015.

Methods Patients ≥12 months of age who were recruited

as part of CSIMA were invited to participate in the COI

survey. The COI tool captured household components

of economic burden, including direct medical and non-

medical costs, and indirect lost productivity costs.

Results Between April 2016 and March 2020, 40 cholera

cases were enrolled in the study, all of whom participated

in the COI survey. Only two patients had any direct medical

costs and five patients reported lost wages due to illness.

The COI per patient was US$14.34 (in 2020), more than

half of which was from direct non- medical costs from

food, water, and transportation to the health centre.

Conclusion For the majority of Malawians who struggle

to subsist on less than US$2 a day, the COI of cholera

represents a significant cost burden to families. While

cholera treatment is provided for free in government- run

health centres, additional investments in cholera control

and prevention at the community level and financial

support beyond direct medical costs may be necessary to

alleviate the economic burden of cholera on households in

southern Malawi.

INTRODUCTION

Cholera is an infection of the intestine caused

by the bacterium Vibrio cholerae that leads to

acute, rapidly dehydrating diarrhoeal disease.

Annually, an estimated 2.86 million cases of

cholera occur in cholera- endemic countries

that result in 95 000 deaths.1 A recent study

estimated that cholera is especially pervasive

throughout sub- Saharan Africa (sSA) where

the human and economic burden of cholera

is greatest, with more than 200 million people

living in areas where cholera is present. Of

these 200 million, 87 million live in areas with

high incidence, defined as >1 case per 1000

people per year.2

While improvements to water, sanitation

and hygiene (WASH) are the best long- term

solution for preventing more diarrhoeal

diseases, these measures remain unavailable

to large proportions of people in sSA, espe-

cially among those living in flood- prone rural

areas. The availability of low- cost inactivated

oral cholera vaccines (OCVs) since 2011

has significantly changed the landscape and

provided a cost- effective short- to- middle- term

approach for cholera prevention and control.3

A number of mass vaccination campaigns—

many of which have taken place in sSA—

have demonstrated that it can be successfully

administered in a variety of settings, including

high- risk settings to prevent an impending

outbreak, or to quickly halt the transmission

of an ongoing outbreak.4 5

In Malawi specifically, cholera has been

reported since the 1970s and is endemic to

the country.6–8 The extent of the cholera

burden in the country has not been well

documented due to the lack of sustainable

diagnostic and surveillance capacity.

One of the worst cholera outbreaks to

date occurred in January 2015 following the

nation’s worst floods in history, which affected

more than 1.1 million people in the Southern

Region and displaced at least 230 000 people

STRENGTHS AND LIMITATIONS OF THIS STUDY

⇒We recruited patients who were cholera- confirmed

at the time they first sought care and interviewed

them regarding costs incurred due to illness with-

in 7 days following their initial health facility visit,

which limited recall bias.

⇒The sample size was relatively small, which limits

the generalisability of the findings.

⇒The cost of illness estimate is likely to be an under-

estimate as it only includes out- of- pocket expendi-

tures of patients who sought care.

2HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

from their homes.9 Within a month of the flood, cholera

cases were being reported in Nsanje and Chikwawa, two

of the worst- hit districts in southern Malawi. The flooding

led to a multistakeholder response to coordinate a reac-

tive OCV mass vaccination campaign in the region.10

Due to the lack of diagnostic capacity, cholera cases were

being diagnosed based on clinical presentation as per the

WHO and national guidelines.11

The OCV mass vaccination campaign was then imple-

mented primarily in Nsanje, which was identified as having

the highest burden of cholera based on prior years’ data

provided by the Malawian Ministry of Health (MOH).

From 30 March 2015 to 23 April 2015, the International

Vaccine Institute (IVI), MOH, WHO and John Snow, Inc

coordinated a reactive mass vaccination campaign that

targeted 160 000 people (320 000 total doses of the OCV

Shanchol (Shantha Biotechnics Pvt, Ltd., India) over

1 year of age. Those living in high- risk areas of Nsanje—

namely, those living in internally displaced camps and

surrounding villages—were the primary targets.10

In the course of a 4- year effort to strengthen cholera

surveillance capacity and infrastructure in Nsanje

following the mass vaccination campaign, we investi-

gated the cost of illness (COI) of cholera for patients who

sought care. Only one study to date has reported on the

COI from cholera in southeastern Malawi (Lake Chilwa

in the districts of Machinga and Zomba).12 The objec-

tive of this study is to provide additional field data on the

economic burden of cholera in Malawi from a household

perspective.

METHODS

As part of the Cholera Surveillance in Malawi (CSIMA)

programme, cholera surveillance was conducted across

22 Nsanje (population >292 000) and 18 Chikwawa

(population >533 000) healthcare facilities from 5 April

2016 to 31 March 2020. IVI staff trained health surveil-

lance assistants (HSAs) and health workers at all Nsanje

and Chikwawa facilities to identify patients who sought

care for acute watery diarrhoea. HSAs are community

health facilitators who live in the area served by the local

healthcare facility who are involved in activities such as

WASH and general health promotion.

Patients who met the inclusion criteria (who were

eligible to receive OCV based being at least 12 months

of age at the start of the vaccination campaign, and

presented to an Nsanje health facility with acute watery

diarrhoea indicative of cholera as defined by the WHO11)

were invited to participate in the diarrhoeal surveil-

lance study. Participants who provided informed written

consent provided a stool specimen to perform a rapid

diagnostic test (RDT) for cholera (Crystal VC RDT; Arkray

Healthcare Pvt, India; previously Span Diagnostics, Surat,

India) and/or a stool sample for culture confirmation at

the national reference laboratory in Lilongwe. The use of

RDTs has been accepted for use by the Malawi MOH, and

there is documented experience with this test kit in other

settings.13 14 While the use of the RDT is not intended to

be a substitute for stool culture, the use of the kit in this

setting ensured that one would not miss any potential

cholera cases during the early surveillance period while

logistics for stool transportation and culture were being

set- up.

Between 6 April 2016 and 12 December 2017, culture-

confirmed and RDT- positive cholera cases were recruited

for the overall study, as well as the COI survey compo-

nent. However, due to low recruitment numbers of RDT-

confirmed and/or culture- confirmed cholera cases,

in part due to limited availability of RDT kits and stool

collection logistical challenges, the inclusion criteria were

expanded from 12 December 2017, through 31 March

2020, to include clinically diagnosed cholera cases in an

outbreak situation to avoid missing potential cases.

While cholera vaccines were administered to residents

in both Nsanje and Chikwawa, the majority of doses were

administered to residents of Nsanje. Thus, only patients

recruited from Nsanje health centres were invited for

the COI portion of the study. The COI from a house-

hold perspective was assessed for patients who provided

written informed consent (regardless of vaccination

status). The COI tool (online supplemental material)

was developed based on a tool that IVI had previously

used for other COI studies, with further refinements

using the guidelines for cost collection in cholera studies

provided by the WHO.15 16 The survey tool captured

household components of economic burden, divided

further into direct medical costs (DMCs), direct non-

medical costs (DNMCs) and indirect costs (ICs) (as

done in the previous studies17), with the payer being the

patients themselves or caregivers/helpers of the patient

(eg, relatives). Experienced interviewers were trained on

how to administer the survey and all survey responses

were validated by the University of Malawi Polytechnic

and MOH collaborators to ensure they were appropriate

for the local context.

A series of a maximum of three interviews were

planned for the COI assessment, with day 0 (ie, day of

diagnosis) being the day of the patient’s health facility

visit: at day 0–7, day 13–15 (beyond the mean duration

of an episode of cholera illness) and day 20–22. To mini-

mise recall bias, the first interview took place as soon as

cholera was confirmed either by a test or a clinician, with

a maximum of 7 days following the first healthcare facility

visit. If a patient preferred to be interviewed while at the

healthcare facility, the trained interviewer conducted the

first COI interview at the time of the initial outpatient or

inpatient visit. Patients who were not feeling well enough

were contacted by an HSA to schedule a future interview

time. Trained interviewers would then visit the patient’s

home at the scheduled time to conduct the first interview.

At the end of each COI assessment, patients were asked

whether they felt they had fully recovered from cholera.

If the patient reported still being ill, the next interview

was scheduled; otherwise, no additional interviews were

conducted.

HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

At each of the interviews, patients (or parent/guardian)

were asked how much money they spent during each

of their visits to a healthcare facility or other treatment

locations (eg, a traditional healer) since becoming ill,

including any visits that may have occurred prior to the

study enrolment date. DMCs included out- of- pocket

payments for services, prescription drugs and any other

health facility fees. DNMCs included transportation and

food expenses incurred by the patient and/or caregivers

who went to the health facility with the patient.

Finally, IC accounted for the patients’ and/or care-

givers’ productivity losses incurred due to lost wages. We

calculated productivity losses using three scenarios based

on (1) self- reported wage losses, (2) minimum wage per

day for all workers between 14 and 50 years of age (the

legal minimum and old- age pension eligibility age18) who

did not report wage losses and (3) minimum wage per

day for all patients >5 years of age who did not report

wage losses, given evidence from Africa that children are

often involved in economic activities that add to a family’s

income.19

In all scenarios, if patients and/or caregivers reported

wage losses, these were calculated based on self- reported

daily lost productivity (half or full days of work lost due

to taking care of the ill patient) and daily wages. For

patients and caregivers who did not report wage losses

(ie, scenarios 2 and 3), we applied the minimum wage of

1346.16 Malawian kwacha (MWK) per day (US$1.83/day

as of 1 January 2020) to account for the monetary value

of productivity losses.20 Productivity losses were not calcu-

lated for caregivers who indicated that they did not cut

back on their usual activities had they not been caring for

the patient. They were also not calculated for caregivers

who reported no income lost (eg, a caregiver who is dedi-

cated to unpaid housework).

Costs were collected in MWK, inflated to 2020 MWK

using World Bank inflation data,21 and converted to

2020 US$ (736.5803 MWK=US$1 on 31 March 2020).22

All analyses were conducted in Stata/IC 13.1 (College

Station, Texas, USA) and Microsoft Excel.

Patient and public involvement

Patients including their caretakers were involved in this

study as participants in the COI interviews. Costs related

to cholera illness were collected from the participants

after obtaining informed consent. The public was not

involved in this study. Patients and the public were not

involved in study development, defining the research

question and study design, recruitment and the conduct

of the study. Early findings of the study were disseminated

through a workshop attended by country policymakers,

health managers and health facility staff.

RESULTS

During our surveillance period, 2201 individuals met the

diarrhoeal illness criteria for stool collection and testing

for cholera in Nsanje. Of these patients, 40 (1.8%) were

identified as cholera cases and were recruited for the

surveillance study. On the day of their health facility visit,

all 40 patients also consented for COI interview. Table 1

summarises selected demographic characteristics, as well

as OCV statuses, of all cases.

Of the 40 cases, 31 (78%) were seen in an outpatient

setting. Duration of illness was 5 days (min–max: 2–17

days) in the outpatient setting and 8 days (min–max: 2–19

days) in the inpatient setting. Most patients (n=34) had

fully recovered by the time the first interview occurred

(scheduled within 7 days of recruitment day 0); 6 patients

had a second interview (at day 13–15) and none required

a third interview. A higher proportion of inpatient cases

were males, whereas outpatient cases were majority

female. Of the 40 cases, 4 were identified clinically, 9

using RDT and 27 using culture confirmation. A larger

proportion of children were seen in the inpatient setting,

compared with outpatient.

The direct and IC of cholera per patient was US$14.34

when averaged across all patients, with the largest propor-

tion of costs (57.9%) being from DNMCs (food, water

and transportation) (table 2). DMCs for drugs and

consumables were zero for nearly all patients; only two

patients seen in the inpatient setting had any drug costs

of US$11.17 (8229 MWK) and US$1.19 (875 MWK) each,

both of whom were seen at a private Christian Health

Association of Malawi (CHAM) facility; these two patient

costs increased the overall average across the cohort to

US$0.31.

Patient and caregiver food costs were US$0.95 and

US$1.61 on average, respectively. Roundtrip transporta-

tion costs were relatively lower for patients at US$1.84,

compared with caregiver transportation costs at US$3.91.

Transportation time on average per patient was 112 min

roundtrip (min, max: 10–360).

We also performed various scenario analyses for ICs

(table 3), where costs were only averaged across patients

and caregivers with non- zero productivity losses in each

scenario. Eight patients were excluded from wage loss

calculations due to missing age or birthdate. Thirty- four

patients had at least one caregiver provide care during

their illness, with a total of 53 caregivers across all patients.

Caregivers only reported whether they were children or

adults (ie, exact ages or birthdates were not ascertained);

all caregivers reported being adults who we assumed were

of working age.

In scenario 1, productivity losses (lost wages) due to

being sick for the duration of illness were US$10.60 on

average (n=5) for patients who reported wage losses,

though one patient reported receiving paid sick leave for

this time (US$10.89), which would reduce the average

to US$10.53 (n=4). Only 15 caregivers (who cared for

eight patients) reported US$6.36 on average in lost wages

due to missing work. In scenario 2, where the minimum

wage was assumed for all patients (n=11) and caregivers

(n=45) of working age, productivity losses were US$8.83

for patients and US$3.94 for caregivers on average. In

scenario 3, where the minimum wage was assumed for all

4HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

patients >5 years of age (n=19), productivity losses were

US$9.78 for patients on average. In this scenario anal-

ysis, there were two patients aged 5–14 years (US$14.16

on average) and five patients aged ≥60 years (US$8.59 on

average). Caregiver costs in scenarios 2 and 3 were the

same (US$3.94) since all caregivers were adults.

Half of all patients (n=20), and two- thirds of inpatients

(n=6), reported having to borrow money from someone

to pay for healthcare, food or transportation as a result

of having cholera (table 4), but most did not have to sell

personal belongings to pay for care. Experiencing at least

some food insecurity in the past year (defined as going

without food at least once in the past 3 months) was an

issue for a large proportion of patients (n=28).

DISCUSSION

Our study estimated patient and caregiver costs associ-

ated with seeking healthcare for the treatment of severe

diarrhoeal illness diagnosed as cholera in Nsanje. We had

few diarrhoeal cases overall. The cost of cholera illness

per patient was US$14.34, with the largest proportion of

costs being from DNMCs (food, water and transporta-

tion) (US$8.30), followed by indirect productivity losses

(US$5.73) in our primary analysis, where costs were aver-

aged across all patients in our cohort.

The majority of our patients were not admitted during

their visit to the health centre. Patients who sought care

in the outpatient setting were symptomatic an average of

1.4 days prior to seeking care. Patients who were admitted

were sick for an average of 2.8 days prior to seeking care

and had an inpatient stay of 2 days. Our patient popu-

lation was slightly skewed towards females and of those

whose age was reported, most patients were adults aged

18 and older. The majority of patients were not vacci-

nated during the OCV campaign in 2015.

Overall, only two patients with cholera had any DMCs;

one was seen in the outpatient setting (875 MWK or

US$1.19) and the other was admitted to a private CHAM

facility (8229 MWK or US$11.17). This finding was

expected, as cholera treatment is provided free of charge

in Malawi. On average, patients and their caregivers

spent US$8.61 in direct costs (US$0.31 in medical costs

and US$8.30 in non- medical costs, including those with

zero costs), almost all of which was due to food and/or

water and transportation costs. In our scenario analysis

Table 1 Demographic and medical characteristics of

cholera cases in Nsanje District, Malawi, 2016–2020

Outpatient

n (%)

Inpatient

n (%)

Total*

n (%)

Total 31 (78) 9 (22) 40 (100)

Sex

Male 9 (29) 6 (67) 15 (38)

Female 17 (55) 3 (33) 20 (50)

Unknown/missing 5 (16) 0 (0) 5 (13)

Age

<5 years 10 (32) 4 (44) 14 (35)

≥5 years to <18 years 2 (6) 1 (11) 3 (8)

≥18 years to <35 years 9 (29) 0 (0) 9 (23)

≥35 years 3 (10) 3 (33) 6 (15)

Unknown/missing 7 (23) 1 (11) 8 (20)

Level of education

Never went to school 13 (42) 3 (33) 16 (40)

Preschool 2 (6) 0 (0) 2 (5)

Completed primary 10 (32) 3 (33) 13 (33)

Completed secondary 2 (6) 0 (0) 2 (5)

Unknown/missing 4 (13) 3 (33) 7 (18)

Employment status

Works for a wage 5 (16) 0 (0) 5 (13)

Does not work for a

wage

26 (84) 9 (100) 35 (88)

Average inpatient stay,

days (min–max)

– 2 (1–4) –

Average number of

symptomatic days prior

to seeking medical care

(min–max)

1.4 (0–4) 2.8 (1–8) 1.7 (0–8)

Average number of days

sick with cholera

5 (2–17) 8 (2–19) 6 (2–19)

Method of transportation

for patients to health

centre

Walked 9 (29) 1 (11) 10 (25)

Biked 12 (39) 5 (56) 17 (43)

Motorcycle 3 (10) 1 (11) 4 (10)

Minibus 5 (16) 1 (11) 6 (15)

Private car 1 (3) 0 (0) 1 (3)

Hired canoe 1 (3) 0 (0) 1 (3)

Ambulance (from MOH) 0 (0) 1 (11) 1 (3)

Vaccination status (OCV

in 2015)

Not vaccinated 16 (52) 5 (56) 21 (53)

One dose 5 (16) 1 (11) 6 (15)

Two doses 6 (19) 0 (0) 6 (15)

Unknown/missing 4 (13) 3 (33) 7 (18)

Cholera confirmation

Continued

Outpatient

n (%)

Inpatient

n (%)

Total*

n (%)

Rapid diagnostic test 5 (56) 4 (44) 9 (22)

Lab culture

confirmation

25 (93) 2 (7) 27 (68)

Clinically identified 1 (25) 3 (75) 4 (10)

*Sum of percentages may exceed 100 due to rounding.

MOH, Ministry of Health; OCV, oral cholera vaccine.

Table 1 Continued

HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

when only those with self- reported wages are consid-

ered, only five patients with cholera (all outpatient cases)

reported productivity losses of US$8.83 on average, and

15 caregivers of patients reported wage losses, averaging

US$3.93. In our scenario analysis, where we applied

the minimum wage to all patients and caregivers who

Table 2 Mean direct and indirect costs (MWK and USD 2020) for cholera cases in Nsanje District, Malawi, 2016–2020*

(averaged across all 40 patients)

Inpatient (n=9) Outpatient (n=31) Total costs (n=40)

% of

total

2020 MWK

(min, max)

2020 USD

(min, max)

2020 MWK

(min, max)

2020 USD

(min, max)

2020

MWK

2020

USD

Direct, medical costs 97 0.13 265 0.36 228 0.31 2.2

Drugs and

consumables†

97 (0–875) 0.13 (0–1.19) 265 (0–8229) 0.36 (0–11.17) 228 0.31 2.6

Direct, non- medical costs 9703 13.17 5073 6.89 6115 8.30 57.9

Patient food and/or

water

505 (0–1353) 0.69 (0–1.84) 753 (0–6148) 1.02 (0–8.35) 697 0.95 6.6

Patient transportation

(roundtrip)

2007 (0–8750) 2.73 (0–11.88) 1161 (0–9836) 1.58 (0–13.35) 1352 1.84 12.8

Caregiver food and/or

water

1332 (0–2734) 1.81 (0–3.71) 1143 (0–12 686) 1.55 (0–17.22) 1186 1.61 11.2

Caregiver transportation

(roundtrip)

5858 (0–13 525) 7.95 (0–18.36) 2016 (0–8346) 2.74 (0–11.33) 2880 3.91 27.3

Indirect (productivity

losses)‡

489 0.66 5304 7.20 4221 5.73 40.0

Patient 0 (0–0) 0 (0–0) 1259 (0–12 519) 1.71 (0–17.00) 976 1.32 9.2

Caregivers 489 (0–2213) 0.66 (0–3.00) 4045 (0–70 526) 5.49 (0–95.75) 3245 4.41 30.7

Total mean costs§ 10 289 13.97 10 643 14.45 10 563 14.34 100.0

*All costs by category are averaged over the total number of patients in each category (ie, patients or caregivers with zero costs are not

excluded in the average).

†Only two patients (one inpatient, one outpatient) had any DMCs, but costs are averaged over the total number of patients.

‡Productivity losses are averaged over the total number of patients in each category (not averaged over the total number of caregivers); six

outpatients and two inpatients had caregivers who reported wage losses, but wages are averaged over the total number of outpatients (n=31)

and inpatients (n=9).

§Costs are first summed across categories for each patient and averaged across total patients.

DMCs, direct medical costs; MWK, Malawian kwacha.

Table 3 Scenario analyses of mean indirect costs for cholera cases with reported wage losses and assuming minimum wage

in Nsanje District, Malawi, 2016–2020

Scenario 1: among those

with self- reported wages

only*

Patients: n=5

Caregivers: n=15 % of

total

indirect

costs

Scenario 2: self- reported +

minimum wage for patients

aged 15–50 years

Patients: n=11

Caregivers: n=45 % of

total

indirect

costs

Scenario 3: self- reported +

minimum wage for patients

aged >5 years

Patients: n=19

Caregivers: n=45 % of

total

indirect

costs

2020 MWK

(min, max)

2020 USD

(min, max)

MWK

(min, max)

2020 USD

(min, max)

MWK

(min, max)

2020 USD

(min, max)

Indirect, productivity losses

Patients* 7807

(5008–12

519)

10.60

(6.80–17.00)

63 6506

(2692–12 519)

8.83

(3.66–17.00)

69 7161

(2019–16 154)

9.78

(2.74–21.93)

Caregivers 8558

(823–25

039)

6.36

(1.12–33.99)

38 5306

(823–25 039)

3.94

(1.12–33.99)

31 5306

(823–25 039)

3.94

(1.12–33.99)

Total indirect

costs

16 365 16.96 11 812 12.77 12 467 13.72

*All 5 patients who worked for a wage were outpatient.

MWK, Malawian kwacha.

6HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

theoretically could be contributing to economic activities

(ie, household work), indirect productivity losses were as

high as US$9.78 per patient and US$3.94 per caregiver.

This latter scenario may overestimate the number of indi-

viduals who experience productivity losses and the actual

economic impact, though the average productivity losses

(US$13.72) were lower than in the self- reported wage

scenario ($16.96).

The overall costs found in our study are substantially

less than one study previously reported in rural Malawi.12

Ilboudo et al reported household costs of US$65.60 in

2016 (US$106.16 in 2020). They reported a much larger

proportion of hospitalised cases: their study sampled 100

cases (which estimated 9% of the overall caseload from

the cholera outbreak), 90 of whom were hospitalised,

whereas we only had 7 hospitalised cases (17.5% of total

cases). Transportation costs in our study were also lower

for both patients and caregivers compared with their

study, which may be attributable to differences in trans-

portation methods and travel distances to health centres.

The largest differences in costs between our study and

Ilboudo et al were in food and lost productivity costs,

likely also driven by the fact that their study had more

hospitalised cases that required more expenses over

several days. Their reported ICs of patient’s productivity

were a larger portion of overall costs (35.1% compared

with our 9.2%), which may be attributed to their study

cohort having longer inpatient stays. The caregiver lost

productivity costs as a proportion of overall costs were

lower in their study (23.5% compared with our 30.7%).

Differences in productivity costs may be attributed to

several reasons, such as differences in wages in Nsanje

versus Machinga and Zomba districts, unemployment

rates and other socioeconomic factors. The differences

may also be attributed to the severity of illness, potentially

attenuated by vaccination. Ilboudo et al assessed costs of

illness from patients who had cholera in the ±1 week prior

to and after the OCV campaign that was underway (which

followed the cholera outbreak). Thus, the proximity in

timing to the outbreak may have meant that few individ-

uals had any immunity to cholera and may have experi-

enced more severe symptoms, whereas in our population,

OCV coverage and immunity was likely higher. Given the

relatively small sample size in both studies, however, more

data are needed from the region to understand why these

costs differed more than other cost components.

We also assessed financial and food insecurity for cases.

Half of our cases had to borrow money from someone

to pay for costs associated with their cholera illness and

treatment, which is similar to the proportion reported by

Ilboudo et al. A large proportion of our cases also faced

food insecurity at some point in the prior year.

Table 4 Financial and food insecurity of cholera cases in Nsanje District, Malawi, 2016–2020

Outpatient (n=31) n (%) Inpatient (n=9) n (%) Total (n=40) n (%)

Borrowing money to pay for healthcare services

Did not borrow money 17 (55) 3 (33) 20 (50)

Borrowed money from a family member 6 (19) 0 (0) 6 (15)

Borrowed money from a friend 4 (13) 5 (56) 9 (23)

Borrowed money from a cooperative 0 (0) 1 (11) 1 (3)

Borrowed money from a neighbour 1 (3) 0 (0) 1 (3)

Borrowed money from the village chief 1 (3) 0 (0) 1 (3)

Borrowed money from boss/employer 1 (3) 0 (0) 1 (3)

Borrowed money from church 1 (3) 0 (0) 1 (3)

Sold items to pay for healthcare services

Did not sell anything 29 (94) 4 (44) 33 (83)

Rented out rice and maize plots 0 (0) 4 (44) 4 (10)

Sold radio 1 (3) 0 (0) 1 (3)

Sold livestock 1 (3) 1 (11) 2 (5)

Frequency of household going without food in the

past year

Never 4 (13) 1 (11) 5 (13)

Once every 3 months 7 (23) 1 (11) 8 (20)

Once per month 3 (10) 2 (22) 5 (13)

Twice per month 2 (6) 1 (11) 3 (8)

Once per week 8 (26) 1 (11) 9 (23)

Almost every day 3 (10) 0 (0) 3 (8)

Unknown/missing 4 (13) 3 (33) 7 (18)

HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

Our study had several limitations. One limitation was the

late start of cholera surveillance (April 2016) relative to

the cholera outbreak (approximately February 2015), in

response to which a vaccination campaign was conducted

(March/April 2015). It is possible that some postvaccina-

tion campaign cholera cases may have occurred in the

year prior to the start of cholera surveillance, particularly

during the November 2015 to April 2016 rainy season;

these cases would not have been included in this study.

The study was also not able to collect COI data from

Chikwawa residents and infants <12 months, which may

have provided different cost estimates. Given the small

number of cholera cases, even after expanding the case

criteria to clinically diagnosed cases (of which there

were only 4), it may not be representative of the general

Nsanje population, particularly those who were sick and

did not seek care. It is also possible that patients may have

shown up for care but were undiagnosed or misdiagnosed

for reasons such as diagnostic sensitivity. While we were

unable to assess any patterns or variation in the use of the

three testing methods (RDT, culture or clinically identi-

fied) by the health centre, it is possible that our recruited

patient cohort is biased towards health centres that were

better equipped to test, recruit and treat patients. For

example, many of the more remote health centres in

Nsanje lacked toilets or latrines for proper stool collec-

tion and have limited access to electricity to ensure the

viability of stool samples, which may have limited the

sensitivity of the stool culture result. Apart from the logis-

tical challenges of recruitment, the area also has a high

number of migrants from Mozambique; migrants may be

less likely to seek care due to several reasons, including

language barriers, discrimination due to cultural differ-

ences, and fear of deportation.23

Health facility costs were also not included in our

costing, which may be a significant portion of the total

costs as most patients reported US$0 in DMCs. A recent

study in rural Malawi estimated that the average treatment

cost to a health facility for a hospitalised cholera case was

US$59.70 in 2016 (US$96.61 in 2020).12 A separate study

on cholera treatment costs at the facility level at this study

site has estimated an economic cost of US$41.86 in 2018

(US$50.79 in 2020) and a financial cost of US$25.43 in

2018 (US$30.85 in 2020).24 Finally, there was the poten-

tial for recall bias, especially for patients who may have

had costs prior to the initial visit to the health centre from

which they were recruited for the study. For costs incurred

from the day of enrolment onward, we attempted to mini-

mise the potential for recall bias by following up first

within a week of the initial visit.

Despite the limitations, our study provides one of the

few COI studies of cholera illness in sSA from the house-

hold perspective. More studies are needed to more fully

evaluate the cholera costs of illness in Malawi. Currently,

spending on health accounts for less than 10% of country

revenues—below the 15% target set by the Abuja Declara-

tion to which Malawi is a signatory.25 Healthcare financing

in Malawi is also unpredictable and unsustainable given

the country’s reliance on development partners’ contri-

butions that account for nearly two- thirds of total health

expenditure.26 Our study supports the need for further

spending in the health sector; for example, building and

staffing additional health centres that reduce the amount

of time patients have to travel could reduce the cost

burden on patients.

While the study was not designed to assess vaccine effec-

tiveness, our surveillance efforts may also be a positive

indication that the cholera vaccine may be associated with

a reduction in the burden of cholera in the middle- term,

as most of our cases were unvaccinated (while approxi-

mately half of the Nsanje population received the cholera

vaccine). Since this study was conducted, in recogni-

tion of the high incidence of cholera and the need for

additional tools to address the burden, the government

of Malawi integrated OCVs into its national cholera

control plan in 2017,27 and there have been several OCV

campaigns implemented since.10 28 Alternatively, given

that cholera often occurs cyclically, it is possible that the

time period during which surveillance occurred was a low

or no cholera transmission interval. Ultimately, investing

more heavily in WASH infrastructure would be the most

effective, though more costly, solution in the long- run to

avert cholera.

In a country where the gross domestic product per

capita per day is less than US$2 (US$625 annually in

2020), a family who has to spend US$14 on average for

cholera illness will very likely have to make financial sacri-

fices to access treatment. Even though the DMCs associ-

ated with cholera care are low, the patient (who is willing

and able to go to the health centre) must bear a high

burden of DNMCs and indirect lost productivity costs.

For those who do not have the means of even going to

a health facility to seek care, the consequences are likely

even more severe; for example, the death of a family

member whose wages supported the family has significant

long- term impacts beyond a single cholera episode.

In conclusion, we find that households face a significant

cost burden when one falls sick with cholera. These costs

are significantly high to warrant additional investments in

the health system to avert future cases of cholera.

Author affiliations

1Department of Health Care Management, Technische Universität Berlin, Berlin,

Germany

2Policy and Economic Research, International Vaccine Institute, Seoul, The Republic

of Korea

3Epidemiology, Public Health, Impact, International Vaccine Institute, Seoul, The

Republic of Korea

4Biostatistics & Data Management, International Vaccine Institute, Seoul, The

Republic of Korea

5Department of Environmental Health, University of Malawi the Polytechnic,

Blantyre, Malawi

6Ministry of Health Malawi, Lilongwe, Malawi

7Epidemiology, Public Health, Impact, International Vaccine Institute, Gwanak- gu,

The Republic of Korea

8Cambridge School of Clinical Medicine, Cambridge Biomedical Campus,

Cambridge Institute of Therapeutic Immunology and Infectious Disease,

Cambridge, UK

8HsiaoA, etal. BMJ Open 2022;12:e052337. doi:10.1136/bmjopen-2021-052337

Open access

Contributors AH and VM conceptualised the study, led the protocol development,

field training and survey implementation in collaboration with H- JS, GDP, DV, MM,

BN, FM and ER. Data collection was supervised by DV, MM and BN, and monitored

by GDP, AH, VM, ER and H- JS. Data analysis and interpretation were done by AH

supported by VM and WQ. The manuscript was written by AH, supported by VM and

WQ. All authors have reviewed, edited and approved the final manuscript. AH and

VM are the guarantors and take full responsibility for the finished work and/or the

conduct of the study, had access to the data, and controlled the decision to publish.

Funding This research was conducted by International Vaccine Institute and

funded by Bill & Melinda Gates Foundation (OPP38590) and the UK Foreign,

Commonwealth and Development Office and Wellcome (214662/Z/18/Z). The

International Vaccine Institute acknowledges its donors including the Republic of

Korea, Swedish International Development Cooperation Agency and Republic of

India.

Competing interests None declared.

Patient and public involvement Patients and/or the public were involved in the

design, or conduct, or reporting or dissemination plans of this research. Refer to the

Methods section for further details.

Patient consent for publication Consent obtained directly from patient(s).

Ethics approval This study was approved by the National Health Sciences

Research Committee (NHSRC) of the Ministry of Health in Malawi (protocol

#16/2/1547; approval #1547) on 29 March 2016. The International Vaccine

Institute’s (IVI) Institutional Review Board (IRB) approved the study on 6 April

2016. All participants (or a parent/guardian) provided written informed consent

prior to interviews. For patients aged <12 years, consent was provided by the

parent/guardian, and in these cases, the patient/caregiver provided the interview

responses. For patients aged 12–17 years, ascent was provided by both the parent/

guardian and child. Adults aged ≥18 years provided consent directly. The IVI IRB and

the NHSRC approved the modification to expand to inclusion of clinically diagnosed

cases on 31 May 2017 and 31 July 2017, respectively. Training of all health

surveillance assistants on the modification occurred on 12 and 13 December 2017,

and the data collection continued until 31 March 2020.

Provenance and peer review Not commissioned; externally peer reviewed.

Data availability statement All data relevant to the study are included in the

article or uploaded as supplementary information.

Supplemental material This content has been supplied by the author(s). It has

not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been

peer- reviewed. Any opinions or recommendations discussed are solely those

of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and

responsibility arising from any reliance placed on the content. Where the content

includes any translated material, BMJ does not warrant the accuracy and reliability

of the translations (including but not limited to local regulations, clinical guidelines,

terminology, drug names and drug dosages), and is not responsible for any error

and/or omissions arising from translation and adaptation or otherwise.

Open access This is an open access article distributed in accordance with the

Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits

others to copy, redistribute, remix, transform and build upon this work for any

purpose, provided the original work is properly cited, a link to the licence is given,

and indication of whether changes were made. See:https://creativecommons.org/

licenses/by/4.0/.

ORCID iDs

AmberHsiao http://orcid.org/0000-0003-2295-0886

FlorianMarks http://orcid.org/0000-0002-6043-7170

VittalMogasale http://orcid.org/0000-0003-0596-8072

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