# Short message service sentinel surveillance of influenza-like illness in Madagascar, 2008-2012

Soatiana Rajatonirina, Jean-Michel Heraud, Laurence Randrianasolo, Arnaud Orelle, Norosoa Razanajatovo, Yolande Raoelina, Lisette Ravolomanana, Fanjasoa Rakotomanana, Robinson Ramanjato, Armand Eugène Randrianarivo-Solofoniaina, et al.

► To cite this version:

Soatiana Rajatonirina, Jean-Michel Heraud, Laurence Randrianasolo, Arnaud Orelle, Norosoa Razanajatovo, et al. Short message service sentinel surveillance of influenza-like illness in Madagascar, 2008-2012. Bulletin of the World Health Organization, 2012, 90 (5), pp.385 - 389. 10.2471/BLT.11.097816. pasteur-01675143

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# Short message service sentinel surveillance of influenza-like illness in Madagascar, 2008–2012

Soatiana Rajatonirina,ª Jean-Michel Heraud,ᵇ Laurence Randrianasolo,ª Arnaud Orelle,ᵇ Norosoa Harline Razanajatovo,ᵇ Yolande Nirina Raoelina,ᶜ Lisette Ravolomanana,ᶜ Fanjasoa Rakotomanana,ª Robinson Ramanjato,ᶜ Armand Eugène Randrianarivo-Solofoniainaᶜ & Vincent Richardᵈ

**Problem** The revision of the International Health Regulations (IHR) and the threat of influenza pandemics and other disease outbreaks with a major impact on developing countries have prompted bolstered surveillance capacity, particularly in low-resource settings.

**Approach** Surveillance tools with well-timed, validated data are necessary to strengthen disease surveillance. In 2007 Madagascar implemented a sentinel surveillance system for influenza-like illness (ILI) based on data collected from sentinel general practitioners.

**Setting** Before 2007, Madagascar's disease surveillance was based on the passive collection and reporting of data aggregated weekly or monthly. The system did not allow for the early identification of outbreaks or unexpected increases in disease incidence.

**Relevant changes** An innovative case reporting system based on the use of cell phones was launched in March 2007. Encrypted short message service, which costs less than 2 United States dollars per month per health centre, is now being used by sentinel general practitioners for the daily reporting of cases of fever and ILI seen in their practices. To validate the daily data, practitioners also report epidemiological and clinical data (e.g. new febrile patient's sex, age, visit date, symptoms) weekly to the epidemiologists on the research team using special patient forms.

**Lessons learnt** Madagascar's sentinel ILI surveillance system represents the country's first nationwide "real-time" surveillance system. It has proved the feasibility of improving disease surveillance capacity through innovative systems despite resource constraints. This type of syndromic surveillance can detect unexpected increases in the incidence of ILI and other syndromic illnesses.

Abstracts in عربي, 中文, Français, Русский and Español at the end of each article.

## Introduction

Four years after the revised International Health Regulations (IHR) went into effect and amidst fears that influenza pandemics and other disease outbreaks could seriously threaten the health of entire populations in developing countries, it became necessary to bolster surveillance capacity, particularly in low-resource settings.¹ This was especially important in such settings because they generally lack the health-care infrastructure, laboratory diagnostic capability and number of physicians needed to effectively control emerging epidemic-prone diseases.

The circulation of the highly pathogenic avian influenza A(H5N1) virus in humans and animals in Asia, Europe and Africa since 2006 has raised fears of the possible emergence of a highly pathogenic pandemic influenza strain.² This has prompted many developing countries to establish surveillance systems for the early detection of the emergence and/or circulation of potential pandemic influenza strains.

Madagascar's disease surveillance systems have traditionally relied on the passive collection and reporting of data aggregated weekly or monthly. Such systems cannot detect incipient disease clusters for prompt investigation and response. In addition, diagnostic capacity outside the capital city is limited and delays in identifying the causal agents of disease outbreaks have often resulted in an inability to launch an appropriate public health response. Madagascar needed a surveillance system that could quickly identify aberrant

patterns of disease activity rather than depend exclusively on case confirmation.

## Approach

In March 2007 Madagascar's Ministry of Health, in collaboration with the Institut Pasteur of Madagascar (IPM), launched a sentinel surveillance system designed to detect incipient disease outbreaks through daily collection of syndromic case data in sentinel health centres,³ backed by biological surveillance (e.g. collection and testing of biological specimens) at selected sentinel sites.

## Management team

The first step in creating the sentinel network was to identify appropriate stakeholders. A steering committee was established with epidemiologists, virologists and managers from the Ministry of Health's epidemiological surveillance service (Direction de la Veille sanitaire et de la Surveillance épidémiologique, DVSSE) and emerging and neglected disease control units (Direction des Urgences et de la Lutte contre les Maladies Négligées, DULMN). Next, regional health department and district managers were brought into the discussions surrounding the selection of potential sentinel centres.

## Sentinel centres

The sentinel network in Madagascar, which is a large island, began with 6 sentinel sites in 2007 and had expanded to 34

<footnote>ª Unité d'Épidémiologie, Institut Pasteur de Madagascar, Antananarivo, Madagascar.</footnote>

<footnote>ᵇ National Influenza Center, Institut Pasteur de Madagascar, Antananarivo, Madagascar.</footnote>

<footnote>ᶜ Ministère de la Santé Publique, Antananarivo, Madagascar.</footnote>

<footnote>ᵈ Unité d'Épidémiologie, Institut Pasteur de Dakar, 36 avenue Pasteur, BP 220, Dakar, Sénégal.
Correspondence to Vincent Richard (e-mail: vrichard@pasteur.sn).</footnote>

<footnote>(Submitted: 18 October 2011 – Revised version received: 12 March 2012 – Accepted: 13 March 2012)</footnote>
by 2011. Expansion was intended to
improve geographic coverage and rep-
resentativeness and to make it possible
to monitor epidemiologic trends in dif-
ferent climate zones.

Sentinel sites are primary health-
care centres that are selected on the
basis of several criteria, including the
presence of at least two general practiti-
ners, the availability of a mobile phone
network, and the degree of commitment
to actively participate in surveillance ac-
tivity. Participation is entirely voluntary.
Sentinel general practitioners (SGPs)
serving on a gratuitous, voluntary basis
are the backbone of the system, which
currently covers about 8% of the Mala-
gasy population.

Data source

To assess the functioning of the surveil-
lance system, we collected data from
sentinel general practitioners from 1
January 2008 to 31 January 2012. All
patients seen at the sentinel centres
were systematically screened by each
practitioner, who reported the number
of cases that met the case definitions
(described later) and the total number
of patient visits on each reporting day.

Data transmission

Sentinel general practitioners were
expected to transmit encrypted data
via cellular telephone (encrypted short
message service, SMS) at least once a
day, from Monday to Friday, despite
occasional clinic closures resulting
from routine weekday and weekend
schedules. Active data collection was
also carried out: if data from a sentinel
centre were not received by 10:00 on a
particular day, IPM staff would contact
the sentinel centre to obtain the missing
data.

The monthly cost of data transmis-
sion per centre was less than 2 United
States dollars (US$).

Case definitions

Standard WHO case definitions were
used for comparability. Fever (an axil-
lary temperature ≥ 37.5 °C) was the
first syndromic symptom targeted.
Three febrile illnesses were selected for
surveillance: malaria (only confirmed
cases), influenza-like illness (ILI) and
arbovirus infection. Cases were defined
as follows: malaria, fever plus a positive
result on the rapid diagnostic test; ILI,
fever with a cough and sore throat; arbo-
virus infection, fever without respiratory

symptoms plus at least two of the follow-
ing: headache, arthralgia, myalgia-like
backache, skin rash, retro-orbital pain,
haemorrhage. Diarrhoea syndrome
was defined as three or more abnor-
mally loose stools during the previous
48 hours. A malaria rapid diagnostic test
was performed on every febrile patient
with the kit provided by the national
malaria programme.

Daily analysis

Data were available for analysis shortly
after each patient's initial visit. The
data obtained daily from the SMS were
entered into a specifically designed MS
Access® database as soon as they arrived
at the IPM. Thus, the turnaround time
between data collection and receipt of
the data, even from remote areas, never
exceeded 24 hours. The data received
through the SMS system included sen-
tinel site code, date of data collection,
number of outpatient consultations,
number of malaria cases, ILI, dengue-
like illness and diarrhoea, and number
of consultations by age group.

Data were checked for variation
from day to day. Analyses of temporal
distribution were conducted at each
sentinel centre for each syndrome cat-
egory of interest. Hence, various health
service-based indicators were monitored
daily. They included the percentage of
cases with fever, confirmed malaria,
ILI and suspected arbovirus infection,
as well as the percentage of diarrhoea
cases with and without fever.

Surveillance data were analysed and
presented using easy-to-interpret tables
and graphs that illustrated the number
of cases of each syndrome under surveil-
lance. In addition, a daily and weekly
baseline (i.e. average number of cases
in the previous years) was calculated
for each syndrome and plotted against
current observations to identify aber-
rant patterns. Increases were reported
immediately by telephone to the Min-
istry of Health to monitor events and
response and decide whether to initiate
an outbreak investigation. The first step
in any outbreak investigation was to
confirm the signals before responding
to an epidemic.

Validation

SGPs reported information on each
patient visit and listed every new febrile
patient's chief complaint or symptoms
on a special paper form sent weekly
to the IPM. The staff of the IPM was

therefore able to validate all information
previously sent via mobile phone.

Reporting

An external report summarizing weekly
and monthly trends in centre activity
were distributed to state and regional
health staff and was shared with par-
ticipating SGPs.

Results

The data collected daily over the study
period from the 34 sentinel centres
corresponded to 862 585 patient visits.
Overall, 86.7% of the data were trans-
mitted within 24 hours.

A total of 95 401 cases (11.1%) presented with fever. The special form was completed for 80 691 of these patients (84.6%). The male to female ratio among patients with a fever syndrome was 0.89:1. Age was available for 79 651 patients (98.7%). The mean age was 12.8 years (95% confidence interval, CI: 12.7–12.9).

ILI accounted for 20 933 (21.9%) of
all cases of febrile illness.

Discussion

The results obtained by the sentinel
surveillance network in Madagascar
are in accordance with the aim pursued
by the country's Ministry of Health.
Sentinel surveillance systems offer
advantages over passive surveillance,
which is limited by incomplete report-
ing.⁴,⁵ They provide a way to overcome
the coverage limitations inherent in the
passive surveillance of disease. However,
efficient and accurate sentinel surveil-
lance systems need to rely on strong
communication systems.

A “real-time” sentinel surveillance
system may be essential for the detec-
tion of infectious disease outbreaks and
the launching of a prompt public health
response (Box 1). The advantage of using
syndromic data for outbreak detection
lies in the speed with which a response
can be launched.⁶,⁷ Mobile phone tech-
nology, which is cheap and universally
available, has been recognized as a useful
tool in health care.⁸ However, published
studies on mobile phone use in health-
care settings have been conducted
almost exclusively in countries where
a shortage of resources and the need
to provide care in remote locations
are the main reasons for using mobile
phones.⁹ The cost of transmitting data
Box 1. Summary of main lessons learnt

* Daily syndromic surveillance using SMS can effectively enhance traditional public health surveillance systems already in place.

* Combined biological surveillance and syndromic surveillance using SMS makes it possible to rapidly detect the circulation of the influenza virus in areas under surveillance.

* By detecting unusual patterns of disease activity, sentinel surveillance using SMS can quicken the response to disease outbreaks.

SMS, short message service.

on a daily basis in Madagascar's sentinel surveillance network is minimal; it costs less than US$ 2 per month per sentinel centre, and each centre's mobile phone equipment costs a mere US$ 10. However, the costs of maintaining the system need to be more accurately estimated, both in terms of monetary expense and the person-hours involved in responding to system alerts. Although the Ministry of Health endorses sentinel general practitioners' voluntary participation, some practitioners are asking for incentives. Motivation has been maintained not through monetary payment but through the provision of medical equipment and training opportunities, including an annual epidemiology work-

shop and an annual meeting of staff in all sentinel sites. We have noted high staff turnover and, to address the problem, health district officers are being trained to train and supervise new staff.

In conclusion, the sentinel surveillance network would not be effective without the active participation of the SGPs. Other African countries would benefit from a similar programme, both in terms of improved disease surveillance and better public health decision-making.

### Acknowledgements

We thank all the staff from the Malagasy National Influenza Centre for influenza testing. We would like to express our

gratitude to all the staff from the DULMN and the DVSSE (Ministry of Health). We are deeply indebted to all practitioners and nurses involved every day in sentinel surveillance in Madagascar. To end, we would also like to thank Stefano Tempia and Adam Cohen from CDC South Africa for helpful comments and discussions during the process of writing

**Funding:** This work was supported by WHO (APW/Ref. OD/AP-08-02451), the French Ministry of Health, the US Centres for Disease Control and Prevention (Cooperative Agreement Number: U51/IP000327-01), the US Department of Health and Human Services (Grant Number 6 IDSEP060001-01-01) via the International Network of Pasteur Institutes, and the President's Malaria Initiative programme (USAIDS). We particularly thank Kathleen Victoir and Marc Jouan from the International Network of Pasteur Institutes.

**Competing interests:** None declared.

## ملخص

الرصد المخفي للاعتلالات الشبيهة بالأنفلونزا في مدغشقر باستخدام خدمة الرسائل القصيرة، في الفترة من 2008-2012

الرسائل القصيرة المشفرة التي تقل تكلفها عن دولارين أمريكيين في الشهر لكل مركز صحي لتقديم التقارير اليومية عن حالات الحمى والاعتلالات الشبيهة بالأنفلونزا (ILI) التي يلاحظونها في ممارساتهم. وللتحقق من البيانات اليومية، يقوم المارسون أيضا بتقديم تقارير عن البيانات الوبائية والسريرية (أي جنس المريض الجديد المحموم وعمره وتاريخ زيارته وأعراضه) أسبوعيا إلى أخصائيي الوبائيات ضمن فريق الأبحاث باستخدام نماذج خاصة للمرضى.

الدروس المستفادة يمثل نظام الترصد المخفي للاعتلالات الشبيهة بالأنفلونزا (ILI) في مدغشقر أول نظام ترصد في "الوقت الحقيقي" على الصعيد الوطني في البلد. وقد أثبت جدوى تحسين قدرات ترصد الأمراض من خلال نظم مبتكرة برغم قيود الموارد. يستطيع هذا النوع من ترصد المتلازمات اكتشاف الزيادات غير المتوقعة في حدوث الاعتلالات الشبيهة بالأنفلونزا (ILI) والأمراض المتلازمية الأخرى.

المشكلة عززت مراجعة اللوائح الصحية الدولية (IHR) والتهديد الذي تمثله جوائح الأنفلونزا وفاشيات الأمراض الأخرى ذات التأثير الكبير على البلدان النامية من قدرات الترصد، وبالأخص في المواقع منخفضة الموارد.

الأسلوب تعتبر أدوات الترصد ذات البيانات التي تم التثبت منها وذات التوقية الجيد ضرورية لتعزيز ترصد الأمراض. وفي عام 2007، نفدت مدغشقر نظاماً للرصد المخفي للاعتلالات الشبيهة بالأنفلونزا (ILI) بناءً على البيانات التي تم جمعها من المارسين العامين المخفيين.

المواقع المحلية قبل عام 2007، كان ترصد الأمراض في مدغشقر يعتمد على أسلوب الجمع السلبي والإبلاغ عن البيانات التي يتم تجميعها أسبوعياً أو شهرياً. ولم يسمح النظام بالتعرف المبكر على الفاشيات أو الزيادات غير المتوقعة في معدل حدوث الأمراض. التغيرات ذات الصلة تم إطلاق نظام مبتكر لتقديم التقارير حول الحالات بالاعتداء على استخدام الهوافط الخلوية في مارس 2007. ويستخدم الآن المارسون العامون المخفيون خدمة
# 摘要

## 2008年-2012年马达加斯加流感样疾病短信服务哨点监测

**问题** 《国际卫生条例(IHR)》的修订,以及流感大流行和其他对发展中国家有重大影响的疾病暴发的威胁,都促使人们加强监测能力,尤其是资源缺乏环境中的监测能力。

**方法** 加强疾病监测需要监测工具拥有及时有效的数据。在2007年,马达加斯加实施了一个流感样疾病(ILI)哨点监测系统,这个系统的基础是从哨点全科医生那里采集的数据。

**当地状况** 在2007年之前,马达加斯加的疾病监测根据的是每周或每月汇总数据的被动采集和报告。系统无法实现疫情或疾病发病率意外上升的提早识别。

**相关变化** 2007年3月,推出一种使用手机的创新病例报告系统。加密短信服务的费用为每个卫生中心每月低于2美元,正被哨点全科医生用于在他们行医期间所看到发热和ILI病例的每日报告。为了验证每日数据,医生每周还需使用特殊的患者信息表向研究小组的流行病学家报告流行病学和临床数据(例如新发发热患者的性别、年龄、就诊日期、症状)。

**经验教训** 马达加斯加的哨点ILI监测系统代表了该国第一个全国性“实时”监测系统。这个系统证明了通过创新系统克服资源局限提高疾病监测能力的可行性。这类症状监测可发现ILI和其他综合征疾病的发病率意外上升。

# Résumé

## Surveillance électronique des maladies de type grippal à Madagascar, 2008-2012

**Problème** La révision des Règlements sanitaires internationaux (RSI) et la menace de pandémies de grippe et d'accès d'autres maladies ayant un impact majeur sur les pays en voie de développement ont poussé au renforcement de la capacité de surveillance, en particulier dans les milieux à faible revenu.

**Approche** Des outils de surveillance munis de données opportunes et validées sont nécessaires pour renforcer la surveillance des maladies. En 2007, Madagascar a mis en place un système de surveillance sentinelle des maladies de type grippal (MTG), basé sur les données collectées chez des médecins généralistes de type sentinelle.

**Environnement local** Avant 2007, la surveillance des maladies à Madagascar reposait sur la collecte et la transmission passives de données collectées sur une base hebdomadaire ou mensuelle. Le système ne permettait pas de déceler de façon précoce les épidémies ou les augmentations imprévues de l'incidence de maladie.

**Changements significatifs** Un système de transmission des cas novateur et basé sur l'utilisation des téléphones portables a été lancé

en mars 2007. Le service SMS (short message service) chiffré, qui coûte moins de 2 dollars américains par mois par centre de santé, est désormais utilisé par les médecins généralistes de type sentinelle pour le compte rendu quotidien des cas de fièvre et de MTG diagnostiqués dans leur cabinet. Pour valider les données quotidiennes, les médecins font également un compte rendu hebdomadaire des données épidémiologiques et cliniques (par exemple, le sexe, l'âge, la date de consultation et les symptômes d'un nouveau patient atteint de fièvre) aux épidémiologistes de l'équipe de recherche, au moyen de formulaires patient spéciaux.

**Leçons tirées** Le système de surveillance sentinelle des MTG à Madagascar représente le premier système de surveillance à l'échelle nationale et "en temps réel" du pays. Il a prouvé qu'il était possible d'améliorer la capacité de surveillance des maladies à travers des systèmes novateurs et malgré les limitations des ressources. Ce type de surveillance syndromique permet de détecter les augmentations imprévues de l'incidence des MTG et des autres maladies syndromiques.

# Резюме

## Дозорный эпидемиологический надзор над гриппоподобными заболеваниями посредством службы коротких сообщений в республике Мадагаскар в 2008–2012 годах

**Проблема** Пересмотр международных медико-санитарных правил (ММСП), а также угроза пандемий гриппа и вспышек других заболеваний с основным ударом по развивающимся странам стали причинами уделения большего внимания надзору, особенно в условиях ограниченных ресурсов.

**Подход** Для усиления надзора за заболеваниями необходимым соответствующий инструментарий и своевременные подтвержденные данные. В 2007 г. республика Мадагаскар внедрила систему дозорного эпидемиологического надзора над гриппоподобными заболеваниями (ГПЗ) на основе данных, собранных от наблюдателей-врачей общей практики.

**Местные условия** До 2007 г. эпидемиологический надзор республики Мадагаскар базировался на пассивном сборе и протоколировании сгруппированных еженедельно или ежемесячно данных. При такой системе раннее распознавание вспышек заболеваний либо внезапного роста заболеваемости было невозможным.

**Осуществленные перемены** В марте 2007 г. была запущена передовая система регистрации случаев заболевания, основанная на применении мобильных телефонов. В настоящее

время врачи общей практики-наблюдатели для ежедневного сообщения о наблюдаяющихся в их практике случаях лихорадки или ГПЗ применяют службу зашифрованных коротких сообщений, использование которой обходится медицинскому центру менее 2 долларов США в месяц. Для подтверждения ежедневных данных практикующие врачи еженедельно сообщают эпидемиологам исследовательской группы также эпидемиологические и клинические данные (например, пол, возраст, перечень симптомов пациента с симптомами лихорадки и дату его посещения), используя для этого специальные анкеты пациента.

**Выводы** Система дозорного эпидемиологического надзора над ГПЗ республики Мадагаскар представляет собой первую общенациональную систему эпидемиологического надзора "реального времени" в этой стране. Она доказала возможность укрепления потенциала надзора над заболеваниями с помощью инновационных систем, несмотря на ограниченность ресурсов. Данный тип синдромного надзора способен обнаружить внезапные увеличения заболеваемости ГПЗ и другими синдромными заболеваниями.
## Resumen

### Servicio de vigilancia centinela de una enfermedad similar a la gripe con mensajes cortos en Madagascar, 2008–2012

**Situación** La revisión del Reglamento Sanitario Internacional (RSI) y la amenaza de las pandemias de gripe y otros brotes de enfermedades con gran impacto en los países en desarrollo han motivado un refuerzo de la capacidad de vigilancia, especialmente en entornos con pocos recursos.

**Enfoque** Las herramientas de vigilancia con datos bien programados y validados son necesarias para aumentar la vigilancia de enfermedades. En 2007, Madagascar puso en práctica un sistema de vigilancia centinela para enfermedades similares a la gripe basado en datos recopilados por profesionales centinela de la salud general.

**Marco regional** Antes de 2007, la vigilancia de enfermedades en Madagascar se basaba en la recopilación pasiva y comunicación de datos recogidos semanal o mensualmente. El sistema no permitía la identificación precoz de brotes ni de aumentos inesperados de la incidencia de la enfermedad.

**Cambios importantes** En marzo de 2007 se lanzó un innovador sistema de comunicación de casos basado en el uso de teléfonos móviles. Los profesionales centinela de la salud emplean actualmente el

servicio de mensajes cortos codificados, que cuesta menos de 2 dólares estadounidenses mensuales por cada centro de salud, para comunicar diariamente los casos de fiebre y de enfermedades similares a la gripe vistos en sus prácticas. Para validar los datos diarios, los profesionales de la salud también comunican semanalmente los datos epidemiológicos y clínicos (por ejemplo, sexo, edad, fecha de visita, síntomas del nuevo paciente febril) a los epidemiólogos del equipo de investigación mediante formularios especiales para los pacientes.

**Lecciones aprendidas** El sistema de vigilancia centinela de la enfermedad similar a la gripe de Madagascar es el primer sistema nacional de vigilancia "a tiempo real" del país. Se ha demostrado la viabilidad de mejorar la capacidad de vigilancia de la enfermedad mediante sistemas innovadores a pesar de las limitaciones de recursos. Este tipo de vigilancia basada en los síntomas puede detectar aumentos inesperados de la incidencia de enfermedades similares la gripe y otras enfermedades sindrómicas.

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