Jc1 suren final

Presenter : Dr. Surendran Venkataraman
Type of Session : Journal article discussion
Title : The use of mosquito repellents at three sites in India
with declining malaria transmission: surveys in the
community and clinic
Date : 20/12/2016
Time : 2-4PM
Wednesday, 21 December 2016 JOURNAL CLUB 2

• Title : The use of mosquito repellents at three sites in India with declining
malaria transmission: surveys in the community and clinic.
• Volume/Issue/Page number :9/1/418
• Date Published :27 July 2016
• DOI :10.1186/s13071-016-1709-9
•Authors list :Anna Maria van Eijk , Lalitha Ramanathapuram, Patrick
L. Sutton, Jane M. Carlton ,Steven A. Sullivan, Nandini Peddy, Sandhya Choubey, Stuti Mohanty, K
Pradhan, Aswin Asokan, Sangamithra Ravishankaran, G Sri Lakshmi Priya, Justin Amala Johnson,
Sangeetha Velayutham, Deena Kanagaraj, Alex Eapen ,Ankita Patel, Nisha Desai, Nikunj Tandel, H.
C. Srivasatava, Ranveer Singh, Samuel C. Wassmer, and S. K. Sharma.
Reasons for choosing: Indexed, International journal with impact factor,
Recently published, Peer reviewed, Field of community
Medicine, field based survey set in India.

BACKGROUND:
1. Vector-borne diseases are a considerable burden in India
commonest being Malaria
2. Use of protection against mosquito bites may result in prevention of
these diseases in addition to reducing mosquito annoyance and
itching.
3. For malaria control , insecticide-treated nets (ITNs) and indoor
residual spraying are methods with proven efficacy.
4. Repellent use is widespread in India, regularly surpassing net use.

BACKGROUND:
5. The efficacy of these personal protection methods has not been
widely evaluated.
6. The evaluation the epidemiology of malaria at three sites in India
(Chennai, Nadiad and Raurkela), provided an opportunity to assess
1. which personal protection methods were used,
2. who was using them and
3. if there was an association between their use and malaria

STROBE check list
Item Comments
Title and
abstract
1.(a) Indicate the study’s design with a
commonly used term in the title or the
abstract
The title does not
convey the study
design clearly
1.(b) Provide in the abstract an informative
and balanced summary of what was done
and what was found
Brief, structured,
appropriate keywords

STROBE check list
Item Introduction Comments
Background
/ rationale
2. Explain the scientific background and
rationale for the study being reported
-Facts?
- Novelty from
previous studies?
Objectives 3. State specific objectives, including any
pre-specified hypotheses
Specific

METHODS:
Setting:
• Chennai:
 Census, Cross-sectional surveys were conducted in the catchment area and
clinic study at the Besant Nagar clinic
 City, Coastal, Tropical wet & dry climate-, Malaria perennial
 P. vivax common; The Main malaria Vector- An. stephensi
• Nadiad :
 Town, Sub-tropical and semi-arid climate; Malaria hypo-endemic.
 Census and Cross-sectional surveys, was conducted in the residential areas
around the NIMR malaria clinic and in Sevaliya and Chetarsumba.
 Clinic study at NIMR clinic, Civil Hospital, Nadiad town.
 P. vivax and P. falciparum oscillating throughout the year.
 The main malaria vector is An. Culicifacies.

METHODS:
Setting: Contd…..
• Rourkela
 Census was conducted in the areas around Sector 1 Health Centre (Malaria
clinic-near slum areas) and the rural forested areas of Sundargarh district.
 Rural, Tropical wet & dry climate, Malaria Meso-Hyperendemic
 P. falciparum common; The Main malaria Vector- An. Culicifacies & An.
Fluviatilis

METHODS:
Procedure:
 Census from households near the clinics
 Four cross-sectional surveys were conducted over two years, each drawing
subjects from a different random selection of census household members.
 Patients visiting the malaria clinics at the three sites with symptoms
indicative of malaria were enrolled in the clinic-based study (not linked to
census data)
•They were subjected to
 a structured questionnaire with sections on malaria history and use of
mosquito protection- ALL
 blood tests for microscopy (Smear for malarial parasite) and hemoglobin
assessment- CROSS-SECTIONAL & CLINIC STUDY ALONE
 Questions on type of housing, water supply, use of malaria protection and
demographics of the household members (age, gender, education and
occupation)- CENSUS ALONE

METHODS:
Laboratory methods:
•Laboratory tests were performed for all individuals enrolled in the cross-
sectional surveys and clinic studies.
•Hemoglobin level was assessed at the time of enrollment using HemoCue
(HemoCue, Ängelholm, Sweden).
•Thin and thick smears obtained from blood collected via a finger prick.
•They were stained using Giemsa and at least 300 fields in the thick smear
were examined using the 100× oil immersion before a slide was determined
negative for malaria.
•The results were expressed as parasites per microliter of blood
•Slides were routinely read by two microscopists and a third was used if
there was disagreement.
•In addition, 10 % of the slides were re-checked for quality control.

METHODS:
Analysis:
•Web based REDCap (Research Electronic Data Capture) database was used to
capture and store all participant data and test results.
•Data were exported into Stata (Stata/IC version 13.1, StataCorp LP, College
Station, USA) for analysis.
•Only households and individuals with information available on repellents were
included in the analysis
• Principle components analysis was used to construct a wealth index to assess
effect of SES.
•Determinants of overall use of repellents and the two most common types used
in a region were examined.
•Factors and their association with the use of repellents at each levels were
evaluated separate for each levels .

METHODS:
Analysis: Contd…
•In the survey and clinic data the association between the use of repellent and
malaria, and of repellent and anemia were explored
•Generalized linear regression with a log link and binomial distribution was used
for multivariate analyses.
•Poisson regression with a robust variance estimator was used for models which
did not converge .
•Factors with a P-value < 0.1 in the univariate model were included in the
multivariate model, and factors with a P-value > 0.05 were removed from the
model, except for factors of special interest.
•The multivariate model for surveys was adjusted for clustering at the household
level.

STROBE check list
Item Methods Comments
Study
design 4. Present key elements of study design
early in the paper
Three sites of data
collection mentioned,
Census ?
Setting
5. Describe the setting, locations and
relevant dates, including periods of
recruitment and data collection
Time period not
specified for each site

STROBE check list
Participants
6. Give the eligibility criteria, and the
sources and methods of selection of
participants
Mentioned
Variables
7. Clearly define all outcomes, exposures,
predictors, potential confounders and effect
modifiers. Give diagnostic criteria, if
applicable
Variables at each level,
Lab tests

STROBE check list
Data sources/
measurement
8. For each variable of interest, give
sources of data and details of methods of
assessment (measurement). Describe
comparability of assessment methods if
there is more than one group
Bias 9. Describe any efforts to address
potential sources of bias
No information on the
potential source of bias
- Endemicity

STROBE check list
Sample size 10. Explain how the study size was arrived
at
No mention about
sample size estimation
in cross sectional
surveys
Quantitative
Variables
11. Explain how quantitative variables
were handled in the analyses. If
applicable, describe which groupings were
chosen and why

STROBE check list
Statistical
methods
12(a) Describe all statistical methods,
including those used to control for
confounding
(c) Explain how missing data were
addressed
(d) If applicable, describe analytical
methods taking account of sampling
strategy
(e) Describe any sensitivity analyses

RESULTS :

STROBE check list
Item Results Comments
Participants
13(a) Report the numbers of individuals at
each stage of the study
(b) Give reasons for non-participation at
each stage
(c) Consider use of a flow diagram
No reasons for non
participation
Descriptive
data
14(a) Give characteristics of study
participants (e.g. demographic, clinical,
social) and information on exposures and
potential confounders
(b) Indicate the number of participants
with missing data for each variable of
interest
Has not compared the
characteristic between
groups

STROBE check list
Item Results Comments
Main results
16(a) Give unadjusted estimates and, if
applicable, confounder-adjusted estimates
and their precision (e.g. 95% confidence
interval). Make clear which confounders
were adjusted for and why they were
included
(b) Report category boundaries when
continuous variables were categorized
Confidence Intervals
for certain data could
have been provided
Other Analyses
17. Report other analyses done – e.g.
analyses of subgroups and interactions,
and sensitivity analyses
Tables instead of
graphs

DISCUSSION:
•The reported use of repellents was generally more common at the household
level during the census than at the individual level in the surveys.
•The higher prevalence of repellents in Chennai and Nadiad could be due to urban
areas being more exposed to health messages- higher SES & Education.
•Vaporizers more in Chennai, Coils most preferable in Nadiad & Rourkela.
•Use of creams was overall low.
•The use of ITNs was low except for Rourkela.
•Households with young children were more likely to use repellents in Chennai
and Nadiad. This was not the case in the household surveys in Raurkela.
•In the clinic studies in Nadiad and Raurkela, a higher use of vaporizers among
children < 5 years of age was noted.
•Although in Nadiad and Chennai, households with young boys appeared more
likely than households with young girls to use vaporizers.
•The use of repellents is usually greater when the burden of mosquitoes increases.

LIMITATIONS:
• No information on the brand and the cost.
• Did not verify the use of the repellent and assure the type it belongs
• Lacked Quantification of use.
• Did not Confirm the proper use/ possession of nets.
• No mention on the efficacy of Repellents (census & survey).

CONCLUSIONS:
• There is considerable repellent use in India, with a wide variety of products
available.
•Their use is mainly determined by socio-economic status and level of
education.
•An attractive option to reduce mosquito bites during day time, and the early
evening.
•Needs further clinical testing of these methods and evaluation of safety will
be useful for an evidence-based recommendation.

STROBE check list
Item Discussion Comments
Key Results 18.Summarize key results with reference
to study objectives Mentioned
Limitations
19.Discuss limitations of the study, taking
into account sources of potential bias or
imprecision. Discuss both direction and
magnitude of any potential bias
Mentioned

STROBE check list
Item Discussion Comments
Interpretation
20.Give a cautious overall
interpretation of results considering
objectives, limitations, multiplicity of
analyses, results from similar
studies, and other relevant evidence
More emphasis
on Relevant
Evidence

FUNDING:
Research reported in this publication was supported by the National
Institute of Allergy And Infectious Diseases of the National Institutes of
Health under Award Number as part of the International Centers for
Excellence in Malaria Research

STROBE check list
Item Discussion
Funding
22. Give the source of funding and the role of the funders for the
present study and, if applicable, for the original study on which
the present article is based

Thank You…

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