Relationships Between the Use of Antimalarial Drugs in Pregnancy and Plasmodium Falciparum Resistance
Condition: Malaria in Pregnancy; Birth Weight; Anaemia
MeSH terms: Malaria; Birth Weight
Study type: Interventional

Summary: 
      Plasmodium falciparum resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP)
      continue to spread, impeding control of this important disease. CQ and SP are still the most
      commonly used antimalarial drugs for malaria prevention during pregnancy and might be made
      less effective by resistance. However, the treatment and prophylaxis regimens used may also
      create conditions for selecting resistant malaria parasite strains. A better understanding of
      the relationships between chemoprophylaxis regimens and resistance would be helpful to
      improve chemoprophylaxis of malaria in pregnancy.

      This work aims to improve the use of chemoprophylaxis in pregnancy by determining whether
      there is a relationship between the use of standard prophylactic regimens with CQ and SP and
      the occurrence of P. falciparum resistant strains in pregnant women. The study consists of 2
      parts. The first part is a randomized trial comparing 3 chemoprophylactic treatment groups: -
      weekly CQ after initial presumptive CQ treatment, - CQ intermittent presumptive treatment
      given as a standard dose at 2nd and 3rd trimester, respectively and SP intermittent
      presumptive treatment given as a single dose at 2nd and 3rd trimester, respectively. These
      treatment groups will also be compared to a group of women delivering at the same health
      centre but who have not been participating in the study. The second part will be a clinical
      trial for assessment of clinical and parasitological efficacy of CQ and SP treatment in
      pregnant women presenting with uncomplicated malaria attacks.

      The study will be conducted from October 2002 to March 2005 in a health centre of
      Ouagadougou, Burkina Faso where malaria transmission is seasonal and resistance to CQ and SP
      is low.
    

Detailed description: 
      OBJECTIVES Overall objective: To improve the use of malaria chemoprophylaxis in pregnancy.

      Specific objectives:

      To investigate the effects of weekly CQ, intermittent presumptive treatment with CQ, and with
      SP on placental, peripheral, and cord parasitaemia and on P. falciparum resistance status in
      primigravidae and secundigravidae.

      To determine the relationships between carriage of P. falciparum resistant strains and
      malaria morbidity (attacks and anaemia) during pregnancy.

      To determine the clinical and parasitological efficacy of CQ and SP in primigravidae and
      secundigravidae.

      MATERIAL AND METHODS

      The study will be conducted in a peripheral health centre of Ouagadougou, Burkina Faso, West
      Africa.

      The largest part of the country is tropical savannah with a rainy season from June to October
      (average rainfall: 1000 mm per year, mean temperature > 25°C), a cold dry season from
      November to February, (min. temp. 15°C) and a hot dry season from March to May. Malaria
      transmission is seasonal (June to December)and the major mosquito vectors are A. gambiae, A.
      funestus and A. arabiensis. Malaria morbidity represents 30 to 50% of febrile illnesses and
      is the most frequent reason for health centres attendance and hospitals admission.Since it's
      first notification in 1986, P. falciparum resistance to CQ increased slowly with a
      considerable variation in space and time and resistance to SP has remained low. CQ clinical
      failures are in general less than 20% in 6-59 months children and parasitological resistance
      is around 30%. Malaria prevention in pregnancy is given as weekly 300 mg CQ following a
      presumptive initial treatment as recommended by the national malaria control programme (MOH).
      ANC services in health centres provide pregnant women with CQ and haematinics. The health
      centre 'Centre médical Paul VI' is a peri-urban health facility of Ouagadougou. It comprises
      general outpatient consultation service, paediatric and maternity wards, and a
      laboratory.Patients come from the peri-urban districts and the neighbouring villages.

      Study design:

      a) Comparative randomized trial.

      Three groups will be studied. Pregnant women (primigravidae and secundigravidae from 12 to 24
      weeks of pregnancy) will be randomly assigned, using random numbers lists, to treatment
      groups A to C as defined below:

        -  Group A : pregnant women receiving weekly 300 mg CQ prophylaxis after a curative dose
           (10mg/kg at days 1 and 2 +5mg/kg at day 3) at the first visit ;

        -  Group B : pregnant women receiving a presumptive CQ treatment at the 2nd and 3rd
           trimester of pregnancy (10mg/kg at days 1 and 2 +5mg/kg at day 3);

        -  Group C: pregnant women receiving a presumptive SP treatment at the 2nd and 3rd
           trimester of pregnancy (25mg sulfadoxine + 1,25mg pyrimethamine/kg in a single dose).

      Another group composed of primiparous and secundiparous women who are not part of the study
      and who come to deliver at the health centre (group D) and who have not received chloroquine
      prophylaxis during pregnancy will be considered as reflecting the normal situation and act as
      a control group. These women will only be included during the first three months of the
      study.

      At inclusion

        1. personal information, anthropometric measures, clinical data, and obstetrical history,
           will be recorded

        2. fingerprick blood will be collected for a thick and a thin blood smear, Hb and on filter
           paper for subsequent PCR tests

        3. Treatment: The single dose of SP and the 3 days of CQ treatment will be administered
           supervised by the research team.

      Study participants will be invited to come to the follow up visits or any time they feel sick
      or need health services.

      Follow-up visits at the beginning of second and third trimester will include:

        1. a clinical and parasitological examination. The health events since the previous visit
           will be recorded, Hb

        2. providing chemoprophylaxis or treatment in accordance with the treatment group.

      At delivery, the following data will be recorded:

        1. delivery outcomes (birth weight, mode of delivery, APGAR score)

        2. mother's peripheral blood for thick blood smear, Hb and filter paper for PCR

        3. placental blood for thick blood smear, and collection on filter paper for PCR

        4. cord blood for thick blood smear. If positive blood will be collected on filter paper
           for PCR

           b)Clinical trial for the assessment of clinical and parasitological efficacy of CQ and
           SP in pregnant women.

           Primigravidae and secundigravidae women presenting with an uncomplicated malaria attack
           will be randomly treated with CQ or SP and regularly followed up to assess clinical and
           parasitological efficacy. A molecular analysis of parasite gene mutations conferring
           resistance to chloroquine (PfCRT), and antifolates (DHFR, DHPS) will be performed.

           The patients will randomly assigned to treatment with either CQ or SP. They will then be
           followed-up during 28 days in accordance with WHO protocol. The follow up criteria are
           clinical (body temperature) and parasitological (peripheral parasitaemia).

           Sample size:

           a) Comparative randomized trial: Considering the prevalence of placenta parasitaemia to
           be 35% in pregnant women who do not get prophylaxis, 24% in women with weekly CQ
           prophylaxis, 15% in women with intermittent presumptive treatment with CQ and 5% in
           women with intermittent presumptive treatment with SP, and using a significance level of
           5%, a power of 80% and 20% drop-out, each group should include 200 subjects.

           a) Drug efficacy assessment in pregnant women Considering the proportion of pregnant
           women with clinical failures to be 10-15% for chloroquine, and using a significance
           level of 5%, a power of 80% and 20% drop-out, a sample of 42 subjects should be
           included.

           Methods:

             1. Comparative randomized trial:

                Pregnant women will be recruited at the ANC unit of the health facility if
                fulfilling the following inclusion criteria and give oral informed consent.

                Inclusion criteria:

                  -  primi or secundigravidae - seen between 12th and 24th weeks of gestation

                  -  with a non 'at risk pregnancy' (multiple pregnancy, obstetric misproportions,
                     previous caesarean, high blood pressure, diabetes, clinical signs of AIDS.

                  -  staying in a neighbouring district or village

                  -  ability to come for follow-up and delivery.

                Exclusion criteria:

                  -  At risk pregnancy

                  -  Severe systemic disease

                  -  Wish to withdraw from participation.

                Inclusion and follow-up procedures:

                The study aims and procedures will be clearly explained to those meeting the
                inclusion criteria.Enrolled women will be registered and a personal health file
                created, to be filled at enrolment, follow-up and, delivery. Each woman will be
                given a health record booklet to be presented at any visit. The following
                information will be recorded:

                At enrolment:

                  -  Identity number, date, and treatment group.

                  -  Name, age, profession, place of residence, address and name of husband and
                     other close relatives.

                  -  Clinical history, axillary temperature, body weight, height, clinical anaemia,
                     jaundice, splenomegaly, hepatomegaly, stethoscopy of heart and lungs, blood
                     pressure and peripheral oedema)

                  -  Obstetrical data: date LMP, uterine size, presumed delivery date, foetal heart
                     beat, previous pregnancy outcome (normal, abortion, stillbirth, complications
                     during pregnancy and labour).

                  -  Biological data: Plasmodium species and density, Hb, filter paper blood for
                     PCR.

                Follow-up:

                  -  Clinical follow-up: fever episodes, diseases, other treatments

                  -  Obstetrical follow-up: uterine height, foetal heart beat

                  -  Biological follow-up: Plasmodium species and density, Hb, filter paper blood
                     for PCR.

                Delivery:

                - Date and time labor started, midwife's name.

                  -  Clinical data: body temperature, blood pressure, and clinical examination.

                  -  Mode of delivery, APGAR scores, and birthweight.

                  -  Biological data: mother's peripheral parasitaemia, haemoglobin concentration,
                     placental parasitaemia, cord parasitaemia. Cord and mother's peripheral and
                     placental blood collection on filter paper for PCR.

                Laboratory methods:

                - malaria diagnosis: a thick and thin smear of fingerprick blood will be prepared
                from each subject. Thin films will be fixed with methanol and stained with Giemsa
                in phosphate buffer (pH 7.2) for 30 min. and examined with a 100X oil immersion
                objective. The parasite species will be determined on the thin film and the
                parasites densities evaluated on the thick film by counting the number of asexual
                P.falciparum parasites against 200 leukocytes and expressed as number of parasites
                by microliter (µl) of blood assuming a standard leukocyte count of 8000/µl. At
                least 100 thick film fields will be examined to declare a slide negative.

                  -  Blood collection on filter paper: fingerprick blood will be collected on
                     Whatmann 3MM chromatography filter paper. About 80-100 µl blood will be
                     directly blotted on the paper strips, air dried and individually placed in
                     plastic bag and conserved at room temperature in bottles containing silicagel.

                  -  HB will be measured using a HemoCue portable photometer.

                  -  Polymerase Chain Reaction (PCR) assays will be performed from blood on filter
                     papers using the methods described by Jelinek et al., 1999, for resistance to
                     antifolates and by Djimde et al.2001 for resistance to CQ.

                Drug efficacy assessment in pregnant women

                The subjects will be recruited at ANC and adult outpatient units of the health
                facility. Those who meet the inclusion criteria will be selected and requested to
                participate (oral informed consent) and then randomly allocated to CQ or SP
                treatment

                Inclusion criteria:

                • primi or secundigravidae from 12 to 24 weeks of gestation

                • pregnant women without 'at risk pregnancy'

                • axillary body temperature > 37.5°C and < 39.5°C

                • no clinical sign of severe malaria

                • mono infection of P. falciparum with a density > 2000 trophozoites /µl of blood

                  -  no sign of other febrile disease

                  -  staying in a neighbouring district or village

                Exclusion criteria:

                  -  severe malaria

                  -  any other febrile disease

                  -  previous side effects to CQ or SP consumption

                  -  loss to follow up.

                Inclusion and follow-up procedures:

                Enrolled women will be recorded with: date, identity number, name, age, profession,
                address, temperature, body weight, parasitaemia, haemoglobin concentration,
                treatment, follow-up temperatures, parasitaemia and Hb, other observations, and
                results of the test. Every subject will be asked to come at precise dates for
                follow up. Those lost of follow up will be actively searched for the next day.

                Methods:

                The WHO 28 days "assessment of therapeutic efficacy of antimalarials drugs for
                uncomplicated falciparum malaria in areas with intense transmission protocol" will
                be used, adapted to pregnant women.

                Data handling and statistical analysis All data will be recorded in pre-designed
                and tested questionnaires and/or registers. Then they will be progressively
                entered, cleared, checked and analysed using SPSS software.

                For the comparative randomized trial, a general analysis will aim to describe the
                study samples through the calculation of variables means (e.g. age, parity,
                parasite density, haemoglobin concentrations, birthweight), the frequency of some
                clinical data as malaria attacks, clinical results, delivery outcomes, mutations
                profiles.

                Then a comparative analysis will compare the proportions of main variables between
                the different treatment groups (peripheral, placenta, and cord blood parasitaemia,
                LBW, prevalence of resistant strains, mutations profiles, clinical and
                parasitological responses) using the chi-square test. The means (birthweight,
                haemoglobin concentrations, and number of clinical attacks) will be compared
                between groups by t-test and one way analysis of variance. Stratified or
                multivariate analysis tests will be used when necessary.
    

Intervention name(s): sulphadoxine-pyrimethamine; chloroquine
Intervention type(s): Drug; Drug
Intervention MeSH terms: Chloroquine; Pyrimethamine; Sulfadoxine; Fanasil, pyrimethamine drug combination
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Single
Primary purpose: Treatment
Keywords: Plasmodium falciparum; malaria; pregnancy; resistance