Journal Article > ResearchFull Text
PLOS One. 2010 June 11; Volume 5 (Issue 6); DOI:10.1371/journal.pone.0011086
Rose AMC, Mueller JE, Gerstl S, Njanpop-Lafourcade BM, Page AL, et al.
PLOS One. 2010 June 11; Volume 5 (Issue 6); DOI:10.1371/journal.pone.0011086
Meningococcal meningitis outbreaks occur every year during the dry season in the "meningitis belt" of sub-Saharan Africa. Identification of the causative strain is crucial before launching mass vaccination campaigns, to assure use of the correct vaccine. Rapid agglutination (latex) tests are most commonly available in district-level laboratories at the beginning of the epidemic season; limitations include a short shelf-life and the need for refrigeration and good technical skills. Recently, a new dipstick rapid diagnostic test (RDT) was developed to identify and differentiate disease caused by meningococcal serogroups A, W135, C and Y. We evaluated the diagnostic performance of this dipstick RDT during an urban outbreak of meningitis caused by N. meningitidis serogroup A in Ouagadougou, Burkina Faso; first against an in-country reference standard of culture and/or multiplex PCR; and second against culture and/or a highly sensitive nested PCR technique performed in Oslo, Norway. We included 267 patients with suspected acute bacterial meningitis. Using the in-country reference standard, 50 samples (19%) were positive. Dipstick RDT sensitivity (N = 265) was 70% (95%CI 55-82) and specificity 97% (95%CI 93-99). Using culture and/or nested PCR, 126/259 (49%) samples were positive; dipstick RDT sensitivity (N = 257) was 32% (95%CI 24-41), and specificity was 99% (95%CI 95-100). We found dipstick RDT sensitivity lower than values reported from (i) assessments under ideal laboratory conditions (>90%), and (ii) a prior field evaluation in Niger [89% (95%CI 80-95)]. Specificity, however, was similar to (i), and higher than (ii) [62% (95%CI 48-75)]. At this stage in development, therefore, other tests (e.g., latex) might be preferred for use in peripheral health centres. We highlight the value of field evaluations for new diagnostic tests, and note relatively low sensitivity of a reference standard using multiplex vs. nested PCR. Although the former is the current standard for bacterial meningitis surveillance in the meningitis belt, nested PCR performed in a certified laboratory should be used as an absolute reference when evaluating new diagnostic tests.
Journal Article > ResearchFull Text
Lancet Infect Dis. 2005 December 1; Volume 5 (Issue 12); DOI:10.1016/S1473-3099(05)70296-6
Olliaro PL, Guerin PJ, Gerstl S, Haaskjold AA, Rottingen JA, et al.
Lancet Infect Dis. 2005 December 1; Volume 5 (Issue 12); DOI:10.1016/S1473-3099(05)70296-6
The state of Bihar in India carries the largest share of the world's burden of antimony-resistant visceral leishmaniasis. We analysed clinical studies done in Bihar with different treatments between 1980 and 2004. Overall, 53 studies were included (all but one published), of which 15 were comparative (randomised, quasi-randomised, or non-randomised), 23 dose-finding, and 15 non-comparative. Data from comparative studies were pooled when appropriate for meta-analysis. Overall, these studies enrolled 7263 patients in 123 treatment arms. Adequacy of methods used to do the studies and report on them varied. Unresponsiveness to antimony has developed steadily in the past to such an extent that antimony must now be replaced, despite attempts to stop its progression by increasing dose and duration of therapy. The classic second-line treatments are unsuited: pentamidine is toxic and its efficacy has also declined, and amphotericin B deoxycholate is effective but requires hospitalisation for long periods and toxicity is common. Liposomal amphotericin B is very effective and safe but currently unaffordable because of its high price. Miltefosine-the first oral drug for visceral leishmaniasis-is now registered and marketed in India and is effective, but should be used under supervision to prevent misuse. Paromomycin (or aminosidine) is effective and safe, and although not yet available, a regulatory submission is due soon. To preserve the limited armamentarium of drugs to treat visceral leishmaniasis, drugs should not be deployed unprotected; combinations can make drugs last longer, improve treatment, and reduce costs to households and health systems. India, Bangladesh, and Nepal agreed recently to undertake measures towards the elimination of visceral leishmaniasis. The lessons learnt in Bihar could help inform policy decisions both regionally and elsewhere.
Protocol > Standardized Survey
Gerstl S, Siddiqui R, Greig J, Lenglet AD, du Cros PAK, et al.
2017 August 24
Vaccination coverage survey protocol - standardised, MSF ERB approved, intersectional
This collection of files includes an overview of the whole process of conducting a vaccination coverage survey and templates for concept papers, the protocol, questionnaires and consent and other related forms. Surveys that use this standardised intersectional protocol do not require MSF Ethics Review Board (ERB) review if the Medical Director of the relevant section takes responsibility for addressing the ethics issues. The exemption criteria of the MSF ERB for standardised intersectional survey protocols must be followed.
This collection of files includes an overview of the whole process of conducting a vaccination coverage survey and templates for concept papers, the protocol, questionnaires and consent and other related forms. Surveys that use this standardised intersectional protocol do not require MSF Ethics Review Board (ERB) review if the Medical Director of the relevant section takes responsibility for addressing the ethics issues. The exemption criteria of the MSF ERB for standardised intersectional survey protocols must be followed.
Journal Article > ResearchFull Text
Malar J. 2010 January 21; Volume 9 (Issue 1); 28.; DOI:10.1186/1475-2875-9-28
Gerstl S, Dunkley S, Mukhtar A, de Smet M, Baker S, et al.
Malar J. 2010 January 21; Volume 9 (Issue 1); 28.; DOI:10.1186/1475-2875-9-28
BACKGROUND
Most malaria rapid diagnostic tests (RDTs) use HRP2 detection, including Paracheck-Pf(R), but their utility is limited by persistent false positivity after treatment. PLDH-based tests become negative more quickly, but sensitivity has been reported below the recommended standard of 90%. A new pLDH test, CareStartTM three-line P.f/PAN-pLDH, claims better sensitivity with continued rapid conversion to negative. The study aims were to 1) compare sensitivity and specificity of CareStartTM to Paracheck-Pf(R) to diagnose falciparum malaria in children under five years of age, 2) assess how quickly false-positive CareStartTM tests become negative and 3) evaluate ease of use and inter-reader agreement of both tests.
METHODS
Participants were included if they were aged between two and 59 months, presenting to a Medecins Sans Frontieres community health centre in eastern Sierra Leone with suspected malaria defined as fever (axillary temperature > 37.5degreesC) and/or history of fever in the previous 72 hours and no signs of severe disease. The same capillary blood was used for the RDTs and the blood slide, the latter used as the gold standard reference. All positive participants were treated with supervised artesunate and amodiaquine treatment for three days. Participants with a persistent false-positive CareStartTM, but a negative blood slide on Day 2, were followed with repeated CareStartTM and blood slide tests every seven days until CareStartTM became negative or a maximum of 28 days.
RESULTS
Sensitivity of CareStartTM was 99.4% (CI 96.8-100.0, 168/169) and of Paracheck-Pf(R), 98.8% (95% CI 95.8-99.8, 167/169). Specificity of CareStartTM was 96.0% (CI 91.9-98.4, 167/174) and of Paracheck-Pf(R), 74.7% (CI 67.6-81.0, 130/174) (p<0.001). Neither test showed any change in sensitivity with decreasing parasitaemia. Of the 155 eligible follow-up CareStartTM participants, 63.9% (99/155) had a false-positive test on day 2, 21.3% (33/155) on day 7, 5.8% (9/155) on day 14, 1.9% (3/155) on day 21 and 0.6% (1/155) on day 28. The median time for test negativity was seven days. CareStartTM was as easy to use and interpret as Paracheck-Pf(R) with excellent inter-reader agreement.
CONCLUSIONS
Both RDTs were highly sensitive, met WHO standards for the detection of falciparum malaria monoinfections where parasitaemia was >100 parasites/mul and were easy to use. CareStartTM persistent false positivity decreased quickly after successful anti-malarial treatment, making it a good choice for a RDT for a hyperendemic falciparum malaria area.
Most malaria rapid diagnostic tests (RDTs) use HRP2 detection, including Paracheck-Pf(R), but their utility is limited by persistent false positivity after treatment. PLDH-based tests become negative more quickly, but sensitivity has been reported below the recommended standard of 90%. A new pLDH test, CareStartTM three-line P.f/PAN-pLDH, claims better sensitivity with continued rapid conversion to negative. The study aims were to 1) compare sensitivity and specificity of CareStartTM to Paracheck-Pf(R) to diagnose falciparum malaria in children under five years of age, 2) assess how quickly false-positive CareStartTM tests become negative and 3) evaluate ease of use and inter-reader agreement of both tests.
METHODS
Participants were included if they were aged between two and 59 months, presenting to a Medecins Sans Frontieres community health centre in eastern Sierra Leone with suspected malaria defined as fever (axillary temperature > 37.5degreesC) and/or history of fever in the previous 72 hours and no signs of severe disease. The same capillary blood was used for the RDTs and the blood slide, the latter used as the gold standard reference. All positive participants were treated with supervised artesunate and amodiaquine treatment for three days. Participants with a persistent false-positive CareStartTM, but a negative blood slide on Day 2, were followed with repeated CareStartTM and blood slide tests every seven days until CareStartTM became negative or a maximum of 28 days.
RESULTS
Sensitivity of CareStartTM was 99.4% (CI 96.8-100.0, 168/169) and of Paracheck-Pf(R), 98.8% (95% CI 95.8-99.8, 167/169). Specificity of CareStartTM was 96.0% (CI 91.9-98.4, 167/174) and of Paracheck-Pf(R), 74.7% (CI 67.6-81.0, 130/174) (p<0.001). Neither test showed any change in sensitivity with decreasing parasitaemia. Of the 155 eligible follow-up CareStartTM participants, 63.9% (99/155) had a false-positive test on day 2, 21.3% (33/155) on day 7, 5.8% (9/155) on day 14, 1.9% (3/155) on day 21 and 0.6% (1/155) on day 28. The median time for test negativity was seven days. CareStartTM was as easy to use and interpret as Paracheck-Pf(R) with excellent inter-reader agreement.
CONCLUSIONS
Both RDTs were highly sensitive, met WHO standards for the detection of falciparum malaria monoinfections where parasitaemia was >100 parasites/mul and were easy to use. CareStartTM persistent false positivity decreased quickly after successful anti-malarial treatment, making it a good choice for a RDT for a hyperendemic falciparum malaria area.
Journal Article > ResearchFull Text
Trop Med Int Health. 2010 April 1; Volume 15 (Issue 4); 480-488.; DOI:10.1111/j.1365-3156.2010.02478.x
Gerstl S, Dunkley S, Mukhtar A, Maes P, de Smet M, et al.
Trop Med Int Health. 2010 April 1; Volume 15 (Issue 4); 480-488.; DOI:10.1111/j.1365-3156.2010.02478.x
OBJECTIVE
Médecins Sans Frontières (MSF) runs a malaria control project in Bo and Pujehun districts (population 158 000) that includes the mass distribution, routine delivery and demonstration of correct use of free, long-lasting insecticide-treated nets (LLINs). In 2006/2007, around 65 000 LLINs were distributed. The aim of this follow-up study was to measure LLIN usage and ownership in the project area.
METHODS
Heads of 900 randomly selected households in 30 clusters were interviewed, using a standardized questionnaire, about household use of LLINs. The condition of any LLIN was physically assessed.
RESULTS
Of the 900 households reported, 83.4% owning at least one LLIN. Of the 16.6% without an LLIN, 91.9% had not participated in the MSF mass distribution. In 94.1% of the households reporting LLINs, the nets were observed hanging correctly over the beds. Of the 1135 hanging LLINs, 75.2% had no holes or 10 or fewer finger-size holes. The most common source of LLINs was MSF (75.2%). Of the 4997 household members, 67.2% reported sleeping under an LLIN the night before the study, including 76.8% of children under 5 years and 73.0% of pregnant women.
CONCLUSION
Our results show that MSF achieved good usage with freely distributed LLINs. It is one of the few areas where results almost achieve the new targets set in 2005 by Roll Back Malaria to have at least 80% of pregnant women and children under 5 years using LLINs by 2010.
Médecins Sans Frontières (MSF) runs a malaria control project in Bo and Pujehun districts (population 158 000) that includes the mass distribution, routine delivery and demonstration of correct use of free, long-lasting insecticide-treated nets (LLINs). In 2006/2007, around 65 000 LLINs were distributed. The aim of this follow-up study was to measure LLIN usage and ownership in the project area.
METHODS
Heads of 900 randomly selected households in 30 clusters were interviewed, using a standardized questionnaire, about household use of LLINs. The condition of any LLIN was physically assessed.
RESULTS
Of the 900 households reported, 83.4% owning at least one LLIN. Of the 16.6% without an LLIN, 91.9% had not participated in the MSF mass distribution. In 94.1% of the households reporting LLINs, the nets were observed hanging correctly over the beds. Of the 1135 hanging LLINs, 75.2% had no holes or 10 or fewer finger-size holes. The most common source of LLINs was MSF (75.2%). Of the 4997 household members, 67.2% reported sleeping under an LLIN the night before the study, including 76.8% of children under 5 years and 73.0% of pregnant women.
CONCLUSION
Our results show that MSF achieved good usage with freely distributed LLINs. It is one of the few areas where results almost achieve the new targets set in 2005 by Roll Back Malaria to have at least 80% of pregnant women and children under 5 years using LLINs by 2010.
Journal Article > ResearchFull Text
PLOS One. 2009 October 5; Volume 4 (Issue 10); DOI:10.1371/journal.pone.0007326
Rose AMC, Gerstl S, Mahamane AE, Sidikou F, Djibo S, et al.
PLOS One. 2009 October 5; Volume 4 (Issue 10); DOI:10.1371/journal.pone.0007326
The Pastorex((R)) (BioRad) rapid agglutination test is one of the main rapid diagnostic tests (RDTs) for meningococcal disease currently in use in the "meningitis belt". Earlier evaluations, performed after heating and centrifugation of cerebrospinal fluid (CSF) samples, under good laboratory conditions, showed high sensitivity and specificity. However, during an epidemic, the test may be used without prior sample preparation. Recently a new, easy-to-use dipstick RDT for meningococcal disease detection on CSF was developed by the Centre de Recherche Médicale et Sanitaire in Niger and the Pasteur Institute in France. We estimate diagnostic accuracy in the field during the 2006 outbreak of Neisseria meningitidis serogroup A in Maradi, Niger, for the dipstick RDT and Pastorex((R)) on unprepared CSF, (a) by comparing each test's sensitivity and specificity with previously reported values; and (b) by comparing results for each test on paired samples, using McNemar's test. We also (c) estimate diagnostic accuracy of the dipstick RDT on diluted whole blood. We tested unprepared CSF and diluted whole blood from 126 patients with suspected meningococcal disease presenting at four health posts. (a) Pastorex((R)) sensitivity (69%; 95%CI 57-79) was significantly lower than found previously for prepared CSF samples [87% (81-91); or 88% (85-91)], as was specificity [81% (95%CI 68-91) vs 93% (90-95); or 93% (87-96)]. Sensitivity of the dipstick RDT [89% (95%CI 80-95)] was similar to previously reported values for ideal laboratory conditions [89% (84-93) and 94% (90-96)]. Specificity, at 62% (95%CI 48-75), was significantly lower than found previously [94% (92-96) and 97% (94-99)]. (b) McNemar's test for the dipstick RDT vs Pastorex((R)) was statistically significant (p<0.001). (c) The dipstick RDT did not perform satisfactorily on diluted whole blood (sensitivity 73%; specificity 57%).Sensitivity and specificity of Pastorex((R)) without prior CSF preparation were poorer than previously reported results from prepared samples; therefore we caution against using this test during an epidemic if sample preparation is not possible. For the dipstick RDT, sensitivity was similar to, while specificity was not as high as previously reported during a more stable context. Further studies are needed to evaluate its field performance, especially for different populations and other serogroups.
Journal Article > ResearchFull Text
BMC Public Health. 2022 February 14; Volume 22 (Issue 1); 295.; DOI: 10.1186/s12889-022-12547-9
Gerstl S, Lee L, Nesbitt RC, Mambula C, Sugianto H, et al.
BMC Public Health. 2022 February 14; Volume 22 (Issue 1); 295.; DOI: 10.1186/s12889-022-12547-9
BACKGROUND
Cervical cancer (CC) is the fourth most common cancer among women worldwide and Malawi has the world's highest rate of cervical cancer related mortality. Since 2016 the National CC Control Strategy has set a screening coverage target at 80% of 25-49-year-old women. The Ministry of Health and Médecins Sans Frontières (MSF) set up a CC program in Blantyre City, as a model for urban areas, and Chiradzulu District, as a model for rural areas. This population-based survey aimed to estimate CC screening coverage and to understand why women were or were not screened.
METHODS
A population-based survey was conducted in 2019. All resident consenting eligible women aged 25-49 years were interviewed (n = 1850) at households selected by two-stage cluster sampling. Screening and treatment coverage and facilitators and barriers to screening were calculated stratified by age, weighted for survey design. Chi square and design-based F tests were used to assess relationship between participant characteristics and screening status.
RESULTS
The percentage of women ever screened for CC was highest in Blantyre at 40.2% (95% CI 35.1-45.5), 38.9% (95% CI 32.8-45.4) in Chiradzulu with supported CC screening services, and lowest in Chiradzulu without supported CC screening services at 25.4% (95% CI 19.9-31.8). Among 623 women screened, 49.9% (95% CI 44.0-55.7) reported that recommendation in the health facility was the main reason they were screened and 98.5% (95% CI 96.3-99.4) recommended CC screening to others. Among 1227 women not screened, main barriers were lack of time (26.0%, 95% CI 21.9-30.6), and lack of motivation (18.3%, 95% CI 14.1-23.3). Overall, 95.6% (95% CI 93.6-97.0) of women reported that they had some knowledge about CC. Knowledge of CC symptoms was low at 34.4% (95% CI 31.0-37.9) and 55.1% (95% CI 51.0-59.1) of participants believed themselves to be at risk of CC.
CONCLUSION
Most of the survey population had heard about CC. Despite this knowledge, fewer than half of eligible women had been screened for CC. Reasons given for not attending screening can be addressed by programs. To significantly reduce mortality due to CC in Malawi requires a comprehensive health strategy that focuses on prevention, screening and treatment.
Cervical cancer (CC) is the fourth most common cancer among women worldwide and Malawi has the world's highest rate of cervical cancer related mortality. Since 2016 the National CC Control Strategy has set a screening coverage target at 80% of 25-49-year-old women. The Ministry of Health and Médecins Sans Frontières (MSF) set up a CC program in Blantyre City, as a model for urban areas, and Chiradzulu District, as a model for rural areas. This population-based survey aimed to estimate CC screening coverage and to understand why women were or were not screened.
METHODS
A population-based survey was conducted in 2019. All resident consenting eligible women aged 25-49 years were interviewed (n = 1850) at households selected by two-stage cluster sampling. Screening and treatment coverage and facilitators and barriers to screening were calculated stratified by age, weighted for survey design. Chi square and design-based F tests were used to assess relationship between participant characteristics and screening status.
RESULTS
The percentage of women ever screened for CC was highest in Blantyre at 40.2% (95% CI 35.1-45.5), 38.9% (95% CI 32.8-45.4) in Chiradzulu with supported CC screening services, and lowest in Chiradzulu without supported CC screening services at 25.4% (95% CI 19.9-31.8). Among 623 women screened, 49.9% (95% CI 44.0-55.7) reported that recommendation in the health facility was the main reason they were screened and 98.5% (95% CI 96.3-99.4) recommended CC screening to others. Among 1227 women not screened, main barriers were lack of time (26.0%, 95% CI 21.9-30.6), and lack of motivation (18.3%, 95% CI 14.1-23.3). Overall, 95.6% (95% CI 93.6-97.0) of women reported that they had some knowledge about CC. Knowledge of CC symptoms was low at 34.4% (95% CI 31.0-37.9) and 55.1% (95% CI 51.0-59.1) of participants believed themselves to be at risk of CC.
CONCLUSION
Most of the survey population had heard about CC. Despite this knowledge, fewer than half of eligible women had been screened for CC. Reasons given for not attending screening can be addressed by programs. To significantly reduce mortality due to CC in Malawi requires a comprehensive health strategy that focuses on prevention, screening and treatment.
MSF Ethics Review Board > Templates & procedures
Gerstl S, Grandesso F, Siddiqui R, Greig J, du Cros PAK, et al.
2022 October 25
Journal Article > ResearchFull Text
Trans R Soc Trop Med Hyg. 2006 October 1; Volume 100 (Issue 10); DOI:10.1016/j.trstmh.2006.03.002
Borel T, Rose AMC, Guillerm M, Sidikou F, Gerstl S, et al.
Trans R Soc Trop Med Hyg. 2006 October 1; Volume 100 (Issue 10); DOI:10.1016/j.trstmh.2006.03.002
There is a great need for a rapid diagnostic test to guide vaccine choice during outbreaks of meningococcal meningitis in resource-poor countries. During a randomised clinical trial conducted during an epidemic of Neisseria meningitidis serogroup A in Niger in 2003, the sensitivity and specificity of the Pastorex latex agglutination test for this serogroup under optimal field conditions were assessed, using culture and/or PCR as the gold standard. Results from 484 samples showed a sensitivity of 88% (95% CI 85-91%) and a specificity of 93% (95% CI 90-95%). Pastorex could be a good alternative to current methods, as it can be performed in a local laboratory with rapid results and is highly specific. Sensitivity can be improved with prior microscopy where feasible. A study specifically to evaluate the Pastorex test under epidemic conditions, using laboratories with limited resources, is recommended.
Conference Material > Video (talk)
Gerstl S, Nesbitt RC
Epicentre Scientific Day Paris 2021. 2021 June 10