Epidemiology & Public Health

Follow up of patients receiving the WHO 2018 recommended rabies PEP using intradermal vaccination protocol

Based on the previous study, WHO endorsed 2018 guidelines to provide three post-exposure prophylaxis (PEP) sessions of two-site intradermal 0.1 mL vaccine doses each at days 0, 3 and 7 is the first one-week PEP regimen to be recommended. To evaluate the protective antibody response survival time, we aim to follow a cohort of around 170 patients at day 14, at 6 months and at 1 year after the first session of the vaccine schedule using the vaccination protocol described above. Both the EPH and immunology units, IPC, are involved in this work (2019- 2020).

Team leaders: S. Ly, L. Borand

Funding: Institut Pasteur du Cambodge

Rabies PEP immune response study (RESIST 2)

Data is available showing that the immune response at Day 14 after a one-week protocol of three intradermal injections at days 0, 3 and 7 is comparable to a 5-dose regimen. The number of doses administered in the one- week, three session protocol, however remains high at 12 intradermal doses. Clinical, epidemiological and biological data are being gathered to estimate whether the existing intramuscular and intradermal protocol can  be shortened (three-session, one-week regimen; without Day 28 session) and the number of doses reduced (6 instead of 8) in PrEP and in PEP protocols, at no risk to patients. Current status: Publication in the Lancet Infectious Diseases Journal. Main partners in Cambodia: MoH

Team leaders: S. Ly, L. Borand, A. Tarantola

Funding: International Division

Rabies – One Health

The purpose of this project is to create a “One Health” network for rabies research and control in dogs and human populations inCambodia, Lao PDR and Vietnam. This three-year project is organized into three research packages and includes several activities: 1) research and working visits between partners, 2) joint seminars and workshops aimed at expert opinions, knowledge exchange and mutual learning, and 3) field surveys (dog demography, vaccination and vaccine coverage follow-up in Kandal Province). A workshop onFAVN diagnostics was organized by IPC in 2018 in collaboration with the Nancy Laboratory for Rabies and Wildlife (ANSES). Demographicparameters, bite incidence risk factors, human/dog relationships, bite management behavior are available: a publication is on track.Serological analyses of post-vaccination sera have been achieved. A second paper is under preparation.

Team leaders: V. Chevalier, Sowath Ly

Funding: Swedish Research Council

PTR field tests for rabies diagnostics

The aim of the Field Tests for Rabies Diagnostics (FiTeRaD) project is to develop and to validate, both in laboratory conditions and in field settings, the first point of care tests (POCTs) for the rapid detection of the etiological agent of rabies (with rabies virus – RABV) in humans.

Team leader: V.Chevalier

Funding: Institut Pasteur Paris

Control of rabies in Battambang Province, Cambodia

The global objective of this project is to reduce rabies induced mortality in Battambang Province, through 5 main activities: (1) information, education and communication; (2) improvement of case monitoring and management

(3) estimation of demographic parameters of the dog population (4) evaluation of the vaccination efficacy in dogs, both at the individual and population level (5) recommendation on vaccination strategies based on demographic parameters, owner acceptability and feasibility.Communication tools, such as leaflets or web communication, have been agreed upon. A second PEP center was opened by IPC inSeptember 2018. Three thousand dogs are being monitored and vaccinated, with a sub-batch of 800 dogs being sampled every 6 months.Demographic parameters, bite incidence risk factors, human/dog relationships, bite management behavior are available: a publication is on track. Serological analyses of post-vaccination sera have been achieved. A second paper is under preparation.

Team leaders: V. Chevalier, Sowath Ly

Funding: Région Occitanie (France)

ECOMORE 2: Mosquito control and education in schools to reduce dengue burden in the community

A clustered randomized controlled trial (2017-2019) covering two dengue seasons was initiated to measure      the impact of an integrated school-based strategy combining mosquito control and education programs on        the transmission of dengue disease in their surrounding communities. One study cluster is a geographic area composed of one school and neighboring villages where students from the school reside. Interventions consisted of a school-based strategy combining: 1) larvicide (Bti) usage in big containers, 2) physicaldestruction of breeding sites, 3) use of dissemination insecticide (Pyriproxyfen in2Care) and 4) educational method. In March 2018, a total of 24 clusters were followed-up, of which twelve were randomly allocated the school-based intervention and twelve were controls. Inall 24 study clusters, active community-based surveillance of dengue-like illnesses among children aged 5-15 years old and saliva serological follow-up among school children of same age were performed as effectiveness outcomes. Results consolidation for preparation of a manuscript are in process.

Team Leaders: S. Ly, P. Piola

Funding: Funded by AFD

Surveillance of Zika-like syndromes and microcephaly

The Zika pandemic that started in 2015 in the Americas caused thousands of microcephalies in newborns from infected pregnant women. From mid-2018 to mid-2019, an active surveillance of Zika-like syndromes in pregnant women attending the antenatal clinic of Calmette Hospital was initiated. All pregnant women with a WHO case definition of Zika-like syndrome were tested by PCR by the IPCvirology unit for confirmation. Mothers of newborns with microcephalies in Calmette Hospital were serologically tested from Zika. This light sentinel surveillance were done to detect emerging ZIKV circulation in Cambodia, with a focus on the most vulnerable group. Few pregnant mothers presented Zika Like syndromes, and none had a Zika infection confirmed by PCR.

Team Leader: P. Piola

Funding: French Ministry of European and Foreign Affairs

STATIS ANRS 12290

Despite the initiation of, highly active antiretroviral therapy (HAART) many patients die of tuberculosis within the first month of treatment. The “STATIS (Systematic vs. Test- tuberculosis guided Anti TB Treatment Impact in Severely Immuno-suppressed HIV-infected Adults Initiating Antiretroviral Therapy With CD4 Cell Counts <100/mm3)’ is a multicentric randomized controlled trial aiming to compare two experimental strategies to reduce the mortality  and occurrence of severe bacterial infections (incl. tuberculosis) at six months in severely immunodeficient adults infected with HIV (CD4 < 100/mm3): 1) a strategy for intensive screening and repeated tuberculosis testing through workable tests during the day (Xpert Mycobacterium tuberculosis (MTB) / RIF, LAM urinary, chest radiography); and, 2) a strategy ofsystematic empirical anti-tuberculosis treatment initiated two weeks before the start of HAART. Recruitment and follow-up of patients iscompleted 199 patients included in Cambodia within a total 1050 included. Main partners in Cambodia are NCHADS, CENAT, and SHCH.

Team leader: L. Borand

Funding: ANRS

miRNA as prediction and/or prognostic markers of IRIS in TB-HIV co-infected patients. ANRS 12358

The role of miRNAs in HIV disease and tuberculosis is yet to be completely defined. The objectives of this study are to identify the miRNA expression profile as potential novel predictive and prognostic biomarker for IRIS, and to identify the miRNA expression profile in TB patients and HIV/TB co-infected patients. Patient recruitment and follow-up ongoing are completed, analysis is ongoing. The main partner in Cambodia is the Sihanouk Hospital Center of Hope.

Team leader: L. Borand

Funding: ANRS

IL-1Ra Study – ANRS 12394: Rapid decrease in Interleukin-1 receptor antagonist plasma concentration following tuberculosis treatment initiation: a proof of concept study in Cambodia and Cote d’Ivoire

In a pilot study previously done with Cambodian patients from the CAMELIA clinical trial, we found that IL-1Ra plasma concentrations dropped dramatically after two months of TB treatment. The objective of this current proof- of-concept study is to demonstrate that IL-1Ra concentrations significantly decrease within two weeks following TB treatment initiation in adults with documented TB. This study is currently under preparation, and the main partner in Cambodia is the Sihanouk Hospital Center of Hope.

Team leaders: L. Borand

Funding: ANRS

TB-Speed research project

The majority of children with TB are not diagnosed or reported and do not benefit from appropriate treatment. TB-Speed is a multicentre (seven countries) research project, aiming at improving the diagnosis of childhood tuberculosis through decentralization of TB diagnosisand systematic tuberculosis diagnostic in vulnerable children. Registration and follow-up of patients in the study are ongoing. The TB-Speed decentralization component is  also ongoing. This research project is currently under preparation, CENAT, the National Pediatric Hospital, the Kampong Cham and Takeo Hospitals, and Batheay and Ang rokar Districts’ health facilities are the main partners inCambodia.

Team Leader: L. Borand.

Funding: UNITAID/5% Initiative.

OPTICAM: Optimizing Latent TB treatment among people living with HIV in Cambodia

The aim of the project is to improve Latent Tuberculosis Infection (LTBI) treatment uptake in people living with HIV in Cambodia by addressing the barriers and assessing the impact of the short-course, 3 drug 3HP use in the LTBI treatment uptake and completion aspart of a comprehensive intervention. Phase 1 study preparation is completed and ongoing activities are currently in process. Main partners in Cambodia are NCHADS, CENAT, and the Clinton Health Access Initiative (CHAI).

Team Leader: L. Borand

Funding: Global Fund 5% Initiative

Ta Prohm – ANRS 12345: Tenofovir as Prevention of Hepatitis B Transmission for Mothers

Despite effective primary prophylaxis, HBV remains a substantial health problem both internationally and in Cambodia where neonatal transmission still occurs. WHO recommends immediate administration of Hepatitis B vaccine and immunoglobulin in newborns to HBsAg+ mothers. Reported failure rates range from 1– 14%, despite serovaccination. Factors associated with failure include HBeAgpositivity and high HBV DNA viral loads in mothers. Antivirals can be utilized to further decrease the risk of vertical transmission, especially in areas where WHO- recommended serovaccination is inaccessible. This project aims to prevent MTCT by reducing the HBV viral load in mothers by antivirals, typically initiated starting week 24 of pregnancy.  Current status: Patients’ recruitment     is completed and follow-up is ongoing. Main partners in Cambodia: Calmette Hospital, NMCH, Jayavarman VII Hospital, National Pediatric Hospital, Kampong Cham and Takeo Provincial Hospitals and seven health centers from Kampong Cham and Takeo Provinces.

Team Leaders: L. Borand, P. Piola

Funding: ANRS

Pilot therapeutic study of DAA treatment for children and adolescents with active HCV infection born from HIV/HCV coinfected women in Cambodia – ANRS 12420

Transmission from mother to child is the main route of acquisition of HCV mono-infection and of HCV/HIV co- infection in children.Approximately 25% of HCV-infected children spontaneously clear the virus but clearance rate seems to decrease for HIV/HCV co-infectedchildren. Advanced liver diseases with cirrhosis occur for less than 5% of children but the proportion of patients with bridgingfibrosis/cirrhosis, evaluated by liver biopsies, was reported to increase from 11% to 20% in a median time of 5.8 years. For HIV/HCV co-infected children, data are scarce. The objective is to evaluate the effectiveness of daclatasvir/sofosbuvir combination for children agedmore than 6 years old and adolescents with active HCV infection. Secondary objectives notably include the evaluation of plasma exposures of sofosbuvir, GS-331007 (predominant circulating metabolite of sofosbuvir), and daclatasvir Current status: the study is under preparation. Main partners in Cambodia: NCHADS and OI/ART sites.

Team Leader: L. Borand

Funding: ANRS

BIRDY (Bacterial infections and antibiotic-resistant diseases among young children in low income countries) – 2014-2018 + ACIP klebsiella pneumoniae

Little is known about bacterial infections and resistance in pediatrics and developing countries. Antimicrobial resistance (AMR) is one of the biggest threats worldwide. BIRDY is an international (Madagascar, Senegal, Cambodia) multicentric and prospective cohort study aiming to estimate bacterial infections and AMR incidence among neonates and young children from rural and urban community settings, to describe and characterize pathogenic and colonizing bacteria, and assess the burden of AMR. In Cambodia, among 815 mothers, group-B streptococcus vaginal carriage was low: <1%, digestive carriage ofKlebsiella pneumoniae was high: 68% and digestive carriage of ESBL-producing enterobacteria was extremely high: 75%. Neonatal mortality was low compared to national data, 6.2 vs 14.0/1000 live-births respectively. Incidence of neonatal sepsis was ~5.2/1000 live-births with 3/4 (75%) isolates resistant to antibiotic recommended by WHO. A national results dissemination meeting was held in April 2019. There are ongoing validation activities. Partners are the Cambodian CDC, twohealth centers, and 3 hospitals.

Team leaders: A. de Lauzanne, L. Borand

Funding: Institut Pasteur Paris, MSD Avenir.

PEEC NIC (Producing extended-spectrum beta lactamase enterobacteriaceae carriage in newborns and infants in Cambodia) – 2016-2018

In low-resources settings, the spread of ESBL-producing Enterobacteriaceae (ESBL-E) in the community is a public health concern. Data are scarce, especially in newborns where the burden of sepsis is high. The objectives of this study are to determine early prevalence of ESBL-E fecal carriage in newborns, to follow acquisition during the first year of life, and identify risk factors and investigate ESBL genes in Cambodia. One hundred forty-seven newborns from two urban and ruralcommunity settings were enrolled and followed for one year. Preliminary results: At day three of life, the prevalence of ESBL-Efecal carriage among newborns was 53% [95%IC: 45-61], remaining stable up to 12 months of life: 52% [95%IC: 44-60]. Most frequently detected ESBL-genes were blaCTXM-15 blaCTXM -55 and blaCTXM-27. Being in an urban setting, delivery at hospital/private clinic and a household of <6 people were positively associated to carriage. This particularly high and precocious prevalence of ESBL-E carriage increases the risk of ESBL-E neonatal infection in Cambodian newborns. A presentation of study results was made at the national result dissemination meeting of BIRDY. Ongoing sharing activities continue. The main partner for this activity is the French National Research Committee for carbapenem resistance.

Team Leader: A. de Lauzanne

Funding: BIRDY project, Lund University-Sweden.

Pertussis immunization programs in low income countries (PERILIC)

Infection by Bordetella pertussis or Bordetella Para pertussis occurs in epidemic cycles and can cause severe acute respiratory diseases especially in infants. Incidence of its clinical form has declined by more than 90% in the industrialized world.That said, WHO listed pertussis as a major cause of death in infants in 2014, coincident with a global resurgence in pertussisincidence. The aim of this study is to document contamination processes, clinical characteristics and prevalence rates ofpertussis cases in children under 6 months old suspected of whooping cough (WP1) and to assess immunization status among household contacts and children from 3-15 years old (WP2). Regarding WP1, participant recruitment and follow-up are completed, while for WP, participant recruitment is completed. Main partners in Cambodia are NIP, NIPH, Several provincial hospitals, private clinics and health centers.

Team leader: L. Borand

Funding: Fondation Total.

A hospital based case-control study to identify risk factors of leptospitoris and to improve post-disaster management of emerging diseases

While extreme weather events such as floods, are associated with leptospirosis outbreaks, little is known about the magnitudeof leptospirosis incidence in Myanmar where floods are a priori increasingly frequent. Leptospirosis in Myanmar is suspected tobe endemic, but it remains underdiagnosed. We contributed to the design of a multicenter hospital-based case-control study, exploring socio-demographic and environmental risk factors of urban leptospirosis in Yangon region. This study will improve leptospirosis surveillance in Myanmar. Partners: National Health Laboratory of Myanmar, Institut Pasteur de NouvelleCalédonie

Team leader: P. Piola

Funding: AFD

Understanding of malaria epidemiology and malaria elimination inside forests

Malaria elimination is a priority in Cambodia, where P.falciparum strains are resistant to artemisinin derivatives and tonearly all partner drugs. However, the main reservoirs of parasites in Cambodia are inside its forests. While 2017 saw adoubling of malaria cases, there is still a very limited understanding of malaria epidemiology and transmission inside forests; hence no malaria elimination strategies specific to this environment. A study done in collaboration with MMEUaims at an in-depth understanding of malaria transmission inside three forests totalling 200km² (Year 1: 2019-2020)followed by an intervention (Year 2: 2020-2021) to eliminate in-forest malaria. Selected individuals from the high-risk group-forest goers-will be trained to develop the necessary skills to work and control malaria inside forests, hopefullyleading to an elimination of malaria inside them and in their surrounding villages. Partnering with IPC in this research are CNM and Partners for Development.

Team leaders: P. Piola, Sophea IV, Amber Kunkel

Funding: Global Fund Initiative 5%.

Effectiveness of malaria elimination inside forests

The overarching objective of this study is to eliminate malaria infections inside forests (and consequently in surrounding villages) within a year (August 2019 to August 2020), achieving this through quarterly in-forest active mass screening and treatment (MSATs with HS-RDTs) and continuous passive detection to efficiently treat all malaria infections and provide them with a vector control kit. Estimates of the malaria incidence from all the health centers (HCs) neighboring intervention forests will be compared to the incidences of approximately 100 HCs neighboring other non-intervention forests in Cambodia (control forests) in similar transmission areas. A significant drop in malaria notifications among HCs surrounding intervention forests compared to control forests would strongly suggest the effectiveness of the abovementioned interventions inside forests, Cambodia’s main reservoirs. This would open new perspectives in malariaelimination strategies in South East Asia. Forest goers are a mobile community accustomed to the harsh working condition inside forests and are the best placed to become a new type of malaria worker- forest malaria workers (FMWs). A tailored Android application will be developed to support FMWs across all components of this project. Thedata uploaded from this MHealth application will be used in near real-time to monitor, track (GPS) and evaluate all field activities and malaria indicators. Main collaborators are Partners for Development, Malaria Consortium, ITC, and CNM.

Team leaders: P. Piola, A. Kunkel

Funding: Resistance to Artemisinin Initiative (Global Fund).

Influenza Surveillance in Cambodia

This study (2017-2019) led by the Virology Unit, IPC, aims to map poultry supply networks and identify supply areas with ahigh prevalence of avian influenza viruses through tracking of middlemen and poultry movement (GPS/GSM trackingdevice) and testing of poultry samples at different steps of supply chain. The project also aims to establish avian influenza viruses (AIVs) and swine influenza viruses (SIVs) surveillance in Cambodian border regions to obtain agreater understanding of the dynamics of cross-border movements of AIVs into Cambodia through follow- up of cohorts of individuals.

EPH Unit team: Malen Chan

Funding: FAO, USAID

ARCAHE

This activity is led by the LBM and LMI DRISA.The objective of this project is twofold: to identify the sources of emergence andspread of resistant bacteria in Cambodia using a “One Health” approach; to evaluate if the MinION technology could be used as diagnostic tool. The expected results will represent the baseline for the setting up of a surveillance system, will allow stakeholders to implement efficient control strategies and will help determine the capacity of MinION technology to be used as diagnostic tool. This activity should start mid 2020

Team Leaders: V. Chevalier, P. Piola

Funding : FSPI – MEAE