Clinical and Sub-clinical Malaria in Overseas Laborers Returning to Vietnam

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1 Clinical and Sub-clinical Malaria in Overseas Laborers Returning to Vietnam LCDR Nicholas J Martin, PhD Naval Medical Research Center-Asia assigned to Armed Forces Research Institute of Medical Science World-Class Care Anytime, Anywhere 1

2 Disclaimer The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government. I am a military service member. This work was prepared as part of my official duties. Title 17, USC, 105 provides that Copyright protection under this title is not available for any work of the U.S. Government. Title 17, USC, 101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person s official duties. World-Class Care Anytime, Anywhere 2

3 Reduced Malaria Burden in Viet Nam MALARIA CASES Significant reductions in morbidity (97%) and mortality (>99%) in the last 25 years New tools and techniques are being investigated to identify hot spots and hot pops World-Class Care Anytime, Anywhere 3

4 Imported Malaria Unresponsive to Treatment? Severe Malaria Not Responsive to Artemisinin Derivatives in Man Returning from Angola to Vietnam Nguyen Van Hong, Alfred Amambua-Ngwa, Nguyen Quang Tuan, Do Duy Cuong, Nguyen Thi Huong Giang, Nguyen Van Dung, Ta Thi Tinh, Nguyen Van Tien, Bui Quang Phuc, Tran Thanh Duong, Anna Rosanas-Urgell, Umberto D Alessandro, Jean-Pierre Van Geertruyden, and Annette Erhart Emerging Infectious Diseases Vol. 20, No. 7, July 2014 LETTERS Severe Malaria Not Responsive to Artemisinin Derivatives in Man Returning from Angola to Vietnam Pascal Ringwald, Arjen M. Dondorp Author affiliations: World Health Organization, Geneva Switzerland (P. Ringwald); Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand (A.M. Dondorp) Emerging Infectious Diseases Vol. 21, No. 7, July 2015 World-Class Care Anytime, Anywhere 4

5 Peacekeepers and Malaria Ranking of contributions by country (all operations as of Oct 2017) Ranking of contributions by country (Africa operations as of Oct 2017) Emerging Infectious Diseases Vol. 20, No. 6, June accessed 17 Nov 17 World-Class Care Anytime, Anywhere 5

6 Travel from Viet Nam for Work >10,000 workers/year travel to Africa and the Middle East Ishizuka. International Labor Migration in Vietnam and the Impact on Receiving Countries Policies Institute of Developing Economics; (2013) World-Class Care Anytime, Anywhere 6

7 Return to Viet Nam from Overseas These workers return; with anecdotal reports of peaks near Tet World-Class Care Anytime, Anywhere 7

8 Imported Malaria Cases Identified During Retrospective Study malaria cases were identified Year in Year 2015 Year in in (92%) were detected by microscopy 192 P. falciparum 29 P. vivax (29) 2 P. ovale 2 P. malariae 4 mixed infections 19 cases (8%) were clinical malaria cases without microscopy confirmation World-Class Care Anytime, Anywhere 8

9 Travel History in Malaria Patients History of travel abroad - Africa Angola Cameroon Others (Mozambique [8], Guinea [4], Congo [4], Côte d'ivoir [2], Burundi [1], Nigeria [1] and Zambia [1]) - Southeast Asia Laos PDR Indonesia Others (Cambodia [5] and Malaysia [1]) 207 (83.8) 172 (69.6) 14 (5.7) 21 (8.5) 40 (16.2) 18 (7.3) 16 (6.5) 6 (2.4) World-Class Care Anytime, Anywhere 9

10 Characteristics Parasite Clearance Day 3 (+) cases (n=41) Day 3 (-) cases (n=155) OR (95%CI) History of travel abroad by regions Southeast Asia Africa 5 (35.7) 36 (19.8) 9 (64.3) 146 (80.2) 2.25 ( ) Age (mean±sd) 32.8± ± ( ) Gender (men; %) 39 (95.1) 144 (92.9) 1.49 ( ) Occupation (%) Farmer Worker Others 4 (9.8) 27 (65.8) 10 (24.4) 8 (5.1) 88 (56.8) 59 (38.1) Ref 0.61 ( ) 0.34 ( ) Number of months of abroad 24 (8.5 36) 14 (6 33) 1.00 ( ) History of overseas malaria (%) 0-1 time 6 (13.6) 38 (86.4) 3.86 ( ) >1 times 14 (37.8) 23 (75.3) Duration of return to diagnosed by groups of days > 14 days 14 days 16 (33.3) 22 (16.5) 32 (66.7) 111 (83.5) 2.52 ( ) World-Class Care Anytime, Anywhere 10

11 Prospective Study In 2017 a prospective study was begun to address limitations noted during the retrospective study 19 patients enrolled 16 identified by microscopy at admission 8 P. falciparum 3 P. vivax 2 P. malariae 3 P. ovale 13 identified by P. falciparum/p. vivax rapid diagnostic test at admission World-Class Care Anytime, Anywhere 11

12 Travel and Work History of Malaria Patients Participants provided information on travel history for this study Most cases reported travel to Angola (9) and Cameroon (4) The majority reported travel for work (15) or business (3) The average trip length was 145 days (range days) Self reported history of malaria 0-1 previous infections 10 2 previous infections 2 3 previous infections 2 4 previous infections 1 >10 previous infections 4 World-Class Care Anytime, Anywhere 12

13 Parasite Clearance Mean parasite clearance for the 19 patients was 3.3 days Average parasite density at admission available for 14 participants was 41,420 ± (range: ,240) 8 Parastemic 7 Febrile World-Class Care Anytime, Anywhere 13

14 Qualitative Data from Prospective Study Focus Group Discussions (FGDs) and In-depth Interviews (IDI) being conducted across study site locations Objectives: To gain an in depth understanding of patterns of migration and patient treatment seeking behavior and knowledge throughout the different stages of migration: pre-departure, upon arrival and on-return. Four (4) IDIs conducted to date and translated to English World-Class Care Anytime, Anywhere 14

15 Qualitative Study Results Reasons for Travelling abroad: "My purpose is to get money "Do business to make money "I go to Angola to make money. I go to Angola because families who used to work there Introduce me to Angola" Knowledge about malaria and malaria prevention before going abroad: "Before going to Angola, I self-searched about Angola on Internet no information about epidemics. I only knew about Malaria after I got it in Angola. "When in Vietnam, I had heard about malaria but I don t remember where. "Yes. I heard about malaria in Vietnam because in the past I used to serve in the Vietnamese army "I know there are many kind of Malaria, Malignant malaria can cause death. Even with treatment, you still can got malignant malaria" "On Internet, there are warnings from Vietnamese community in Angola World-Class Care Anytime, Anywhere 15

16 Qualitative Study Results Learning/knowledge about malaria and malaria prevention whilst abroad: "I only know about malaria when I got malaria and must had treatment" "(from) Everyone whom I lived with had told me about Malaria and the common situation. Every person who go to Angola will get Malaria" "I can t understand the reason why I got malaria because I keep clean, don t share room and I work mainly in the office" "Physician didn t remind me about malaria prevention. In treatment, physician said I should not eat fishy food and take a bath in long time" "On Angolan TV, regularly, they have broadcasts to recommend about Malaria, Yellow fever, Ebola breakout, and they motivate people to use mosquito repellents, clean living area for mosquito prevention." Malaria Prevention behaviors: " didn t have any preventions. I slept with bed net but it was my habit before" "I used antimalaria whenever I felt unwell headache, digestive disorders. This medicine can be bought popularly at Pharmacies without prescription." World-Class Care Anytime, Anywhere 16

17 Conclusions Understanding travel and malaria importation patterns can aid in policy development Treatment seeking behavior appeared to contribute to delayed parasite clearance Discordance between rapid diagnostic tests and microscopy could result in missed treatment Importation of P. malariae, P. ovale, and P. knowlesi (not observed here) would be missed with current RDTs Molecular analysis of prospectively collected samples is planned to better understand risk of imported malaria Study of transport or emergence of drug resistance (if markers are present) World-Class Care Anytime, Anywhere 17

18 Acknowledgements We would like to thank the following: Study participants who volunteered their time Naval Medical Research Center Asia & Vysnova Partners Dr. Sara Canavati Ms. Thu Minh Nguyen National Institute of Malariology, Parasitology and Entomology Dr. Ngo Duc Thang National Hospital of Tropical Diseases Dr. Ngyuen Vin Kinh Dr. Le Thi Hoi US Defense Health Program Research, Development, Testing and Evaluation for supporting this project (work unit number D1430) Ethics review conducted by NHTD IRB (86/QD-NDTW) World-Class Care Anytime, Anywhere 18