Joint malaria surveys lead towards improved cross-border cooperation between Savannakhet province, Laos and Quang Tri province, Vietnam

Abstract

BackgroundIn Savannakhet province, Laos and Quang Tri province, Vietnam, malaria is still an important health problem and most cases are found in the mountainous, forested border areas where ethnic minority groups live. The objectives of this study were to obtain a better joint understanding of the malaria situation along the border and, on the basis of that, improve malaria control methods through better cooperation between the two countries.MethodsFourteen villages in Savannakhet and 22 villages in Quang Tri were randomly selected within 5 km from the border where a blood survey for microscopic diagnosis (n = 1256 and n = 1803, respectively), household interviews (n = 400, both sides) and vector surveys were conducted between August and October 2010. Satellite images were used to examine the forest density around the study villages.ResultsMalaria prevalence was significantly higher in Laos (5.2%) than in Vietnam (1.8%) and many other differences were found over the short distance across the border. Bed net coverage was high (> 90%) in both Laos and Vietnam but, while in Laos more than 60% of the nets were long-lasting insecticide-treated, Vietnam used indoor residual spraying in this area and the nets were untreated. Anopheles mosquitoes were more abundant in Laos than in Vietnam, especially many Anopheles dirus were captured in indoor light traps while none were collected in Vietnam. The forest cover was higher around the Lao than the Vietnamese villages. After this study routine exchange of malaria surveillance data was institutionalized and for the first time indoor residual spraying was applied in some Lao villages.ConclusionsThe abundance of indoor-collected An. dirus on the Laos side raises doubts about the effectiveness of a sole reliance on long-lasting insecticide-treated nets in this area. Next to strengthening the early detection, correct diagnosis and prompt, adequate treatment of malaria infections, it is recommended to test focal indoor residual spraying and the promotion of insect repellent use in the early evening as additional vector interventions. Conducting joint malaria surveys by staff of two countries proved to be effective in stimulating better collaboration and improve cross-border malaria control.

Cross-Border Malaria: A Major Obstacle for Malaria Elimination

“…Malaria treatment in the border areas is often inadequate. Inadequate public health facilities in border areas lead local populations to seek treatment from private health professionals, many of whom provide counterfeit or substandard antimalarial drugs, or monotherapies, resulting in an increased risk of antimalarial drug resistance (Pongvongsa et al, 2012;Wijeyaratne et al, 2005). Thus, these groups are among the principal contributors to the emergence of multidrug resistant, which is a particular problem along the ThailandeMyanmar and ThailandeCambodia borders (Satitvipawee et al, 2012;Thimasarn, 2003;WHO, 2010).…”

“…Malaria control strategies and policies as well as the quality and management of the health care systems and conventions in data collection may differ across national borders, making cross-border collaboration difficult (Pongvongsa et al, 2012). However, the phenomenon of cross-border malaria provides a strong rationale to develop harmonized cross-border programmes in conjunction with national efforts (Delacollette et al, 2009).…”

“…Ethnic groups are often spread across borders, and people may cross the international border to meet relatives and friends (Pongvongsa et al, 2012;Noor et al, 2013). Immigrant VFRs frequently return to visit family members whom they had left behind or to introduce new additions to the family of origin.…”

Diversity of Anopheles mosquitoes in Binh Phuoc and Dak Nong Provinces of Vietnam and their relation to disease

“…Several factors contribute to the maintenance of malaria transmission in this region of Vietnam, including a high density of the main vector Anopheles dirus [3,7,8], migration of people from malaria endemic areas [9] and failure to use preventive measures while working in the forest [10]. Moreover, use of insecticides and prophylactic drugs has resulted in resistance in some Anopheles species [11-13] and malarial parasites [14,15].…”

Genetic features of P. falciparum parasites collected in 2012-2016 and anti-malaria resistance along China-Myanmar border

“…Among neighboring countries, drug policies may differ considerably. So, parasites populations at borders might experience divergent drug selection pressures, favoring the emergence of multiple drug resistant parasites [23,[26][27][44][45][46][47][48]. Yunnan province of China is one part of the GMS.…”