Molecular Survey of Hemoglobinopathies in Myanmar Workers in Northeast Thailand Revealed an Unexpectedly High Prevalence of α+-Thalassemia

Abstract

To provide the molecular information on hemoglobinopathies in the Myanmar population, the study was carried out on Myanmar workers in Khon Kaen Province in northeast Thailand. A total of 300 anonymous Myanmar factory workers were randomly recruited during their annual medical checkup. Hemoglobinopathies were identified using hemoglobin (Hb) and DNA analyses. These identified heterozygous α⁰-thalassemia (α⁰-thal) [– –^SEA (Southeast Asian) deletion] (n?=?5, 1.7%), heterozygous α⁺-thal (n?=?103, 34.3%), homozygous α⁺-thal (n?=?12, 4.0%), heterozygous β-thalassemia (β-thal) (n?=?3, 1.0%), heterozygous β-thal with homozygous α⁺-thal (n?=?2, 0.7%), double heterozygous β-thal/α⁰-thal (n?=?1, 0.3%)], heterozygous Hb E (HBB: c.79G>A) with α⁰-thal/α⁺-thal (n?=?1, 0.3%), heterozygous Hb E (n?=?27, 9.0%), heterozygous Hb E with α⁺-thal (n?=?24, 8.0%), homozygous Hb E with α⁰-thal/α⁺-thal (n?=?1, 0.3%), homozygous Hb E (n?=?3, 1.0%) and homozygous Hb E with heterozygous α⁺-thal (n?=?3, 1.0%). No thalassemia defect was found in the remaining 115 subjects (38.4%). Haplotypes associated with Hb E and Hb Dhonburi (or Hb Neapolis) [β126(H4)Val→Gly, codon 126 (T>G), HBB: c.380T>G] are reported. While the proportions of α⁰-thal, β-thal and Hb E are comparable to those described in neighboring countries, a markedly high prevalence of α⁺-thal (48.6% in total) is unexpected. The molecular information obtained should provide necessary information for diagnostic improvement and planning of a prevention and control program of severe thalassemia in the Myanmar population.     

Efficacy of oral single dose therapy with artemisinin-naphthoquine phosphate in uncomplicated falciparum malaria

All artemisinin-based combination therapies (ACTs), recommended by the World Health Organization, are 3-day regimens. A considerable level of non-compliance on ACTs has been reported from some countries. The study aimed to assess the therapeutic efficacy of single dose treatment with new generation ACT containing artemisinin plus naphthoquine. An oral single dose of eight tablets (400 mg of naphthoquine + 1000 mg artemisinin) of the combination drug was administered to adult uncomplicated falciparum malaria patients. Observations of fever, parasite clearance and reappearance, and other clinical manifestations were made on Days 0, 1, 2, 3, 7, 14, 21 and 28. Fifty-three adult falciparum positive cases, with fever or history of fever within the previous 24 h, were included in the final evaluation of the study. Mean fever clearance time, parasite clearance time were 18.2 ± 8.6 h and 34.6 ± 14.3 h, respectively. Adequate clinical and parasitological response was achieved in 52 cases, the rate being 98.1% (95% CI, 91.1-99.9). One patient was classified as late parasitological failure because of the reappearance of falciparum parasite on Day 14. The drug was well tolerated and no adverse reactions were detected in the patients. Since it is a single dose therapy, health workers can administer the drug as directly observed treatment.     

Transmission Risk from Imported Plasmodium vivax Malaria in the China–Myanmar Border Region

Malaria importation and local vector susceptibility to imported Plasmodium vivax infection are a continuing risk along the China–Myanmar border. Malaria transmission has been prevented in 3 border villages in Tengchong County, Yunnan Province, China, by use of active fever surveillance, integrated vector control measures, and intensified surveillance and response.     

Plasmodium vivax resistance to chloroquine in Dawei, southern Myanmar

Objective  To assess the efficacy of chloroquine in the treatment of Plasmodium vivax malaria in in Dawei District, southern Myanmar.
Methods  Enrolled patients at Sonsinphya clinic >6 months of age were assessed clinically and parasitologically every week for 28 days. To differentiate new infections from recrudescence, we genotyped pre- and post-treatment parasitaemia. Blood chloroquine was measured to confirm resistant strains.
Results  Between December 2002 and April 2003, 2661 patients were screened, of whom 252 were included and 235 analysed. Thirty-four per cent (95% CI: 28.1–40.6) of patients had recurrent parasitaemia and were considered treatment failures. 59.4% of these recurrences were with a different parasite strain. Two (0.8%) patients with recurrences on day 14 had chloroquine concentrations above the threshold of 100 ng/ml and were considered infected with chloroquine resistant parasites. 21% of failures occurred during the first 3 weeks of follow-up: early recurrence and median levels of blood chloroquine comparable to those of controls suggested P. vivax resistance.
Conclusions  Plasmodium vivax resistance to chloroquine seems to be emerging in Dawei, near the Thai-Burmese border. While chloroquine remains the first-line drug for P. vivax infections in this area of Myanmar, regular monitoring is needed to detect further development of parasite resistance.     

TB, HIV-associated TB and multidrug-resistant TB on Thailand's border with Myanmar, 2006-2007

Objective To measure the burden and improve management of tuberculosis (TB), HIV‐associated TB and MDR TB in Tak Province, Thailand, which borders Myanmar. Methods From September 2006 to August 2007, we collected uniform data about TB cases and enhanced human immunodeficiency virus (HIV) counselling and testing. We provided mycobacterial culture and drug‐susceptibility testing in public or non‐governmental organization facilities. Patients were classified by nationality and, for non‐Thais, by migration status. Results Of 1662 TB cases in the 12‐month period, 1087 (65%) occurred in non‐Thais. Of non‐Thais, 415 (38%) lived in Myanmar but crossed the border for healthcare. HIV infection was diagnosed in 18% of Thais compared with 12% of non‐Thais (P < 0.01); HIV status was unknown for 22% of Thais and 27% of non‐Thais (P = 0.02). Overall, multidrug‐resistant (MDR) TB was diagnosed in 27 patients, 19 (70%) in non‐Thais. Among TB cases never previously treated for TB, no MDR cases were diagnosed in Thais or in Myanmar refugees, but six cases were diagnosed in migrants from Myanmar. Conclusions In Thailand, TB, HIV‐associated TB and MDR TB in migrants from Myanmar are important public health problems; they need to be resolved in both the countries.     

Cross-border malaria control for internally displaced persons: observational results from a pilot programme in eastern Burma/Myanmar

Objectives  To document the feasibility of a cross-border community based integrated malaria control programme implemented by internally displaced persons in eastern Burma/Myanmar.
Methods  This pilot study was conducted from February 2003 through January 2005 in seven villages of displaced ethnic Karen. Interventions comprised early diagnosis of Plasmodium falciparum and treatment with mefloquine and artesunate, distribution of long-lasting insecticide treated nets (LLITNs), and educational messages. The primary outcome measure was P. falciparum prevalence during bi-annual universal screenings with the Paracheck-Pf^® (Orchid Biomedical Systems, Goa, India) device. Secondary outcomes were P. falciparum incidence and process indicators related to net use and malaria knowledge, attitudes and practices (KAP).
Results  P. falciparum prevalence in original programme areas declined from 8.4% [95% confidence interval (CI) 8.3–8.6] at baseline to 1.1% (95% CI 1.1–1.2) in the final screening. Annual incidence in original areas declined from 232 to 70 cases/1000/year [incidence rate ratio 0.30 (95% CI 0.24–0.39)]. The proportion of household members sleeping under a LLITN improved from 0% to 89% and malaria KAP improved in all areas.
Conclusions  Integrated malaria control organized and implemented by displaced persons is feasible in eastern Burma/Myanmar. The decline in P. falciparum prevalence and incidence suggest that it may be possible to reduce the burden of disease and the reservoir of malaria in eastern Burma/Myanmar, with implications for malaria control in the greater Mekong region.