Malaria control along China-Myanmar Border during 2007-2013: an integrated impact evaluation.

BACKGROUND: Implementing effective interventions remain a lot of difficulties along all border regions. The emergence of artemisinin resistance of Plasmodium falciparum strains in the Greater Mekong Subregion is a matter of great concern. China has effectively controlled cross-border transmission of malaria and artemisinin resistance of P. falciparum along the China-Myanmar border. METHODS: A combined quantitative and qualitative study was used to collect data, and then an integrated impact evaluation was conducted to malaria control along the China-Myanmar border during 2007-2013. RESULTS: The parasite prevalence rate (PPR) in the five special regions of Myanmar was decreased from 13.6 % in March 2008 to 1.5 % in November 2013. Compared with the baseline (PPR in March 2008), the risk ratio was only 0.11 [95 % confidence interval (CI), 0.09-0. 14) in November 2013, which is equal to an 89 % reduction in the malaria burden. Annual parasite incidence (API) across 19 Chinese border counties was reduced from 19.6 per 10 000 person-years in 2006 to 0.9 per 10 000 person-years in 2013. Compared with the baseline (API in 2006), the API rate ratio was only 0.05(95 % CI, 0.04-0.05) in 2013, which equates to a reduction of the malaria burden by 95.0 %. Meanwhile, the health service system was strengthened and health inequity of marginalized populations reduced along the international border. CONCLUSION: The effective collaboration between China, Myanmar and the international non-governmental organization promptly carried out the core interventions through simplified processes. The integrated approaches dramatically decreased malaria burden of Chinese-Myanmar border.

[Surgical treatment and prognosis analysis on medullary thyroid carcinoma].

OBJECTIVE: To study the clinical characteristics, the surgical treatments and the prognostic factors of medullary thyroid carcinoma. METHODS: Eighty-two cases of medullary thyroid carcinoma undergoing surgeries between January 1999 and December 2004 were reviewed. There were 39 males and 43 females. Age ranged from 16 to 77 years old, with a median of 46 years old. The calcitonin, chromogranin A and neuron-specific enolase were analysed by immunohistochemistry in samples, and calcitonin was detected in 24 cases. Of them, 28 cases underwent lobectomy with isthmectomy, 24 for remained lobe dissection, 16 for total thyroidectomy, and 14 only for neck and upper mediastinal lymph node dissection. Of the 82 cases, 68 cases underwent trachea esophageal ditch dissection, 53 for unilateral neck dissection, 11 for bilateral neck dissection, 13 for upper mediastinal lymph node dissection through trans-cervical approach, and 5 for mediastinal lymph node dissection through inverted T-shaped incision. RESULTS: Immunohistochemical examination revealed that the expression rates of calcitonin, chromogranin A and neuron-specific enolase were 95.8%, 88.9% and 80.0% respectively. Total metastasis rate of neck lymph nodes was 68.8%, and the rates in level II, III, IV, V and VI were 27.3%, 47.7%, 59.1%, 11.4% and 52.3% respectively. The overall five-year survival rate was 87.8%. The recurrent rate of contralateral lobes was 5.8% and local recurrent rate was 7.3% respectively. Univariate analysis showed that gender, age and TNM stage were significant prognostic factors. Multivariate analysis revealed that distant metastasis was an independent prognostic factor. CONCLUSIONS: Standard radical surgery of the primary and metastatic lesion is key to the treatment of medullary thyroid carcinoma. Lobectomy with isthmectomy should be applied to sporadic medullary thyroid carcinoma, with regular postoperative follow-up, and total thyroidectomy to familial or bilateral medullary thyroid carcinoma. Therefore, detecting the calcitonin is very important for medullary thyroid carcinoma patients' prognosis.

[Therapeutic efficacy and safety of compound dihydroartemisinin/piperaquine for uncomplicated Plasmodium falciparum infection in Laiza City of Myanmar bordering on China].

OBJECTIVE: To assess the efficacy and safety of compound dihydroartemisinin/piperaquine (DHAPIP) for treating uncomplicated falciparum malaria in Laiza city of Myanmar at the China-Myanmar border area. METHODS: A clinical trial was conducted in Laiza City and its four suburban natural villages bordering with China from September to December in 2008. Patients (aged 2-60 years) infected by Plasmodium falciparum without clinical complications (> or = 250 asexual parasite x microl(-1) of whole blood) were recruited for the assessment. The cases were given a 2-day course with DHAPIP tablets each containing 40 mg of dihydroartemisinin and 320 mg of piperaquine phosphate, and the total dosage varied with the body weight. For example, a patient with 50 kg body weight was given 8 tablets divided into 4 times at an interval of 8-10 h. The cases were then followed-up at DO, D1, D2, D3, D7, D14, D21 and D28 for observing their symptoms, the density of parasite, body temperature and side reaction. The therapeutic efficacy was assessed by using WHO classification of therapeutic response to the treatment of antimalarial drugs, including the time of fever subsidence, the clearance time of asexual parasites and the clearance rate of gametocytes. RESULTS: Among the 74 cases enrolled, 64 completed 28-day follow-up. The therapeutic efficacy reached 100% with adequate clinical and parasitological responses. The mean fever subsidence time was (22.5 +/- 8.2) h. The median of clearance time of asexual parasites in blood was 30.0 h [(17.1-168.2) h]. The rate of eliminating asexual parasites and fever subsidence in D3 and D7 was (93.8% and 100%) and (100% and 100%), respectively. The clearance rate of gametocytes in day-28 was 75.0%. It showed 9.9% of side reaction with 7 cases suffering from mild adverse responses among 71 of full-course medication. CONCLUSION: DHAPIP is efficacious and safe for the treatment of uncomplicated falciparum malaria in Laiza city of Myanmar in the border area.

[Genotyping of Plasmodium vivax in China-myanmar border by circumsporozoite protein].

By using a series of type-specific primers for Plasmodium vivax circumsporozoite protein (CSP) gene and nested PCR, genotyping was conducted for the specimens of Plasmodium vivax isolated from China-Myanmar border. In 174 isolates of P. vivax, four genotypes, namely, tropical zone family strain, temperate zone family strain, genotype-mixed infection and PV-II type, were identified each accounting for 54.6%, 35.6%, 6.9%, and 2.9%, respectively. The tropical zone family strain was dominant in the border area. There was no significant difference on the P.v CSP genotype constitution between Laza isolate of Myanmar and Tengchong isolate of Yunnan, China.

[Clinical analysis of 60 cases with maxillary squamous cell carcinoma].

OBJECTIVE: To study the clinical characters, treatment modalities and prognosis of patients with maxillary squamous cell carcinoma. METHODS: The clinical data of 60 patients with maxillary squamous cell carcinoma treatment between January 1994 and December 2004 were analyzed retrospectively. The patients were treated with three therapy modalities including radiotherapy alone (22 cases), radiotherapy and surgery (R + S, 29 cases) and concurrent chemo-radio-therapy adjuvant surgery (CCR + S, 9 cases). RESULTS: The five year survival rate were 18.2%, 51.7% and 33.3% for patients in the radiotherapy alone group, the R + S group and the CCR + S group, respectively. Patients receiving R + S combined modality therapy had a significantly higher five year survival rate than the patients who were treated radiotherapy alone (χ(2) = 15.62, P < 0.01). The five year survival rate (51.7%) of patients in R + S group was significantly higher than that (33.3%) of patients in CCR + S group (χ(2) = 4.28, P < 0.05), and also higher than that (18.2%) of patients in radiotherapy group (χ(2) = 9.49, P < 0.01). CONCLUSIONS: The combined therapy of radiation and surgery was a good choice of treatment for the patients with maxillary sinus squamous cell carcinoma. The role of concurrent chemo-radiotherapy adjuvant surgery in the treatment of maxillary sinus squamous cell carcinoma needs further to research.

[Serological detection of malaria for people entering China from 19 ports of entry covering 8 border prefectures of Yunnan].

OBJECTIVE: To evaluate malaria situation in areas of Yunnan Province bordering with Myanmar, Laos and Vietnam. METHODS: Blood samples on filter paper were collected from the entry people in March to December of 2007 involving 19 national and provincial ports of entry. Indirect fluorescent antibody test (IFAT) was carried out by using the blood samples collected before June 30 as the first half year and after July 1 as the second half year. Analysis was made on the relationship of IFAT positive rate and GMRT to malaria incidence in the province reported by the China information system for disease control and prevention. RESULTS: IFAT positive rate in the first half year (5.6%) was 20.9% higher than that of second half year (4.4%) (chi2=12.95%, P<0.05). There was a positive correlation between IFAT positive rate and the number of malaria cases reported in 2007 from the 8 bordering prefectures (r=0.8124, P<.05). The highest IFAT positive rate was found in Dehong (8.7%), Baoshan (7.1%), and Lingcang (65%). Among the 19 entry ports, the highest IFAT positive rate was found in 5 entry ports: Lvliang, Laying, Jiegao, Houqiao, and Qingshuihe, all in China-Myanmar border. The IFAT positive rate in the Chinese entry people increased with their days of staying outside the border. Among the entry people, the highest antibody positive rate was from those of Myanmar nationality (11.7%) followed by those from Yunnan (3.7%). CONCLUSION: To certain extent, higher malaria incidence outside the border impacts that of Yunnan Province.

[Sensitivity of Plasmodium vivax to chloroquine in Laza City, Myanmar].

Fourty-eight patients infected by Plasmodium vivax were randomly divided into chloroquine regimen groups A and B. Each case in group A received a total dosage of 1 200 mg(base) over a 3-day period (600 mg on the first day then 300 mg daily). Cases in group B each received total dosage of 1 500 mg (base) in 3 days (750 mg on the first day then 375 mg daily). Body temperature and blood smears were examined on days 0, 1, 2, 3, 7, 14, 21 and 28, respectively. All patients were negative for asexual parasites within 3 days. The cure rate on day 28 was 100%. Results showed that P. vivax is sensitive to chloroquine in Laza, Myanmar, and chloroquine can still be used for the imported vivax malaria cases at the China-Myanmar border.

[Epidemiological survey on malaria situation in Motuo County of Tibet, China].

OBJECTIVE: To make an epidemiological investigation on malaria in Motuo County, Linzhi Prefecture of Tibet. METHODS: In July of the year 2006, the following activities were conducted in 2 selected villages from each of the three townships, i.e., Motuo, Dexing and Beibeng: malaria history survey among inhabitants in recent 2 years; collection of blood samples of inhabitants for examining malaria parasites, IFAT and detecting G6PD, respectively; mosquito collection in human dwellings and cattle shelters at night and various resting sites at day-time; mosquito collection by outdoor human baiting capture; classification and composition calculation of mosquito species and man biting rates; ELISA for detecting sporozoite infection of Anopheles. RESULTS: The mean rate of two-year malaria history was 8.98% (118/1314) and the parasite rate was 3.13% (38/1216, all P. vivax) in the inhabitants. The parasite positive rate among the feverish patients was 7.14% (3/42). IFAT revealed a malaria antibody rate of 40.24% (472/1173). The G6PD deficiency rate was 1.74% (21/1208). Five hundred and thirteen anopheline mosquitoes were caught. They were An. maculatus (474) which occupied 92.4% (474/513), An. peditaeniatus (35), An. kochi (3) and An. sinensis (1). The mean indoor density of An. maculatus was 4.75/night in human houses, and 69.5/night in cattle shelters. The outdoor human biting rate was 22.75/half-night/person, and the sporozoite rate of An. maculatus in anopheline saliva glands was 0 by ELISA. CONCLUSION: Motuo County is an endemic area of vivax malaria with An. maculatus as the potential vector.

Effects of frozen storage on the structure of sarcocysts in pig muscle and implications in taxonomic studies.

UNLABELLED: The morphology of the cyst wall of Sarcocystis has unique characteristics that can be used in species identification. To find a suitable way to preserve Sarcocystis cyst samples for species identification, by light microscopy and electron microscopy, we recorded the morphological changes in the cysts of Sarcocystis suihominis and Sarcocystis miescheriana from pig muscle, induced by storage at -20 degrees C. Comparisons were made between fresh cysts and those subjected to frozen storage for periods of 3 days, 20 days and 30 days. RESULTS: cyst wall of the two Sarcocystis species appeared unaffected by storage. There was no obvious change in the length, nor in the width of the protrusions after storage (P>0.05), but the structure of the bradyzoite in the sarcocyst was in many cases disintegrated at -20 degrees C in 20 days for S. miescheriana and 30 days for S. suihominis. To our knowledge this is the first report that Sarcocystis cyst in muscle can be stored at -20 degrees C before and remain suitable for ultrastructural morphological study. Consequently, this paper proposes freezing as a convenient storage method for samples used in taxonomic studies of Sarcocystis.

[Evaluation of the enzyme-linked immunosorbant assay in detecting circumsporozoite protein of anopheline vectors in Yunnan].

OBJECTIVE: To detect circumsporozoite protein (CSP) in anopheline vectors from south Yunnan and to evaluate ELISA in the detection. METHODS: Salivary glands of the anopheline mosquitoes were taken for finding sporozoites by microscopy and part of the glands was used for detecting CSP by ELISA. An. minimus was experimentally infected by blood from vivax malaria patient (with Plasmodium vivax) and examined for sporozoites and CSP. Eight species of anopheline mosquitoes were caught in the field and examined. Monoclonal antibodies to P. falciparum (Pf2A10) and P. vivax (Pv210, Pv247) were used in ELISA for detecting CSP. RESULTS: Sporozoites were found in the salivary glands of 27 out of 36 An. minimus experimentally infected (75.0%), 29 were ELISA CSP positives (80.6%), and 26 of the 27 mosquitoes showed Pv210 CSP positive. Among 1010 parous anopheline mosquitoes from the field, 7 were found sporozoite positive (0.69%), 8 were ELISA CSP positive (0.79%), and 6 of the 7 mosquitoes showed CSP positive. Of 4675 wild mosquitoes in 8 anopheline species with different ages, 11 were found CSP positive (0.24%) including An. minimus, An. sinensis and An. maculatus with a positive rate of 0.20%, 0.24% and 0.39% respectively. Among the 11 mosquitoes, 9 were Pv210 positive and 2 were Pf2A10 positive. CONCLUSION: CSP detection by ELISA is a useful method to monitor the malaria transmission capacity of anopheline vectors.

Assessment of therapeutic efficacy of chloroquine against falciparum malaria in an outbreak area in Xishuangbanna, Yunnan.

OBJECTIVE: To investigate the failure of treatment with chloroquine in Yunnan in order to help formulate adequate antimalarial drug policy. METHODS: A World Health Organization 28-day in vivo test on therapeutic response for uncomplicated falciparum malaria in area with low or moderate transmission was adopted. Patients of age > or = 6 months old were admitted without limitation in density of parasitaemia and body temperature. Clinical and parasitological observation was conducted for patients on day 0, 1, 2, 3, 4, 7, 14, 21, 28 and 35. RESULTS: Of 62 patients identified as malaria cases infected by Plasmodium falciparum only, Plasmodium vivax only or by both species, 52 cases infected by Plasmodium falciparum only were included in the study. The overall treatment failure rate was 40.7%, with early treatment failure (ETF) rate of 1.8% and late treatment failure rate (LTF) of 38.9%. CONCLUSION: The treatment failure rate was much higher than the rate of 25% recommended by WHO. It is suggested that use of single chloroquine should be stopped in the treatment of falciparum malaria cases in such area. No relationship was found between the failure rate and the density of malaria parasites.