Clinical study on treatment of facial seborrheic dermatitis with intense pulsed light combined with 30% supramolecular salicylic acid.

OBJECTIVES: In this study, we investigated the effects of intense pulsed light (IPL) combined with 30% supramolecular salicylic acid on facial seborrheic dermatitis. METHODS: A total of 45 patients with mild or moderate facial seborrheic dermatitis were selected from our hospital between September 2018 and September 2019. The patients were divided into three groups consisting of 15 patients each. The first group was exposed to a combination of IPL and 30% supramolecular salicylic acid treatment, the second group was exposed to the IPL treatment alone, and the third group was exposed to the 30% supramolecular salicylic acid treatment alone. They were treated once every 4 weeks in three consecutive rounds. RESULTS: Facial lesions and symptoms were observed 4 and 12 weeks after the first treatment, and adverse reactions were recorded. The combination group showed significant improvement in symptoms 4 weeks after the first treatment, while the individual treatment groups showed no significant improvement. After three rounds of treatments, seborrheic dermatitis had significantly decreased in the three groups; the efficacy of the combined treatment group was significantly higher than that of the IPL group and the 30% supramolecular salicylic acid group. CONCLUSION: IPL combined with 30% supramolecular salicylic acid was effective in the treatment of facial seborrheic dermatitis and provided a quicker result with no adverse reactions.

Clinical study on treatment of facial seborrheic dermatitis with intense pulsed light combined with 30% supramolecular salicylic acid

OBJECTIVES: In this study, we investigated the effects of intense pulsed light (IPL) combined with 30% supramolecular salicylic acid on facial seborrheic dermatitis. METHODS: A total of 45 patients with mild or moderate facial seborrheic dermatitis were selected from our hospital between September 2018 and September 2019. The patients were divided into three groups consisting of 15 patients each. The first group was exposed to a combination of IPL and 30% supramolecular salicylic acid treatment, the second group was exposed to the IPL treatment alone, and the third group was exposed to the 30% supramolecular salicylic acid treatment alone. They were treated once every 4 weeks in three consecutive rounds. RESULTS: Facial lesions and symptoms were observed 4 and 12 weeks after the first treatment, and adverse reactions were recorded. The combination group showed significant improvement in symptoms 4 weeks after the first treatment, while the individual treatment groups showed no significant improvement. After three rounds of treatments, seborrheic dermatitis had significantly decreased in the three groups; the efficacy of the combined treatment group was significantly higher than that of the IPL group and the 30% supramolecular salicylic acid group. CONCLUSION: IPL combined with 30% supramolecular salicylic acid was effective in the treatment of facial seborrheic dermatitis and provided a quicker result with no adverse reactions.

Extensive Resistance of Anopheles sinensis to Insecticides in Malaria-Endemic Areas of Hainan Province, China.

Anopheles sinensis is one of the major malaria vectors and among the dominant species in Hainan Province, China. The resistance of An. sinensis to insecticides is an important threat to malaria control. However, few reports on insecticide resistance of An. sinensis were reported in this area. Eight districts in Hainan Province were selected as the study areas. Insecticide susceptibility bioassays were tested on wild-caught female mosquitoes of An. sinensis to 4% dichlorodiphenyltrichloroethane (DDT), 0.05% deltamethrin, and 5% malathion by using the World Health Organization standard resistance tube assay procedure. All the tested An. sinensis mosquitoes demonstrated resistance to 4% DDT, with less than 72% mortality in the standard assay. The populations from Baisha and Qiongzhong demonstrated possible resistance to 0.05% deltamethrin, with 94-95% mortality, whereas the populations from other districts demonstrated resistance to 0.05% deltamethrin in the standard assay. The populations from Baisha, Qiongzhong, and Dongfang demonstrated susceptibility to 5% malathion, but the populations from other districts demonstrated resistance. These results facilitate the improvement of effective control strategies for malaria vector mosquitoes in Hainan.

A Cost-Effectiveness Analysis of Plasmodium falciparum Malaria Elimination in Hainan Province, 2002-2012.

In Hainan Province, China, great achievements in elimination of falciparum malaria have been made since 2010. There have been no locally acquired falciparum malaria cases since that time. The cost-effectiveness of elimination of falciparum malaria has been analyzed in Hainan Province. There were 4,422 falciparum malaria cases reported from 2002 to 2012, more cases occurred in males than in females. From 2002 to 2012, a total of 98.5 disability-adjusted life years (DALYs) were reported because of falciparum malaria. Populations in the age ranges of 15-25 and 30-44 years had higher incidences and DALYs than other age groups. From 2002 to 2012, malaria-related costs for salaries of staff, funds from the provincial government, national government, and the GFATM were US$3.02, US$2.24, US$1.44, and US$5.08 million, respectively. An estimated 9,504 falciparum malaria cases were averted during the period 2003-2012. The estimated cost per falciparum malaria case averted was US$116.5. The falciparum malaria elimination program in Hainan was highly effective and successful. However, funding for maintenance is still needed because of imported cases.

Genetic diversity of Plasmodium vivax population before elimination of malaria in Hainan Province, China.

BACKGROUND: Hainan Province is one of the most severe endemic regions with high transmission of Plasmodium falciparum and Plasmodium vivax in China. However, the incidence of P. falciparum and P. vivax has dropped dramatically since 2007 and a national elimination malaria programme (NEMP) was launched after 2010. To better understand the genetic information on P. vivax population before elimination of malaria in Hainan Province, the extent of genetic diversity of P. vivax isolates in Hainan Province was investigated using four polymorphic genetic markers, including P. vivax merozoite surface proteins 1, 3α, and 3ß (pvmsp-1, pvmsp-3α, and pvmsp-3ß) and circumsporozoite protein (pvcsp). METHODS: Isolates of P. vivax (n = 27) from Hainan Province were collected from 2009 to 2010 and pvmsp-1 and pvcsp were analysed by DNA sequencing, respectively. Using polymerase chain reaction-restriction fragment length polymorphism were analysed in pvmsp-3α, and pvmsp-3ß. RESULTS: The DNA sequencing analysis on pvmsp1 revealed that there were three allele types: Salvador-1 (Sal-1), Belem and recombinant (R) types. Among them, Sal-1 type was a dominant strain with eight variant subtypes (88.9%), whereas R- (3.7%) and Belem-type strains (7.4%) had one variant subtypes, respectively. All the isolates carried pvcsp with VK210 type accounting for 85.2% (23/27 isolates) and VK247 type accounting for 14.8% (4/27). Only type A and type B alleles were successfully amplified in pvmsp-3α gene, and a high level of polymorphism was observed in pvmsp-3α. Considering pvmsp-3ß gene, type A was the predominant type in 17 isolates (63%), whereas type B was dominant in only ten isolates (37%). CONCLUSION: The present data indicate that there was high degree of genetic diversity among P. vivax population in Hainan Province of China during the pre-elimination stage of malaria, with 26 unique haplotypes observed among 27 samples.

Sensitivity of Plasmodium falciparum to antimalarial drugs in Hainan Island, China.

Pyronaridine and artesunate have been shown to be effective in falciparum malaria treatment. However, pyronaridine is rarely used in Hainan Island clinically, and artesunate is not widely used as a therapeutic agent. Instead, conventional antimalarial drugs, chloroquine and piperaquine, are used, explaining the emergence of chloroquine-resistant Plasmodium falciparum. In this article, we investigated the sensitivity of P. falciparum to antimalarial drugs used in Hainan Island for rational drug therapy. We performed in vivo (28 days) and in vitro tests to determine the sensitivity of P. falciparum to antimalarial drugs. Total 46 patients with falciparum malaria were treated with dihydroartemisinin/piperaquine phosphate (DUO-COTECXIN) and followed up for 28 day. The cure rate was 97.8%. The mean fever clearance time (22.5 ± 10.6 hr) and the mean parasite clearance time (27.3 ± 12.2 hr) showed no statistical significance with different genders, ages, temperatures, or parasite density (P > 0.05). The resistance rates of chloroquine, piperaquine, pyronarididine, and artesunate detected in vitro were 71.9%, 40.6%, 12.5%, and 0%, respectively (P < 0.0001). The resistance intensities decreased as follows: chloroquine > piperaquine > pyronarididine > artesunate. The inhibitory dose 50 (IC50) was 3.77 × 10(-6) mol/L, 2.09 × 10(-6) mol/L, 0.09 × 10(-6) mol/L, and 0.05 × 10(-6) mol/L, and the mean concentrations for complete inhibition (CIMC) of schizont formation were 5.60 × 10(-6) mol/L, 9.26 × 10(-6) mol/L, 0.55 × 10(-6) mol/L, and 0.07 × 10(-6) mol/L, respectively. Dihydroartemisinin showed a strong therapeutic effect against falciparum malaria with a low toxicity.

Lessons from malaria control to elimination: case study in Hainan and Yunnan provinces.

Reduction patterns of Plasmodium falciparum and P. vivax malaria transmission and the role of an integrated strategy of case management and vector control are compared between different ecological zones. The epidemiology of malaria in Hainan and Yunnan provinces was disparate, even though distinct malaria control strategies have been adapted to different situations based on risk group, vector behaviours, local health infrastructure, and environmental conditions. The island Hainan appears to be victorious in eliminating malaria. However, there is still a long way to go to prevent the reintroduction of malaria in Hainan province and eliminating malaria in the border areas of Yunnan province. This review of the experiences and challenges from malaria control to elimination in Hainan and Yunnan provinces of southern China will provide a basis for the future elimination of malaria in the whole country.

Prevention measures and socio-economic development result in a decrease in malaria in Hainan, China.

BACKGROUND: Historically, the incidence of malaria in the Hainan Province, China has been high. However, since 2001 the malaria incidence in Hainan has decreased due to large-scale, public educational, promotional campaigns and the adoption of preventative measures against malaria following the fast growth of socio-economic development. The present study analysed the correlation between prevention measures and social economic development on the incidence of malaria in Hainan from 2001 to 2013. METHODS: The data of malaria preventative measures and socio-economic development were collected from various cities and counties in Hainan Province from 2001 to 2013 and analysed by the grey correlation analysis system. RESULTS: Seasonal preventive medication and local fiscal revenue increases are significantly related to the reduction of malaria incidence from 2001 to 2013 (R1 = 0.751677; R5 = 0.764795). CONCLUSION: Malaria prevention and control measures and local economic development in Hainan decreased malaria incidence from 2001 to 2013.

[Resistance of Anopheles sinensis to three common insecticides in Hainan Province].

Anopheles sinensis adults were collected by cow-baited trap in Haikou City, Sanya City, Lingshui County, Changjiang County and Qiongzhong County of Hainan Province during 2011-2013. The mosquitoes were exposed to insecticide impregnated papers with discriminating concentrations of DDT (4%), deltamethrin (0.05%), and malathion (5%) using WHO standard assays. Knockdown rate was recorded at 10, 15, 20, 30, 40, 50, and 60 min, and KT50 values were calculated. Mortality was recorded after 24 hours of exposure. The resistance level was graded as sensitive group (S) with a mortality rate of 98%-100%, preliminary resistance group (M) with mortality rate of 80%-97%, and resistance group (R) with mortality rate of lower than 80%. The results showed that the mortality rate of An. sinensis in Qiongzhong County in 24 h-post-exposure to 0.05% deltamethrin was 95.0% with a resistance degree of M. That to 0.05% deltamethrin in the other 4 sites was 17.0%-63.0%, all with a resistance degree of R. That to 4% DDT in Haikou, Sanya, Lingshui, Qiongzhong and Changjiang was 36.0%, 27.0%, 24.0%, 59.1%, and 82.0%, with a resistance level of R, R, R, R, and M, respectively. That to 5% malathion in Haikou, Sanya, and Lingshui was 16.0%-41.0%, all with a resistance degree of R, while that to malathion in Qiongzhong and Changjiang was 100% and 98.0%, respectively, with a resistance level of S.

Eliminating Plasmodium falciparum in Hainan, China: a study on the use of behavioural change communication intervention to promote malaria prevention in mountain worker populations.

BACKGROUND: In the island of Hainan, the great majority of malaria cases occur in mountain worker populations. Using the behavioral change communication (BCC) strategy, an interventional study was conducted to promote mountain worker malaria prevention at a test site. This study found the methods and measures that are suitable for malaria prevention among mountain worker populations. METHODS: During the Plasmodium falciparum elimination stage in Hainan, a representative sampling method was used to establish testing and control sites in areas of Hainan that were both affected by malaria and had a relatively high density of mountain workers. Two different methods were used: a BCC strategy and a conventional strategy as a control. Before and after the intervention, house visits, core group discussions, and structural surveys were utilized to collect qualitative and quantitative data regarding mountain worker populations (including knowledge, attitudes, and practices [KAPs]; infection status; and serological data), and these data from the testing and control areas were compared to evaluate the effectiveness of BCC strategies in the prevention of malaria. RESULTS: In the BCC malaria prevention strategy testing areas, the accuracy rates of malaria-related KAP were significantly improved among mountain worker populations. The accuracy rates in the 3 aspects of malaria-related KAP increased from 37.73%, 37.00%, and 43.04% to 89.01%, 91.53%, and 92.25%, respectively. The changes in all 3 aspects of KAP were statistically significant (p < 0.01). In the control sites, the changes in the indices were not as marked as in the testing areas, and the change was not statistically significant (p > 0.05). Furthermore, in the testing areas, both the percentage testing positive in the serum malaria indirect fluorescent antibody test (IFAT) and the number of people inflicted decreased more significantly than in the control sites (p < 0.01). CONCLUSION: The use of the BCC strategy significantly improved the ability of mountain workers in Hainan to avoid malarial infection. Educational and promotional materials and measures were developed and selected in the process, and hands-on experience was gained that will help achieve the goal of total malaria elimination in Hainan.

[Analysis of malaria epidemic situation in Hainan Province, 2010].

A total of 78 malaria cases were reported in 2010 and the incidence of malaria in this year was 9 per million in Hainan Province. The positive rate of blood tests in floating population was higher than that in local residents, and the antibody-positive rate of residents was higher than that of students, and all the reported malaria patients received the correct treatment. The rate of the therapy for vivax malaria relapse was 96.56% and the rate of prevention medicine in the high-risk groups was 94.15%. Totally 4 086 households were sprayed with insecticides and 26 843 persons were protected. Meanwhile, 153 116 LLINs were used and 250 851 persons were protected. In conclusion, the measures of malaria elimination is effective, however, we should strengthen malaria epidemic reports, case verification, treatment of epidemic foci, malaria prevention on floating population, malaria surveillance and so on.

[Relationship between falciparum malaria incidence and the number of Anopheles dirus in Hainan from 2001 to 2008].

OBJECTIVE: To analyze the relationship between falciparum malaria incidence and the number of Anopheles dirus in Hainan Province from 2001 to 2008, so as to provide the evidence for malaria control and prevention in Hainan Province. METHODS: The falciparum malaria incidence and the numbers of Anopheles dirus in 2001 - 2008 were calculated according to the data from Wuzhishan City and Qiongzhong County in Hainan Province. The Cochran-Armitage trend test was employed to explore the trend of falciparum malaria incidence. And Spearman rank correlation analysis was applied to analyze the relationship between the falciparum malaria incidence and the numbers of Anopheles dirus in Hainan from 2001 to 2008. RESULTS: A fluctuating but distinctly declining temporal trend of falciparum malaria incidence was identified in these two areas (Z(Wuzhishan) = -6.16, P < 0.01; Z(Qionghong) = -7.17, P < 0.01). The falciparum malaria incidences were not correlated with the numbers of Anopheles dirus in these two areas (r(wuzhishan) = 0.36, P > 0.05; r(Qiongzhong) = 0.67, P > 0.05). CONCLUSION: The control and prevention of falciparum malaria should be implemented from many aspects, as well as Anopheles dirus control, environment management, susceptible people protection and so on.

[Resistance assay of malaria vectors to four kinds of common insecticides in some endemic areas of Hainan Province].

OBJECTIVE: To determine the resistance of malaria vectors to four kinds of common insecticides in some endemic areas of Hainan Province. METHODS: Anopheline mosquitoes were collected between 2008 and 2010 from malaria endemic areas where insecticides were used for years. Anopheles dirus were collected from human-baited trap in Wangxia Town of Changjiang County. An. minimus and An. sinensis were collected by cow-baited trap in Jiangbian Town of Dongfang City. F0 generation female An. sinensis, F1 generation of female An. dirus and An. minimus were selected and exposed to insecticide impregnated papers with discriminating concentrations of DDT (4%), deltamethrin (0.05%), cyfluthrin (0.15%), and malathion (5%) using WHO standard assays. Knockdown rate was recorded at 10, 15, 20, 30, 40, 50, and 60 min, and KTm values were calculated. Mortality was recorded after 24 hours of exposure. RESULTS: Mortality in An. dirus was 100% to DDT, deltamethrin and malathion. Knockdown rate of An. dirus exposed to DDT and deltamethrin was 82.0% and 100%, with a KT50 value of 46.9 and 18.4 min, respectively. Mortality of An. minimus to DDT, deltamethrin, cyfluthrin and malathion was 98.1%, 99.0%, 100%, and 100%, respectively. The knockdown rate of An. minimus to DDT, deltamethrin, and cyfluthrin was 96.3%, 99.0%, and 100%, respectively, and the KTs value was 31.3, 16.8, and 7.4 min, respectively. Mortality of An. sinensis to DDT, deltamethrin, and malathion was 19.8%, 22.9%, and 43.8%, respectively. Knockdown rate of An. sinensis to DDT and deltamethrin was 2.0%, the KT50 can not be calculated. CONCLUSION: An. dirus and An. minimus, the main malaria vectors in the survey sites of Hainan Province, are susceptible to the four insecticides, while secondary malaria vector An. sinensis showed resistance to DDT, deltamethrin, and malathion.

[Investigation on serology, risk factor and awareness of angiostrongylus cantonensis in Hainan province].

Five survey sites were selected from Hainan Province and one village were randomly extracted in each site. A survey that covered knowledge and risk factor on angiostrongyliasis cantonensis was conducted and infection rate of Angiostrongylus cantonensis tested by ELISA. Among 393 sampled people, the sero-positive IgG rate was 20.6% and about 39.7% residents were found with a history of eating snails in recent half year, 12.5% from respondents had the habit of eating raw snails. Questionnairing showed that the ratio of awareness on A. cantonensis was 8.4%. All factors were analyzed by multi-logistic module and showed that the history of snail-eating and resident area may be the risk factors.

[Epidemiology of soil-transmitted nematode infections in central mountain area of Hainan province].

The epidemiology of soil-transmitted intestinal nematodes were observed in the central mountain area without anti-helminthic therapy from 1986 to 2008. The results showed that the overall prevalence decreased from 96.4% in 1986 to 35.7% in 2008. The prevalence of Ancylostoma duodenale, Ascaris lumbricoides and Trichuris trichiura decreased from 84.7%. 80.9%, 31.8% in 1986 to 32.5%, 0.3%, 4.2% in 2008, respectively. The proportion of light infection with Ancylostoma duodenale, Ascaris lumbricoides and Trichuris trichiura increased from 56.6%, 41.2%, and 66.9% in 1986 to 97.9%, 100%, and 83.7% in 2008, respectively. While that of heavy infection decreased from 6.8%, 11.9%, and 3.8% in 1986 all to zero in 2008. Water and toilet renovation, rural income increase and the improvement of sanitation and living conditions made the prevalence of soil-transmitted intestinal nematode decreased.

Global sequence variation in the histidine-rich proteins 2 and 3 of Plasmodium falciparum: implications for the performance of malaria rapid diagnostic tests.

BACKGROUND: Accurate diagnosis is essential for prompt and appropriate treatment of malaria. While rapid diagnostic tests (RDTs) offer great potential to improve malaria diagnosis, the sensitivity of RDTs has been reported to be highly variable. One possible factor contributing to variable test performance is the diversity of parasite antigens. This is of particular concern for Plasmodium falciparum histidine-rich protein 2 (PfHRP2)-detecting RDTs since PfHRP2 has been reported to be highly variable in isolates of the Asia-Pacific region. METHODS: The pfhrp2 exon 2 fragment from 458 isolates of P. falciparum collected from 38 countries was amplified and sequenced. For a subset of 80 isolates, the exon 2 fragment of histidine-rich protein 3 (pfhrp3) was also amplified and sequenced. DNA sequence and statistical analysis of the variation observed in these genes was conducted. The potential impact of the pfhrp2 variation on RDT detection rates was examined by analysing the relationship between sequence characteristics of this gene and the results of the WHO product testing of malaria RDTs: Round 1 (2008), for 34 PfHRP2-detecting RDTs. RESULTS: Sequence analysis revealed extensive variations in the number and arrangement of various repeats encoded by the genes in parasite populations world-wide. However, no statistically robust correlation between gene structure and RDT detection rate for P. falciparum parasites at 200 parasites per microlitre was identified. CONCLUSIONS: The results suggest that despite extreme sequence variation, diversity of PfHRP2 does not appear to be a major cause of RDT sensitivity variation.

[Tribendimidine enteric coated tablet in treatment of 1,292 cases with intestinal nematode infection--a phase IV clinical trial].

OBJECTIVE: To further evaluate the efficacy and safety of tribendimidine in treatment of adult patients with intestinal nematode infections. METHODS: An open and multi-center clinical trial was conducted in the provinces of Hainan, Sichuan and Guizhou. A total of 1,292 infected cases aged 15-70 years were enrolled in the study. Modified Kato-Katz method was used to diagnose the cases with intestinal nematode infections and assess the efficacy 3-4 weeks post treatment. Patients with Ascaris lumbricoides infection were treated orally with tribendimidine enteric coated tablets at a single dose of 300 mg, while in the patients with Ancylostoma duodenale, mixed A. duodenale and A. lumbricoides, or with other helminth infections, a single dose of 400 mg was administered. RESULTS: The cure rate and effective rate of the patients with Ancylostoma infection were 88.4% (1,009/1,141) and 99.1% (1,131/1,141), respectively, while in patients with A. lumbricoides infection, they were 95.0% (419/441) and 99.8% (440/441), respectively. The cure rate of tribendimidine enteric coated tablet given to patients with Trichuris trichiura infection at a single dose of 400 mg was 76.8% (109/142). The adverse effect induced by tribendimidine was light and transient with a rate of 3.3% (42/1,292). No apparent impact was seen on blood and urine routine examinations, hepatic and renal functions as well as ECG examination. CONCLUSION: It is further confirmed that under the used dosage for expanding treatment in larger sample of patients with various ages and infected with Ancylostoma duodenale, A. lumbricoides and other helminths, tribendimidine enteric coated tablet is safe with satisfactory efficacy.

[Efficacy of dihydroartemisinin-piperaquine and artemether-lumefantrine in the treatment of uncomplicated falciparum malaria in Hainan, China].

OBJECTIVE: To assess the therapeutic efficacy of the combinations dihydroartemisinin-piperaquine and artemether-lumefantrine in treating uncomplicated falciparum malaria cases in an area with high level resistance of Plasmodium falciparum to chloroquine in Hainan Province. METHODS: Patients aged 1 to 60 with uncomplicated P. falciparum infection and parasite density 1,000 to 200,000 parasites/microl were enrolled following an informed consent. Eligible patients were randomly assigned to 2 groups for receiving either a 3-day course of dihydroartemisinin-piperaquine (40/320 mg, DP, group A) or 6-dose course of artemether/lumefantrine (20/120 mg tablets, AL, group B) over three days. They were followed up with clinical and laboratory examinations until day 28 using standard WHO in vivo antimalarial drug test protocol. RESULTS: Altogether 107 eligible patients were enrolled but 106 completed the study. Adequate clinical and parasitological response (ACPR) was observed in 51 (100%) and 55 (100%) cases in groups A and B respectively. The mean time of fever clearance and mean time of asexual parasite clearance were (20.99 +/- 11.38) h and (36.45 +/- 12.60) h in AL and (22.35 +/- 13.26)h and (34.99 +/- 12.28) h in DP, respectively. There was no statistical difference on the mean time of fever clearance and asexual parasite clearance between AL and DP (P > 0.05). None of the participants showed recrudescence and serious adverse effect. CONCLUSION: Both combinations artemether-lumefantrine and dihydroartemisinin-piperaquine show a high cure rate and proper tolerability among the patients with uncomplicated falciparum malaria in Hainan.

The control and surveillance of filariasis in Hainan Province, China.

Hainan is a single bancroftian filariasis endemic province where filariasis is prevalent in all 18 cities and counties. A program to control filariasis was started in 1953. The strategy of eliminating infection sources has been adopted as the principal intervention measure in filariasis control. Over 30 years, the sustained effort throughout the province reached the point of basic elimination of filariasis in 1987. After the basic elimination of filariasis, the patterns of filariasis transmission in residual microfilaremia cases in Hainan Province were studied so as to provide a scientific basis for formulating strategies to eliminate filariasis. According to the "Technical scheme for surveillance in areas where fialariasis has been basically eliminated" issued by the Ministry of Health, a longitudinal and cross-sectional and entomological surveillance of fialariasis was carried out using parasitological and entomological and serological methods in the whole province during 1983-2004. In the cross-sectional and entomological surveillances, the last microfilaremia case was found in 1999, no mosquitoes were found to be infected with filarial larvae. A total of 132 microfilaremia cases found in the longitudinal surveillance become negative by 10 years. Since 1997 no mosquitoes were found to be infected with filarial larvae in the longitudinal surveillance. Serological surveillance of the population showed the mean positive rate of IFAT dropped from 10.63% in 1990 to 0.28% in 2000, which being similar to that of nonendemic areas. The results show that residual sources of infection after basic elimination of filariasis were tending to be naturally eliminated and transmission of filariasis has been interrupted in Hainan Province.

[Study on the haplotypes of pfcrt polymorphism from Hainan Province].

OBJECTIVE: To develop a method for comparing the haplotypes of pfcrt polymorphism of Hainan Province with those from other areas of the world. METHODS: Nested PCR was used to amplify the polymorphic region including codon 72 to 76 and 97 of pfcrt gene. The PCR products were digested by ApoI restriction endonuclease to determine the allelic types. According to the allelic types, 6 products from each of mutant type and wild type were sequenced to analyze the haplotypes of pfcrt polymorphism. RESULTS: Bands in size of 195 bp appeared in all 19 samples. After ApoI digestion, 11 samples contained one ApoI site when codon 76 of the pfcrt gene codes for lysine (K76), which were visualized by the presence of 98 bp and 97 bp restriction fragments. The DNA sequencing revealed that 6 samples of chloroquine resistant P. falciparum carried pfcrt alleles encoding an amino acid haplotype of CVIET (residues 72-76), and the haplotype of CVMNK was found in other 6 samples with wild type pfcrt gene. CONCLUSION: Haplotypes of pfcrt polymorphism from Hainan were the same as those from southeast Asia and Africa.