ABSTRACT
Objective To perform an epidemiological investigation on a case with visceral leishmaniasis in Zhengzhou City, Henan Province, and to identify the source of infection, so as to illustrate the transmission chain and assess the risk of local leishmaniasis transmission. Methods The medical data were collected from a case with visceral leishmaniasis in Zhengzhou City, and the patient’s bone marrow smears were detected by microscopy. Serum anti-Leishmania antibody test and PCR assay were performed among high-risk residents and all dogs in the village where the patient lived. Sandflies were captured using light traps and artificial traps, and the captured female Phlebotomus chinensis was subjected to PCR assay. The internal transcribed spacer 1 (ITS1) gene was amplified with a nested PCR assay using the genomic DNA extracted from visceral leishmaniasis patients, positive dogs and sandflies, and the sequences were aligned with those download from NCBI. In addition, a phylogenetic tree was created based on the ITS1 gene. Results The visceral leishmaniasis patient had recurrent irregular fever, reduced complete blood counts, low hemoglobin, and a large number of Leishmania amastigotes in bone marrow smears, and was therefore diagnosed as visceral leishmaniasis. Both rk39 rapid diagnostic test and PCR assay tested negative among 324 residents living neighboring the patient’s residence, while 21.39% (43/201) dogs were positive for rk39 rapid diagnostic test and 13.93% (28/201) positive for PCR assay. There were 17 female Ph. chinensis tested positive for Leishmania (0.82%) by PCR assay, and the ITS gene sequences from visceral leishmaniasis patients, positive dogs and sandflies shared a 100% homology with L. infantum. The Leishmania species was therefore characterized as L. infantum. Conclusions L. infantum infection occurs in visceral leishmaniasis patients, dogs and sandflies in Zhengzhou City, indicating a complete transmission chain and a high transmission risk of visceral leishmaniasis by L. infantum. Intensified control measures are required to prevent local transmission of leishmaniasis in Zhengzhou City.
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Objective To investigate the susceptibility of Anopheles sinensis to malathion, deltamethrin and lambda-cyhalothrin in Puyang City, Henan Province, so as to provide the scientific basis for local malaria vector control. Methods An. sinensis was captured from Puyang County, Puyang City of Henan Province in September 2018 and July 2020, and the susceptibility of field captured An. sinensis to malathion, deltamethrin and lambda-cyhalothrin was tested using the filter-paper bioassay recommended by WHO. The insecticide resistance level was assessed based on the WHO criteria. Results In 2018 and 2010, the half knock-down times (KT50) of malathion were 91.08 min and 40.95 min for An. sinensis, with knock-down rates of 37.50% and 60.87% 60 min post-exposure to malathion and 24-hour mortality rates of 90.91% and 100%, respectively, and the insecticide resistance levels were moderately resistant (M) and susceptible (S). The KT50 of deltamethrin were 415.56 min and 341.19 min for An. sinensis in 2018 and 2020, with knock-down rates of 22.92% and 16.98% 60 min post-exposure to malathion and 24-hour mortality rates of 22.92% and 16.98%, and the insecticide resistance levels were all resistant (R). The KT50 of lambda-cyhalothrin were 164.22 min and 236.22 min for An. sinensis in 2018 and 2020, with knock-down rates of 30.39% and 38.30% 60 min postexposure to malathion and 24 h mortality rates of 19.60% and 21.28%, respectively, and the insecticide resistance levels were all R. Conclusion An. sinensis is relatively susceptible to malathion but has developed high-level resistance to deltamethrin and lambda-cyhalothrin in Puyang City, Henan Province..
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Objective To analyze the epidemiological characteristics of malaria in Henan Province from 1950 to 2019, so as to provide the scientific evidence for consolidating malaria elimination achievements in the province. Methods The epidemiological situation of malaria and demographic data in Henan Province from 1950 to 2019 were collected, and the statistical analyses were performed using a descriptive epidemiological method. The spatial temporal distribution of malaria cases was identified using the software ArcGIS version 10.3. Results During the period from 1950 through 2019, the progress of malaria elimination was divided into 4 stages in Henan Province, including the baseline-survey and key-control stage, morbidity-control and incidence-reduction stage, basic-eradication and achievement-consolidation stage and elimination stage. The spatial distribution of malaria cases shifted from south of the Huai River and the plain regions between the Yellow River and Taihang Mountain to the Huang-Huai-Hai Plain and Nanyang Basin, then was concentrated in eastern part of southern Huai River where Anopheles anthropophagus was distributed, and finally was gradually under control following malaria outbreak in Eastern Henan Plain. In addition, the species of Plasmodium changed from P. vivax, P. falciparum and P. malariae co-endemics to a single P. vivax infection, and the current co-endemics of 5 invasive malaria parasites, and the malaria vectors shifted from co-existence of Anopheles sinensis and An. anthropophagus to An. sinensis alone. Conclusions There has been a large change in the epidemiological characteristics of malaria in Henan Province from 1950 to 2019. Although malaria has been eliminated in Henan Province, the consolidation of the malaria elimination achievements remain a great challenge due to overseas imported malaria.
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Objective To understand the epidemic status of malaria and progress of malaria elimination in Henan Province in 2018, so as to provide the scientific evidence for formulating the control strategy of malaria. Methods All data pertaining to the epidemic status of malaria and malaria case were captured from Henan Province in 2018, and the epidemic status of malaria and the diagnosis and treatment of malaria cases were analyzed using a descriptive epidemiological method. Results A total of 174 malaria cases were reported in Henan Province in 2018, with a male-to-female ratio of 33.8∶1. The cases were predominantly found at 30- and 40- years, and farmer was the highest-risk population. All cases were imported for overseas countries and 96.55% (168/174) were from Africa. The cases were reported across 17 cities of the province, and 63.22% (110 cases) were detected in 4 cities of Zhengzhou, Luoyang, Xuchang and Puyang. Both the median duration from onset to initial admission and the median time from the initial admission to definitive diagnosis were 1 d. There were 6 cases (3.45%) with more than 7 days to visit a doctor, and there were 13 cases (7.47%) with definitive diagnosis of over 7 days (delay in definitive diagnosis). All malaria cases were reported within 24 h, and 98.28% (171/174) completed case investigations within 3 d. All 18 cities had achieved malaria elimination by December 2018. Conclusions All malaria cases reported in Henan Province in 2018 are imported from overseas countries. Intensifying malaria surveillance among returnees from Africa and Southeast Asia and timely identification and treatment of imported malaria cases are required to prevent the development of secondary malaria cases, so as to ensure the achievement of malaria elimination in Henan Province on schedule.
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Objective To analyze the epidemiological and clinical data of an imported case of visceral leishmaniasis in Henan Province, and explore the method of laboratory diagnosis of kala-azar. Methods The epidemiological and clinical data of an imported visceral leishmaniasis patient were analyzed. Leishmania donovani bodies in bone marrow smears were observed microscopically. The antibody was detected by using rK39 dipstick test strips. Two pairs of specific primers, K13A-K13B and LITSR-L5.8S, were used to amplify kinetoplast DNA and internal transcribed spacer of rDNA of the parasite, respectively. Results The patient had been in the epidemic area of visceral leishmaniasis, and had symptoms such as irregular fever, splenomegaly, pancytopenia, and inversed ratio of albumin and globulin. The amastigotes of L. donovani were found in the bone marrow smears, and rK39 test strip was positive, and the PCR products of K13A-K13B and LITSR-L5.8S were 87 bp and 285 bp respectively. The similarities of the two fragment sequences to the corresponding sequences of L. donovani were 94% and 100%, respectively. Conclusion The case is diagnosed as visceral leishmaniasis according to the epidemiological data, clinical manifestations and laboratory test results of the patient, and the pathogen is L. donovani.
ABSTRACT
Objective To analyze the epidemiological and clinical data of an imported case of visceral leishmaniasis in Henan Province, and explore the method of laboratory diagnosis of kala-azar. Methods The epidemiological and clinical data of an imported visceral leishmaniasis patient were analyzed. Leishmania donovani bodies in bone marrow smears were observed microscopically. The antibody was detected by using rK39 dipstick test strips. Two pairs of specific primers, K13A-K13B and LITSR-L5.8S, were used to amplify kinetoplast DNA and internal transcribed spacer of rDNA of the parasite, respectively. Results The patient had been in the epidemic area of visceral leishmaniasis, and had symptoms such as irregular fever, splenomegaly, pancytopenia, and inversed ratio of albumin and globulin. The amastigotes of L. donovani were found in the bone marrow smears, and rK39 test strip was positive, and the PCR products of K13A-K13B and LITSR-L5.8S were 87 bp and 285 bp respectively. The similarities of the two fragment sequences to the corresponding sequences of L. donovani were 94% and 100%, respectively. Conclusion The case is diagnosed as visceral leishmaniasis according to the epidemiological data, clinical manifestations and laboratory test results of the patient, and the pathogen is L. donovani.