scholarly journals Seasonality, parity rates and transmission indices of Mansonella ozzardi (Manson) (Nematoda: Onchocercidae) by Cerqueirellum argentiscutum (Shelley & Luna Dias) (Diptera: Simulidae) in a lower Solimões River community, Amazonas, Brazil

2004 ◽  
Vol 34 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Jansen Fernandes de Medeiros ◽  
Victor Py-Daniel
Keyword(s):  
Infection Rate ◽  
Rainy Season ◽  
Parasitic Infection ◽  
Black Flies ◽  
Transmission Potential ◽  
Biting Rate ◽  
Solimões River

Mansonella ozzardi is transmitted by two dipterian families, Ceratopogonidae (midges) and Simuliidae (black flies). In Brazil, black flies are vectors for this filariasis until now. In this paper, we determined the seasonality, parity capacity and parasitic infection rate of Cerqueirellum argentiscutum. The work was carried out in the Porto Japão community, Lower Solimões River, Amazonas, Brazil. Results show that the black flies were more abundant during the rainy season (from December to May). The number of parous flies was higher in every sampling during the course of year. Monthly Biting Rate (MBR1 123742.00, MBR2 86701.50) was high, although Parasitic Infection Rate (PIR1 0.06, PIR2 0.08) and Annual Transmission Potential (ATP 7.25) were low in numbers.

scholarly journals An entomological study of onchocerciasis vectors, Simulium damnosum s.l., in Kinshasa, Democratic Republic of Congo

2021 ◽  
Author(s):  
Jean-Claude MAKENGA BOF ◽  
Paul MANSIANGI ◽  
Josué ZANGA ◽  
Félicien ILUNGA ◽  
Yves COPPIETERS
Keyword(s):  
Aquatic Plants ◽  
Democratic Republic Of Congo ◽  
Abundant Species ◽  
Host Population ◽  
Black Flies ◽  
River Blindness ◽  
Transmission Potential ◽  
Simulium Damnosum ◽  
Plastic Bags ◽  
Biting Rate

Abstract Background Onchocerciasis, a parasitic disease caused by the filarial worm Onchocerca volvulus transmitted through the bite of Simulium (black flies), is a cause of global concern, with the African population being majorly affected. This study focused on the bite rates, bite cycle, and transmission potential of Simulium damnosum s.l. in two sites with river blindness outbreaks in Kinshasa, DRC: Gombe (S1) and Mont-Ngafula at Kimwenza (S2). Methods From August 1, 2019, to July 31, 2020, we captured adult female black flies near breeding sites along the Congo River at S1 and Lukaya Valley at S2. Collections using human baits at the two sites were conducted for five days/month. Results A total of 6082 black flies of species Simulium squamosum (classified based on other entomological surveys) were captured during the study period. The daily cycle of aggression revealed two peaks: one between 8 and 9 a.m. and the other between 4 and 5 p.m. Low bite rates were observed between 11 a.m. and 1 p.m. The annual biting rate/person reached 13,463 in S1 and 23,638 in S2, with a total of 37,101 bites/person. The average daily biting rate, 37 ± 10 and 69 ± 23 bites/day/person in S1 and S2, respectively, did not differ significantly (P = 0.8901). The high density of the host population can disrupt the transmission of vector-borne diseases by diluting the transmission indices. There was no evidence of onchocerciasis transmission at the study sites because of inadequate laboratory facilities in the DRC. Various larval supports have been identified: at Gombe: aquatic plants, plastic bags, dead leaves, and rocks; at Kimwenza: Ledermaniella ledermanii (the most abundant species at the site), plastic bags, artificial waste, and aquatic plants. Conclusions The study provides further evidence for the need for alternative strategies to eliminate the parasite in the formerly hyper-endemic foci.

scholarly journals Prevalence of Mansonella ozzardi among riverine communities in the municipality of Lábrea, State of Amazonas, Brazil

2011 ◽  
Vol 44 (2) ◽  
pp. 186-190 ◽  
Author(s):  
Jansen Fernandes Medeiros ◽  
Victor Py-Daniel ◽  
Ulysses Carvalho Barbosa
Keyword(s):  
Infection Rate ◽  
Prevalence Rate ◽  
Blood Smear ◽  
Parasitic Infection ◽  
Age Groups ◽  
Farm Workers ◽  
Black Flies ◽  
Prevalence Rates ◽  
Thick Blood Smear ◽  
High Prevalence

INTRODUCTION: Estimate the prevalence of Mansonella ozzardi infection and calculate the parasitic infection rate (PIR) in simuliid black flies in the municipality of Lábrea, State of Amazonas, Brazil. METHODS: Prevalence was measured using the thick blood smear method collected from the fingers and was related to age, sex and occupation. Simuliidae were collected with a suction apparatus, then stained with hematoxylin and dissected to verify the PIR. RESULTS: The average prevalence rate of M. ozzardi among the 694 individuals examined was 20.7%. Infection was higher in men (27.6%) than in women (14.3%) (p < 0.001) and occurred in most age groups, with the highest prevalence in the following age groups: 38-47 (40%), 48-57 (53.1%) and >58 (60.5%). The highest prevalence rates were observed in the retired (64%), followed by farm workers (47.1%). Infection by M. ozzardi was only identified in Cerqueirellum amazonicum (Simuliidae) with a PIR of 0.6%. CONCLUSIONS: This study showed a high prevalence of M. ozzardi in the riverine communities of Lábrea due to the lack of policies regarding the treatment of microfilaremic individuals in the region and an abundance of competent vectors for M. ozzardi.

scholarly journals Seasonal prevalence, intensity and organal distribution of Helminth parasites in macrognathus aculeatus

1970 ◽  
Vol 20 (2) ◽  
pp. 117-122
Author(s):  
Hamida Khanum ◽  
Salma Begum ◽  
Aleya Begum
Keyword(s):  
Seasonal Variation ◽  
Key Words ◽  
Infection Rate ◽  
Rainy Season ◽  
Parasitic Infection ◽  
Helminth Parasites ◽  
Seasonal Prevalence ◽  
Female Fish ◽  
Intensity Of Infection ◽  
Macrognathus Aculeatus

Examination of 122 individuals of Macrognathus aculeatus (popularly known as Tara Baim), collected monthly, from the river Buriganga during March, 2007 to February, 2008 revealed 77 fishes were infected with various helminth parasites with an infection rate of 63.11% and intensity of infection of 3.18. A total of 245 parasites were recovered from different organs of the fishes, with the highest number from the intestine. Six species of helminths were detected, of which two were trematodes (Clinostomum piscidum and Rhynchooharynx paradoxa), one species of cestode (Marsipometra parva) and three species of nematodes (Pseudoproleptus vestibules, Cucullanus cirratus and Porrocaecum trichiuri L3 larva). The prevalence and intensity of parasitic infection were a bit higher in female fish than in male. The parasites were much more abundant in rainy season (75%) followed by summer (62.5%) and winter (31.81%). The larger fishes were heavily infected (71.01%) than medium (53.33%) and smaller (52.17%) fishes. Key words: Macrognathus aculeatus; Helminth; Prevalence; Intensity; Organal distribution;  Seasonal variation DOI: http://dx.doi.org/10.3329/dujbs.v20i2.8971 DUJBS 2011; 20(2): 117-122

scholarly journals Parasitic Infection with Cirrhina mrigala (Hamilton) Collected from Rajshahi, Bangladesh

1970 ◽  
Vol 43 (2) ◽  
pp. 243-250
Author(s):  
Abdus Salam Bhuiyan ◽  
Abu Saleh Md. Musa ◽  
Golam Mohammad Musa ◽  
Tanjeena Zaman
Keyword(s):  
Seasonal Variation ◽  
Key Words ◽  
Infection Rate ◽  
Rainy Season ◽  
Parasitic Infection ◽  
Water Bodies ◽  
Body Parts ◽  
Metazoan Parasites ◽  
Fish Group ◽  
External Body

The parasitic infection was studied on Cirrhina mrigala, an indigenous major carp in different water bodies of Rajshahi district during April 2006 to January 2007. A total of 83 specimens of C. mrigala were examined during the study period of which 74 fishes were observed to be infected by numerous protozoan and metazoan parasites. A total number of 3063 parasites were recorded from the infected fishes. Ten different parasitic genera, Trichodina, Myxobolus, Chilodonella, Ichthyophthirius, Dactylogyrus, Gyrodactylus, Fellodistomum, Eucreadium, Camallanus and Argulus were identified from the hosts sampled. Among them seven were cetoparasites and three were endoparasites. Parasites were collected from different body parts of the fishes. Most of the parasites were collected from external body surfaces and gills. Prevalence, intensity and abundance of the infection with parasites were varied to different length groups of the hosts and months of the year. In case of length, the medium sized fishes were more infected than the maximum sized and their prevalence, intensity and abundance were highest. Infection rate was lowest in larger size fish group. In seasonal variation, the maximum infection was observed in pre-winter and the lowest number was recorded in rainy season. Key words: Parasitic infection, Cirrhina mrigala, Prevalence, Intensity, Abundance.  DOI: 10.3329/bjsir.v43i2.968 Bangladesh J. Sci. Ind. Res. 43(2), 243-250, 2008

scholarly journals Filariasis Control in Coastal Nigeria: Predictive Significance of Baseline Entomological Indices of Anopheles gambiae s.l. (Diptera: Culicidae)

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Dominic Ibe ◽  
Gloria N. Wokem
Keyword(s):  
Anopheles Gambiae ◽  
Rainy Season ◽  
Light Trap ◽  
Control Programme ◽  
Dry Season ◽  
Human Landing Catch ◽  
Transmission Potential ◽  
Biting Rate ◽  
Human Landing ◽  
Anopheles Gambiae S.L

This work aimed at collecting filariasis transmission data of Anopheles gambiae to be used in predicting future trends in filariasis transmission and control programme outcomes. Collection of the mosquitoes was made by human landing catch and light trap methods. In all, 5,813 females were caught from September 2005 to August 2006. Mosquito population started to expand at the onset of the rains. The highest density was found after peak temperature. The A. gambiae s.l. biting peaked around midnight; 39.7% were parous and 0.3% were infective. The highest percentage of parous females caught was near midnight, ranging between 42.0% and 47.5% from 22.00 to 03.00 hours. Biting rate in the rainy season was 2.6 times higher than it in the dry season. Transmission potential was 3.6 times higher during the rains than during the dry season. The percentage infectivity was relatively high (13.2%) in June, corresponding to 8.8 infective bites per person per month. All infective A. gambiae, were caught between 22.00 and 03.00 hours. The average load of L3 larvae per infective A. gambiae was 1.4 L3/mosquito. The monthly transmission potential calculated for each month indicated that transmission was ongoing for most of the months of the year, especially in the rainy season.

Escape mechanisms of African trypanosomes: why trypanosomosis is keeping us awake

Parasitology ◽  
2014 ◽  
Vol 142 (3) ◽  
pp. 417-427 ◽  
Author(s):  
JENNIFER CNOPS ◽  
STEFAN MAGEZ ◽  
CARL De TREZ
Keyword(s):  
Immune Response ◽  
Trypanosoma Brucei ◽  
Parasitic Infection ◽  
Mammalian Host ◽  
Tsetse Flies ◽  
African Trypanosomes ◽  
Transmission Potential ◽  
Highly Sensitive ◽  
Commercially Important ◽  
And Control

SUMMARYAfrican trypanosomes have been around for more than 100 million years, and have adapted to survival in a very wide host range. While various indigenous African mammalian host species display a tolerant phenotype towards this parasitic infection, and hence serve as perpetual reservoirs, many commercially important livestock species are highly disease susceptible. When considering humans, they too display a highly sensitive disease progression phenotype for infections withTrypanosoma brucei rhodesienseorTrypanosoma brucei gambiense, while being intrinsically resistant to infections with other trypanosome species. As extracellular trypanosomes proliferate and live freely in the bloodstream and lymphatics, they are constantly exposed to the immune system. Due to co-evolution, this environment however no longer poses a hostile threat, but has become the niche environment where trypanosomes thrive and obligatory await transmission through the bites of tsetse flies or other haematophagic vectors, ideally without causing severe side infection-associated pathology to their host. Hence, African trypanosomes have acquired various mechanisms to manipulate and control the host immune response, evading effective elimination. Despite the extensive research into trypanosomosis over the past 40 years, many aspects of the anti-parasite immune response remain to be solved and no vaccine is currently available. Here we review the recent work on the different escape mechanisms employed by African Trypanosomes to ensure infection chronicity and transmission potential.

A stage structured model of malaria transmission and efficacy of mosquito larvicides in its control

2014 ◽  
Vol 05 (04) ◽  
pp. 1450023 ◽  
Author(s):  
Manju Agarwal ◽  
Archana S. Bhadauria
Keyword(s):  
Parasitic Infection ◽  
Transmission Efficiency ◽  
Immature Stage ◽  
Human Populations ◽  
Stability Switch ◽  
Reproduction Ratio ◽  
Maturation Delay ◽  
Biting Rate ◽  
Mosquito Larvicides ◽  
The Stability

In this paper, we analyze a stage structured mathematical model for the transmission of malaria and its control by killing mosquitoes in larvae (immature) stage. Both the Mosquito and human populations are divided into susceptible and infective class. Susceptible class of mosquito population is further divided into mature and immature. The model is analyzed by using stability theory of nonlinear ordinary differential equations. Basic reproduction ratio is derived which is found to be the decreasing function of maturation delay and larvicidal activity. In addition, it is observed that biting rate of mosquito, transmission efficiency of parasitic infection from infective human to mosquito and critical value of maturation delay are the key parameters determining the stability switch in the system. Numerical simulation is also carried out to confirm the analytical results obtained in the paper.

scholarly journals The Abundance and Biting Patterns of Culex quinquefasciatus Say (Culicidae) in the Coastal Region of Nigeria

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Gloria N. Wokem ◽  
Christiana Okonofua
Keyword(s):  
Culex Quinquefasciatus ◽  
Rainy Season ◽  
Coastal Region ◽  
Dry Season ◽  
Human Landing Catch ◽  
Light Traps ◽  
Transmission Potential ◽  
Human Landing ◽  
The Mean

This study was aimed at determining the abundance and biting patterns of Culex quinquefasciatus in the coastal region of Nigeria. Collections were done by human landing catch and by CDC miniature light traps from September 2005 to August 2006. A total of 3798 C. quinquefasciatus females were collected. The highest number of females was caught in the month of August and it represented nearly a quarter (24.0%) of the total females collected. In all, 38.8% of females dissected were parous. The abundance of C. quinquefasciatus followed the pattern of rainfall with the population starting to expand at the onset of the rains. The highest increase was found after the temperature had peaked. The mean of biting was 3.2 times more in the rainy season than in the dry season, whereas the transmission potential was higher in the dry season. C. quinquefasciatus is presently regarded as a biting nuisance having no significant epidemiological importance yet. Efforts at its control should be intensified before it is too late.

scholarly journals A study on prevalence of ecto- and endo-parasitic infection of cattle at Savar, Dhaka

2020 ◽  
pp. 29-35
Author(s):  
MZ Hassan ◽  
MM Rahman ◽  
MZ Ali ◽  
MA Yousuf ◽  
M Hasan ◽  
...  
Keyword(s):  
Rainy Season ◽  
Tick Infestation ◽  
Clinical Observation ◽  
Adult Animal ◽  
Parasitic Infection ◽  
Winter Season ◽  
Gastrointestinal Infection ◽  
Adult Cattle ◽  
Livestock Species ◽  
One Year

A prevalence study was conducted to observe both ecto-and endo-parasitic (gastrointestinal) infection throughout one year surveillance. The study was conducted from July 2014 to June 2015 through Parasitology Laboratory, BLRI, Savar, Dhaka. The study considered age of cattle, season and type of parasitic infestation. In the study area total number of cattle population was 2000 in which 500 fecal and 200 ectoparasitic samples was collected considering three respective seasons like rainy, summer and winter. The fecal samples were examined by direct smear method followed by McMaster counting techniques and examine under microscope. After collection of samples within 24 hours all sample were tested by preserving at 40C temperature. In clinical observation, the overall prevalence of endoparasitic (gastrointestinal) infection was 68% and ectoparasitic infection was 60%. Prevalence of endoparasite was more frequent in rainy season (52.65%) followed by summer (27.05%) and winter season (20.29%) whereas prevalence of ectoparasite was more frequent in summer (39%) followed by rainy (13.5%) and winter (7.5%) season. The parasitic prevalence load was low in winter season. In endoparasitic infection, the higher prevalence of Paramphistomum spp. (20%) was found in rainy season whereas Haemonchus spp. (14%) and Toxocara spp. (12%) were higher in summer. In cattle, prevalence of Paramphistomum spp. (25.14%) and Haemonchus spp. (18.58%) was higher in adult cattle (above 6 months), whereas prevalence of Toxocara spp. (36.67%) and Coccidial oocyst (23.33%) was higher in calf (under 6 month) than adult animal (above 6 months) of age. The overall prevalence of ectoparasite was 60% and tick infestation was highest (22.5%) followed by lice (17.5%), mange (12.5%) and maggot fly (7.5%). High humidity (above 70%) and temperature provoke high endo- and ecto-parasite infection in the environment and infect cattle as well as other livestock species. Bangladesh J. of Livestock Res. 21-25: 29-35, 2018

Effect of rumen emptying on biting rate of cows grazingBrachiaria brizanthaat three stocking rates in Yucatán, México

2006 ◽  
Vol 34 ◽  
pp. 117-123 ◽  
Author(s):  
R. Grajalez-Zepeda ◽  
A.J. Ayala-Burgos ◽  
L. Ramírez-Aviléz ◽  
C. Aguilar-Pérez ◽  
J.L. Puerto-Nájera
Keyword(s):  
Rainy Season ◽  
The Other ◽  
Average Weight ◽  
Stocking Rate ◽  
Bite Rate ◽  
Other Hand ◽  
Biting Rate ◽  
Stocking Rates ◽  
Representative Samples

SummaryThe experiment was carried out in the east of Yucatán, in pastures ofB. brizantha. It was of three months duration during the end of the rainy season. Four rumen cannulated cows with an average weight of 442 kg were used at all of three stocking rates: Low (2LU/ha), Medium (4LU/ha) and High (6LU/ha), to evaluate the effect of an empty rumen on the rate of biting, which was measured as the time taken to take 20 uninterrupted bites on ten occasions. The measurements were made on two sequential days at 09.00 h, the first under normal conditions, the second with an empty rumen. There was no effect (P<0.050 of rumen emptying on the rate of biting which was 24 bites per minute when the animals were normal, and 25 bites a minute when the rumen was empty. On the other hand, there was a reduction of 8% in the rate of biting for the animals at the high stocking rate compared with the low and medium stocking rates. The finding that bite rate was not affected by an empty the rumen is evidence which gives confidence in the use of cannulated animals as collectors of representative samples of forage under grazing conditions.

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