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The fate of Brugia pahangi microfilariae in Armigeres subalbatus during the first 48 hours post ingestion

Zahedi M

Trop. Med. Parasitol., 1994 Mar;45(1):33-5.
PMID: 7915044

In Armigeres subalbatus, 60% and 3% of the ingested Brugia pahangi microfilariae (mf) respectively migrated into the haemocoel and the thorax within 5 minutes post ingestion (p.i.). Most of the mf had migrated from the gut into the haemocoel within the first 10 minutes p.i. There was no correlation between the number of mf ingested and the migration rate though those in mosquitoes with a low mf burden tend to migrate earlier. At 24 hours p.i., 5-30% of the mf were still in the gut; 19% of these mf were immobile. At 48 hours p.i. only 2% of the mf were mobile. B. pahangi mf isolated from blood meals at 24 hours p.i., failed to develop when inoculated into Armigeres subalbatus. 54% and 73% of the mf isolated from a 24 hour old clotted blood of a B. pahangi-infected cat and fresh peripheral cat blood respectively developed into stage-1 larva. Probably mf left in the midgut at 24 hours p.i. are the young and immature worms and are physiologically incapable of penetrating the gut.

Matched MeSH terms: Culicidae/parasitology*
Efficacy of diethylcarbamazine and pirimiphos-methyl residual spraying in controlling brugian filariasis

Chang MS, Ho BC, Chan KL

Trop. Med. Parasitol., 1991 Jun;42(2):95-102.
PMID: 1680246

A control programme against subperiodic brugian filariasis was implemented in three villages, (Kg. Ampungan, Kg. Sebangkoi and Kg. Sebamban) in Sarawak, Malaysia. In Kampong Ampungan, the mass administration of diethylcarbamazine (DEC-citrate) combined with residual house spraying of pirimiphos-methyl reduced microfilarial rate to 8% of the pre-treatment level and microfilarial density (MfD50) to 44% of the pre-treatment level over a period of four years. In Kampong Sebangkoi and Kampong Sebamban, where only mass DEC therapy was applied, the microfilarial rate and MfD50 declined distinctly in the second blood survey but increased gradually in two subsequent follow-up blood surveys. In Kg, Ampungan, we observed a significant reduction of infective biting rate (88.3%), infection rate (62.5%) and transmission potential (88.1%) of Mansonia bonneae at the fourth spray round. The corresponding reduction rates in Kg. Sebangkoi and Kg. Sebamban were 35.3%, 26.7%, 42.2% and 24%, 30.8% and 15.4% respectively. The biting density of the vector was reduced by 79.8% indoors and 31.8% outdoors at the sprayed village, while only a slight decrease in densities (17.9% indoors and 12.4% outdoors) was observed at the unsprayed village. Bioassay tests revealed that pirimiphos-methyl had a substantial fumigant effect on the vector. The integrated control measure in controlling subperiodic brugian filariasis is discussed.

Matched MeSH terms: Culicidae/parasitology
Fulltext Vector and reservoir host of a case of human Brugia pahangi infection in Selangor, peninsular Malaysia

Muslim A, Fong MY, Mahmud R, Sivanandam S

Trop Biomed, 2013 Dec;30(4):727-30.
PMID: 24522144 MyJurnal

A case of human eye infection caused by Brugia pahangi was reported in 2010 in a semi rural village in Selangor, peninsular Malaysia. Our report here reveals results of investigation on the vector and animal host for the transmission of the infection. We conducted entomological survey and cat blood examination in the vicinity of the patient's home. The mosquito species Armigeres subalbatus was incriminated as the vector, whereas cat served as the reservoir host.

Matched MeSH terms: Culicidae/parasitology*
Fulltext First report of mermithid parasitism (Nematoda: Mermithidae) in mosquitoes (Diptera: Culicidae) from Lao PDR

Vythilingam I, Sidavong B, Seng TC, Phonemixay T, Phompida S, Krishnasamy M

Trop Biomed, 2005 Jun;22(1):77-9.
PMID: 16880758

Unidentified mermithid nematodes were found in the abdominal cavity of three species of Anopheles mosquitoes from LAO PDR. This is a first record of mermithid nematodes in adult mosquitoes from Lao PDR. Two worms were found in each adult host and the infection was more prevalent in the northern region compared to the south.

Matched MeSH terms: Culicidae/parasitology*
Environmental variables associated with immature stage habitats of culicidae collected in aboriginal villages in Pahang, Malaysia

Ali WN, Ahmad R, Nor ZM, Ismail Z, Ibrahim MN, Hadi AA, et al.

Southeast Asian J. Trop. Med. Public Health, 2012 Nov;43(6):1387-99.
PMID: 23413702

Many of the most widely spread vector-borne diseases are water related, in that the mosquito vectors concerned breed or pass part of their lifecycle in or close to water. A major reason for the study of mosquito larval ecology is to gather information on environmental variables that may determine the species of mosquitoes and the distribution of larvae in the breeding habitats. Larval surveillance studies were conducted six times between May 2008 and October 2009 in Pos Lenjang, Kuala Lipis, Pahang. Twelve environmental variables were recorded for each sampling site, and samples of mosquito larvae were collected. Larval survey studies showed that anopheline and culicine larvae were collected from 79 and 67 breeding sites, respectively. All breeding sites were classified into nine habitat groups. Culicine larvae were found in all habitat groups, suggesting that they are very versatile and highly adaptable to different types of environment. Rock pools or water pockets with clear water formed on the bank of rivers and waterfalls were the most common habitats associated with An. maculatus. Environmental variables influence the suitability of aquatic habitats for anopheline and culicine larvae, but not significantly associated with the occurrence of both larvae genera (p>0.05). This study provides information on mosquito ecology in relation to breeding habitats that will be useful in designing and implementing larval control operations.

Matched MeSH terms: Culicidae/parasitology
Current status of filariasis in Malaysia

Marzhuki MI, Tham AS, Poovaneswari S

Southeast Asian J. Trop. Med. Public Health, 1993;24 Suppl 2:10-4.
PMID: 7973937

The Filariasis Control Program was established more than 30 years ago in the country and the disease is still a public health problem in some states. Since 1983, a total of 17 filariasis control teams were formed throughout the country to carry out filariasis control work. The teams conduct house and population censuses, nocturnal mass blood surveys and treatment of microscopically confirmed cases. Individual case follow-up is being carried out after 3-5 months while the locality is resurveyed after about 2-3 years. During the years 1988 to 1990, there appeared to be a decreasing trend in the number of filariasis cases detected countrywide. In 1991, brugian filariasis accounted for 92% of the cases detected. The microfilaria rate (MFR) also showed a decreasing trend countrywide for the years 1988 (0.57%) to 1990 (0.35%) but there was an increase in 1991 although it remained well below the 5% MFR targeted in the program objective, In 1991, the filariasis control teams and the district multi-purpose teams collected a total of 167, 151 blood slides out of which 871 were found to be positive for microfilaria. To determine the true endemicity of filariasis in the country, the malaria district multi-purpose teams are also utilized to assist in probe surveys in new areas of the district. Two species of filarial worms, namely Brugia malayi and Wuchereria bancrofti, and the mosquito vectors belonging to the Anopheles and Mansonia genera are involved in the transmission of filariasis in Malaysia. Monkeys and domestic cats are the reservoir hosts for the subperiodic strain of B. malayi.

Matched MeSH terms: Culicidae/parasitology
Genetic aspects of lymphatic filariasis

Yong HS, Mak JW

Southeast Asian J. Trop. Med. Public Health, 1993;24 Suppl 2:37-9.
PMID: 7973944

The genetics of human susceptibility to lymphatic filariasis, the genetic basis of filarial susceptibility in vector mosquitos, and the genetic constitution of human filarial parasites and their mosquito vectors are reviewed. It is evident that our present knowledge on the genetics of lymphatic filariasis is still very meagre. The need to study various genetic aspects of the disease is highlighted.

Matched MeSH terms: Culicidae/parasitology
Control of Mansonia mosquitos, vectors of brugian filariasis in Sarawak, Malaysia

Chang MS, Chan KL, Ho BC

Southeast Asian J. Trop. Med. Public Health, 1993;24 Suppl 2:93-104.
PMID: 7973956

Two field trials in the control of subperiodic brugian filariasis vectors, mainly Mansonia bonneae and Mansonia dives were carried out in Sarawak, East Malaysia. In the first trial, malathion ultra-low volume (ULV) spray was used to control the Mansonia mosquitos in two filariasis endemic villages. Six spray rounds were applied at biweekly intervals at Kampung Rasau and two spray rounds were applied at monthly intervals in Kampung Triboh. ULV malathion spray reduced biting Ma. bonneae population for 3 days after spraying. The biting density decreased to 50% of the pre-treatment level by the 12th - 13th day and reached the pre-treatment level by the 24th - 25th day. Contact bioassay tests on caged Mansonia mosquitos revealed considerable penetration of the malathion aerosol indoors and relatively adequate coverage outdoors. The estimated number of bites per case per day was 1.09 to 4 times less in the sprayed kampung than in an unsprayed control kampung. The parous and daily survival rates of Mansonia mosquitos were not significantly affected by the spraying. In a second trial, chemotherapy with diethylcarbamazine citrate (DEC) was combined with vector control through indoor residual spraying in Kampung Ampungan. The results were compared with the use of only DEC mass treatment in Kampung Sebangkoi and Kampung Sebamban. The combined control measures in Kampung Ampungan reduced the MfD-50 to 44% of the pre-treatment level over a period of 4 years. In the other two kampungs where only mass DEC therapy was applied, the microfilarial rate and MfD-50 declined significantly in the second blood survey but increased gradually in two subsequent follow-up blood surveys. The total insecticidal impact for Ma. bonneae was 3.9 to 1 indoors and 2.7 to 1 outdoors. These results indicated that quarterly pirimiphos-methyl indoor spraying used in integrated control could reduce indoor transmission by 3.9 times. The infective rate from the Ma. bonneae dissected in all three kampungs after the interventions, irrespective of DEC treatment alone or in combination with pirimiphos-methyl residual spraying were reduced by two fold. However the infection rate of brugian filarial larvae in Kampung Ampungan was significantly reduced after the use of DEC and insecticide. Annual Transmission Potential (ATP) showed a high significant reduction in Kampung Ampungan (p > 0.001) compared with Kampungs Sebangkoi and Schambam. In Ampungan, the ATP was reduced by 8.5 times indoors after the MDA and insecticidal application and 3 times outdoors. The reduction rate for Sebangkoi and Sebamban both indoors and outdoors were less than 2 fold.(ABSTRACT TRUNCATED AT 400 WORDS)

Matched MeSH terms: Culicidae/parasitology*
Update on the bionomics of Mansonia vectors of brugian filariasis

Chiang GL

Southeast Asian J. Trop. Med. Public Health, 1993;24 Suppl 2:69-75.
PMID: 7973951

The genus Mansonia is divided into two subgenera, Mansonia and Mansonioides. The subgenus Mansonioides includes the important vectors of lymphatic filariasis caused by Brugia malayi in South and Southeast Asia. Six species of this subgenus are vectors of two types of brugian filariasis, periodic and subperiodic. All six species, viz Mansonia bonneae, Ma. dives, Ma. uniformis, Ma. annulifera, Ma. annulata and Ma. indiana are present in this country. The ecological factors governing the larval and adult biology and their control measures are discussed.

Matched MeSH terms: Culicidae/parasitology
Comparative susceptibility of five strains of Mansonia uniformis (Diptera:Culicidae) in Malaysia to infection with subperiodic Brugia malayi

Chiang GL, Loong KP, Eng KL

Southeast Asian J. Trop. Med. Public Health, 1989 Jun;20(2):169-74.
PMID: 2575285

Five strains of Ma. uniformis from Malaysia were tested for their susceptibility to infection with subperiodic B. malayi. All were found to be susceptible with infection rates ranging from 62% to 100%. The susceptibility rates were directly related to the microfilarial densities of the cat at the time of feeding. Statistical analysis showed no significant difference (p greater than 0.05) among the means of the indices of experimental infection as well as the percentage of infective mosquitoes of the five strains and an old laboratory colony. They were all equally susceptible to subperiodic B. malayi.

Matched MeSH terms: Culicidae/parasitology*
Filariasis in Bengkoka Peninsula, Sabah, Malaysia: bionomics of Mansonia sp

Chiang GL, Cheong WH, Samarawickrema WA

Southeast Asian J. Trop. Med. Public Health, 1984 Sep;15(3):294-302.
PMID: 6151743

Studies on age groups within activity cycles, age composition and survivorship in natural populations of Mansonia in Kampung Pantai, Bengkoka Peninsula of Sabah state have been described. Early activity of 3-5 parous Ma. bonneae during the first hour after sunset was noted. Age composition of Ma. bonneae at forest shade, indoor and outdoor of house, comparative buffalo vs human bait outdoor in Kampung Pantai showed all round high parous rates ranging from 66.7 to 75.4%. Population 3-parous and older ranged from 18.8 to 26.7%. Nine of the 14 infective Ma. bonneae were 3-parous and this segment of the population was engaged in active transmission. High parous rates were observed in Ma. dives and Ma. uniformis taken in small numbers. Parous rates of Ma. bonneae taken in Kampung Delima and Kampung Taradas were also high. Estimates of daily survivorship of Ma. bonneae and Ma. dives determined by two methods were very high.

Matched MeSH terms: Culicidae/parasitology
Armigeres subalbatus incriminated as an important vector of the dog heartworm Dirofilaria immitis and the bird Cardiofilaria in urban Kuala Lumpur

Cheong WH, Mak JW, Naidu S, Mahadevan S

Southeast Asian J. Trop. Med. Public Health, 1981 Dec;12(4):611-2.
PMID: 6124044
Matched MeSH terms: Culicidae/parasitology*
Studies of Coquillettidia (coquillettidia) crassipes (Vanderwulp, 1881) in relation to transmission of Cardiofilaria nilesi

Klinkaewnarong W, Chiang GL, Eng KL

Southeast Asian J. Trop. Med. Public Health, 1985 Mar;16(1):10-4.
PMID: 2862708

Field surveillance of Cq. crassipes was conducted in an open housing estate near Kuala Lumpur using IMR traps baited with chicken and gerbils. Chicken bait attracted more Cq. crassipes. There was significant difference between chicken and gerbil as bait. The mosquitoes preferred to feed at canopy level. The parous rate was 20.41% and the infection rate for Cardiofilaria nilesi was 2.04%. None of the 120 chicken and 5 ducks, in a village close to the open housing estate, examined for microfilariae were positive. Ar. durhami and Ar. subalbatus did not support development of C. nilesi. However, Cq. crassipes is an extremely efficient vector of C. nilesi.

Matched MeSH terms: Culicidae/parasitology*
Parasitological and entomological studies on filariasis in seven villages, Serian District, Sarawak, East Malaysia

Rubis P, Chang MS, Nagum AJ, Jau JL

Southeast Asian J. Trop. Med. Public Health, 1981 Mar;12(1):30-5.
PMID: 6114566

A total of 82 persons have been found to be positive for microfilaria a sub-periodic Brugia malayi out of 1,613 examined in seven villages in Serian District. This represents an average microfilaria infection rate of 5.1% with a range of zero to 10.7%. It is found that males are more predominantly affected than females with a ratio of 3:1. It is also confirmed that Mansonia dives and M. bonneae are possible vectors for the transmission of the disease although Anopheles species cannot be ruled out owing to the small number of specimens examined. The study is confined to areas where indoor DDT spraying has been done since 1960 and only in two of the areas it has been terminated in 1966. Yet to be published data shows higher filaria infection rate than any of these villages.

Matched MeSH terms: Culicidae/parasitology*
Lankesteria, a gregarine protozoan, previously unreported in mosquitoes of Malaysia

Else JG, Dangsupa P

Southeast Asian J. Trop. Med. Public Health, 1974 Sep;5(3):454.
PMID: 4154508
Matched MeSH terms: Culicidae/parasitology*
Fulltext The Plasmodium falciparum male gametocyte protein P230p, a paralog of P230, is vital for ookinete formation and mosquito transmission

Marin-Mogollon C, van de Vegte-Bolmer M, van Gemert GJ, van Pul FJA, Ramesar J, Othman AS, et al.

Sci Rep, 2018 10 08;8(1):14902.
PMID: 30297725 DOI: 10.1038/s41598-018-33236-x

Two members of 6-cysteine (6-cys) protein family, P48/45 and P230, are important for gamete fertility in rodent and human malaria parasites and are leading transmission blocking vaccine antigens. Rodent and human parasites encode a paralog of P230, called P230p. While P230 is expressed in male and female parasites, P230p is expressed only in male gametocytes and gametes. In rodent malaria parasites this protein is dispensable throughout the complete life-cycle; however, its function in P. falciparum is unknown. Using CRISPR/Cas9 methodology we disrupted the gene encoding Pfp230p resulting in P. falciparum mutants (PfΔp230p) lacking P230p expression. The PfΔp230p mutants produced normal numbers of male and female gametocytes, which retained expression of P48/45 and P230. Upon activation male PfΔp230p gametocytes undergo exflagellation and form male gametes. However, male gametes are unable to attach to red blood cells resulting in the absence of characteristic exflagellation centres in vitro. In the absence of P230p, zygote formation as well as oocyst and sporozoite development were strongly reduced (>98%) in mosquitoes. These observations demonstrate that P230p, like P230 and P48/45, has a vital role in P. falciparum male fertility and zygote formation and warrants further investigation as a potential transmission blocking vaccine candidate.

Matched MeSH terms: Culicidae/parasitology*
Zoonotic Brugia pahangi filariasis in a suburbia of Kuala Lumpur City, Malaysia

Tan LH, Fong MY, Mahmud R, Muslim A, Lau YL, Kamarulzaman A

Parasitol Int, 2011 Jan;60(1):111-3.
PMID: 20951228 DOI: 10.1016/j.parint.2010.09.010

Five local Malaysian patients with clinical manifestations consistent with lymphatic filariasis were referred to our medical centre between 2003 and 2006. Although no microfilariae (mf) were detected in their nocturnal blood samples, all were diagnosed to have lymphatic filariasis on the basis of clinical findings and positive serology results. PCR on their blood samples revealed that two of the patients were infected with Brugia pahangi, an animal filarial worm hitherto not known to cause human disease in the natural environment. All the patients were successfully treated with anti-filarial drugs: four patients were treated with a combination of diethylcarbamazine (DEC) and albendazole, and one with doxycycline. Four of them were residents of Petaling Jaya, a residential suburbia located 10 km southwest of Kuala Lumpur city, Malaysia. The fifth patient was a frequent visitor of the suburbia. This suburbia has no history or record of B. malayi infection. The most likely vector of the worm was Armigeres subalbatus as extensive entomological surveys within the suburbia revealed only adult females of this mosquito species were infected with B. pahangi larvae. Wild monkeys caught in the suburbia were free from B. pahangi mf, but domestic cats were mf positive. This suggests that infected cats might be the source of the zoonotic infection in the suburbia.

Matched MeSH terms: Culicidae/parasitology
Fulltext Armigeres subalbatus incriminated as a vector of zoonotic Brugia pahangi filariasis in suburban Kuala Lumpur, Peninsular Malaysia

Muslim A, Fong MY, Mahmud R, Lau YL, Sivanandam S

Parasit Vectors, 2013;6:219.
PMID: 23898840 DOI: 10.1186/1756-3305-6-219

In 2011, we reported occurrence of natural human infections with Brugia pahangi, a filarial worm of dogs and cats, in a surburb of Kuala Lumpur, the capital city of Malaysia. Our preliminary entomological survey at that time suggested the mosquito species Armigeres subalbatus as the vector of the zoonotic infections. In this present report, we provide biological evidence to confirm our preliminary finding.

Matched MeSH terms: Culicidae/parasitology*
Fulltext An update on the mosquito fauna and mosquito-borne diseases distribution in Cameroon

Bamou R, Mayi MPA, Djiappi-Tchamen B, Nana-Ndjangwo SM, Nchoutpouen E, Cornel AJ, et al.

Parasit Vectors, 2021 Oct 11;14(1):527.
PMID: 34635176 DOI: 10.1186/s13071-021-04950-9

The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon.

Matched MeSH terms: Culicidae/parasitology
Fulltext Predicting the geographical distributions of the macaque hosts and mosquito vectors of Plasmodium knowlesi malaria in forested and non-forested areas

Moyes CL, Shearer FM, Huang Z, Wiebe A, Gibson HS, Nijman V, et al.

Parasit Vectors, 2016 Apr 28;9:242.
PMID: 27125995 DOI: 10.1186/s13071-016-1527-0

BACKGROUND: Plasmodium knowlesi is a zoonotic pathogen, transmitted among macaques and to humans by anopheline mosquitoes. Information on P. knowlesi malaria is lacking in most regions so the first step to understand the geographical distribution of disease risk is to define the distributions of the reservoir and vector species.
METHODS: We used macaque and mosquito species presence data, background data that captured sampling bias in the presence data, a boosted regression tree model and environmental datasets, including annual data for land classes, to predict the distributions of each vector and host species. We then compared the predicted distribution of each species with cover of each land class.
RESULTS: Fine-scale distribution maps were generated for three macaque host species (Macaca fascicularis, M. nemestrina and M. leonina) and two mosquito vector complexes (the Dirus Complex and the Leucosphyrus Complex). The Leucosphyrus Complex was predicted to occur in areas with disturbed, but not intact, forest cover (> 60% tree cover) whereas the Dirus Complex was predicted to occur in areas with 10-100% tree cover as well as vegetation mosaics and cropland. Of the macaque species, M. nemestrina was mainly predicted to occur in forested areas whereas M. fascicularis was predicted to occur in vegetation mosaics, cropland, wetland and urban areas in addition to forested areas.
CONCLUSIONS: The predicted M. fascicularis distribution encompassed a wide range of habitats where humans are found. This is of most significance in the northern part of its range where members of the Dirus Complex are the main P. knowlesi vectors because these mosquitoes were also predicted to occur in a wider range of habitats. Our results support the hypothesis that conversion of intact forest into disturbed forest (for example plantations or timber concessions), or the creation of vegetation mosaics, will increase the probability that members of the Leucosphyrus Complex occur at these locations, as well as bringing humans into these areas. An explicit analysis of disease risk itself using infection data is required to explore this further. The species distributions generated here can now be included in future analyses of P. knowlesi infection risk.

Matched MeSH terms: Culicidae/parasitology

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