Azhar Maqbool

Morphological and molecular characterisation of Echinococcus granulosus in livestock and humans in Punjab, Pakistan

Cystic echinococcus poses an important economic and public health problem to Pakistan. Our study determined the prevalence and genotypes of Echinococcus present in domestic livestock and humans in Punjab, Pakistan. Out of 39,738 animals examined, 6.67% of animals were found infected. The prevalence and fertility of hydatid cysts was highest in camels (prevalence 17.29%; proportion fertile 95%), followed by sheep (prevalence 7.52%; proportion fertile 86.4%), buffalo (prevalence 7.19%; proportion fertile 84.3%), goats (prevalence 5.48%; proportion fertile 79.09%) and cattle (prevalence 5.18%; proportion fertile 75.25%). Phylogenetic analysis of the cytochrome oxidase-1 gene revealed that the common sheep strain (G1) and buffalo strain (G3) are cycling among livestock in Punjab and that these strains are highly adapted to goats, camels and cattle. Both human cysts were found to belong to the common sheep strain (G1) of E. granulosus, reinforcing this strain has the most potential for zoonotic transfer. Both morphological and molecular results support earlier studies suggesting that Echinococcus of sheep and buffalo origin is phenotypically and genetically similar which adds further evidence to support its recognition as one species viz, Echinococcus granulosus sensu stricto.

Neospora caninum prevalence in dogs raised under different living conditions.

Neospora caninum is an important cause of abortion in dairy cattle worldwide. Dogs are important in the epidemiology of N. caninum because they act as definitive hosts shedding oocysts in the environment. Vertical transmission of the parasite is well recognized as an important aspect of the epidemiology of the parasite but the importance of horizontal transmission has been less studied. A N. caninum competitive ELISA was used to examine serum samples from 600 dogs that were raised under 4 different living conditions. Samples from 138 dogs living on 24 dairies with a prevalence (0-70%) of anti-N. caninum antibodies in the cattle, 294 pet dogs without neurological signs, 76 from pet dogs exhibiting neurological signs, and 92 stray dogs were examined. The overall seroprevalence of N. caninum was 23.5% (95% CI = ± 2.99) in the 600 dogs. Significant (P < 0.05) differences were observed between the 4 different populations of dogs. The number of N. caninum positive samples were: 51 (36.9%, 95% CI = ± 3.09) of 138 dogs from dairies, 31 (10.5%, 95% CI = ± 6.38) of 294 pet dogs without neurological signs, disorders, 22 (28.9%, 95% CI = ± 6.70) of 76 pet dogs with neurological signs, and 37 (40.2%, 95% CI = ± 2.83) of 92 stray dogs. Seropositivity to N. caninum in dogs from dairies was associated with a high prevalence of N. caninum antibodies in the cattle. At the 3 dairies where no dogs were present, the seroprevalence to N. caninum in the cattle was significantly lower (P < 0.05) than in the 21 dairies where dogs were present. Seroprevalence was significantly higher (P < 0.05) in male dogs (97 of 366; 26.5%, 95% CI = ± 3.40) than in female dogs (44 of 234; 18.8%, 95% CI = ± 5.65). Seroprevalence in dogs increased with age suggesting postnatal exposure to N. caninum infection however, this increase was not significant (P > 0.05). The prevalence of N. caninum antibodies was not significantly (P>0.05) different in dogs based on breed. These findings suggest a relationship between N. caninum infection of dogs from dairies and cattle on these dairies. However, further research is required to determine what is the most important way dogs acquire infection and how to prevent dogs from shedding oocysts.

Effects of Age and Breed on the Prevalence of Neospora caninum in Commercial Dairy Cattle from Pakistan

Abstract: Neospora caninum is a major cause of bovine abortion worldwide. A serological survey was carried out to determine the seroprevalence of exposure to N. caninum in dairy cattle based on age and breed from Punjab and Sindh provinces, Pakistan. Serum samples from 641 animals from 12 herds from Punjab (n = 7) and Sindh (n = 5) provinces were tested for antibodies against N. caninum using a commercially available competitive enzyme-linked immunosorbent assay. Positive reactions to N. caninum were seen in 277 (43%) of the 641 of the samples. Seropositive animals were present in all 12 herds. Animals over 2 yr of age (47%) and crossbreds (55%) were more likely to be seropositive than the other cattle examined. These results indicate that N. caninum infection is widespread among dairy cattle in Pakistan.

Seroprevalence of Neospora caninum and Brucella abortus in Dairy Cattle Herds with High Abortion Rates

abstract:  The protozoan Neospora caninum and the bacterium Brucella abortus are well-recognized causes of abortion in dairy cattle. Serum samples (n  =  240) from aborting (n  =  141) and at-risk (n  =  99) animals from 5 herds with high abortion rates in Punjab Province, Pakistan, were tested for antibodies to N. caninum using monoclonal antibody–based ELISA and for antibodies to B. abortus using the serum agglutination test. Antibodies to N. caninum and B. abortus were detected in 105 (43.8%) and 135 (56.3%) cattle, respectively. Prevalences of antibodies to N. caninum and B. abortus were higher in aborting cows (46.8% and 76.6%, P < 0.05) than in animals at risk (39.4% and 27.3%, P > 0.05). Sixty-six animals (27.5%) were seropositive to both N. caninum and B. abortus, and results showed no significant difference (P > 0.05) with respect to geographical district, breed, and age. This is the first report of N. caninum infection among dairy cattle herds in Pakistan.

Entamoeba infections in different populations of dogs in an endemic area of Lahore, Pakistan.

Entamoeba histolytica, a protozoan parasite that affects humans and other primates all over the world. It is a common waterborne pathogen in endemic areas that have fecal oral transmission cycle. The aim of the present study was to examine the prevalence of E. histolytica and other Entamoeba species cysts in three different dog populations. Fecal samples from 600 dogs were collected and processed to detect Entamoeba cysts using the triple fecal test (light microscopy) and fecal antigens of E. histolytica were detected using a fecal antigen ELISA (TechLab E. histolytica II). Because it is impossible to differentiate E. histolytica from Entamoeba dispar and E. moshkovskii, using light microscopy we referred to all cysts morphologically consistent with E. histolytica as E. histolytica/dispar/moskovskii to reflect this uncertainty. Samples from 197 household dogs without clinical signs, 122 samples from household dogs exhibiting clinical signs of diarrhea, dysentery and vomiting and 281 stray dogs with no specific clinical signs were examined. Entamoeba histolytica-like cysts were observed in 94 (15.6%, 95% CI=±3.88) by triple fecal test microscopy and E. histolytica antigens were demonstrated in 66 (11%, 95% CI=±4.41) by fecal antigen ELISA in 600 fecal samples. Significant differences (P≤0.05) in prevalence were found between the three populations. Twenty (10.1%, 95% CI=±7.86) and 11 (5.6%, 95% CI=±7.70) of 197 fecal samples from household dogs without clinical signs were positive by microscopy and by antigen ELISA, respectively. Twenty-nine (23.8%, 95% CI=±6.58) and 23 (18.8%, 95% CI=±7.81) of 122 the fecal samples from household dogs with clinical signs were positive by microscopy and by antigen ELISA, respectively. Forty-five (16.01%, 95% CI=±5.62) and 32 (11.3%, 95% CI=±6.38) of 281 fecal samples from stray dogs were positive by microscopy and by fecal antigen ELISA, respectively. Dogs from the youngest age group (6 months to 1 year) were more likely to be E. histolytica antigen positive than were dogs from the other two older age groups, with a significant difference (P≤0.05) between all age groups. Statistically, no significant (P≥0.05) difference of prevalence was seen in male and female dogs. The local dogs had the highest prevalence rate of E. histolytica antigens (36 of 246, 14.2%, 95% CI=±6.32) followed by imported breeds (11 of 115, 9.5%, 95% CI=±10.4) and crossbred (19 of 239, 8.3%, 95% CI=±7.47), indicating a significant (P≤0.05) trend of positivity between various breeds of dogs. These findings suggest that dogs may play an important role in the epidemiology of this pathogen.

Control of Coccidiosis in Calves by Vaccination

The immunizing effect of inactivated sporulated oocyst and inactivated sonicated vaccines against bovine coccidiosis was observed in calves. Indirect haemagglutination (IHA) test was developed for detecting antibodies to coccidian. Serum antibody levels in calves were measured against soluble oocyst (sporulated) antigen. IHA antibody titer was significantly higher (P<0.05) in calves vaccinated with inactivated sonicated vaccines as compared to the calves vaccinated with inactivated sporulated vaccines. Results of the challenge experiments indicated that the inactivated sonicated vaccine gave protection to the challenge calves as immune calves contained high level of antibodies that resisted heavy dose of challenge. Disease was observed in control group (non-vaccinated) calves post challenge whereas vaccinated remained healthy. Then the oocyst count per gram of faeces was significantly higher (P<0.05) in control group (unvaccinated) as compared with the vaccinated groups.

Prevalence of Entamoeba histolytica-Like Cysts Compared to E. histolytica Antigens Detected by ELISA in the Stools of 600 Patients from Three Socioeconomic Communities in the Metropolitan City of Lahore, Pakistan

Abstract:  Amoebiasis, caused by Entamoeba histolytica, has a worldwide distribution and is of public health significance in many developing countries. It has a fecal–oral transmission cycle and is most prevalent in developing countries in regions where substandard sanitary conditions exist due to poverty. Little is known about the epidemiology of E. histolytica infection and its presence in different socioeconomic communities in developing countries. We undertook the present study in the city of Lahore, Pakistan, and our prediction was that the prevalence of E. histolytica-like cysts and E. histolytica stool antigen would be lower in patients from upper socioeconomic levels than in individuals from middle or lower socioeconomic levels. We investigated the prevalence of E. histolytica in humans from 3 socioeconomic communities in territories of Lahore, Pakistan. Six hundred fecal samples were collected and examined using both microscopy (triple fecal test) to detect cysts of E. histolytica-like amoeba and ELISA (stool antigen ELISA) to demonstrate diagnostic stool antigens of E. histolytica. Samples were from individuals living under conditions deemed to be upper socioeconomic class (n = 287), middle socioeconomic class (n = 172), and lower socioeconomic class (n = 141). The total prevalence of positive samples was 22.5% (135/600) by triple test and 16.8% (101/600) by stool antigen ELISA in the 600 fecal samples. Statistically, significant (P < 0.05) differences in prevalence were seen between the 3 socioeconomic class groups. Forty-four (15.3%) and 32 (11.1%) of 287 in the fecal samples from the upper socioeconomic class were positive by triple test and by antigen ELISA, respectively. Thirty-nine (22.6%) and 29 (16.8%) of 172 in the fecal samples from the middle socioeconomic class were positive by the triple test and by antigen ELISA, respectively. Fifty-two (36.8%) and 40 (28.3%) of 141 in the fecal samples from the lower socioeconomic class were positive by the triple test and by antigen ELISA, respectively. We accept our hypothesis based on these findings. We also demonstrated that fecal samples collected from the youngest age group (1 mo–5 yr) were more likely to be positive for E. histolytica antigens than were samples from the other 3 age groups, and that prevalence was significantly higher (P < 0.05) in the summer than in the other 3 seasons. These results highlight the importance of surveillance of this relatively ignored pathogen in this developing metropolitan city in Pakistan.

Treatment of dairy buffaloes naturally infected with sarcoptic mange

Therapeutic trials of sarcoptic mange in buffaloes were studied at local Livestock farms, Lahore (Pakistan). A total of 600 buffaloes were examined over 1 year period (August 2006 to July 2007) for prevalence study, while 60 buffaloes were selected for therapeutic trial. Sarcoptic mange was recorded in 66 (11%) animals. The highest monthly prevalence was reported during the months of January and February (18%) followed by December and March (16%) whereas lowest during the month of July (2%). Over all highest seasonally prevalence was recorded during winter (16.5%) and lowest during summer (5%). Moreover, highest infestation rate was recorded among young (<3 months) buffaloes than with age >3 months. Sex-wise prevalence indicated more prevalence in buffalo bulls (13.15%) than female buffaloes (9.28%). Therapeutic trials were carried out by using ivermectin, doramectin and trichlorphon as per manufacturer’s recommendations for a period of 10 days, while one group was kept as untreated control. Negative skin scraping, disappearance of gross lesions, stoppage of itching and regrowth of normal hair were taken as the criterion to assess the efficacy of these drugs.

Prevalence of Toxoplasma gondii, Neospora caninum, and Sarcocystis Species DNA in the Heart and Breast Muscles of Rock Pigeons (Columbia livia)

Little is known about the prevalence of protozoan parasites in the muscles of rock pigeons (Columbia livia). The muscles from 54 (heart from 45 and breast from 54) rock pigeons were examined for DNA of Toxoplasma gondii, Neospora caninum, and Sarcocystis species using PCR. Twenty-four were female and 30 were males. The birds were part of flocks of pigeons housed at the tombs of saints in Lahore, Pakistan. Birds that died or were euthanized due to poor health were submitted for necropsy at the Department of Parasitology, University of Veterinary and Animal Sciences, Lahore, Pakistan, where DNA isolations and PCR were conducted. Nineteen (35.1%) of the birds were positive for T. gondii DNA. Seven males and 12 females were positive. Breast tissue was always infected in T. gondii positive birds, while the heart was infected in 13 (28.8%) of breast positive birds. Five (9.2%) of the pigeons, 2 males and 3 females, were positive for N. caninum. The distribution of N. caninum DNA was more variable in the muscles of pigeons than T. gondii and was found only in the heart of 1 (female), heart and breast muscle of 2 (male), and only the breast muscle of 2 birds (female). One of the 54 rock pigeons (female) was positive for both T. gondii (heart and breast) and N. caninum (heart only). Two of the positive Neospora caninum amplicons were sequenced and had 97% nucleotide identity with N. caninum isolates. Sarcocystis DNA was not found in any bird. The prevalence of T. gondii in rock pigeons and their predation by cats suggest that they may play an unrecognized role in maintaining environmental contamination with T. gondii oocysts by cats. Our study indicates that rock pigeons are intermediate hosts of N. caninum and this information will aid in understanding the epidemiology of N. caninum.

Antibody Prevalence and Risk Factors for Toxoplasma gondii Infection in Women from Multan, Pakistan

Toxoplasma gondii infections are prevalent in humans and warm‐blooded animals. Maternal infections during pregnancy may have devastating consequences for transplacentally infected neonates. This study was conducted to examine the seroprevalence of antibodies to T. gondii in pregnant women of childbearing age and determine risk factors associated with pregnancy history, pet ownership, social and cultural factors at Nishtar Hospital, Multan. Samples were collected from 403 women and examined using a commercially available enzyme‐linked immunosorbent assay (ELISA). The overall prevalence of antibodies to T. gondii was 17.6% (71) in the 403 samples collected from women. Antibodies to T. gondii were present in 19.4% (45) of 232 pregnant women and 15.2% (26) of the samples from 171 non‐pregnant women. This study identified miscarriage history, pet ownership, type of residence, marital status, source of drinking water and eating habits as significant (P < 0.05) risk factors associated with the presence of antibodies to T. gondii infection. Seroprevalence was not significantly different (P > 0.05) in women from different ethnic groups based upon lifestyle and culture.