Survey of Rhipicephalus microplus resistance to ivermectin at cattle farms with history of macrocyclic lactones use in Yucatan, Mexico.

Engorged females of Rhipicephalus microplus were collected from 30 cattle farms in Yucatan, Mexico to evaluate ivermectin resistance. The larval progeny of each tick sample were produced in laboratory and evaluated using the larval immersion test to obtain the larval mortality. Concentration-mortality data were subjected to probit analysis to generate lethal concentrations (LC). Resistance ratio (RR) of each tick sample was calculated by dividing its LC with that of an ivermectin-susceptible strain (Deutch). Field populations of R. microplus demonstrated various levels of resistance to ivermectin. The top three resistant populations were CHPAT (RR(50)=10.23, RR(99)=179.6), SDGO (RR(50)=7.37, RR(99)=115.3) and FND (RR(50)=7.09, RR(99)=50.22). The level of ivermectin resistance in most tick samples from cattle farms in Yucatan, Mexico were relatively low. However, the intensive use of macrocyclic lactones to control both endo- and ectoparasites in the region will likely lead to a more serious resistance problem that may cause control failure in the future.

First report of the cattle tick Rhipicephalus microplus resistant to ivermectin in Mexico.

Three cattle farms with ticks, Rhipicephalus microplus, thought to be resistant to ivermectin in Yucatan, Mexico were studied (SFDO, SPN, LUADY). Each field-population was collected and tested twice several months apart. The larval immersion test was used on the progeny of collected adult females to test the susceptibility to ivermectin. Dose-mortality regressions, lethal concentrations (LC), their confidence intervals and slope were estimated by probit analysis. Resistance ratios (RR) were determined in the three investigated populations at the LC(50) and LC(99) estimates. The LUADY (RR(50): 2.04 and 2.29, RR(99): 2.67 and 3.55), SPN (RR(50): 3.55 and 3.68, RR(99): 8.19-11.06) and SFDO (RR(50): 6.84 and 8.59, RR(99): 54.17 and 87.86) ticks had significantly higher LC(50)/LC(99) than the reference susceptible Deutch strain, demonstrating resistance in the field-collected populations. Furthermore, there was significant difference between LC(50)/LC(99) of the SFDO, SPN and LUADY tick populations, which indicates not only the presence of resistant populations, but also different levels of resistance to ivermectin in the field populations studied. There was no difference observed at the LC(50) nor LC(99) estimates at two different times of collection from any of the three populations studied. In conclusion, we report for the first time field populations of R. microplus resistant to ivermectin in Mexico.

A serological survey for avian infectious bronchitis virus and Newcastle disease virus antibodies in backyard (free-range) village chickens in Mexico.

The commercial flocks in Yucatan, Mexico are free of Newcastle disease virus (NDV) in its velogenic viscerotropic form, but little is known about the disease status of backyard poultry. A seroprevalence survey in 30 villages using haemagglutination inhibition (HI) tests for infectious bronchitis virus (IBV) and NDV antibodies was carried out from December 1997 to June 1998. The seroprevalences were 56.5% (95% CI 50-63%) for IBV and 2.2% (95% CI 0.5-3.8%) for NDV. All the villages had chickens that were positive for antibodies to IBV and nine of the villages had chickens that were positive for antibodies to NDV. This suggests that IBV may be responsible for a large proportion of the respiratory disease observed in backyard chickens in Yucatan. The implications of these findings are discussed, including the highly susceptible status of the backyard chickens in Yucatan to NDV and the possibility of this virus being one cause of the syndrome known as mortandad by the local people.

Patterns in living arrangements and familial support for the elderly in the Philippines.

PIP: This study examined living arrangements of the elderly in the Philippines. Data were obtained from the 1996 Survey on the Near Elderly and Elderly, among a nationally representative sample of 2285 persons aged over 50 years, and 1131 aged over 60 years. Findings indicate that 5.5% of the elderly lived alone, 7.9% lived with a spouse only, and 9.8% lived with persons other than a spouse or children. 28.4% lived with single children, and 28.5% of elderly persons and couples lived with 1 or more ever-married children. 13.4% of persons and couples lived with never- and ever-married children. There were more rural people who lived alone. Among those living alone, a high proportion were separated or divorced women. About 1 in 4 elderly believed that the widowed should live alone. About 1 in 3 believed that a widow should live with a child. About 40% of married persons believed that the best arrangement was living by themselves, even though few did so. The elderly living with a child tended to own the house. 69.2% coresided with a child, and 76.8% coresided or lived next door to a child. Coresidence with a child was unaffected by the number of living children. Coresidence increased with age and was more common among males, married, and urban residents. 28.6% lived with a single son and 21.7% lived with a single daughter. More parents received money from a non-coresident child. The proportion of parents who gave money to children was lower than the proportion who received money from children. 92.5% of the elderly cared for a grandchild. A large proportion of elderly both accepted the concept of homes for the aged and would live in an institutional setting.^ieng

FP client-worker interaction as an ingredient of quality of care.

PIP: In order to contribute to the improvement of the clinic-level management of the family planning (FP) programs of the Philippine FP Program, an assessment was made of client-staff interactions. Data were collected during May-June 1990 from 107 FP personnel and 1440 clients using a purposive sampling procedure which identified project sites on the basis of their FP performance; evenly divided the sample between government-sponsored programs and nongovernmental organizations; and randomly drew a sample of clients which included past users, never users, and current users. Data were gathered from a survey and from observations of at least 27 client-staff interactions in each of the four project sites. The observations were followed by in-depth interviews. While the interactions were positively viewed by the clients, some of the service providers (perhaps coping with an overly large case load) tended to shorten the duration of the interaction. The recommendations which arose from this study include: 1) FP personnel in this study, who indicated a preference for recruiting new acceptors rather than motivating past users, should be given a travel allowance and time to use the effective technique of home visits to try to reduce the number of drop-outs; 2) specific topics and counseling techniques should be included in the training courses for FP personnel; 3) the clinic setting must be improved to conform to quality standards and provide privacy for clients; and 4) clinic visits should be personally satisfying for the client as well as efficient.^ieng