Isolation of HIV-1 from Filipino commercial sex workers (CSWs).

Peripheral blood mononuclear cells (PBMC) from 36 HIV-1 antibody positive Filipino female commercial sex workers (CSWs) were co-cultivated at a 1:1 ratio with phytohemagglutinin-P activated PBMC from healthy, HIV-1 antibody negative donors. After 3-18 (mean 7.2) days of incubation at 37 degrees C in 5% CO2, 29 cultures showed evidence of replication of HIV-1: increasing concentrations of p24 antigen in the growth medium and the appearance of multinucleated giant cells. Although the length of incubation required for the appearance of cytopathogenic effect for each particular isolate was essentially the same when either 6 microwell plates were seeded with 3.0 x 10(6) cells/well or 24 well plates were seeded with 1.5 x 10(6) cells/well, the 24 well format was more sensitive. The ability to isolate HIV-1 from PBMC did not appear to be associated with the progression of disease or the presence or absence of any specific clinical findings. However, if the PBMC were from individuals with a concomitant p24 antigenemia, the incubation time required for isolation was significantly shorter (mean 3.8 days). The absolute CD4+ lymphocyte count was also slightly reduced in the culture positive, p24 antigenemic patients (range 302-813 cells/mm3, mean 502 cells/mm3) compared to the culture positive, p24 serum negative cases (range 311-1,511 cells/mm3, mean 830 cells/mm3). The p24 serum negative cases with CD4+ counts of < 500 cells/mm3 had positive PBMC cultures by 6 days of incubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Ecology of mosquitos (Diptera: Culicidae) at a site endemic with Japanese encephalitis on Luzon, Republic of the Philippines.

A 2-year study of the ecology of mosquitos was conducted in a rice-growing area in the Philippines. Forty-four species in 8 genera were collected using 6 techniques, with Culex vishnui being most abundant. Of all the Anopheles collected, most species were exophagic, while most of the Culex species collected were endophagic. Anthropophilic or zoophilic feeding patterns were estimated using man-to-animal biting ratios. Peak periods of mosquito abundance occurred several months after the onset of both the rainy season and the rice irrigation period. Seasonal populations of the more abundant species revealed 3 distinct patterns: 1) populations are high during the rainy season and low during the irrigation period; 2) populations are equally strong during both periods; and 3) populations are highest during the irrigation period. Species' biting activity was grouped into 2 patterns: 1) those that feed primarily from 1800-0000; and 2) those that feed evenly throughout the night. Mosquito abundance and Japanese encephalitis virus activity were related to rainfall and rice-growing practices.

HIV-1 seropositive women in the Philippines: pregnancy outcome and perinatal transmission of HIV-1.

Annual surveillance studies were initiated in 1985 to determine the incidence and prevalence of HIV-1 infection in female prostitutes registered through the Social Hygiene Clinic System of the Philippine Department of Health. All of the confirmed HIV-1 seropositive women detected in the above surveys who could be contacted were followed up about every three months to monitor their clinical and immunological status. Since we regularly interviewed and examined these HIV-1 seropositive women, we were able to note the occurrence of pregnancies following HIV diagnosis. By September 1990, 54 HIV-1 seropositive women (aged 18-35) detected from the above surveys had been interviewed and examined. Twenty-six of these HIV-1 positive women had a total of 37 pregnancies. Eight were pregnant at the time of HIV diagnosis: three term deliveries, one premature delivery (PD) at eight months, three abortions, and one lost to follow-up while still pregnant. Five of these eight had repeat pregnancies: two term deliveries, two abortions, and one lost to follow-up while pregnant. Eighteen other women became pregnant one or more times after HIV diagnosis: seven term deliveries, 13 abortions, two PDs, one ectopic pregnancy terminated, one currently pregnant, and one lost to follow-up during pregnancy. There was no clear indication from clinical examinations and CD4+ cell counts that pregnancy exacerbated the course of HIV-1 related disease in these women. One of the 12 term infants has died and eight have developed non-specific findings that are suggestive but not diagnostic of HIV infection.2+ strongly seropositive by both ELISA and Western blot assay at 16 months.

Sexual behavior of Filipino female prostitutes after diagnosis of HIV infection.

A study of female prostitutes in Manila who tested positive for human immunodeficiency virus (HIV) antibody ascertained demographic and sexual behavior information following diagnosis. Counselling alone did not appear to have a major impact on the sexual behavior of the HIV positive women since most continued to work as prostitutes. Switching from high risk to low risk jobs in bars is not effective in preventing HIV positive women from engaging in prostitution. Revoking work permits is only effective if enforced with adequate follow up. Alternative job training programs may offer a viable approach.

The use of intravenous gammaglobulin in dengue fever, a case report.

We managed a serologically documented case of dengue fever with thrombocytopenia with IV IgG. Acute and convalescent ELISA and HI titers indicated an acute dengue infection with a secondary response that clinically, and by laboratory parameters dramatically improved after IV IgG administration. The use of IV IgG in cases of thrombocytopenia associated with dengue has both theoretical advantages and disadvantages. IV IgG may have a role in the management of DHF/DSS because of the significant morbidity and mortality associated with DHF/DSS. A prospective randomized study should be developed to determine if IV IgG does indeed effect the course of thrombocytopenia in dengue infections.

Isolation of dengue viruses from hospitalized patients in the Philippines, 1983-1986.

Between 1983-1986, 336 strains of dengue virus were isolated from 1,911 patients who had been hospitalized with clinically suspected DF/DHF in Manila and nearby areas. Multiple serotypes were present every year. Although DEN 3 was the most common serotype isolated (40%) over the entire study period, DEN 2 and DEN 1 were more frequently isolated in 1983 and 1984, respectively. DEN 4 was consistently the least common serotype recovered. During 1984, geographic differences in the pattern of serotypes isolated were found for two heavily populated areas located only 70 km apart. A higher proportion of DEN 2 isolates were recovered from patients with gastrointestinal bleeding compared to DEN 1 and DEN 3. A higher proportion of DEN 1 and DEN 3 isolates came from patients experiencing a 1 degree infection compared to DEN 2, and the mean homologous HI antibody titer of the sera that DEN 2 was isolated from was significantly higher than the homologous titers of sera from which DEN 1 and DEN 3 were isolated.

Central nervous system leptospirosis in the Philippines.

One hundred hospitalized patients in Manila, Philippines with aseptic meningoencephalitis were screened for leptospirosis. On the basis of a microscopic agglutination titer of 1:1,600 or greater, the diagnosis was made in five cases, yet in no instance had leptospirosis been included in the differential diagnosis on admission to the hospital. Four of the five patients first noted neurologic symptoms during the second week of illness; two patients presented with encephalitis, two with meningitis and the fifth with hemiparesis. No case was complicated by renal dysfunction or jaundice. By the time of discharge from the hospital, two patients had recovered completely and the other three had markedly improved. Our data show that leptospirosis is an important but overlooked cause of aseptic meningoencephalitis in the Philippines. This is probably also the case in other parts of the tropics where Leptospira interrogans infection remains a significant public health problem.

Dengue fever in American military personnel in the Philippines: clinical observations on hospitalized patients during a 1984 epidemic.

From June - August, 1984, 24 American military personnel were hospitalized with dengue (DEN) at Clark Air Base in the Philippines. Their infections were confirmed by serology using the hemagglutination-inhibition test and/or by virus isolation in Aedes pseudoscutellaris cell cultures. Most of the patients had a secondary type of antibody response probably reflecting prior vaccination against yellow fever. Three serotypes of DEN virus were isolated; 7 isolates of DEN 1, 4 isolates of DEN 3 and 3 isolates of DEN 2. All of the patients were Caucasian males between the ages of 20-43 years. All of the cases were clinically diagnosed as classical dengue fever. A platelet count of less than or equal to 100,000/microliters was a common finding (83.3%); however, hemoconcentration was not documented. Other major findings were the occurrence of mild hypotension (62.5%) and petechiae (37.5%). One patient presented with shock and upper gastrointestinal bleeding, but his diagnosis was complicated by a history of epigastric pain and use of aspirin. Although all of the patients fully recovered, the severity of illness was clearly documented by the average-length of hospitalization (5.9 days) and average time absent from work (8.7 days).

Dengue fever/dengue haemorrhagic fever in Filipino children: clinical experience during the 1983-1984 epidemic.

A total of 377 Filipino children out of a total of 5,427 admissions from October 31, 1983 to March 31, 1984 were found to have dengue fever/dengue haemorrhagic fever The present clinical presentation of these infections was basically similar to that in previous epidemics but hepatomegaly and pleural effusion were less frequent and cardiac involvement, more frequent. The discrepancies between the clinical syndromes and HI antibody responses were evident; thus, the values used for the interpretation of the antibody titers must be reassessed.

Comparison of vector competence for West Nile virus of colonized populations of Culex tritaeniorhynchus from southern Asia and the Far East.

Seven colonized stocks of Cx. tritaeniorhynchus from different geographic areas of Southern Asia and the Far East were assayed for susceptibility to WN virus infection by membrane feeding and by intrathoracic inoculation. Infected females also were tested for their ability to transmit virus to baby mice. No geographic pattern of differential susceptibility to WN virus infection was apparent from the experiments; however, the per os ID50 of one strain from Khulna, Bangladesh was over 10-fold greater than the ID50's of stocks from Karachi, Pakistan and Sendai, Japan. No difference in susceptibility was found by parenteral inoculation of virus. Likewise, greater than or equal to 90% of infected females from all the colonies were able to transmit virus.