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Biomedical subjects

M Alvero

Publications and source records attributed to M Alvero.

5 recordsLinked to original sources

Field evaluation of environmental sanitation measures against cholera.

Data obtained in a controlled field study over 5 years in 4 communities showed that the provision of sanitary facilities for human waste disposal can reduce the incidence of cholera by as much as 68%, while the provision of a safe water supply can decrease it by 73%. Where both toilets and water supplies are provided, the incidence can be reduced by as much as 76%. There was evidence that cholera infection gaining access to communities with these facilities tends to spread less and produce fewer secondary cases than in a community where such facilities are not provided.

Adolescent↗

Cholera incidence in a population offered cholera vaccination: comparison of cooperative and uncooperative groups.

From May 1964 to December 1965, a controlled field trial of the effectiveness of cholera and cholera El Tor vaccines was conducted in Negros Occidental, Philippines. Some people did not volunteer for vaccination, and of those who did some received cholera vaccine and others a control (typhoid) vaccine. After analysing he incidence of cholera among these three groups it was found that the morbidity and mortality rates were significantly higher in the unvaccinated group than in either the control vaccine group or the cholera vaccine group. This would indicate that the unvaccinated group is basically different from the vaccinated control group. The clinical course of the disease was the same whether the patient had been vaccinated or not. The reasons for non-vaccination were investigated and should be taken into account by public health agencies when immunization programmes are being planned.

Adolescent↗

A controlled field trial of the effectiveness of cholera and cholera El Tor vaccines in the Philippines.

A controlled field trial on some 584 000 people in an endemic cholera El Tor area in the Philippines demonstrated that cholera vaccines gave moderate protection of short duration. Injection of a single dose of vaccine prepared from either Vibrio cholerae or El Tor vibrios gave over 50% protection for the first 2 months. The immunity conferred by the V. cholerae vaccine declined rapidly after 3 to 4 months. The effectiveness of the El Tor vaccine continued for 6 months. An oil-adjuvant vaccine prepared from V. cholerae conferred an equally high degree of protection for a longer period of time, but, owing to severe vaccination reactions, its use could not be recommended.

Adjuvants, Immunologic↗

Studies on cholera carriers.

Cholera carrier studies in the Philippines in 1964-66 showed a prevalence rate of 21.7% among household contacts of cholera patients, and 8.4% in occupants of houses next door to one where a cholera patient lived, as opposed to 0.34% in the general population. The duration of the carrier state among 19 household carriers isolated for examination varied from 5 to 19 days. The vibrio concentration in the stool of contact carriers was 10(2)-15(5) per gram, as compared with 10(6)-19(9) per ml of rice-water stool in cholera cases.The agglutinin titre increased with time for carriers, as it does for patients. It declined to a very low level 8-12 weeks after recovery, with the exception of one proved long-term carrier.The strains isolated from carriers were identical in all respects, including virulence in infant rabbits, with strains isolated from patients-except that 3 carrier strains were rough.

Adolescent↗

A long-term carrier of cholera: cholera Dolores.

The first known long-term carrier of cholera, found in the Philippines, is described. The carrier, Dolores M., who had suffered from El Tor cholera in August 1962, continued intermittently to excrete vibrios of the same characteristics as the original isolates until the date of reporting (1966). Duodenal intubation proved that the vibrios are lodged in her biliary tract. Her serum antibody titre continued to remain high in the absence of vaccination against cholera.

Biliary Tract↗