Mary Ann Lansang

Local knowledge and treatment of malaria in Agusan del Sur, The Philippines

Information about local knowledge of malaria, its transmission, treatment and prevention were gathered at the outset of a Malaria Control Program in order to incorporate this information into community interventions. Data were collected using focus groups and indepth interviews with caretakers of children who had had a recent episode of malaria. These were supplemented as baseline data through a survey and the ongoing participation of researchers in the intervention. Local knowledge of malaria was influenced by clinical diagnosis and was based on the coexistence of signs of illness. People conventionally self-medicated or used herbs for symptomatic relief prior to seeking clinical diagnosis and treatment, with treatment delay influenced by the logistic difficulties within the region, direct and indirect costs associated with treatment seeking, and delays in the return of results once a blood film for diagnosis was made. People were familiar with mosquito control activities conducted by the Malaria Control Service and, as a result, most respondents associated malaria with mosquitos. However, the role of the mosquito as the sole vector, and the means by which malaria was transmitted, were not well appreciated.

Patterns of treatment for malaria in Tayabas the Philippines: implications for control.

This paper describes local understandings of illness and documents treatment‐seeking behaviour in Tayabas, Quezon, The Philippines. Data were collected using focus group discussions and narrative interviews with adults, and with mothers of children, who had had confirmed malaria during a two‐month surveillance period. Signs and symptoms of malaria are important in directing individual diagnosis, treatment‐seeking and therapy. Household therapy with antimalarials, and more commonly antipyretics and herbs, as used before seeking care from either the formal or informal sector. Care outside the home was sought where symptoms continued and/or worsened, with an average period of time from onset of symptoms to presentation to a clinic of six days. Accessibility to clinics is not a problem in the study area and hence the primary reason for delay was propensity to self‐treat first and to discontinue medication when feeling better. These factors affect the control of malaria and the potential to reduce transmission. Better advice to the community regarding the importance of diagnosis and compliance with antimalarial therapy is indicated.

Mother to child transmission of hepatitis B virus in the Philippines

SummaryA follow-up study of mother to infant transmission of hepatitis B virus was conducted in the Philippines between 1981 and 1983. The prevalence of HBsAg among 527 mothers was 8.5%. Overall, seven out of 17 (41.2%) infants born to HBsAg carrier mothers became HBsAg positive within the first 12 months of life. The risk of becoming HBsAg positive was about 20 times higher for infants born to HBsAg positive mothers than for infants born to HBsAg negative mothers (OR=18.9, 95% Ci=2.0−86.6). The risk was even higher if the mother was a carrier of both HBsAg und HBeAg (OR=91.0, 95% Ci=49.2−164.8). However, the risk of transmission was very low if the mother was an HBsAg carrier and anti-HBe positive. It was estimated that mother to infant transmission accounts for about one third of HBsAg positivity at one year of age. The implications of these findings in the planning of vaccination campaigns to prevent HBV infections are discussed.ZusammenfassungIn den Philippinen wurde zwischen 1981 und 1983 eine Verlaufsstudie zur Mutter-Kind-Übertragung des Hepatitis-B-Virus durchgeführt. Bei 527 Müttern fand sich eine HBsAg-Prävalenz von 8,5%. Sieben von 17 Neugeborenen (41,2%) der HBsAg-Carrier-Mütter wurden im Ablauf der ersten 12 Lebensmonate HBsAg-positiv. Bei Kindern HBsAg-positiver Mütter war das Risiko einer HBsAg-Serokonversion 20mal höher als bei Kindern HBsAg-negativer Mütter (OR=18,9; 95%; Ci=2,0−86,6). Bei Müttern, die nicht nur HBsAg, sondern auch HBeAg-Carrier waren, bestand ein noch größeres Risiko für das Kind, HBsAg-positiv zu werden (OR=91,0; 95%; Ci=49,2−164,8). Bei Müttern, die HBsAg-Carrier, aber anti-HBe-positiv waren, bestand nur ein sehr geringes Übertragungsrisiko. Schätzungsweise sind ein Drittel der Fälle von HBsAg-Positivität bei einjährigen Kindern auf Mutter-Kind-Übertragung zurückzuführen. Die Bedeutung dieser Daten für die Planung von Impfaktionen zur Prävention von HBV-Infektionen wird diskutiert.

Sensitivity and specificity of capillary blood HBsAg as a surrogate marker for HBeAg in pregnant women

Infants at high risk of acquiring hepatitis B virus (HBV) infection from their hepatitis B e antigen (HBeAg)‐positive mothers are prime targets for early HBV immunization. The usefulness of fingerprick blood of pregnant women as a surrogate marker to identify infants who would need immunization soon after birth was evaluated. Using HBeAg from venous blood as the standard, the detection of hepatitis B surface antigen (HBsAg) by reverse passive haemagglutination in capillary blood yielded an overall sensitivity of 97% and a specificity of 96% for detecting HBeAg at a cutoff titre of 22.5. Pregnant women with a capillary HBsAg titre of 22.5 or greater are 24 times more likely to infect their babies, while the chances of transmitting HBV infection with a titre lower than the cutoff point are almost nil. When the cost of HBV vaccine eventually comes down to levels suitable for public health use, a cutoff titre of 22.5 is suggested in order to identify infants who should be vaccinated soon after birth.