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The author reflects on the results derived from the cross sectional survey and hepatitis C antibody (anti-HCV) testing conducted by Dr. Janjua and his colleagues in 2000 adults living in Pakistan. An overview of the results of the survey along with several risk factors that contributed for HCV infection including age, sex and lower family income is offered. He suggests that HCV could be on prevented by community education of the inhabitants and health care providers .

Introduction: In areas of low-to-moderate risk of malaria transmission, the World Health Organization recommends parasitic confirmation before treatment. Such areas have usually low budget for health care and malaria diagnosis is mostly based on clinical assumption. Algorithms have been developed to improve health care providers' identification of clinical malaria and could be used as screening to reduce the number of individuals requiring parasitic confirmation before treating., Methods: Prospective clinical and parasitological data were collected from inhabitants of four villages from March 1984 through March 1985. Symptoms and signs recorded by physicians were used in multivariate models to test the best predictors of malaria. Sensitivity and specificity were calculated for various cut-offs of scores and compared to clinical diagnosis., Results: A total of 8.941 individuals were evaluated during the 1-year period of data collection. The overall prevalence of malaria parasitemia was 19.7% (n=1762). Of the 4280 people evaluated during the high season period, 24% (n=1024) presented any parasitemia, 55.3% (566/1024) due to Plasmodium falciparum. The final clinical algorithm included history of fever, rigors, headache, absence of myalgia, backache or cough, nausea or vomiting, and splenomegaly on examination as predictable variables. At a cut-off score of 2.0, the sensitivity of the algorithm was higher for the entire sample (57% vs. 43%), for high season period (70% vs. 53%), for children less than 6 years of age (59% vs. 40%), for individuals with parasitemia due to P. falciparum (65% vs. 48%), and for high P. falciparum parasitemic individuals at high season (84% vs. 68%). However, specificity was usually lower unless a higher cut off was used, in which case the gain in sensitivity by using the algorithm was reduced., Conclusion: In low-to-moderate transmission areas in which health related resources are scarce, a clinical algorithm increases the identification of real cases of malaria and could be used as screening for further parasitic identification.

The relationship between quantitative Plasmodiumfalciparum or P. vivax parasitemia and clinical illness has not been defined in Pakistan or in other areas where malaria transmission is not highly endemic. Standardized questionnaires were given to and physical examinations and parasitologic tests were performed in 8,941 subjects seen in outpatient clinics in 4 villages for 13 consecutive months in the Punjab region of Pakistan. The results, based on multivariable analysis, showed that a clinical diagnosis of malaria, a history of fever, rigors, headache, myalgia, elevated temperature, and a palpable spleen among children were all strongly associated with the presence and density of P. falciparum or P. vivax malaria in a monotonic dose-response fashion. The malaria attributable fraction of a clinical diagnosis of malaria, and the same symptoms and signs also increased with increasing P. falciparum and, to a lesser extent, P. vivax, parasitemia. Unlike in sub-Saharan Africa, clinical illness due to malaria often occurs in the Punjab among adolescents and adults and in patients with parasite densities less than 1,000/microl. Clinical guidelines based upon parasitemia and symptomatology must be adjusted according to the intensity of transmission and be specific for each geographic area.

Splenomegaly and parasitaemia were correlated in 2891 children examined in outpatient clinics during 13 consecutive months in 4 Punjabi villages. The average monthly splenomegaly rate varied from 0.05-0.13 before the monsoon malaria transmission season to 0.18-0.27 during and after this season. Moderate splenic enlargement reached a peak during the malaria transmission season, while the highest proportion of very enlarged spleens occurred towards the end of, and after, the transmission season. Children with splenomegaly were 3 times more likely to have Plasmodium falciparum and 1.5 times more likely to have P. vivax parasitaemias than were children without palpable spleens. The larger the spleen the more likely a P. falciparum infection, whereas P. vivax was more commonly associated with minimal spleen enlargement. Although the probability of a child with splenomegaly having a malaria parasitaemia was highest (0.58-0.72) during and immediately following periods of malaria transmission, the odds ratio of malaria infections among those with splenomegaly to those without was at its lowest (1.41-2.11) during those months. Mean P. falciparum parasitaemias were significantly higher in infected children with moderately enlarged spleens than in infected children with nonpalpable spleens or in those with minimal or extensive splenomegaly. These results are compatible with splenomegaly being a result of both the malaria infection and the immune response. Early in infection many children had parasitaemia without splenomegaly; after the parasitaemia had cleared splenomegaly often persisted.

We evaluated amodiaquine as a replacement drug for treating falciparum malaria in an area of Pakistani Punjab where chloroquine-resistant Plasmodium falciparum has recently emerged. Amodiaquine appeared to be 4 to 8 times more effective than chloroquine when P. falciparum isolates were tested in vitro. However, the recrudescence rate was greater than 50% after oral treatment with 20 mg/kg amodiaquine given over two successive days. This lack of therapeutic response from amodiaquine may have been due to selection of resistant parasites in the villages where the study was performed through extensive use of chloroquine for presumptive malaria treatment during the preceding 18 months. We conclude that amodiaquine is not a suitable replacement for chloroquine for treating falciparum malaria in our study area despite in vitro sensitivity data suggesting that it would be efficacious. Baseline in vitro sensitivity to mefloquine is also reported.

To investigate the susceptibility of Plasmodium falciparum to chloroquine in Pakistani Punjab, in-vivo and in-vitro drug susceptibility was tested in 3 villages. Of 66 patients followed for up to 14 days after chloroquine treatment, 53 (80%) had parasites sensitive to chloroquine, 10 (15%) had parasites with early RI resistance, and 3 (5%) had parasites with RII resistance. Of 42 falciparum isolates investigated in vitro, 12 were sensitive, 8 intermediate, and 22 resistant to chloroquine. The degree of in-vivo resistance correlated with the degree of in-vitro resistance. It is concluded that chloroquine resistance is common among falciparum parasites in Pakistan and that this chloroquine resistance could explain the recent increase in the prevalence of falciparum malaria in the Punjab. Alternative antimalarials should therefore be investigated for both treatment and chemoprophylaxis against falciparum parasites in Pakistan.

In 4 villages in the Pakistani Punjab, clinic surveys (CS) provided similar results on total malaria and malaria species prevalence as those from mass surveys (MS)--and at a fraction of the effort. This was true at 3 different levels of malaria transmission. Both methods requiring blood films from all interviewed subjects are believed to be superior to the classical active (ACD) and passive (PCD) case detection methods which sample only patients with a history of recent fever. These latter methods would not detect the large population of oligo- and asymptomatic parasitaemic subjects in the semi-immune population of malaria endemic areas.

Analysis of data obtained from Giemsa-stained blood films from patients with mixed Plasmodium vivax and P. falciparum parasitaemias seen in outpatient clinics held over 20 consecutive months in 4 villages in the Pakistani Punjab suggest that infections with P. falciparum and P. vivax were independent of each other. There was no evidence to support the hypothesis that P. falciparum suppressed P. vivax. A likely explanation for the seasonal variation in species parasitaemia rates in the Punjab is that P. vivax was predominant early in the transmission season due to late relapses, while P. falciparum was predominant later in the transmission season because of community-wide development of immunity to P. vivax.

Fansidar (SP), a combination of sulfadoxine and pyrimethamine, was evaluated for its usefulness as a curative agent for treating individual malaria patients and for reducing the community reservoir of Plasmodium falciparum in 4 villages near Lahore, Pakistan, where resistance of 4-aminoquinolines has recently been reported. Following the end of the major malaria transmission season, we carried out a month-long mass treatment campaign during which SP was given to all available villagers who had parasitemias detected during a concurrent house-to-house malaria blood film survey. Of the 82 falciparum patients followed for 14 days after SP treatment, 80 (97.5%) had parasites sensitive to the investigated drug. Parasitemia clearance time after SP was remarkedly short (1.25 +/- 0.53 days; mean +/- SD). However, we were unable to reduce the parasite reservoir of P. falciparum and P. vivax in these villages, probably because we treated only 337, about one-third, of the parasitemic patients. We conclude that SP is an effective drug for treating individual malaria patients from areas in Pakistan where 4-aminoquinoline-resistant parasites are present, but that more research is needed for assessing its usefulness in reducing community reservoirs of malaria.

The prevalence of malaria in 4 villages 60 km south of Lahore, Punjab, where Anopheles culicifacies is the vector was estimated from blood films made during three mass malaria surveys (MS) and at 204 clinics (CS) held over 18 consecutive months. The highest parasite rate occurred during October 1984 when 43% of the CS population had parasitaemias. Plasmodium vivax predominated early in the major transmission season (23% and 15% vivax parasitaemias in August 1983 and 1984 respectively) whereas P. falciparum was the most common species later in the transmission season (an average falciparum prevalence of 37% in October and November 1984) and following the transmission season through March. Despite the proximity and habitat similarity of the 4 villages, both total and species malaria prevalence rates showed inter-village differences. Asexual stage and gametocyte parasite rates in children were 2 to 5 times higher than in adults. No increased mortality due to malaria was detected among the 4000 study population. Malaria was stable and endemic, albeit seasonally transmitted, in these 4 villages during 1983 and 1984.