High altitude epidemic malaria in Bamian province, central Afghanistan.

We report an epidemic of Plasmodium falciparum malaria in the remote valley of Bamian (altitude 2250 m-2400 m) in the central highlands of Afghanistan. A team of malaria experts from the World Health Organization and HealthNet International carried out the investigation. A total of 215 peripheral blood smears were obtained and 63 cases of malaria (90.5% P. falciparum, the remainder P. vivax) were confirmed. The study revealed that areas vulnerable to malaria in Afghanistan are more widespread than previously recognized. The area had been malaria-free until recently, when the disease appears to have been introduced as a consequence of protracted conflict and resultant population movement, and transmitted locally during the short summer months. The outbreak led to severe morbidity and high mortality in a province having only a few poorly-provisioned health care facilities.

High altitude epidemic malaria in Bamian province, central Afghanistan

We report an epidemic of Plasmodium falciparum malaria in the remote valley of Bamian [altitude 2250 m-2400 m] in the central highl and s of Afghanistan. A team of malaria experts from the World Health Organization and HealthNet International carried out the investigation. A total of 215 peripheral blood smears were obtained and 63 cases of malaria [90.5% P. falciparum, the remainder P. vivax] were confirmed. The study revealed that areas vulnerable to malaria in Afghanistan are more widespread than previously recognized. The area had been malaria-free until recently, when the disease appears to have been introduced as a consequence of protracted conflict and resultant population movement, and transmitted locally during the short summer months. The outbreak led to severe morbidity and high mortality in a province having only a few poorly-provisioned health care facilities

Control of malaria in Pakistan by applying deltamethrin insecticide to cattle: a community-randomised trial.

BACKGROUND: The standard method of malaria control in south Asia, indoor spraying of houses with residual insecticide, is becoming prohibitively expensive to implement and new approaches are needed. Since the region's vector mosquitoes feed predominantly on domestic animals and only secondarily on human beings, to apply insecticide to surfaces of cattle instead might be more costeffective. We aimed to investigate whether domestic livestock treated with deltamethrin (applied by a sponging method) would prove toxic to mosquitoes and therefore aid in malaria control. METHODS: Six Afghan refugee settlements in Pakistan were randomly assigned to one of two groups. In one group livestock were treated with deltamethrin during the malaria transmission seasons of 1995 and 1997, whereas in the other group livestock were treated during the 1996 season. Malaria was monitored by passive case detection at village clinics and by cross-sectional surveillance. Mosquitoes were also monitored. FINDINGS: According to clinic records the incidence of malaria caused by Plasmodium falciparum decreased by 56% (95% CI 14-78%) and P vivax by 31% (5-50%) in livestock-treated villages. Cross-sectional surveys showed comparable decreases in parasite prevalence. The density and life expectancy of Anopheles stephensi and A culicifacies populations were reduced in treated villages. The efficacy of livestock treatment was similar to that of indoor spraying but campaign costs were 80% less. When applied in a highly endemic settlement, the incidence of falciparum malaria decreased from 280 episodes per 1000 person-years to nine episodes per 1000 person-years. INTERPRETATIONS: Insecticide treatment of livestock is a cost-effective and promising alternative for south Asia and other regions where primary vectors are zoophilic.

Resistance of Plasmodium falciparum malaria to chloroquine is widespread in eastern Afghanistan.

After two decades of war and conflict in Afghanistan, the public-health system is in disarray and malaria has re-emerged as a major disease, with Plasmodium falciparum malaria becoming increasingly common. The limited healthcare services that are available are mainly delivered by non-governmental organizations in collaboration with the Ministry of Health. Although chloroquine (CQ) remains the official first-line treatment against P. falciparum malaria, there is little information on the severity or distribution of resistance to this drug in Afghanistan. In-vivo surveys, co-ordinated by the Malaria Reference Centre in Jalalabad, were therefore performed to determine the frequency and grades of CQ resistance in the three eastern provinces of Kunar, Nangarhar and Laghman. Of the 142 cases enrolled in the study, only 47 (33%) were sensitive. Most of the cases (55%) showed RI resistance but RII/RIII resistance was not uncommon (11%). The prevalence of resistance appeared similar in children and adults, in males and females, and in each of the three provinces investigated. Gametocyte carriage post-treatment was elevated in the resistant cases. As in neighbouring Pakistan, the resurgence of P. falciparum in Afghanistan is probably associated with the transmission and spread of chloroquine-resistant strains. The first-line therapy used against P. falciparum malaria must be changed in order to reverse this trend.

An outbreak of cutaneous leishmaniasis in an Afghan refugee settlement in north-west Pakistan.

Cutaneous leishmaniasis (CL) due to Leishmania tropica appears to be an emerging disease in parts of north-east Afghanistan and north-west Pakistan. Timargara, an Afghan refugee camp of 17 years' standing, in the district of Dir, North West Frontier Province of Pakistan, experienced a major outbreak of CL in 1997 for the first time. As part of the investigation, each section of the camp was surveyed for CL. Around 38% of the 9200 inhabitants bore active lesions and a further 13% had scars from earlier attacks. According to interview statements, 99% of earlier infections had healed within the previous 2 years. To confirm the diagnosis, a sample of current CL lesions was examined parasitologically. Amastigotes were detectable by microscopy in only 36% of lesions. However, 48% of slide-negative cases produced positive cultures and some cases negative to both microscopy and culture were positive by PCR. Overall detection rate was about 80%. The sandfly Phlebotomus sergenti, a known vector of L. tropica, was captured within the camp, indicating local transmission. CL has not been reported from this area of Pakistan before. Although the majority of refugees left Afghanistan 2 decades ago, cross-border movement of men is common. The Afghanistan capital, Kabul, is currently experiencing a major epidemic of CL; infected migrant carriers from Kabul are probably the source of the outbreak in Timargara.

Randomized controlled trials of 5- and 14-days primaquine therapy against relapses of vivax malaria in an Afghan refugee settlement in Pakistan.

Primaquine is the only drug available that can eliminate hypnozoites from the liver and prevent relapses of vivax malaria. The World Health Organization recommends a course of 14-21 days depending on region and strain. The National Malaria Control and Eradication Programmes of Pakistan and India have adhered to a 5-day course as their standard as it is deemed more practical to implement and because facility for detecting glucose 6-phosphate dehydrogenase (G6PD) deficiency is seldom available at the periphery. Evidence for the efficacy of the 5-day regimen is controversial or lacking. Two, year-long, randomized controlled trials were undertaken in an Afghan refugee camp in north-western Pakistan using a process of passive case detection and treatment at the camp's clinic: the first trial compared treatment with chloroquine alone versus chloroquine plus 5-days primaquine, the second trial compared chloroquine alone versus chloroquine plus 14-days primaquine. Chloroquine is not hypnozoitocidal and was administered to eliminate the erythrocytic stages and to alleviate clinical symptoms. The daily primaquine dose was 0.25 mg/kg bodyweight and the total chloroquine dose was 25 mg/kg over 3 days. During the first trial 52% (129/250) of the non-primaquine group recorded a 2nd clinical-parasitaemic episode and 23% recorded a 3rd, whereas 51% (128/250) of the 5-days primaquine group reported a 2nd episode and 21% recorded a 3rd. During the second trial 49% (49/100) of the non-primaquine group recorded a 2nd episode and 25% recorded a 3rd, whereas only 32% (32/100) of the 14-days primaquine group recorded a 2nd and only 2% recorded a 3rd. The 5-days primaquine regimen has no value as an anti-relapse therapy and should be abandoned. In extended tests in vivo in which vivax cases (n = 31) were treated with chloroquine 25 mg/kg and 14-days primaquine, there was no parasite recrudescence within 28 days and hence no evidence of resistance to chloroquine.

Permethrin-treated chaddars and top-sheets: appropriate technology for protection against malaria in Afghanistan and other complex emergencies.

Insecticide-treated mosquito nets (ITN) provide excellent protection against malaria; however, they have a number of shortcomings that are particularly evident in politically unstable countries or countries at war: not everyone at risk can necessarily afford a net, nets may be difficult to obtain or import, nets may not be suitable for migrants or refugees sleeping under tents or plastic shelter. There is a need to develop cheaper, locally appropriate alternatives for the most impoverished and for victims of complex emergencies. Afghan women, in common with many Muslim peoples of Asia, wear a veil or wrap known as a chaddar to cover the head and upper body. This cloth doubles as a sheet at night, when they are used by both sexes. A randomized controlled trial was undertaken in which 10% of the families of an Afghan refugee camp (population 3950) in north-western Pakistan had their chaddars and top-sheets treated with permethrin insecticide at a dosage of 1 g/m2 while a further 10% had their chaddars treated with placebo formulation. Malaria episodes were recorded by passive case detection at the camp's health centre. From August to November the odds of having a falciparum or vivax malaria episode were reduced by 64% in children aged 0-10 years and by 38% in refugees aged < 20 years in the group using permethrin-treated chaddars and top-sheets. Incidence in refugees over 20 years of age was not significantly reduced. The cost of the permethrin treatment per person protected (US$0.17) was similar to that for treating bednets (and cost only 10-20% of the price of a new bednet). An entomological study simulating real-life conditions indicated that host-seeking mosquitoes were up to 70% less successful at feeding on men sleeping under treated chaddars and some were killed by the insecticide. Permethrin-treated top-sheets and blankets should provide appropriate and effective protection from malaria in complex emergencies. In Islamic and non-Islamic countries in Asia, treated chaddars and top-sheets should offer a satisfactory solution for the most vulnerable who cannot afford treated nets.

Resistance of falciparum malaria to chloroquine and sulfadoxine-pyrimethamine in Afghan refugee settlements in western Pakistan: surveys by the general health services using a simplified in vivo test.

Surveys of drug resistant falciparum malaria were conducted in several Afghan refugee settlements, distributed over a 700 km range in western Pakistan, during the transmission seasons of 1994 and 1995. Symptomatic malaria patients were recruited by a process of passive case detection at the refugees' basic health units. To facilitate follow-up by local health workers, a modified version of the WHO extended in vivo test was adopted in which blood smears were taken from each subject, and clinical symptoms recorded, at weekly intervals. Resistance to chloroquine and sulfadoxine-pyrimethamine was identified in every settlement. The frequency of chloroquine resistance ranged from 18% to 62%. Resistance occurred mostly as RI, with RII resistance never exceeding 11%. Resistance to sulfadoxine-pyrimethamine occurred at much lower frequencies, ranging from 4% to 25%. There was a resumption of clinical symptoms at the onset of parasite recrudescence in over 90% of cases. The policy of using chloroquine as first-line treatment might be changed in favour of sulfadoxine-pyrimethamine in most camps and areas of western Pakistan. The modified in vivo test was almost as accurate as the normal WHO in vivo test in identifying the grade of resistance, and should prove a useful tool for the monitoring of resistance to common antimalarials by district health services.

Transmission and control of vivax malaria in Afghan refugee settlements in Pakistan.

Regular biting collections were conducted in 1993-1994 to investigate seasonal fluctuations in the abundance of anophelines in Afghan refugee villages in north-western Pakistan. Enzyme-linked immunosorbent assay were used to test heads-plus-thoraces for the presence of malaria sporozoites. Anophelines giving positive results for Plasmodium vivax were captured in every month except January. Nine species were positive. Biting rates showed a marked increase in May, after the spring rains, and thus spring transmission of vivax malaria seems certain. However, transmission of vivax malaria reached its peak only after the monsoon in July. To determine the optimal time to control vivax malaria by indoor spraying with residual insecticide, spray campaigns were conducted in either spring or summer in 14 refugee villages. Villages sprayed in July 1994 showed a mean reduction in annual incidence of 62% (95% confidence interval [CI] +/-6%) relative to the previous year, whereas villages sprayed in April 1994 showed only a 15% reduction (95% CI +/- 32%). Parasite prevalence surveys conducted in April and October 1994 confirmed the greater efficacy of spray campaigns waged in July. The insecticide malathion proved as effective as the pyrethroid lambdacyhalothrin, even though several species of anopheline were resistant to malathion.

Sustainability of pyrethroid-impregnated bednets for malaria control in Afghan communities.

Between 1992 and 1995 a series of studies was undertaken to assess the long-term suitability of pyrethroid-impregnated bednets (PIBs) for malaria control in Afghan refugee communities in two villages in North-West Frontier Province, Pakistan. During 1992, 86% of bednet owners volunteered to have their bednets re-impregnated, and a further 15% of families purchased nets at two-thirds of cost price. From 1992 onwards, 27% of the villagers returned to Afghanistan, and annual house spraying campaigns were introduced to protect those still resident but sleeping without bednets. Within 3 years, these campaigns, together with PIBs, reduced the annual incidence of malaria by 87%, from 597 to 78 cases per 1000 population. Nevertheless, 65% of resident families continued to re-impregnate their nets annually with permethrin. To assess whether PIBs were still being used and were still protective, in view of these reduced transmission rates, we carried out a case--control study in 1994 on febrile or otherwise symptomatic patients presenting at village health centres. Comparison of the slide-positivity rates of PIB users and those without bednets showed that regular usage reduced the odds of contracting falciparum and vivax malaria to 0.22 (95% confidence interval (CI): 0.09-0.55) and 0.31 (95% CI: 0.19-0.51), respectively. There was no evidence of a sex- or age-bias in bednet use or in protective effect. The results indicate that a community-based PIB programme is an appropriate malaria control measure in areas where management or security problems make traditional house-spraying campaigns impossible. A relevant finding for those involved in the monitoring of bednet distribution projects is that the local coverage of bednets and the local impact on malaria, even when introduced to remote areas, can be estimated very cheaply by health centre microscopists who simply catalogue blood film diagnoses according to patients' bednet use practices.

PIP: A series of studies was conducted between 1992 and 1995 to assess the long-term suitability of pyrethroid-impregnated bednets (PIBs) in controlling malaria in Afghan refugee communities in two villages in North-West Frontier Province, Pakistan. During 1992, 86% of bednet owners volunteered to have their bednets re-impregnated, and an additional 15% of families bought bednets at two-thirds of cost. From 1992 onwards, 27% of the villagers returned to Afghanistan where annual house spraying campaigns were introduced to protect those still resident but sleeping without bednets. Within 3 years, those campaigns, together with PIBs, reduced the annual incidence of malaria by 87%, from 597 to 78 cases per 1000 population. 65% of resident families continued to reimpregnate their nets annually with permethrin. A case-control study conducted in 1994 on febrile or otherwise symptomatic patients presenting at village health centers found that the regular use of bednets reduced the odds of contracting falciparum and vivax malaria to 0.22 and 0.31, respectively. No evidence was found of sex or age bias in bednet use or in protective effect.

Chloroquine resistance in Pakistan and the upsurge of falciparum malaria in Pakistani and Afghan refugee populations.

Surveys conducted in Pakistan during the last decade show that falciparum malaria has become resistant to chloroquine in Pakistani and Afghan refugee populations throughout the country. Although RI resistance is common everywhere (with a frequency of 30%-84%), RII is rarer (2%-36%), and RIII resistance has yet to be detected. The national policy is to prescribe chloroquine as first-line treatment of malaria. A repeated in-vivo survey in a sentinel village indicated that prescription of chloroquine can lead to a 15% increase in the frequency of resistance in a single year, and similar trends were observed in other districts. Coinciding with the spread of resistance is a 6-fold increase in the number of falciparum cases recorded nationally between 1982 and 1992 and a parallel, 5-fold increase in the number of cases recorded in the Afghan refugee population. Resistance contributes to this trend in various ways. Firstly, patients with resistant malaria make repeated visits to health centres. In the sentinel village, for example, where resistance was measured at 71%, recrudescent infections inflated by 66% the genuine incidence of new infections recorded at the health centre. Secondly, owing to ineffective treatment, resistant infections are often still patent during the post-transmission season. This may enlarge the 'overwintering' parasite reservoir, leading to a surge of new cases when transmission resumes. Other factors potentially contributing to the upsurge in falciparum include the decrease availability of insecticide for indoor spraying. Despite the problems posed by resistance for case management, the evidence from the vector-control programme among the refugees is that malaria control through well-targeted campaigns of insecticide spraying is still able to reduce the incidence of falciparum malaria to a level that existed before the advent of resistance.

Pyrethroid-impregnated bed nets for personal protection against malaria for Afghan refugees.

A field trial of permethrin-impregnated bed nets (PIBs) was conducted in 2 Afghan refugee villages in Pakistan. Nets were issued to only 10% of families (= 1398 people); this simulated a situation in which bed nets are gradually adopted by villagers in Afghanistan. A further 10% lacking bed nets were selected as controls from the same villages. An initial survey showed that 86% of household heads were aware that malaria was transmitted by mosquito bites, but only 2% had used bed nets before. Trial families were encouraged to attend the village health centres if they fell ill. Microscopy records showed that, between July and December 1991, 22.4% of the control group became infected with Plasmodium vivax and 13.0% contracted P. falciparum while in the intervention group only 9.9% contracted P. vivax (relative risk 0.58, confidence interval [CI] 95% 0.49-0.68) and only 3.8% contracted P. falciparum (relative risk 0.39, 95% CI 0.29-0.53). A single treatment of the nets with permethrin at 0.5g/m2 remained protective throughout the 6 months' transmission season. 73% of families claimed to use their nets every night; members of families who claimed to use nets less regularly showed an incidence similar to that of the control group. There was no sex or age difference in net use or protective efficacy. Headlouse infestation rates were reduced in PIB users. Few nets were washed, given away or sold. The prospect for PIBs as personal protection appears good, despite people's lack of previous experience.

Rinderpest in the Landhi Dairy Colony.

Earlier diagnostic reports of rinderpest in buffaloes in the Landhi Dairy Colony were discounted by most veterinarians in Pakistan. Four recent investigations have shown beyond doubt that the affliction was indeed rinderpest.